ϟ

Christian Dohmen

Here are all the papers by Christian Dohmen that you can download and read on OA.mg.
Christian Dohmen’s last known institution is . Download Christian Dohmen PDFs here.

Claim this Profile →
DOI: 10.1001/jama.2015.0846
2015
Cited 453 times
Anticoagulant Reversal, Blood Pressure Levels, and Anticoagulant Resumption in Patients With Anticoagulation-Related Intracerebral Hemorrhage
Although use of oral anticoagulants (OACs) is increasing, there is a substantial lack of data on how to treat OAC-associated intracerebral hemorrhage (ICH).To assess the association of anticoagulation reversal and blood pressure (BP) with hematoma enlargement and the effects of OAC resumption.Retrospective cohort study at 19 German tertiary care centers (2006-2012) including 1176 individuals for analysis of long-term functional outcome, 853 for analysis of hematoma enlargement, and 719 for analysis of OAC resumption.Reversal of anticoagulation during acute phase, systolic BP at 4 hours, and reinitiation of OAC for long-term treatment.Frequency of hematoma enlargement in relation to international normalized ratio (INR) and BP. Incidence analysis of ischemic and hemorrhagic events with or without OAC resumption. Factors associated with favorable (modified Rankin Scale score, 0-3) vs unfavorable functional outcome.Hemorrhage enlargement occurred in 307 of 853 patients (36.0%). Reduced rates of hematoma enlargement were associated with reversal of INR levels <1.3 within 4 hours after admission (43/217 [19.8%]) vs INR of ≥1.3 (264/636 [41.5%]; P < .001) and systolic BP <160 mm Hg at 4 hours (167/504 [33.1%]) vs ≥160 mm Hg (98/187 [52.4%]; P < .001). The combination of INR reversal <1.3 within 4 hours and systolic BP of <160 mm Hg at 4 hours was associated with lower rates of hematoma enlargement (35/193 [18.1%] vs 220/498 [44.2%] not achieving these values; OR, 0.28; 95% CI, 0.19-0.42; P < .001) and lower rates of in-hospital mortality (26/193 [13.5%] vs 103/498 [20.7%]; OR, 0.60; 95% CI, 0.37-0.95; P = .03). OAC was resumed in 172 of 719 survivors (23.9%). OAC resumption showed fewer ischemic complications (OAC: 9/172 [5.2%] vs no OAC: 82/547 [15.0%]; P < .001) and not significantly different hemorrhagic complications (OAC: 14/172 [8.1%] vs no OAC: 36/547 [6.6%]; P = .48). Propensity-matched survival analysis in patients with atrial fibrillation who restarted OAC showed a decreased HR of 0.258 (95% CI, 0.125-0.534; P < .001) for long-term mortality. Functional long-term outcome was unfavorable in 786 of 1083 patients (72.6%).Among patients with OAC-associated ICH, reversal of INR <1.3 within 4 hours and systolic BP <160 mm Hg at 4 hours were associated with lower rates of hematoma enlargement, and resumption of OAC therapy was associated with lower risk of ischemic events. These findings require replication and assessment in prospective studies.clinicaltrials.gov Identifier: NCT01829581.
DOI: 10.1002/ana.21390
2008
Cited 378 times
Spreading depolarizations occur in human ischemic stroke with high incidence
Abstract Objective Cortical spreading depression (CSD) and periinfarct depolarization (PID) have been shown in various experimental models of stroke to cause secondary neuronal damage and infarct expansion. For decades it has been questioned whether CSD or PID occur in human ischemic stroke. Here, we describe CSD and PID in patients with malignant middle cerebral artery infarction detected by subdural electrocorticography (ECoG). Methods Centres of the Co‐operative Study of Brain Injury Depolarisations (COSBID) recruited 16 patients with large middle cerebral artery infarction. During surgery for decompressive hemicraniectomy, an electrode strip was placed on the periinfarct region, from which four ECoG channels were acquired. Results A total of 1,638 hours was recorded; mean monitoring time per patient was 109.2 hours. A total of 127 CSD and 42 PID events were observed. In CSD, a stereotyped slow potential change spreading between adjacent channels was accompanied by transient depression of ECoG activity. In PID, a slow potential change spread between neighboring channels despite already established suppression of ECoG activity. Most CSDs and PIDs appeared repetitively in clusters. CSD or PID was observed in all but two patients. In these two patients, the electrode strip had been placed over infarcted tissue, and accordingly, no local ECoG or recurrent transient depolarization activity occurred throughout the observation period. Interpretation CSD and PID occurred spontaneously with high frequency in this study of patients with malignant middle cerebral artery infarction. This suggests that the large volume of experimental studies of occlusive stroke that implicate spreading depolarizations in its pathophysiology can be translated, with appropriate caution, to patients and their treatment. Ann Neurol 2008
DOI: 10.1177/0271678x16654495
2016
Cited 310 times
The continuum of spreading depolarizations in acute cortical lesion development: Examining Leão’s legacy
A modern understanding of how cerebral cortical lesions develop after acute brain injury is based on Aristides Leão's historic discoveries of spreading depression and asphyxial/anoxic depolarization. Treated as separate entities for decades, we now appreciate that these events define a continuum of spreading mass depolarizations, a concept that is central to understanding their pathologic effects. Within minutes of acute severe ischemia, the onset of persistent depolarization triggers the breakdown of ion homeostasis and development of cytotoxic edema. These persistent changes are diagnosed as diffusion restriction in magnetic resonance imaging and define the ischemic core. In delayed lesion growth, transient spreading depolarizations arise spontaneously in the ischemic penumbra and induce further persistent depolarization and excitotoxic damage, progressively expanding the ischemic core. The causal role of these waves in lesion development has been proven by real-time monitoring of electrophysiology, blood flow, and cytotoxic edema. The spreading depolarization continuum further applies to other models of acute cortical lesions, suggesting that it is a universal principle of cortical lesion development. These pathophysiologic concepts establish a working hypothesis for translation to human disease, where complex patterns of depolarizations are observed in acute brain injury and appear to mediate and signal ongoing secondary damage.
DOI: 10.1016/s1474-4422(16)00110-1
2016
Cited 288 times
Fresh frozen plasma versus prothrombin complex concentrate in patients with intracranial haemorrhage related to vitamin K antagonists (INCH): a randomised trial
Background Haematoma expansion is a major cause of mortality in intracranial haemorrhage related to vitamin K antagonists (VKA-ICH). Normalisation of the international normalised ratio (INR) is recommended, but optimum haemostatic management is controversial. We assessed the safety and efficacy of fresh frozen plasma (FFP) versus prothrombin complex concentrate (PCC) in patients with VKA-ICH. Methods We did an investigator-initiated, multicentre, prospective, randomised, open-label, blinded-endpoint trial. Patients aged at least 18 years with VKA-ICH who presented within 12 h after symptom onset with an INR of at least 2·0 were randomly assigned (1:1) by numbered sealed envelopes to 20 mL/kg of intravenous FFP or 30 IU/kg of intravenous four-factor PCC within 1 h after initial cerebral CT scan. The primary endpoint was the proportion of patients with INR 1·2 or lower within 3 h of treatment initiation. Masking of treatment was not possible, but the primary analysis was observer masked. Analyses were done using a treated-as-randomised approach. This trial is registered with EudraCT, number 2008-005653-37, and ClinicalTrials.gov, number NCT00928915. Findings Between Aug 7, 2009, and Jan 9, 2015, 54 patients were randomly assigned (26 to FFP and 28 to PCC) and 50 received study drug (23 FFP and 27 PCC). The trial was terminated on Feb 6, 2015, after inclusion of 50 patients after a safety analysis because of safety concerns. Two (9%) of 23 patients in the FFP group versus 18 (67%) of 27 in the PCC group reached the primary endpoint (adjusted odds ratio 30·6, 95% CI 4·7–197·9; p=0·0003). 13 patients died: eight (35%) of 23 in the FFP group (five from haematoma expansion, all occurring within 48 h after symptom onset) and five (19%) of 27 in the PCC group (none from haematoma expansion), the first of which occurred on day 5 after start of treatment. Three thromboembolic events occurred within 3 days (one in the FFP group and two in the PCC group), and six after day 12 (one and five). 43 serious adverse events (20 in the FFP group and 23 in the PCC group) occurred in 26 patients. Six serious adverse events were judged to be FFP related (four cases of haematoma expansion, one anaphylactic reaction, and one ischaemic stroke) and two PCC related (ischaemic stroke and pulmonary embolism). Interpretation In patients with VKA-related intracranial hemorrhage, four-factor PCC might be superior to FFP with respect to normalising the INR, and faster INR normalisation seemed to be associated with smaller haematoma expansion. Although an effect of PCC on clinical outcomes remains to be shown, our data favour the use of PCC over FFP in intracranial haemorrhage related to VKA. Funding Octapharma.
DOI: 10.1177/0271678x16654496
2016
Cited 265 times
Recording, analysis, and interpretation of spreading depolarizations in neurointensive care: Review and recommendations of the COSBID research group
Spreading depolarizations (SD) are waves of abrupt, near-complete breakdown of neuronal transmembrane ion gradients, are the largest possible pathophysiologic disruption of viable cerebral gray matter, and are a crucial mechanism of lesion development. Spreading depolarizations are increasingly recorded during multimodal neuromonitoring in neurocritical care as a causal biomarker providing a diagnostic summary measure of metabolic failure and excitotoxic injury. Focal ischemia causes spreading depolarization within minutes. Further spreading depolarizations arise for hours to days due to energy supply-demand mismatch in viable tissue. Spreading depolarizations exacerbate neuronal injury through prolonged ionic breakdown and spreading depolarization-related hypoperfusion (spreading ischemia). Local duration of the depolarization indicates local tissue energy status and risk of injury. Regional electrocorticographic monitoring affords even remote detection of injury because spreading depolarizations propagate widely from ischemic or metabolically stressed zones; characteristic patterns, including temporal clusters of spreading depolarizations and persistent depression of spontaneous cortical activity, can be recognized and quantified. Here, we describe the experimental basis for interpreting these patterns and illustrate their translation to human disease. We further provide consensus recommendations for electrocorticographic methods to record, classify, and score spreading depolarizations and associated spreading depressions. These methods offer distinct advantages over other neuromonitoring modalities and allow for future refinement through less invasive and more automated approaches.
DOI: 10.1161/strokeaha.113.001232
2013
Cited 245 times
Prospective, Multicenter, Single-Arm Study of Mechanical Thrombectomy Using Solitaire Flow Restoration in Acute Ischemic Stroke
Background and Purpose— Mechanical thrombectomy using stent retriever devices have been advocated to increase revascularization in intracranial vessel occlusion. We present the results of a large prospective study on the use of the Solitaire Flow Restoration in patients with acute ischemic stroke. Methods— Solitaire Flow Restoration Thrombectomy for Acute Revascularization was an international, multicenter, prospective, single-arm study of Solitaire Flow Restoration thrombectomy in patients with large vessel anterior circulation strokes treated within 8 hours of symptom onset. Strict criteria for site selection were applied. The primary end point was the revascularization rate (thrombolysis in cerebral infarction ≥2b) of the occluded vessel as determined by an independent core laboratory. The secondary end point was the rate of good functional outcome (defined as 90-day modified Rankin scale, 0–2). Results— A total of 202 patients were enrolled across 14 comprehensive stroke centers in Europe, Canada, and Australia. The median age was 72 years, 60% were female patients. The median National Institute of Health Stroke Scale was 17. Most proximal intracranial occlusion was the internal carotid artery in 18%, and the middle cerebral artery in 82%. Successful revascularization was achieved in 79.2% of patients. Device and procedure-related severe adverse events were found in 7.4%. Favorable neurological outcome was found in 57.9%. The mortality rate was 6.9%. Any intracranial hemorrhagic transformation was found in 18.8% of patients, 1.5% were symptomatic. Conclusions— In this single-arm study, treatment with the Solitaire Flow Restoration device in intracranial anterior circulation occlusions results in high rates of revascularization, low risk of clinically relevant procedural complications, and good clinical outcomes in combination with low mortality at 90 days. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT01327989.
DOI: 10.1093/brain/aws152
2012
Cited 184 times
Effect of analgesics and sedatives on the occurrence of spreading depolarizations accompanying acute brain injury
Spreading depolarizations are waves of mass neuronal and glial depolarization that propagate across the injured human cortex. They can occur with depression of neuronal activity as spreading depressions or isoelectric spreading depolarizations on a background of absent or minimal electroencephalogram activity. Spreading depolarizations are characterized by the loss of neuronal ion homeostasis and are believed to damage functional neurons, leading to neuronal necrosis or neurological degeneration and poor outcome. Analgesics and sedatives influence activity-dependent neuronal ion homeostasis and therefore represent potential modulators of spreading depolarizations. In this exploratory retrospective international multicentre analysis, we investigated the influence of midazolam, propofol, fentanyl, sufentanil, ketamine and morphine on the occurrence of spreading depolarizations in 115 brain-injured patients. A surface electrode strip was placed on the cortex, and continuous electrocorticographical recordings were obtained. We used multivariable binary logistic regression to quantify associations between the investigated drugs and the hours of electrocorticographical recordings with and without spreading depolarizations or clusters of spreading depolarizations. We found that administration of ketamine was associated with a reduction of spreading depolarizations and spreading depolarization clusters (P < 0.05). Midazolam anaesthesia, in contrast, was associated with an increased number of spreading depolarization clusters (P < 0.05). By using a univariate odds ratio analysis, we also found a significant association between ketamine administration and reduced occurrence of isoelectric spreading depolarizations in patients suffering from traumatic brain injury, subarachnoid haemorrhage and malignant hemispheric stroke (P < 0.05). Our findings suggest that ketamine—or another N-methyl-d-aspartate receptor antagonist—may represent a viable treatment for patients at risk for spreading depolarizations. This hypothesis will be tested in a prospective study.
DOI: 10.1212/wnl.0b013e3182886932
2013
Cited 175 times
Propagation of cortical spreading depolarization in the human cortex after malignant stroke
To investigate hemodynamic response pattern and spatiotemporal propagation of cortical spreading depolarization in the peri-infarct region of malignant hemispheric stroke.In this prospective observational case study we used intraoperative laser speckle technology to measure cerebral blood flow in patients with malignant hemispheric stroke. Additionally, postoperative occurrence of cortical spreading depolarization was monitored using a subdural recording strip for electrocorticography and infarct progression was assessed by serial MRI.In 7 of 20 patients, 19 blood flow changes typical of cortical spreading depolarizations occurred during a 20-minute period. Thirteen events were characterized by increase, 2 by biphasic response, and 4 by decrease of blood flow. Propagation velocity ranged from 1.7 to 9.2 mm/min and propagation area from 0.1 to 4.8 cm(2). Intrinsic optical signal alterations preceded and low-frequency vascular fluctuations were suppressed during the hemodynamic responses. A mean number of 56 ± 82 cortical spreading depolarizations per patient was recorded and a mean infarct progression of 30 ± 13 cm(3) was detected in 5 of 7 patients.We visualize the spatiotemporal propagation of spreading depolarizations in the human cerebral cortex intraoperatively. In patients with focal ischemia, multiple cortical spreading depolarizations with either hyperemic or hypoemic flow responses occurred. Our data suggest that, in patients with focal ischemia, cortical spreading depolarizations are associated with both unfavorable and protective hemodynamic responses.
DOI: 10.1093/brain/awab457
2022
Cited 46 times
Spreading depolarizations in ischaemia after subarachnoid haemorrhage, a diagnostic phase III study
Focal brain damage after aneurysmal subarachnoid haemorrhage predominantly results from intracerebral haemorrhage, and early and delayed cerebral ischaemia. The prospective, observational, multicentre, cohort, diagnostic phase III trial, DISCHARGE-1, primarily investigated whether the peak total spreading depolarization-induced depression duration of a recording day during delayed neuromonitoring (delayed depression duration) indicates delayed ipsilateral infarction. Consecutive patients (n = 205) who required neurosurgery were enrolled in six university hospitals from September 2009 to April 2018. Subdural electrodes for electrocorticography were implanted. Participants were excluded on the basis of exclusion criteria, technical problems in data quality, missing neuroimages or patient withdrawal (n = 25). Evaluators were blinded to other measures. Longitudinal MRI, and CT studies if clinically indicated, revealed that 162/180 patients developed focal brain damage during the first 2 weeks. During 4.5 years of cumulative recording, 6777 spreading depolarizations occurred in 161/180 patients and 238 electrographic seizures in 14/180. Ten patients died early; 90/170 developed delayed infarction ipsilateral to the electrodes. Primary objective was to investigate whether a 60-min delayed depression duration cut-off in a 24-h window predicts delayed infarction with >0.60 sensitivity and >0.80 specificity, and to estimate a new cut-off. The 60-min cut-off was too short. Sensitivity was sufficient [= 0.76 (95% confidence interval: 0.65-0.84), P = 0.0014] but specificity was 0.59 (0.47-0.70), i.e. <0.80 (P < 0.0001). Nevertheless, the area under the receiver operating characteristic (AUROC) curve of delayed depression duration was 0.76 (0.69-0.83, P < 0.0001) for delayed infarction and 0.88 (0.81-0.94, P < 0.0001) for delayed ischaemia (reversible delayed neurological deficit or infarction). In secondary analysis, a new 180-min cut-off indicated delayed infarction with a targeted 0.62 sensitivity and 0.83 specificity. In awake patients, the AUROC curve of delayed depression duration was 0.84 (0.70-0.97, P = 0.001) and the prespecified 60-min cut-off showed 0.71 sensitivity and 0.82 specificity for reversible neurological deficits. In multivariate analysis, delayed depression duration (β = 0.474, P < 0.001), delayed median Glasgow Coma Score (β = -0.201, P = 0.005) and peak transcranial Doppler (β = 0.169, P = 0.016) explained 35% of variance in delayed infarction. Another key finding was that spreading depolarization-variables were included in every multiple regression model of early, delayed and total brain damage, patient outcome and death, strongly suggesting that they are an independent biomarker of progressive brain injury. While the 60-min cut-off of cumulative depression in a 24-h window indicated reversible delayed neurological deficit, only a 180-min cut-off indicated new infarction with >0.60 sensitivity and >0.80 specificity. Although spontaneous resolution of the neurological deficit is still possible, we recommend initiating rescue treatment at the 60-min rather than the 180-min cut-off if progression of injury to infarction is to be prevented.
DOI: 10.1093/brain/awq117
2010
Cited 180 times
Spreading depolarizations cycle around and enlarge focal ischaemic brain lesions
How does infarction in victims of stroke and other types of acute brain injury expand to its definitive size in subsequent days? Spontaneous depolarizations that repeatedly spread across the cerebral cortex, sometimes at remarkably regular intervals, occur in patients with all types of injury. Here, we show experimentally with in vivo real-time imaging that similar, spontaneous depolarizations cycle repeatedly around ischaemic lesions in the cerebral cortex, and enlarge the lesion in step with each cycle. This behaviour results in regular periodicity of depolarization when monitored at a single point in the lesion periphery. We present evidence from clinical monitoring to suggest that depolarizations may cycle in the ischaemic human brain, perhaps explaining progressive growth of infarction. Despite their apparent detrimental role in infarct growth, we argue that cycling of depolarizations around lesions might also initiate upregulation of the neurobiological responses involved in repair and remodelling.
DOI: 10.1161/01.str.0000147043.29399.f6
2004
Cited 175 times
Which Time-to-Peak Threshold Best Identifies Penumbral Flow?
In acute ischemic stroke, the hypoperfused but viable tissue is the main therapeutic target. In clinical routine, time-to-peak (TTP) maps are frequently used to estimate the hemodynamic compromise and to calculate the mismatch volume. We evaluated the accuracy of TTP maps to identify penumbral flow by comparison with positron emission tomography (PET).Magnetic resonance imaging (MRI) and PET were performed in 11 patients with acute ischemic stroke (median 8 hours after stroke onset, 60 minutes between MRI and PET imaging). The volumes defined by increasing TTP thresholds (relative TTP delay of >2, >4, >6, >8, and >10 seconds) were compared with the volume of hypoperfusion (<20 mL/100 g per min) assessed by 15O-water PET. In a volumetric analysis, each threshold's sensitivity, specificity, and predictive values were calculated.The median hypoperfusion volume was 34.5 cm3. Low TTP thresholds included large parts of the hypoperfused but also large parts of normoperfused tissue (median sensitivity/specificity: 93%/60% for TTP >2) and vice versa (50%/91% for TTP >10). TTP >4 seconds best identifies hypoperfusion (84%/77%). The positive predictive values increased with the size of hypoperfusion.This first comparison of quantitative PET-CBF with TTP maps in acute ischemic human stroke indicates that the TTP threshold is crucial to reliably identify the tissue at risk; TTP >4 seconds best identifies penumbral flow; and TTP maps overestimate the extent of true hemodynamic compromise depending on the size of ischemia. Only if methodological restrictions are kept in mind, relative TTP maps are suitable to estimate the mismatch volume.
DOI: 10.1021/mp9000124
2009
Cited 174 times
Synthesis and Biological Evaluation of a Bioresponsive and Endosomolytic siRNA−Polymer Conjugate
Extracellular stability of electrostatically formed siRNA polyplexes is a significant concern in the delivery process. To overcome the risk of polyplex dissociation in the extracellular environment, siRNA was covalently incorporated into a pH- and redox-responsive polymer conjugate. The novel siRNA conjugate consists of polylysine (PLL) as RNA binding and protecting polycation, polyethylene glycol (PEG) as solubilizing and shielding polymer, the lytic peptide melittin masked by dimethylmaleic anhydride (DMMAn) removable at endosomal pH, and the siRNA attached at the 5'-end of the sense strand via a bioreducible disulfide bond. The purified siRNA conjugate was stable in the presence of the polyanion heparin at conditions where the analogous electrostatic siRNA polyplexes disassemble. Only the combination of heparin plus a reducing agent such as glutathione triggered the release of siRNA from the conjugate. High in vitro biocompatibility (absence of cytotoxicity or hemolytic activity at neutral pH) and efficient and sequence-specific gene silencing was found at > or =25 nM siRNA, comparable to the corresponding electrostatic polyplexes. In vivo toxicity studies of this formulation demonstrated that conjugates remain to be optimized for therapeutic application.
DOI: 10.1002/anie.201102165
2011
Cited 171 times
Solid‐Phase Synthesis of Sequence‐Defined T‐, i‐, and U‐Shape Polymers for pDNA and siRNA Delivery
Artificial oligo(ethylene amino) acids, together with selected natural amino acids and fatty acid modifications, have been used for the solid-phase-assisted synthesis of polymers with precise sequence, topology, and modifications (see picture). First proof-of-concept studies demonstrate the high potential of such polymers in pDNA and siRNA delivery. K=lysine, A=alanine. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
DOI: 10.1002/ana.21943
2010
Cited 157 times
Recurrent spreading depolarizations after subarachnoid hemorrhage decreases oxygen availability in human cerebral cortex
Abstract Objective Delayed ischemic neurological deficit (DIND) contributes to poor outcome in subarachnoid hemorrhage (SAH) patients. Because there is continuing uncertainty as to whether proximal cerebral artery vasospasm is the only cause of DIND, other processes should be considered. A potential candidate is cortical spreading depolarization (CSD)‐induced hypoxia. We hypothesized that recurrent CSDs influence cortical oxygen availability. Methods Centers in the Cooperative Study of Brain Injury Depolarizations (COSBID) recruited 9 patients with severe SAH, who underwent open neurosurgery. We used simultaneous, colocalized recordings of electrocorticography and tissue oxygen pressure (p ti O 2 ) in human cerebral cortex. We screened for delayed cortical infarcts by using sequential brain imaging and investigated cerebral vasospasm by angiography or time‐of‐flight magnetic resonance imaging. Results In a total recording time of 850 hours, 120 CSDs were found in 8 of 9 patients. Fifty‐five CSDs (∼46%) were found in only 2 of 9 patients, who later developed DIND. Eighty‐nine (∼75%) of all CSDs occurred between the 5th and 7th day after SAH, and 96 (80%) arose within temporal clusters of recurrent CSD. Clusters of CSD occurred simultaneously, with mainly biphasic CSD‐associated p ti O 2 responses comprising a primary hypoxic and a secondary hyperoxic phase. The frequency of CSD correlated positively with the duration of the hypoxic phase and negatively with that of the hyperoxic phase. Hypoxic phases significantly increased stepwise within CSD clusters; particularly in DIND patients, biphasic p ti O 2 responses changed to monophasic p ti O 2 decreases within these clusters. Monophasic hypoxic p ti O 2 responses to CSD were found predominantly in DIND patients. Interpretation We attribute these clinical p ti O 2 findings mainly to changes in local blood flow in the cortical microcirculation but also to augmented metabolism. Besides classical contributors like proximal cerebral vasospasm, CSD clusters may reduce O 2 supply and increase O 2 consumption, and thereby promote DIND. ANN NEUROL 2010;67:607–617
DOI: 10.1161/01.str.0000251642.18522.b6
2007
Cited 143 times
Identification and Clinical Impact of Impaired Cerebrovascular Autoregulation in Patients With Malignant Middle Cerebral Artery Infarction
To study cerebrovascular autoregulation and its impact on clinical course in patients with impending malignant middle cerebral artery infarction, we used invasive multimodal neuromonitoring, including measurement of cerebral perfusion pressure, tissue oxygen pressure, and microdialysis.Fifteen patients with a stroke that involved >50% of the middle cerebral artery territory were included. Probes were placed into the ipsilateral frontal lobe. Autoregulation was assessed by calculation of the cerebral perfusion pressure-oxygen reactivity index (COR) and the correlation coefficient (R) of cerebral perfusion pressure and tissue oxygen pressure at 24 and 72 hours after stroke.COR and R at 24 hours after stroke were higher in the 8 patients with a malignant course (ie, massive edema formation) compared with the 7 patients with a benign course (COR, 1.99+/-1.46 versus 0.68+/-0.29; R, 0.49+/-0.28 versus 0.06+/-0.31; P<0.05), indicating impaired autoregulation in the malignant course group. At 72 hours, further increases in COR and R were observed in the malignant course group in contrast to the benign course group with stable values over time (COR, 3.31+/-2.38 versus 0.75+/-0.31; R, 0.75+/-011 versus 0.36+/-0.27; P<0.05). With a COR of 0.99, a cutoff value for prediction of a malignant course was found. The lactate-pyruvate ratio was higher in patients with a malignant compared with a benign course at both time points. COR, R, and the lactate-pyruvate ratio showed significant correlations with outcome parameters as a midline shift on cranial computed tomography and score on the modified Rankin scale after 3 months.We found early impairment of cerebrovascular autoregulation in peri-infarct tissue of patients who developed malignant brain edema, whereas autoregulation was preserved in patients with a benign course. Impaired cerebral autoregulation seems to play a key role for development of a malignant course and might serve as a predictive marker. Impaired cerebral autoregulation also accentuates the need for consequent adjustment of cerebral perfusion pressure in patients with impaired autoregulation.
DOI: 10.1007/s12028-014-0085-6
2015
Cited 128 times
Evidence-Based Guidelines for the Management of Large Hemispheric Infarction
DOI: 10.1021/nn300960m
2012
Cited 122 times
Nanosized Multifunctional Polyplexes for Receptor-Mediated SiRNA Delivery
Although our understanding of RNAi and our knowledge on designing and synthesizing active and safe siRNAs significantly increased during the past decade, targeted delivery remains the major limitation in the development of siRNA therapeutics. On one hand, practical considerations dictate robust chemistry reproducibly providing precise carrier molecules. On the other hand, the multistep delivery process requires dynamic multifunctional carriers of substantial complexity. We present a monodisperse and multifunctional carrier system, synthesized by solid phase supported chemistry, for siRNA delivery in vitro and in vivo. The sequence-defined assembly includes a precise cationic (oligoethanamino)amide core, terminated at the ends by two cysteines for bioreversible polyplex stabilization, at a defined central position attached to a monodisperse polyethylene glycol chain coupled to a terminal folic acid as cell targeting ligand. Complexation with an endosomolytic influenza peptide-siRNA conjugate results in nanosized functional polyplexes of 6 nm hydrodynamic diameter. The necessity of each functional substructure of the carrier system for a specific and efficient gene silencing was confirmed. The nanosized polyplexes showed stability in vivo, receptor-specific cell targeting, and silencing of the EG5 gene in receptor-positive tumors. The nanosized appearance of these particles can be precisely controlled by the oligomer design (from 5.8 to 8.8 nm diameter). A complete surface charge shielding together with the high stability result in good tolerability in vivo and the absence of accumulation in nontargeted tissues such as liver, lung, or spleen. Due to their small size, siRNA polyplexes are efficiently cleared by the kidney.
DOI: 10.1038/mtna.2011.10
2012
Cited 108 times
Defined Folate-PEG-siRNA Conjugates for Receptor-specific Gene Silencing
Gene silencing mediated by small interfering RNA (siRNA) is a novel approach in the development of new cancer therapeutics. Polycations used for nucleic acid delivery still remain heterogeneous compounds, despite continuous progress in polymer synthetic technologies. Here we report the development of a structural defined folic acid polyethylene glycol (PEG) siRNA conjugate accessible via click chemistry yielding a monodisperse ligand-PEG-siRNA conjugate. The folic acid targeting ligand was synthesized by solid phase supported peptide chemistry. The conjugate was shown to be specifically internalized into folic acid receptor expressing cells. When combined with a structurally defined polycation, again synthesized with the precision of solid phase chemistry, efficient receptor specific gene silencing is achieved.
DOI: 10.1001/jama.2019.13014
2019
Cited 97 times
Association of Surgical Hematoma Evacuation vs Conservative Treatment With Functional Outcome in Patients With Cerebellar Intracerebral Hemorrhage
The association of surgical hematoma evacuation with clinical outcomes in patients with cerebellar intracerebral hemorrhage (ICH) has not been established.To determine the association of surgical hematoma evacuation with clinical outcomes in cerebellar ICH.Individual participant data (IPD) meta-analysis of 4 observational ICH studies incorporating 6580 patients treated at 64 hospitals across the United States and Germany (2006-2015).Surgical hematoma evacuation vs conservative treatment.The primary outcome was functional disability evaluated by the modified Rankin Scale ([mRS] score range: 0, no functional deficit to 6, death) at 3 months; favorable (mRS, 0-3) vs unfavorable (mRS, 4-6). Secondary outcomes included survival at 3 months and at 12 months. Analyses included propensity score matching and covariate adjustment, and predicted probabilities were used to identify treatment-related cutoff values for cerebellar ICH.Among 578 patients with cerebellar ICH, propensity score-matched groups included 152 patients with surgical hematoma evacuation vs 152 patients with conservative treatment (age, 68.9 vs 69.2 years; men, 55.9% vs 51.3%; prior anticoagulation, 60.5% vs 63.8%; and median ICH volume, 20.5 cm3 vs 18.8 cm3). After adjustment, surgical hematoma evacuation vs conservative treatment was not significantly associated with likelihood of better functional disability at 3 months (30.9% vs 35.5%; adjusted odds ratio [AOR], 0.94 [95% CI, 0.81 to 1.09], P = .43; adjusted risk difference [ARD], -3.7% [95% CI, -8.7% to 1.2%]) but was significantly associated with greater probability of survival at 3 months (78.3% vs 61.2%; AOR, 1.25 [95% CI, 1.07 to 1.45], P = .005; ARD, 18.5% [95% CI, 13.8% to 23.2%]) and at 12 months (71.7% vs 57.2%; AOR, 1.21 [95% CI, 1.03 to 1.42], P = .02; ARD, 17.0% [95% CI, 11.5% to 22.6%]). A volume range of 12 to 15 cm3 was identified; below this level, surgical hematoma evacuation was associated with lower likelihood of favorable functional outcome (volume ≤12 cm3, 30.6% vs 62.3% [P = .003]; ARD, -34.7% [-38.8% to -30.6%]; P value for interaction, .01), and above, it was associated with greater likelihood of survival (volume ≥15 cm3, 74.5% vs 45.1% [P < .001]; ARD, 28.2% [95% CI, 24.6% to 31.8%]; P value for interaction, .02).Among patients with cerebellar ICH, surgical hematoma evacuation, compared with conservative treatment, was not associated with improved functional outcome. Given the null primary outcome, investigation is necessary to establish whether there are differing associations based on hematoma volume.
DOI: 10.1212/wnl.0000000000008688
2020
Cited 91 times
Myasthenic crisis demanding mechanical ventilation
To determine demographic characteristics, clinical features, treatment regimens, and outcome of myasthenic crisis (MC) requiring mechanical ventilation (MV).Analysis of patients who presented with MC between 2006 and 2015 in a German multicenter retrospective study.We identified 250 cases in 12 participating centers. Median age at crisis was 72 years. Median duration of MV was 12 days. Prolonged ventilation (>15 days) depended on age (p = 0.0001), late-onset myasthenia gravis (MG), a high Myasthenia Gravis Foundation of America Class before crisis (p = 0.0001 for IVb, odds ratio [OR] = infinite), number of comorbidities (>3 comorbidities: p = 0.002, OR 2.99), pneumonia (p = 0.0001, OR 3.13), and resuscitation (p = 0.0008, OR 9.15). MV at discharge from hospital was necessary in 20.5% of survivors. Patients with early-onset MG (p = 0.0001, OR 0.21), thymus hyperplasia (p = 0.002, OR 0), and successful noninvasive ventilation trial were more likely to be ventilated for less than 15 days. Noninvasive ventilation in 92 cases was sufficient in 38%, which was accompanied by a significantly shorter duration of ventilation (p = 0.001) and intensive care unit (ICU) stay (p = 0.01). IV immunoglobulins, plasma exchange, and immunoadsorption were more likely to be combined sequentially if the duration of MV and the stay in an ICU extended (p = 0.0503, OR 2.05). Patients who received plasma exchange or immunoadsorption as first-line therapy needed invasive ventilation significantly less often (p = 0.003). In-hospital mortality was 12%, which was significantly associated with the number of comorbidities (>3) and complications such as acute respiratory distress syndrome and resuscitation. Main cause of death was multiorgan failure, mostly due to sepsis.Mortality and duration of MC remained comparable to previous reports despite higher age and a high disease burden in our study. Prevention and treatment of complications and specialized neurointensive care are the cornerstones in order to improve outcome.
DOI: 10.1007/s00392-018-1366-4
2018
Cited 85 times
Recommendations for extracorporeal cardiopulmonary resuscitation (eCPR): consensus statement of DGIIN, DGK, DGTHG, DGfK, DGNI, DGAI, DIVI and GRC
DOI: 10.1016/j.jstrokecerebrovasdis.2015.04.013
2015
Cited 84 times
Mechanical Thrombectomy of M2-Occlusion
There is growing evidence for the efficacy of mechanical thrombectomy in acute stroke patients with large-vessel occlusions in the anterior circulation. Although distal occlusions of the middle cerebral artery (MCA) can cause severe clinical symptoms, endovascular therapy is not considered here as the first choice. The aim of our study was to prove the efficacy and safety of mechanical thrombectomy for distal occlusion types in the anterior circulation (M2-segment).Stentretriever-based thrombectomy was performed in 119 patients with acute MCA occlusions between October 2011 and April 2013: 104 (87.4%) were M1- and 15 (12.6%) M2-occlusions. These groups were compared with regard to recanalization success, periprocedural complications, hemorrhage, and modified Rankin Scale (mRS) at 90 days.Thrombolysis in cerebral infarction 2b/3 reperfusion was more frequent in M2- than in M1-occlusions (93.3% versus 76.0%; P = .186). There was no significant difference in the mean National Institutes of Health Stroke Scale between the M1- and the M2-group both at admission and at discharge (16.18 ± 7.30 versus 13.73 ± 8.30, P = .235; 9.36 ± 8.60 versus 7.43 ± 9.84, P = .446). A good clinical outcome (mRS 0-2) at 3 months was more frequent in the M2-group (60% versus 43.3%; P = .273) and mortality was higher in the M1-group (21.2% versus 6.7%; P = .297). There were 3 periprocedural complications in the M1- and none in the M2-group.Endovascular treatment of M2-occlusions in severely affected patients is not associated with a higher procedural risk or postprocedural hemorrhage. Compared with M1-occlusions, there was a greater chance for a good angiographic and clinical result in our case series. Therefore, stentretriever-based thrombectomy should also be considered for patients with severe symptoms because of an acute M2-occlusion.
DOI: 10.1002/anie.201603648
2016
Cited 82 times
A Single Methylene Group in Oligoalkylamine-Based Cationic Polymers and Lipids Promotes Enhanced mRNA Delivery
Abstract The development of chemically modified mRNA holds great promise as a new class of biologic therapeutics. However, the intracellular delivery and endosomal escape of mRNA encapsulated in nanoparticles has not been systematically investigated. Here, we synthesized a diverse set of cationic polymers and lipids from a series of oligoalkylamines and subsequently characterized their mRNA delivery capability. Notably, a structure with an alternating alkyl chain length between amines showed the highest transfection efficiency, which was linked to a high buffering capacity in a narrow range of pH 6.2 to 6.5. Variation in only one methylene group resulted in enhanced mRNA delivery to both the murine liver as well as porcine lungs after systemic or aerosol administration, respectively. These findings reveal a novel fundamental structure–activity relationship for the delivery of mRNA that is independent of the class of mRNA carrier and define a promising new path of exploration in the field of mRNA therapeutics.
DOI: 10.1093/eurheartj/ehy056
2018
Cited 75 times
Management of therapeutic anticoagulation in patients with intracerebral haemorrhage and mechanical heart valves
Evidence is lacking regarding acute anticoagulation management in patients after intracerebral haemorrhage (ICH) with implanted mechanical heart valves (MHVs). Our objective was to investigate anticoagulation reversal and resumption strategies by evaluating incidences of haemorrhagic and thromboembolic complications, thereby defining an optimal time-window when to restart therapeutic anticoagulation (TA) in patients with MHV and ICH.We pooled individual patient-data (n = 2504) from a nationwide multicentre cohort-study (RETRACE, conducted at 22 German centres) and eventually identified MHV-patients (n = 137) with anticoagulation-associated ICH for outcome analyses. The primary outcome consisted of major haemorrhagic complications analysed during hospital stay according to treatment exposure (restarted TA vs. no-TA). Secondary outcomes comprised thromboembolic complications, the composite outcome (haemorrhagic and thromboembolic complications), timing of TA, and mortality. Adjusted analyses involved propensity-score matching and multivariable cox-regressions to identify optimal timing of TA. In 66/137 (48%) of patients TA was restarted, being associated with increased haemorrhagic (TA = 17/66 (26%) vs. no-TA = 4/71 (6%); P < 0.01) and a trend to decreased thromboembolic complications (TA = 1/66 (2%) vs. no-TA = 7/71 (10%); P = 0.06). Controlling treatment crossovers provided an incidence rate-ratio [hazard ratio (HR) 10.31, 95% confidence interval (CI) 3.67-35.70; P < 0.01] in disadvantage of TA for haemorrhagic complications. Analyses of TA-timing displayed significant harm until Day 13 after ICH (HR 7.06, 95% CI 2.33-21.37; P < 0.01). The hazard for the composite-balancing both complications, was increased for restarted TA until Day 6 (HR 2.51, 95% CI 1.10-5.70; P = 0.03).Restarting TA within less than 2 weeks after ICH in patients with MHV was associated with increased haemorrhagic complications. Optimal weighing-between least risks for thromboembolic and haemorrhagic complications-provided an earliest starting point of TA at Day 6, reserved only for patients at high thromboembolic risk.
DOI: 10.1212/nxi.0000000000000514
2019
Cited 62 times
Management and prognostic markers in patients with autoimmune encephalitis requiring ICU treatment
To assess intensive care unit (ICU) complications, their management, and prognostic factors associated with outcomes in a cohort of patients with autoimmune encephalitis (AE).This study was an observational multicenter registry of consecutively included patients diagnosed with AE requiring Neuro-ICU treatment between 2004 and 2016 from 18 tertiary hospitals. Logistic regression models explored the influence of complications, their management, and diagnostic findings on the dichotomized (0-3 vs 4-6) modified Rankin Scale score at hospital discharge.Of 120 patients with AE (median age 43 years [interquartile range 24-62]; 70 females), 101 developed disorders of consciousness, 54 autonomic disturbances, 42 status epilepticus, and 39 severe sepsis. Sixty-eight patients were mechanically ventilated, 85 patients had detectable neuronal autoantibodies, and 35 patients were seronegative. Worse neurologic outcome at hospital discharge was associated with necessity of mechanical ventilation (sex- and age-adjusted OR 6.28; 95% CI, 2.71-15.61) tracheostomy (adjusted OR 6.26; 95% CI, 2.68-15.73), tumor (adjusted OR 3.73; 95% CI, 1.35-11.57), sepsis (adjusted OR 4.54; 95% CI, 1.99-10.43), or autonomic dysfunction (adjusted OR 2.91; 95% CI, 1.24-7.3). No significant association was observed with autoantibody type, inflammatory changes in CSF, or pathologic MRI.In patients with AE, mechanical ventilation, sepsis, and autonomic dysregulation appear to indicate longer or incomplete convalescence. Classic ICU complications better serve as prognostic markers than the individual subtype of AE. Increased awareness and effective management of these AE-related complications are warranted, and further prospective studies are needed to confirm our findings and to develop specific strategies for outcome improvement.
DOI: 10.1161/01.str.0000083624.74929.32
2003
Cited 140 times
Prediction of Malignant Course in MCA Infarction by PET and Microdialysis
To predict malignant course in patients with large middle cerebral artery (MCA) infarction, we combined PET imaging and neuromonitoring, including microdialysis.Thirty-four patients with stroke of >50% of the MCA territory in early cerebral CT scan were included. Probes for microdialysis and measurement of intracranial pressure and tissue oxygen pressure (Pto2) were placed into the ipsilateral frontal lobe. PET was performed with 11C-flumazenil to assess CBF and irreversible neuronal damage.PET measurements within 24 hours after stroke showed larger volumes of ischemic core (mean, 144.5 versus 62.2 cm3) and larger volumes of irreversible neuronal damage (157.9 versus 47.0 cm3) in patients with malignant course (ie, edema formation with midline shift) than in patients with benign course. Mean cerebral blood flow values within the ischemic core were significantly lower and the volume of the ischemic penumbra was smaller in the malignant than in the benign group. In patients with malignant course, cerebral perfusion pressure dropped to <50 to 60 mm Hg 22 to 72 hours (mean, 52.0 hours) after onset of symptoms; subsequently, Pto2 dropped and glutamate increased, indicating secondary ischemia. Maximal changes in the monitored variables reached significant levels for glutamate, aspartate, GABA, glycerol, lactate-to-pyruvate ratio, hypoxanthine, intracranial pressure, cerebral perfusion pressure, and Pto2.PET allowed prediction of malignant MCA infarction within the time window suggested for hemicraniectomy. Neuromonitoring helped to classify the clinical courses by characterizing pathophysiological sequelae of malignant edema formation. In contrast to PET, however, it did not predict fatal outcome early enough for successful implementation of invasive therapies.
DOI: 10.1038/jcbfm.2010.40
2010
Cited 101 times
Experimental and Preliminary Clinical Evidence of an Ischemic Zone with Prolonged Negative DC Shifts Surrounded by a Normally Perfused Tissue Belt with Persistent Electrocorticographic Depression
In human cortex it has been suggested that the tissue at risk is indicated by clusters of spreading depolarizations (SDs) with persistent depression of high-frequency electrocorticographic (ECoG) activity. We here characterized this zone in the ET-1 model in rats using direct current (DC)-ECoG recordings. Topical application of the vasoconstrictor endothelin-1 (ET-1) induces focal ischemia in a concentration-dependent manner restricted to a region exposed by a cranial window, while a healthy cortex can be studied at a second naïve window. SDs originate in the ET-1-exposed cortex and invade the surrounding tissue. Necrosis is restricted to the ET-1-exposed cortex. In this study, we discovered that persistent depression occurred in both ET-1-exposed and surrounding cortex during SD clusters. However, the ET-1-exposed cortex showed longer-lasting negative DC shifts and limited high-frequency ECoG recovery after the cluster. DC-ECoG recordings of SD clusters with persistent depression from patients with aneurysmal subarachnoid hemorrhage were then analyzed for comparison. Limited ECoG recovery was associated with significantly longer-lasting negative DC shifts in a similar manner to the experimental model. These preliminary results suggest that the ischemic zone in rat and human cortex is surrounded by a normally perfused belt with persistently reduced synaptic activity during the acute injury phase.
DOI: 10.1039/c2ob06907e
2012
Cited 67 times
Solid-phase-assisted synthesis of targeting peptide–PEG–oligo(ethane amino)amides for receptor-mediated gene delivery
In the forthcoming era of cancer gene therapy, efforts will be devoted to the development of new efficient and non-toxic gene delivery vectors. In this regard, the use of Fmoc/Boc-protected oligo(ethane amino)acids as building blocks for solid-phase-supported assembly represents a novel promising approach towards fully controlled syntheses of effective gene vectors. Here we report on the synthesis of defined polymers containing the following: (i) a plasmid DNA (pDNA) binding domain of eight succinoyl-tetraethylenpentamine (Stp) units and two terminal cysteine residues; (ii) a central polyethylene glycol (PEG) chain (with twenty-four oxyethylene units) for shielding; and (iii) specific peptides for targeting towards cancer cells. Peptides B6 and c(RGDfK), which bind transferrin receptor and αvβ3 integrin, respectively, were chosen because of the high expression of these receptors in many tumoral cells. This study shows the feasibility of designing these kinds of fully controlled vectors and their success for targeted pDNA-based gene transfer.
DOI: 10.1016/j.omtn.2017.04.006
2017
Cited 58 times
Translation of Angiotensin-Converting Enzyme 2 upon Liver- and Lung-Targeted Delivery of Optimized Chemically Modified mRNA
Changes in lifestyle and environmental conditions give rise to an increasing prevalence of liver and lung fibrosis, and both have a poor prognosis. Promising results have been reported for recombinant angiotensin-converting enzyme 2 (ACE2) protein administration in experimental liver and lung fibrosis. However, the full potential of ACE2 may be achieved by localized translation of a membrane-anchored form. For this purpose, we advanced the latest RNA technology for liver- and lung-targeted ACE2 translation. We demonstrated in vitro that transfection with ACE2 chemically modified messenger RNA (cmRNA) leads to robust translation of fully matured, membrane-anchored ACE2 protein. In a second step, we designed eight modified ACE2 cmRNA sequences and identified a lead sequence for in vivo application. Finally, formulation of this ACE2 cmRNA in tailor-made lipidoid nanoparticles and in lipid nanoparticles led to liver- and lung-targeted translation of significant amounts of ACE2 protein, respectively. In summary, we provide evidence that RNA transcript therapy (RTT) is a promising approach for ACE2-based treatment of liver and lung fibrosis to be tested in fibrotic disease models.
DOI: 10.1016/j.ebiom.2019.04.054
2019
Cited 55 times
Early blood-brain barrier dysfunction predicts neurological outcome following aneurysmal subarachnoid hemorrhage
BackgroundDisease progression and delayed neurological complications are common after aneurysmal subarachnoid hemorrhage (aSAH). We explored the potential of quantitative blood-brain barrier (BBB) imaging to predict disease progression and neurological outcome.MethodsData were collected as part of the Co-Operative Studies of Brain Injury Depolarizations (COSBID). We analyzed retrospectively, blinded and semi-automatically magnetic resonance images from 124 aSAH patients scanned at 4 time points (24–48 h, 6–8 days, 12–15 days and 6–12 months) after the initial hemorrhage. Volume of brain with apparent pathology and/or BBB dysfunction (BBBD), subarachnoid space and lateral ventricles were measured. Neurological status on admission was assessed using the World Federation of Neurosurgical Societies and Rosen-Macdonald scores. Outcome at ≥6 months was assessed using the extended Glasgow outcome scale and disease course (progressive or non-progressive based on imaging-detected loss of normal brain tissue in consecutive scans). Logistic regression was used to define biomarkers that best predict outcomes. Receiver operating characteristic analysis was performed to assess accuracy of outcome prediction models.FindingsIn the present cohort, 63% of patients had progressive and 37% non-progressive disease course. Progressive course was associated with worse outcome at ≥6 months (sensitivity of 98% and specificity of 97%). Brain volume with BBBD was significantly larger in patients with progressive course already 24–48 h after admission (2.23 (1.23–3.17) folds, median with 95%CI), and persisted at all time points. The highest probability of a BBB-disrupted voxel to become pathological was found at a distance of ≤1 cm from the brain with apparent pathology (0·284 (0·122–0·594), p < 0·001, median with 95%CI). A multivariate logistic regression model revealed power for BBBD in combination with RMS at 24-48 h in predicting outcome (ROC area under the curve = 0·829, p < 0·001).InterpretationWe suggest that early identification of BBBD may serve as a key predictive biomarker for neurological outcome in aSAH.FundDr. Dreier was supported by grants from the Deutsche Forschungsgemeinschaft (DFG) (DFG DR 323/5-1 and DFG DR 323/10–1), the Bundesministerium für Bildung und Forschung (BMBF) Center for Stroke Research Berlin 01 EO 0801 and FP7 no 602150 CENTER-TBI.Dr. Friedman was supported by grants from Israel Science Foundation and Canada Institute for Health Research (CIHR). Dr. Friedman was supported by grants from European Union's Seventh Framework Program (FP7/2007–2013; grant #602102).
DOI: 10.1007/s12028-016-0256-8
2016
Cited 51 times
Severe Cerebral Venous and Sinus Thrombosis: Clinical Course, Imaging Correlates, and Prognosis
DOI: 10.1093/braincomms/fcad080
2023
Cited 8 times
Spreading depolarization and angiographic spasm are separate mediators of delayed infarcts
In DISCHARGE-1, a recent Phase III diagnostic trial in aneurysmal subarachnoid haemorrhage patients, spreading depolarization variables were found to be an independent real-time biomarker of delayed cerebral ischaemia. We here investigated based on prospectively collected data from DISCHARGE-1 whether delayed infarcts in the anterior, middle, or posterior cerebral artery territories correlate with (i) extravascular blood volumes; (ii) predefined spreading depolarization variables, or proximal vasospasm assessed by either (iii) digital subtraction angiography or (iv) transcranial Doppler-sonography; and whether spreading depolarizations and/or vasospasm are mediators between extravascular blood and delayed infarcts. Relationships between variable groups were analysed using Spearman correlations in 136 patients. Thereafter, principal component analyses were performed for each variable group. Obtained components were included in path models with a priori defined structure. In the first path model, we only included spreading depolarization variables, as our primary interest was to investigate spreading depolarizations. Standardised path coefficients were 0.22 for the path from extravascular bloodcomponent to depolarizationcomponent (P = 0.010); and 0.44 for the path from depolarizationcomponent to the first principal component of delayed infarct volume (P < 0.001); but only 0.07 for the direct path from bloodcomponent to delayed infarctcomponent (P = 0.36). Thus, the role of spreading depolarizations as a mediator between blood and delayed infarcts was confirmed. In the principal component analysis of extravascular blood volume, intraventricular haemorrhage was not represented in the first component. Therefore, based on the correlation analyses, we also constructed another path model with bloodcomponent without intraventricular haemorrhage as first and intraventricular haemorrhage as second extrinsic variable. We found two paths, one from (subarachnoid) bloodcomponent to delayed infarctcomponent with depolarizationcomponent as mediator (path coefficients from bloodcomponent to depolarizationcomponent = 0.23, P = 0.03; path coefficients from depolarizationcomponent to delayed infarctcomponent = 0.29, P = 0.002), and one from intraventricular haemorrhage to delayed infarctcomponent with angiographic vasospasmcomponent as mediator variable (path coefficients from intraventricular haemorrhage to vasospasmcomponent = 0.24, P = 0.03; path coefficients from vasospasmcomponent to delayed infarctcomponent = 0.35, P < 0.001). Human autopsy studies shaped the hypothesis that blood clots on the cortex surface suffice to cause delayed infarcts beneath the clots. Experimentally, clot-released factors induce cortical spreading depolarizations that trigger (i) neuronal cytotoxic oedema and (ii) spreading ischaemia. The statistical mediator role of spreading depolarization variables between subarachnoid blood volume and delayed infarct volume supports this pathogenetic concept. We did not find that angiographic vasospasm triggers spreading depolarizations, but angiographic vasospasm contributed to delayed infarct volume. This could possibly result from enhancement of spreading depolarization-induced spreading ischaemia by reduced upstream blood supply.
DOI: 10.1021/bm101464n
2011
Cited 68 times
Epidermal Growth Factor–PEG Functionalized PAMAM-Pentaethylenehexamine Dendron for Targeted Gene Delivery Produced by Click Chemistry
Aim of this study was the site-specific conjugation of an epidermal growth factor (EGF)-polyethylene glycol (PEG) chain by click chemistry onto a poly(amido amine) (PAMAM) dendron, as a key step toward defined multifunctional carriers for targeted gene delivery. For this purpose, at first propargyl amine cored PAMAM dendrons with ester ends were synthesized. The chain terminal ester groups were then modified by oligoamines with different secondary amino densities. The oligoamine-modified PAMAM dendrons were well biocompatible, as demonstrated in cytotoxicity assays. Among the different oligoamine-modified dendrons, PAMAM-pentaethylenehexamine (PEHA) dendron polyplexes displayed the best gene transfer ability. Conjugation of PAMAM-PEHA dendron with PEG spacer was conducted via click reaction, which was performed before amidation with PEHA. The resultant PEG-PAMAM-PEHA copolymer was then coupled with EGF ligand. pDNA transfections in HuH-7 hepatocellular carcinoma cells showed a 10-fold higher efficiency with the polyplexes containing conjugated EGF as compared to the ligand-free ones, demonstrating the concept of ligand targeting. Overall gene transfer efficiencies, however, were moderate, suggesting that additional measures for overcoming subsequent intracellular bottlenecks in delivery have to be taken.
DOI: 10.1002/anie.201005120
2011
Cited 63 times
pH‐Responsive Release of Acetal‐Linked Melittin from SBA‐15 Mesoporous Silica
Angewandte Chemie International EditionVolume 50, Issue 30 p. 6828-6830 Communication pH-Responsive Release of Acetal-Linked Melittin from SBA-15 Mesoporous Silica† Dr. Axel Schlossbauer, Dr. Axel Schlossbauer Department of Chemistry and Center for Nanoscience, University of Munich (LMU), Butenandtstrasse 5-13, 81377 München (Germany), Fax: (+49) 89-2180-77622 http://bein.cup.uni-muenchen.deSearch for more papers by this authorChristian Dohmen, Christian Dohmen Department of Pharmacy and Center for Nanoscience, Butenandtstrasse 5-13, 81377 München (Germany)Search for more papers by this authorDr. David Schaffert, Dr. David Schaffert Department of Pharmacy and Center for Nanoscience, Butenandtstrasse 5-13, 81377 München (Germany)Search for more papers by this authorProf. Dr. Ernst Wagner, Prof. Dr. Ernst Wagner Department of Pharmacy and Center for Nanoscience, Butenandtstrasse 5-13, 81377 München (Germany)Search for more papers by this authorProf. Dr. Thomas Bein, Corresponding Author Prof. Dr. Thomas Bein bein@lmu.de Department of Chemistry and Center for Nanoscience, University of Munich (LMU), Butenandtstrasse 5-13, 81377 München (Germany), Fax: (+49) 89-2180-77622 http://bein.cup.uni-muenchen.deDepartment of Chemistry and Center for Nanoscience, University of Munich (LMU), Butenandtstrasse 5-13, 81377 München (Germany), Fax: (+49) 89-2180-77622 http://bein.cup.uni-muenchen.deSearch for more papers by this author Dr. Axel Schlossbauer, Dr. Axel Schlossbauer Department of Chemistry and Center for Nanoscience, University of Munich (LMU), Butenandtstrasse 5-13, 81377 München (Germany), Fax: (+49) 89-2180-77622 http://bein.cup.uni-muenchen.deSearch for more papers by this authorChristian Dohmen, Christian Dohmen Department of Pharmacy and Center for Nanoscience, Butenandtstrasse 5-13, 81377 München (Germany)Search for more papers by this authorDr. David Schaffert, Dr. David Schaffert Department of Pharmacy and Center for Nanoscience, Butenandtstrasse 5-13, 81377 München (Germany)Search for more papers by this authorProf. Dr. Ernst Wagner, Prof. Dr. Ernst Wagner Department of Pharmacy and Center for Nanoscience, Butenandtstrasse 5-13, 81377 München (Germany)Search for more papers by this authorProf. Dr. Thomas Bein, Corresponding Author Prof. Dr. Thomas Bein bein@lmu.de Department of Chemistry and Center for Nanoscience, University of Munich (LMU), Butenandtstrasse 5-13, 81377 München (Germany), Fax: (+49) 89-2180-77622 http://bein.cup.uni-muenchen.deDepartment of Chemistry and Center for Nanoscience, University of Munich (LMU), Butenandtstrasse 5-13, 81377 München (Germany), Fax: (+49) 89-2180-77622 http://bein.cup.uni-muenchen.deSearch for more papers by this author First published: 17 June 2011 https://doi.org/10.1002/anie.201005120Citations: 59 † This work was funded by the DFG through the cluster "Nanosystems Initiative Munich" and the SFB 749. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Free to go: A pH-labile immobilization of the melittin peptide with acetal linkers in the pore system of a SBA-15 host allows release of the peptide upon decrease of the pH value from 7.4 to 5.5. Such a release is shown by melittin-induced lysis of mouse erythrocytes. The method could be used to prepare new silica-based peptide delivery systems for targeted cancer therapy. Citing Literature Supporting Information Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Filename Description anie_201005120_sm_miscellaneous_information.pdf570.6 KB miscellaneous_information Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Volume50, Issue30July 18, 2011Pages 6828-6830 RelatedInformation
DOI: 10.1007/s12028-013-9848-8
2013
Cited 58 times
Changes in Neuron-Specific Enolase are More Suitable Than Its Absolute Serum Levels for the Prediction of Neurologic Outcome in Hypothermia-Treated Patients with Out-of-Hospital Cardiac Arrest
DOI: 10.1007/s00415-022-11034-w
2022
Cited 14 times
Decline in the number of patients with meningitis in German hospitals during the COVID-19 pandemic
In 2020, a wide range of hygiene measures was implemented to mitigate infections caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In consequence, pulmonary infections due to other respiratory pathogens also decreased. Here, we evaluated the number of bacterial and viral meningitis and encephalitis cases during the coronavirus disease 2019 (COVID-19) pandemic.In a multicentre retrospective analysis of data from January 2016 until December 2020, numbers of patients diagnosed with bacterial meningitis and other types of CNS infections (such as viral meningitis and encephalitis) at 26 German hospitals were studied. Furthermore, the number of common meningitis-preceding ear-nose-throat infections (sinusitis, mastoiditis and otitis media) was evaluated.Compared to the previous years, the total number of patients diagnosed with pneumococcal meningitis was reduced (n = 64 patients/year in 2020 vs. n = 87 to 120 patients/year between 2016 and 2019, all p < 0.05). Additionally, the total number of patients diagnosed with otolaryngological infections was significantly lower (n = 1181 patients/year in 2020 vs. n = 1525 to 1754 patients/year between 2016 and 2019, all p < 0.001). We also observed a decline in viral meningitis and especially enterovirus meningitis (n = 25 patients/year in 2020 vs. n = 97 to 181 patients/year between 2016 and 2019, all p < 0.001).This multicentre retrospective analysis demonstrates a decline in the number of patients treated for viral and pneumococcal meningitis as well as otolaryngological infections in 2020 compared to previous years. Since the latter often precedes pneumococcal meningitis, this may point to the significance of the direct spread of pneumococci from an otolaryngological focus such as mastoiditis to the brain as one important pathophysiological route in the development of pneumococcal meningitis.
DOI: 10.1038/s41551-023-01094-2
2023
Cited 6 times
A computationally designed antigen eliciting broad humoral responses against SARS-CoV-2 and related sarbecoviruses
The threat of spillovers of coronaviruses associated with the severe acute respiratory syndrome (SARS) from animals to humans necessitates vaccines that offer broader protection from sarbecoviruses. By leveraging a viral-genome-informed computational method for selecting immune-optimized and structurally engineered antigens, here we show that a single antigen based on the receptor binding domain of the spike protein of sarbecoviruses elicits broad humoral responses against SARS-CoV-1, SARS-CoV-2, WIV16 and RaTG13 in mice, rabbits and guinea pigs. When administered as a DNA immunogen or by a vector based on a modified vaccinia virus Ankara, the optimized antigen induced vaccine protection from the Delta variant of SARS-CoV-2 in mice genetically engineered to express angiotensin-converting enzyme 2 and primed by a viral-vector vaccine (AZD1222) against SARS-CoV-2. A vaccine formulation incorporating mRNA coding for the optimized antigen further validated its broad immunogenicity. Vaccines that elicit broad immune responses across subgroups of coronaviruses may counteract the threat of zoonotic spillovers of betacoronaviruses.
DOI: 10.1016/j.clineuro.2006.06.003
2007
Cited 60 times
Early electroencephalography in acute ischemic stroke: Prediction of a malignant course?
In patients with large middle cerebral artery (MCA) infarction space occupying brain edema may lead to a malignant course with up to 80% mortality under conservative treatment. As interventional treatment strategies must be started before the deterioration occurs predictors of a malignant course are necessary.This study reports on the results of early electroencephalography (EEG) within 24h after onset of stroke in 25 patients suffering a large MCA infarct (12 patients with a malignant and 13 with a non-malignant course). EEG analysis was performed according well-established indicators for focal as well as global changes.Our findings indicate that the absence of delta activity and the presence of theta and fast beta frequencies within the focus predict a benign course (p < 0.05), whereas diffuse generalized slowing and slow delta activity in the ischemic hemisphere may point to a malignant course.This study shows that in patients suffering from large MCA infarction early EEG delivers useful information to select those patients who develop malignant edema.
DOI: 10.1089/hum.2011.041
2011
Cited 44 times
Image-Guided Tumor-Selective Radioiodine Therapy of Liver Cancer After Systemic Nonviral Delivery of the Sodium Iodide Symporter Gene
We reported the induction of tumor-selective iodide uptake and therapeutic efficacy of (131)I in a hepatocellular carcinoma (HCC) xenograft mouse model, using novel polyplexes based on linear polyethylenimine (LPEI), shielded by polyethylene glycol (PEG), and coupled with the epidermal growth factor receptor-specific peptide GE11 (LPEI-PEG-GE11). The aim of the current study in the same HCC model was to evaluate the potential of biodegradable nanoparticle vectors based on pseudodendritic oligoamines (G2-HD-OEI) for systemic sodium iodide symporter (NIS) gene delivery and to compare efficiency and tumor specificity with LPEI-PEG-GE11. Transfection of HCC cells with NIS cDNA, using G2-HD-OEI, resulted in a 44-fold increase in iodide uptake in vitro as compared with a 22-fold increase using LPEI-PEG-GE11. After intravenous application of G2-HD-OEI/NIS HCC tumors accumulated 6-11% ID/g (123)I (percentage of the injected dose per gram tumor tissue) with an effective half-life of 10 hr (tumor-absorbed dose, 281 mGy/MBq) as measured by (123)I scintigraphic gamma camera or single-photon emission computed tomography computed tomography (SPECT CT) imaging, as compared with 6.5-9% ID/g with an effective half-life of only 6 hr (tumor-absorbed dose, 47 mGy/MBq) for LPEI-PEG-GE11. After only two cycles of G2-HD-OEI/NIS/(131)I application, a significant delay in tumor growth was observed with markedly improved survival. A similar degree of therapeutic efficacy had been observed after four cycles of LPEI-PEG-GE11/(131)I. These results clearly demonstrate that biodegradable nanoparticles based on OEI-grafted oligoamines show increased efficiency for systemic NIS gene transfer in an HCC model with similar tumor selectivity as compared with LPEI-PEG-GE11, and therefore represent a promising strategy for NIS-mediated radioiodine therapy of HCC.
DOI: 10.1111/ene.12389
2014
Cited 36 times
Tryptophan immunoadsorption for the treatment of autoimmune encephalitis
Detection of autoantibodies against neuronal surface antigens and their correlation with the pattern and severity of symptoms led to the definition of new autoimmune-mediated forms of encephalitis and was essential for the initiation of immunotherapies including plasma exchange. The elimination of autoantibodies using selective immunoadsorption (IA) is a pathophysiologically guided therapeutic approach but has not yet been evaluated in a separate analysis.A retrospective analysis was performed of patients with autoimmune encephalitis who were treated with tryptophan IA in six neurological clinics between 2009 and 2013. The modified Rankin scale (mRS) was used to evaluate neurological status before and after IA.Data on 13 patients were documented. Twelve patients were positive for specific autoantibodies (NMDA-R, GABA, GAD, Lgl1). Patients received a series of a median of six IA treatments. Median mRS of all patients was 3.0 before IA and 2.0 after IA (P < 0.001). Eleven patients improved by at least one point in mRS after IA.For autoimmune-mediated forms of encephalitis rapid elimination of autoantibodies with selective IA seems to be an effective therapeutic option as part of multimodal immune therapy.
DOI: 10.1007/s00115-017-0332-0
2017
Cited 32 times
Prolongiertes Weaning in der neurologisch-neurochirurgischen Frührehabilitation
DOI: 10.1016/j.jconrel.2021.09.016
2021
Cited 21 times
Dynamic mRNA polyplexes benefit from bioreducible cleavage sites for in vitro and in vivo transfer
Currently, messenger RNA (mRNA)-based lipid nanoparticle formulations revolutionize the clinical field. Cationic polymer-based complexes (polyplexes) represent an alternative compound class for mRNA delivery. After establishing branched polyethylenimine with a succinylation degree of 10% (succPEI) as highly effective positive mRNA transfection standard, a diverse library of PEI-like peptides termed sequence-defined oligoaminoamides (OAAs) was screened for mRNA delivery. Notably, sequences, which had previously been identified as potent plasmid DNA (pDNA) or small-interfering RNA (siRNA) carriers, displayed only moderate mRNA transfection activity. A second round of screening combined the cationizable building block succinoyl tetraethylene pentamine and histidines for endosomal buffering, tyrosine tripeptides and various fatty acids for mRNA polyplex stabilization, as well as redox-sensitive units for programmed intracellular release. For the tested OAA carriers, balancing of extracellular stability, endosomal lytic activity, and intracellular release capability was found to be of utmost importance for optimum mRNA transfection efficiency. OAAs with T-shape topology containing two oleic acids as well-stabilizing fatty acids, attached via a dynamic bioreducible building block, displayed superior activity with up to 1000-fold increased transfection efficiency compared to their non-reducible analogs. In the absence of the dynamic linkage, incorporation of shorter less stabilizing fatty acids could only partly compensate for mRNA delivery. Highest GFP expression and the largest fraction of transfected cells (96%) could be detected for the bioreducible OAA with incorporated histidines and a dioleoyl motif, outperforming all other tested carriers as well as the positive control succPEI. The good in vitro performance of the dynamic lead structure was verified in vivo upon intratracheal administration of mRNA complexes in mice.
DOI: 10.1007/s00415-021-10603-9
2021
Cited 20 times
MuSK-antibodies are associated with worse outcome in myasthenic crisis requiring mechanical ventilation
Myasthenic crisis (MC) is a life-threatening condition for patients with myasthenia gravis (MG). Muscle-specific kinase-antibodies (MuSK-ABs) are detected in ~ 6% of MG, but data on outcome of MuSK-MCs are still lacking. We made a subgroup analysis of patients who presented with MC with either acetylcholine-receptor-antibody positive MG (AchR-MG) or MuSK-MG between 2006 and 2015 in a retrospective German multicenter study. We identified 19 MuSK-AB associated MCs in 15 patients and 161 MCs in 144 patients with AchR-ABs only. In contrast to patients with AchR-AB, MuSK-AB patients were more often female (p = 0.05, OR = 2.74) and classified as Myasthenia Gravis Foundation of America-class IV before crisis (p = 0.04, OR = 3.25). MuSK-AB patients suffer more often from multiple chronic disease (p = 0.016, OR = 4.87) and were treated more invasively in terms of plasma exchanging therapies (not significant). The number of days of mechanical ventilation (MV) (43.0 ± 53.1 vs. 17.4 ± 18; p < 0.0001), days on an intensive care unit (ICU) (45.3 ± 49.5 vs. 21.2 ± 19.7; p < 0.0001), and hospital-length of stay (LOS) (55.9 ± 47.6 vs. 28.8 ± 20.9 days; p < 0.0001) were significantly increased in MuSK-MC. Remarkable is that these changes were mainly due to patients with MusK-ABs only, whereas patients' outcome with both antibodies was similar to AchR-MCs. Furthermore, our data showed a shortened duration of MV after treatment with plasma exchanging therapies compared to treatment with intravenous immunoglobulin in MuSK-MCs. We conclude that MuSK-AB-status is associated with a longer need of MV, ICU-LOS, and hospital-LOS in MC, and therefore recommend early initiation of a disease-specific therapy.
DOI: 10.1161/strokeaha.121.038455
2022
Cited 13 times
Association of Intraventricular Fibrinolysis With Clinical Outcomes in Intracerebral Hemorrhage: An Individual Participant Data Meta-Analysis
Background: In patients with intracerebral hemorrhage (ICH), the presence of intraventricular hemorrhage constitutes a promising therapeutic target. Intraventricular fibrinolysis (IVF) reduces mortality, yet impact on functional disability remains unclear. Thus, we aimed to determine the influence of IVF on functional outcomes. Methods: This individual participant data meta-analysis pooled 1501 patients from 2 randomized trials and 7 observational studies enrolled during 2004 to 2015. We compared IVF versus standard of care (including placebo) in patients treated with external ventricular drainage due to acute hydrocephalus caused by ICH with intraventricular hemorrhage. The primary outcome was functional disability evaluated by the modified Rankin Scale (mRS; range: 0–6, lower scores indicating less disability) at 6 months, dichotomized into mRS score: 0 to 3 versus mRS: 4 to 6. Secondary outcomes included ordinal-shift analysis, all-cause mortality, and intracranial adverse events. Confounding and bias were adjusted by random effects and doubly robust models to calculate odds ratios and absolute treatment effects (ATE). Results: Comparing treatment of 596 with IVF to 905 with standard of care resulted in an ATE to achieve the primary outcome of 9.3% (95% CI, 4.4–14.1). IVF treatment showed a significant shift towards improved outcome across the entire range of mRS estimates, common odds ratio, 1.75 (95% CI, 1.39–2.17), reduced mortality, odds ratio, 0.47 (95% CI, 0.35–0.64), without increased adverse events, absolute difference, 1.0% (95% CI, −2.7 to 4.8). Exploratory analyses provided that early IVF treatment (≤48 hours) after symptom onset was associated with an ATE, 15.2% (95% CI, 8.6–21.8) to achieve the primary outcome. Conclusions: As compared to standard of care, the administration of IVF in patients with acute hydrocephalus caused by intracerebral and intraventricular hemorrhage was significantly associated with improved functional outcome at 6 months. The treatment effect was linked to an early time window &lt;48 hours, specifying a target population for future trials.
DOI: 10.1007/s00415-022-11023-z
2022
Cited 12 times
Seronegative myasthenic crisis: a multicenter analysis
Myasthenic crisis (MC) is a life-threatening condition for patients with myasthenia gravis (MG). Seronegative patients represent around 10-15% of MG, but data on outcome of seronegative MCs are lacking. We performed a subgroup analysis of patients who presented with MC with either acetylcholine-receptor-antibody-positive MG (AChR-MG) or seronegative MG between 2006 and 2015 in a retrospective German multicenter study. We identified 15 seronegative MG patients with 17 MCs and 142 AChR-MG with 159 MCs. Seronegative MCs were younger (54.3 ± 14.5 vs 66.5 ± 16.3 years; p = 0.0037), had a higher rate of thymus hyperplasia (29.4% vs 3.1%; p = 0.0009), and were more likely to be female (58.8% vs 37.7%; p = 0.12) compared to AChR-MCs. Time between diagnosis of MG and MC was significantly longer in seronegative patients (8.2 ± 7.6 vs 3.1 ± 4.4 years; p < 0.0001). We found no differences in duration of mechanical ventilation (16.2 ± 15.8 vs 16.5 ± 15.9 days; p = 0.94) and length of stay at intensive care unit (17.6 ± 15.2 vs 17.8 ± 15.4 days; p = 0.96), or in-hospital mortality (11.8% vs. 10.1%; p = 0.69). We conclude that MC in seronegative MG affects younger patients after a longer period of disease, but that crisis treatment efficacy and outcome do not differ compared to AChR-MCs.
DOI: 10.1161/01.str.32.8.1863
2001
Cited 62 times
Predictive Value of Neurochemical Monitoring in Large Middle Cerebral Artery Infarction
Space-occupying brain edema is a life-threatening complication in patients with large hemispheric stroke. Early identification of patients at risk is necessary to decide on invasive therapies such as decompressive hemicraniectomy or hypothermia. To assess potential predictors of malignant brain edema by measurement of intracranial pressure (ICP) and microdialysis in patients with large hemispheric stroke and different clinical course.In an ongoing prospective clinical study, an ICP and microdialysis probe were placed into the parenchyma of the ipsilateral frontal lobe of 10 patients. Extracellular concentrations of glutamate, lactate, pyruvate, and glycerol were measured continuously. Repeated cranial CT scans were scrutinized for size of infarction and presence of mass effect.The dynamics of the different substances varied in accordance with the clinical course, size of infarction, and local brain edema: Increase in ICP and in glutamate concentration and lactate-pyruvate ratio was followed by massive edema and large infarcts; generally low and stable ICP and substrate concentrations were found in patients without progressive space-occupying infarcts.In patients with large hemispheric infarction, bedside monitoring with microdialysis is feasible and might be helpful together with ICP recording to follow the development of malignant brain edema.
DOI: 10.1161/01.str.0000100158.51986.eb
2003
Cited 62 times
Extracellular Concentrations of Non–Transmitter Amino Acids in Peri-Infarct Tissue of Patients Predict Malignant Middle Cerebral Artery Infarction
Space-occupying brain edema is a life-threatening complication in patients with large middle cerebral artery (MCA) infarction. To determine predictors of this detrimental process, we investigated alterations of extracellular non-transmitter amino acid concentrations in peri-infarct tissue.Thirty-one patients with infarctions covering >50% of the MCA territory in early cranial CT scans were included in the study. Probes for microdialysis, intracranial pressure, and tissue oxygen pressure were placed into the noninfarcted ipsilateral frontal lobe. Positron emission tomography imaging was performed in 16 of these patients to measure cerebral blood flow in the tissue around the neuromonitoring probes.Fourteen of the 31 patients developed a malignant MCA infarction, and 17 did not. The patients in the malignant group had significantly lower extracellular concentrations of non-transmitter amino acids than those in the benign group in the first 12 hours of neuromonitoring. At this time, CBF values determined in regions of interest around the probes by positron emission tomography and tissue oxygen pressure showed that the monitored tissues were not yet infarcted, and no differences in transmitter amino acids concentrations were found between the 2 groups. Furthermore, extracellular concentrations of non-transmitter amino acids were negatively correlated with size of infarction.We assume that reduction of non-transmitter amino acid concentrations reflects an expansion of the extracellular space by vasogenic edema formation in peri-infarct tissue of patients with malignant MCA infarction. Our findings facilitate early prediction of malignant edema formation and may help to increase knowledge of the pathophysiology of the peri-infarct zone of large MCA infarction.
DOI: 10.1159/000330648
2011
Cited 38 times
The Severity of Ischemia Determines and Predicts Malignant Brain Edema in Patients with Large Middle Cerebral Artery Infarction
&lt;i&gt;Background:&lt;/i&gt; In order to determine the impact of the severity of ischemia on malignant edema formation, we investigated various degrees of perfusional deficit by &lt;sup&gt;11&lt;/sup&gt;C-flumazenil PET in patients with large middle cerebral artery (MCA) infarction. &lt;i&gt;Methods:&lt;/i&gt; 17 patients with large MCA stroke were included. Cerebral blood flow (CBF) was measured 15.9 ± 6.4 h after the ictus. Patients were divided into a malignant (n = 9) and a benign group (n = 8) as a function of their clinical courses and edema. Edema was measured as maximal midline shift on follow-up CTs. Total hypoperfusion volume was divided into different subvolumes according to the degree of CBF reduction. &lt;i&gt;Results:&lt;/i&gt; Subvolumes of severe ischemia relative to total ischemic area were significantly larger in the malignant group than in the benign group and were significantly correlated with edema formation. The highest correlation and best predictive values for edema formation with a sensitivity, specificity, and a positive and negative predictive value of 100% were found for subvolumes with severe ischemia. Correlation coefficients and prediction decreased for subvolumes with less severe perfusional deficit, pointing to the risk of misclassifying patients when relying on the volume of total perfusional deficit alone. &lt;i&gt;Conclusions:&lt;/i&gt; Malignant MCA infarction seems to be determined more by the volume of severe perfusional deficit than that of total perfusional deficit. Assessment of severely ischemic areas allows prediction of malignant edema formation and might help to select candidates for hemicraniectomy.
DOI: 10.1159/000331011
2011
Cited 34 times
Immunoadsorption in Patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy with Unsatisfactory Response to First-Line Treatment
&lt;i&gt;Background/Aims:&lt;/i&gt; First-line treatment options for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) are corticosteroids, intravenous immunoglobulin, and plasma exchange. In a significant number of patients, first-line therapy fails, and long-term maintenance treatment still remains a therapeutic challenge. Immunoadsorption (IA) may be an alternative to classical plasma exchange in the therapy of immune-mediated neurologic diseases. The aim of this investigation was to evaluate efficacy and safety of IA in patients with CIDP with unsatisfactory response to first-line treatment options. &lt;i&gt;Methods:&lt;/i&gt; CIDP patients received adjunct IA treatment using tryptophan-immune adsorbers. The inflammatory neuropathy cause and treatment disability (INCAT) score was used to grade disability and monitor treatment effects. &lt;i&gt;Results:&lt;/i&gt; In total, 14 CIDP patients were analyzed. Ten patients were treated in hospital. After one IA treatment series, the INCAT score decreased significantly in all 10 patients. Four of these 14 patients were treated in outpatient clinics using long-term maintenance IA with 1–2 treatments per week. In these 4 patients, effects of long-term maintenance IA resulted in an improvement of overall disability. In all patients, IA was safe, well tolerated, and no severe adverse effects occurred. &lt;i&gt;Conclusion:&lt;/i&gt; IA could be an effective and safe option for CIDP patients with unsatisfactory response to first-line treatment options and for long-term maintenance treatment.
DOI: 10.1002/mds.25494
2013
Cited 31 times
Malignant deep brain stimulation‐withdrawal syndrome in a patient with Parkinson's disease
Movement DisordersVolume 28, Issue 12 p. 1640-1641 Clinical Vignettes Malignant deep brain stimulation-withdrawal syndrome in a patient with Parkinson's disease Janina Neuneier MD, Corresponding Author Janina Neuneier MD Department of Neurology, University Hospital Cologne, Cologne, GermanyCorrespondence to: Dr. J. Neuneier, Department of Neurology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany; [email protected]; and Dr. L. Timmermann, Department of Neurology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany; [email protected]Search for more papers by this authorMichael T. Barbe MD, Michael T. Barbe MD Department of Neurology, University Hospital Cologne, Cologne, Germany Institute for Neuroscience and Medicine (INM-3), Cognitive Neuroscience, Research Center Juelich, Juelich, GermanySearch for more papers by this authorChristian Dohmen MD, Christian Dohmen MD Department of Neurology, University Hospital Cologne, Cologne, GermanySearch for more papers by this authorMohammad Maarouf MD, Mohammad Maarouf MD Department of Stereotaxy and Functional Neurosurgery, University Hospital Cologne, Cologne, GermanySearch for more papers by this authorJochen Wirths MD, Jochen Wirths MD Department of Stereotaxy and Functional Neurosurgery, University Hospital Cologne, Cologne, GermanySearch for more papers by this authorGereon R. Fink MD, Gereon R. Fink MD Department of Neurology, University Hospital Cologne, Cologne, Germany Institute for Neuroscience and Medicine (INM-3), Cognitive Neuroscience, Research Center Juelich, Juelich, GermanySearch for more papers by this authorLars Timmermann MD, Corresponding Author Lars Timmermann MD Department of Neurology, University Hospital Cologne, Cologne, GermanyCorrespondence to: Dr. J. Neuneier, Department of Neurology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany; [email protected]; and Dr. L. Timmermann, Department of Neurology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany; [email protected]Search for more papers by this author Janina Neuneier MD, Corresponding Author Janina Neuneier MD Department of Neurology, University Hospital Cologne, Cologne, GermanyCorrespondence to: Dr. J. Neuneier, Department of Neurology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany; [email protected]; and Dr. L. Timmermann, Department of Neurology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany; [email protected]Search for more papers by this authorMichael T. Barbe MD, Michael T. Barbe MD Department of Neurology, University Hospital Cologne, Cologne, Germany Institute for Neuroscience and Medicine (INM-3), Cognitive Neuroscience, Research Center Juelich, Juelich, GermanySearch for more papers by this authorChristian Dohmen MD, Christian Dohmen MD Department of Neurology, University Hospital Cologne, Cologne, GermanySearch for more papers by this authorMohammad Maarouf MD, Mohammad Maarouf MD Department of Stereotaxy and Functional Neurosurgery, University Hospital Cologne, Cologne, GermanySearch for more papers by this authorJochen Wirths MD, Jochen Wirths MD Department of Stereotaxy and Functional Neurosurgery, University Hospital Cologne, Cologne, GermanySearch for more papers by this authorGereon R. Fink MD, Gereon R. Fink MD Department of Neurology, University Hospital Cologne, Cologne, Germany Institute for Neuroscience and Medicine (INM-3), Cognitive Neuroscience, Research Center Juelich, Juelich, GermanySearch for more papers by this authorLars Timmermann MD, Corresponding Author Lars Timmermann MD Department of Neurology, University Hospital Cologne, Cologne, GermanyCorrespondence to: Dr. J. Neuneier, Department of Neurology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany; [email protected]; and Dr. L. Timmermann, Department of Neurology, University Hospital Cologne, Kerpener Str. 62, 50937 Cologne, Germany; [email protected]Search for more papers by this author First published: 15 July 2013 https://doi.org/10.1002/mds.25494Citations: 27 Relevant conflicts of interest/financial disclosures: Nothing to report. Full financial disclosures and author roles may be found in the online version of this article. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1 Benabid AL, Chabardes S, Mitrofanis J, Pollak P. Deep brain stimulation of the subthalamic nucleus for the treatment of Parkinson's disease. Lancet Neurol 2009; 8: 67–81. 2 Moro E, Lozano AM, Pollak P, et al. Long-term results of a multicenter study on subthalamic and pallidal stimulation in Parkinson's disease. Mov Disord 2010; 25: 578–586. 3 Castrioto A, Lozano AM, Poon Y-Y, Lang AE, Fallis M, Moro E. Ten-year outcome of subthalamic stimulation in Parkinson disease: a blinded evaluation. Arch Neurol 2011; 68: 1550–1556. 4 Umemura A, Oka Y, Yamamoto K, Okita K, Matsukawa N, Yamada K. Complications of subthalamic nucleus stimulation in Parkinson's disease. Neurol Med Chir (Tokyo) 2011; 51: 749–755. 5 Anheim M, Fraix V, Chabardes S, Krack P, Benabid AL, Pollak P. Lifetime of Itrel II pulse generators for subthalamic nucleus stimulation in Parkinson's disease. Mov Disord 2007; 22: 2436– 2439. 6 Hariz MI, Johansson F. Hardware failure in parkinsonian patients with chronic subthalamic nucleus stimulation is a medical emergency. Mov Disord 2001; 16: 166–168. 7 Douglas A, Morris J. It was not just a heatwave! Neuroleptic malignant-like syndrome in a patient with Parkinson's disease. Age Ageing 2006; 35: 640–641. 8 Mizuno Y, Takubo H, Mizuta E, Kuno S. Malignant syndrome in Parkinson's disease: concept and review of the literature. Parkinsonism Relat Disord 2003; 9(suppl 1): S3–S9. Citing Literature Volume28, Issue12October 2013Pages 1640-1641 ReferencesRelatedInformation
DOI: 10.1016/j.jconrel.2017.01.045
2017
Cited 23 times
cmRNA/lipoplex encapsulation in PLGA microspheres enables transfection via calcium phosphate cement (CPC)/PLGA composites
In this study lipoplexes containing chemically modified messenger RNA (cmRNA) were incorporated into poly (lactic-co-glycolic acid) (PLGA) microspheres via water-in-oil-in-water (W/O/W) double emulsion solvent evaporation technique. The nanoparticle encapsulation by microparticle formation was optimized to achieve lipoplex release and maximum transfection efficiency in surrounding cells. It was possible to adjust characteristic features in surface topology and size of the PLGA-microspheres by varying the extent of lipoplex loading into the polymer matrix. The partial release of lipids and mRNA out of the microparticle system, their accumulation in cells and the production of encoded protein were visualized via fluorescence microscopy. These bioactive microspheres, containing cmRNA bearing lipoplexes, were developed for the incorporation of a therapeutic component into injectable calcium phosphate cements (CPC). Due to the incorporation of PLGA/lipoplex microspheres as a degradable entity, the porosity of the cement phase could additionally be adjusted. This approach of complex nanoparticle incorporation into polymer/cement composites represents a promising example for combining transcript therapy with biomechanical engineering.
DOI: 10.1177/0271678x17699629
2017
Cited 23 times
Standard-sampling microdialysis and spreading depolarizations in patients with malignant hemispheric stroke
Spreading depolarizations (SD) occur in high frequency in patients with malignant hemispheric stroke (MHS). Experimentally, SDs cause marked increases in glutamate and lactate, whereas glucose decreases. Here, we studied extracellular brain glutamate, glucose, lactate, pyruvate and the lactate/pyruvate ratio in relationship to SDs after MHS. We inserted two microdialysis probes in peri-infarct tissue at 5 and 15 mm to the infarct in close proximity to a subdural electrode strip. During 2356.6 monitoring hours, electrocorticography (ECoG) revealed 697 SDs in 16 of 18 patients. Ninety-nine SDs in electrically active tissue (spreading depressions, SDd) were single (SDds) and 485 clustered (SDdc), whereas 10 SDs with at least one electrode in electrically inactive tissue (isoelectric SDs, SDi) were single (SDis) and 103 clustered (SDic). More SDs and a significant number of clustered SDs occurred during the first 36 h post-surgery when glutamate was significantly elevated (> 100 µM). In a grouped analysis, we observed minor glutamate elevations with more than two SDs per hour. Glucose slightly decreased during SDic at 5 mm from the infarct. Directions of SD-related metabolic changes correspond to the experimental setting but the long sampling time of standard microdialysis precludes a more adequate account of the dynamics revealed by ECoG.
DOI: 10.1007/s00062-017-0651-3
2017
Cited 23 times
Mechanical Thrombectomy in Basilar Artery Occlusion
DOI: 10.1161/strokeaha.118.023492
2019
Cited 23 times
Characteristics in Non–Vitamin K Antagonist Oral Anticoagulant–Related Intracerebral Hemorrhage
Background and Purpose- Given inconclusive studies, it is debated whether clinical and imaging characteristics, as well as functional outcome, differ among patients with intracerebral hemorrhage (ICH) related to vitamin K antagonists (VKA) versus non-vitamin K antagonist (NOAC)-related ICH. Notably, clinical characteristics according to different NOAC agents and dosages are not established. Methods- Multicenter observational cohort study integrating individual patient data of 1328 patients with oral anticoagulation-associated ICH, including 190 NOAC-related ICH patients, recruited from 2011 to 2015 at 19 tertiary centers across Germany. Imaging, clinical characteristics, and 3-months modified Rankin Scale (mRS) outcomes were compared in NOAC- versus VKA-related ICH patients. Propensity score matching was conducted to adjust for clinically relevant differences in baseline parameters. Subgroup analyses were performed regarding NOAC agent, dosing and present clinically relevant anticoagulatory activity (last intake <12h/24h or NOAC level >30 ng/mL). Results- Despite older age in NOAC patients, there were no relevant differences in clinical and hematoma characteristics between NOAC- and VKA-related ICH regarding baseline hematoma volume (median [interquartile range]: NOAC, 14.7 [5.1-42.3] mL versus VKA, 16.4 [5.8-40.6] mL; P=0.33), rate of hematoma expansion (NOAC, 49/146 [33.6%] versus VKA, 235/688 [34.2%]; P=0.89), and the proportion of patients with unfavorable outcome at 3 months (mRS, 4-6: NOAC 126/179 [70.4%] versus VKA 473/682 [69.4%]; P=0.79). Subgroup analyses revealed that NOAC patients with clinically relevant anticoagulatory effect had higher rates of intraventricular hemorrhage (n/N [%]: present 52/109 [47.7%] versus absent 9/35 [25.7%]; P=0.022) and hematoma expansion (present 35/90 [38.9%] versus absent 5/30 [16.7%]; P=0.040), whereas type of NOAC agent or different NOAC-dosing regimens did not result in relevant differences in imaging characteristics or outcome. Conclusions- If effectively anticoagulated, there are no differences in hematoma characteristics and functional outcome among patients with NOAC- or VKA-related ICH. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT03093233.
DOI: 10.1007/s00115-003-1627-x
2004
Cited 41 times
Zerebrale Mikrodialyse beim Schlaganfall
DOI: 10.1016/j.brainres.2004.12.046
2005
Cited 39 times
Extracellular correlates of glutamate toxicity in short-term cerebral ischemia and reperfusion: A direct in vivo comparison between white and gray matter
Glutamate toxicity and cellular calcium overload are thought to be pathophysiological key factors not only in gray matter (GM) but also in white matter (WM) ischemia. Correlates of excitotoxicity have never been directly investigated in vivo in GM and WM ischemia and reperfusion. We measured simultaneously amino acids, purines, and calcium in relation to tissue depolarization using microdialysis and ion-selective electrodes and regional CBF using hydrogen clearance in GM and WM of cats during 10 min of global ischemia and 120 min of reperfusion. CBF ceased during ischemia. Reperfusion was followed by hyperperfusion that turned into hypoperfusion within 60 min in both GM and WM. Direct current potential decreased in ischemia to around −15 mV in GM and −10 mV in WM and shifted back after reperfusion towards control levels in both compartments. Extracellular calcium decreased in GM during ischemia, whereas it increased in WM. After reperfusion, calcium returned to control levels in both GM and WM. Glutamate, aspartate, GABA, and taurine increased in GM but not in WM during ischemia and reperfusion. Adenosine increased transiently in both compartments peaking during the first minutes of reperfusion, and returned thereafter to control levels. Contrasting with GM, deleterious processes such as glutamate accumulation and cellular Ca2+ influx do not occur in WM during short-term ischemia and reperfusion. Rather, an intrinsic neuroprotective role of adenosine may be discussed. In our view, therefore, therapeutic strategies against glutamate toxicity in short-term ischemia and reperfusion should be mainly focused on GM.
DOI: 10.1001/archneur.65.5.659
2008
Cited 34 times
Ocular Flutter, Generalized Myoclonus, and Trunk Ataxia Associated With Anti-GQ1b Antibodies
<h3>Objective</h3> To describe a movement disorder characterized by ocular flutter, trunk ataxia, and mild generalized myoclonus associated with anti-GQ1b antibodies. <h3>Design</h3> Case report. <h3>Setting</h3> University hospital. <h3>Patient</h3> A 37-year-old woman presented with rapid, conjugated, and periodic oscillations of the eyes with a strict preponderance for the horizontal plane (ocular flutter); trunk ataxia; and occasional arrhythmic muscle jerks (myoclonus) most pronounced at the neck. <h3>Results</h3> Brain magnetic resonance imaging results were normal. Cerebrospinal fluid examination revealed mild lymphocytic pleocytosis. Results of extensive serological tests on viral, bacterial, and fungal infections from blood and cerebrospinal fluid samples were unremarkable. Results of screening examinations for neoplasms and paraneoplastic antibodies, including whole-body fludeoxyglucose F18 positron emission tomography, were normal. Positive titers of IgG and IgM anti-GQ1b antibodies were found. <h3>Conclusions</h3> This is the first description of an association between the clinical syndrome of ocular flutter, mild stimulus sensitive myoclonus, and trunk ataxia and anti-GQ1b antibodies. The association with ganglioside antibodies lends further support to the notion of an autoimmune-associated pathology of the syndrome.
DOI: 10.1016/j.clineuro.2012.03.045
2013
Cited 22 times
Occurrence and recurrence of spontaneous chronic subdural haematoma is associated with a factor XIII deficiency
In some patients, chronic subdural haematoma (cSDH) appears to occur spontaneously with frequent re-bleeding events. The pathophysiology of this phenomenon is still poorly understood. Because coagulation factor XIII (FXIII) is known to be involved in vascular integrity, endothelial barrier function and wound healing, we evaluated the role of FXIII in spontaneous cSDH. We prospectively scrutinised the origin of cSDH in 117 patients and identified a subgroup of patients suffering from spontaneous cSDH who were included in this study. We analysed the plasma activity of FXIII and standard coagulation parameters and compared these data to age- and sex-matched healthy controls. We assessed the occurrence of re-bleeding events using clinical and imaging data and compared FXIII activity in patients with and without re-bleeding events. Out of 117 cSDH patients, 18 individuals suffered from spontaneous cSDH in this study. The patients with spontaneous cSDH showed significantly lower FXIII activity than the control group (65% [52.75, 80.25] (median [IQR]) vs. 93% [81, 111], P = 0.001), whereas standard coagulation parameters did not differ significantly between the groups. Six patients developed re-bleeding events after haematoma evacuation, and these patients expressed significantly lower FXIII activity compared to the other 12 patients (47.5% [33.5, 64] vs. 78.5% [58, 87], P = 0.005). The patient group with FXIII ≤ 68.5% differed significantly from the group with FXIII > 68.5% when categorised by the occurrence of re-bleeding events (n = 6/9 vs. n = 0/9, P = 0.009). This cut-off value predicted the re-bleeding events with a sensitivity of 100% and a specificity of 75% (positive predictive value: 66%, negative predictive value: 100%). FXIII deficiency may play a pathophysiological role in spontaneous cSDH, so we suggest investigating FXIII activity because it may predict re-bleeding events after treatment. In individuals with considerably low FXIII activity, FXIII substitution may mitigate the chronic nature of this disease.
DOI: 10.1007/s00063-018-0452-8
2018
Cited 20 times
Recommendations for extracorporeal cardiopulmonary resuscitation (eCPR)
DOI: 10.1136/jnnp-2018-319786
2019
Cited 18 times
Heparin for prophylaxis of venous thromboembolism in intracerebral haemorrhage
Objective To determine the occurrence of intracranial haemorrhagic complications (IHC) on heparin prophylaxis (low-dose subcutaneous heparin, LDSH) in primary spontaneous intracerebral haemorrhage (ICH) (not oral anticoagulation-associated ICH, non-OAC-ICH), vitamin K antagonist (VKA)-associated ICH and non-vitamin K antagonist oral anticoagulant (NOAC)-associated ICH. Methods Retrospective cohort study (RETRACE) of 22 participating centres and prospective single-centre study with 1702 patients with VKA-associated or NOAC-associated ICH and 1022 patients with non-OAC-ICH with heparin prophylaxis between 2006 and 2015. Outcomes were defined as rates of IHC during hospital stay among patients with non-OAC-ICH, VKA-ICH and NOAC-ICH, mortality and functional outcome at 3 months between patients with ICH with and without IHC. Results IHC occurred in 1.7% (42/2416) of patients with ICH. There were no differences in crude incidence rates among patients with VKA-ICH, NOAC-ICH and non-OAC-ICH (log-rank p=0.645; VKA-ICH: 27/1406 (1.9%), NOAC-ICH 1/130 (0.8%), non-OAC-ICH 14/880 (1.6%); p=0.577). Detailed analysis according to treatment exposure (days with and without LDSH) revealed no differences in incidence rates of IHC per 1000 patient-days (LDSH: 1.43 (1.04–1.93) vs non-LDSH: 1.32 (0.33–3.58), conditional maximum likelihood incidence rate ratio: 1.09 (0.38–4.43); p=0.953). Secondary outcomes showed differences in functional outcome (modified Rankin Scale=4–6: IHC: 29/37 (78.4%) vs non-IHC: 1213/2048 (59.2%); p=0.019) and mortality (IHC: 14/37 (37.8%) vs non-IHC: 485/2048 (23.7%); p=0.045) in disfavour of patients with IHC. Small ICH volume (OR: volume &lt;4.4 mL: 0.18 (0.04–0.78); p=0.022) and low National Institutes of Health Stroke Scale (NIHSS) score on admission (OR: NIHSS &lt;4: 0.29 (0.11–0.78); p=0.014) were significantly associated with fewer IHC. Conclusions Heparin administration for venous thromboembolism (VTE) prophylaxis in patients with ICH appears to be safe regarding IHC among non-OAC-ICH, VKA-ICH and NOAC-ICH in this observational cohort analysis. Randomised controlled trials are needed to verify the safety and efficacy of heparin compared with other methods for VTE prevention.
DOI: 10.1177/0885066620967646
2020
Cited 15 times
Early Tracheostomy Is Associated With Shorter Ventilation Time and Duration of ICU Stay in Patients With Myasthenic Crisis—A Multicenter Analysis
Myasthenic crisis (MC) requiring mechanical ventilation (MV) is a rare and serious complication of myasthenia gravis. Here we analyzed the frequency of performed tracheostomies, risk factors correlating with a tracheostomy, as well as the impact of an early tracheostomy on ventilation time and ICU length of stay (LOS) in MC.Retrospective chart review on patients treated for MC in 12 German neurological departments between 2006 and 2015 to assess demographic/diagnostic data, rates and timing of tracheostomy and outcome.In 107 out of 215 MC (49.8%), a tracheostomy was performed. Patients without tracheostomy were more likely to have an early-onset myasthenia gravis (27 [25.2%] vs 12 [11.5%], p = 0.01). Patients receiving a tracheostomy, however, were more frequently suffering from multiple comorbidities (20 [18.7%] vs 9 [8.3%], p = 0.03) and also the ventilation time (34.4 days ± 27.7 versus 7.9 ± 7.8, p < 0.0001) and ICU-LOS (34.8 days ± 25.5 versus 12.1 ± 8.0, p < 0.0001) was significantly longer than in non-tracheostomized patients. Demographics and characteristics of the course of the disease up to the crisis were not significantly different between patients with an early (within 10 days) compared to a late tracheostomy. However, an early tracheostomy correlated with a shorter duration of MV at ICU (26.2 days ± 18.1 versus 42.0 ± 33.1, p = 0.006), and ICU-LOS (26.2 days ± 14.6 versus 42.3 ± 33.0, p = 0.003).Half of the ventilated patients with MC required a tracheostomy. Poorer health condition before the crisis and late-onset MG were associated with a tracheostomy. An early tracheostomy (≤ day 10), however, was associated with a shorter duration of MV and ICU-LOS by 2 weeks.
DOI: 10.1007/s12028-007-9025-z
2007
Cited 29 times
Evoked Potentials in Acute Ischemic Stroke within the First 24 h: Possible Predictor of a Malignant Course
DOI: 10.1007/s10072-012-1102-1
2012
Cited 20 times
Prognostic value of electroencephalography and evoked potentials in the early course of malignant middle cerebral artery infarction
DOI: 10.1177/0333102412441414
2012
Cited 20 times
Spreading depolarizations in a case of migraine-related stroke
Background: Cortical spreading depolarization (CSD) has been implicated in the pathophysiology of migraine with aura. Patients that suffer from this type of migraine have shown a higher risk of developing an ischaemic stroke. Case: A 42-year-old female exhibited reoccurring migraine attacks for the first time 1 month before suffering an ischaemic infarction. Imaging studies revealed an occlusion in the right middle cerebral artery. Other possible disorders were excluded. It was possible to register 20 CSDs, of which 12 coincided with high levels of glutamate and lactate/pyruvate ratio. Loss of electrocorticographic activity was observed for 89 hours after the 8th depolarization. Conclusions: Migraine with aura symptoms may be induced by CSDs triggered by hypoperfusion states. Our case supports the idea of the migraine with aura–stroke continuum.
DOI: 10.1152/jn.01012.2015
2016
Cited 18 times
Prognostic value of somatosensory evoked potentials, neuron-specific enolase, and S100 for short-term outcome in ischemic stroke
To predict short-term outcome in acute ischemic stroke, we analyzed somatosensory evoked potentials (SEP) and biochemical parameters [neuron-specific enolase (NSE) and S100 protein] in a prospective study with serial measurement. In 31 patients with 1st middle cerebral artery infarction, serum NSE and S100 protein were measured daily between days 1 and 6 poststroke. The N20 and N70 components of the SEP (SEP20 and SEP70) were determined on days 1 and 6. SEP and biochemical markers in stroke patients were compared with a control group. Short-term outcome was assessed by the modified Rankin Scale (mRS) at days 7-10 and was dichotomized between good (mRS 0-2) and poor (mRS ≥3) outcome. Specificity and positive predictive value (PPV) were high at day 1 for SEP (SEP20: 100% for both; SEP70: 93 and 88%, respectively) compared with lower values for NSE (67 and 50%) and S100 (23 and 57%). In contrast, S100 showed the highest sensitivity at day 1 with 77% compared with a relatively low sensitivity of NSE (31%) and SEP (SEP20: 35%, SEP70: 47%). The biochemical markers showed an improving sensitivity over time with best values (>90%) between days 3 and 4 at the expense of a lower specificity. Specificity and PPV of SEP on day 6 was still 100% with sensitivity increasing up to 53% (SEP20) and 60% (SEP70). SEP could early differentiate between good and poor outcome and reliably predict poor outcome. Since biochemical markers and SEP complement each other in the prognosis of stroke, a combined application of these markers seems promising.
DOI: 10.1007/s00101-018-0473-y
2018
Cited 18 times
Recommendations for extracorporeal cardiopulmonary resuscitation (eCPR)
DOI: 10.1016/j.seizure.2017.08.006
2017
Cited 17 times
New onset status epilepticus in older patients: Clinical characteristics and outcome
PurposeWe here evaluated (1) the differential characteristics of status epilepticus (SE) in older (≥60 years) compared to younger adults (18–59 years). In particular, we were interested in (2) the proportion and characteristics of new onset SE in patients with no history of epilepsy (NOSE) in older compared to younger adults, and (3) predictive parameters for clinical outcome in older subjects with NOSE.MethodsWe performed a monocentric retrospective analysis of all adult patients (≥18 years) admitted with SE to our tertiary care centre over a period of 10 years (2006–2015) to evaluate clinical characteristics and short-time outcome at discharge.ResultsOne-hundred-thirty-five patients with SE were included in the study. Mean age at onset was 64 years (range 21–90), eighty-seven of the patients (64%) were older than 60 years. In 76 patients (56%), SE occurred as NOSE, sixty-seven percent of them were aged ≥60 years. There was no age-dependent predominance for NOSE. NOSE was not a relevant outcome predictor, especially regarding age-related subgroups. Older patients with NOSE had less frequently general tonic clonic SE (GTCSE; p = 0.001) and were more often female (p = 0.01). Regarding outcome parameters and risk factors in older patients with NOSE, unfavourable outcome was associated with infections during in-hospital treatment (0.04), extended stay in ICU (p = 0.001), and generally in hospital (p < 0.001).ConclusionIn our cohort, older patients represented the predominant subgroup in patients with SE. Older patients suffered more often from non-convulsive semiology and had a less favourable short-time outcome. NOSE was not a predictive outcome parameter in older patients. Data suggest that avoiding infections should have a priority because higher infection rates were associated with unfavourable outcome.
DOI: 10.1007/s00415-024-12208-4
2024
POLAR: prediction of prolonged mechanical ventilation in patients with myasthenic crisis
DOI: 10.1007/s12028-009-9252-6
2009
Cited 21 times
Selective Immune Adsorption Treatment of Severe Guillain Barré Syndrome in the Intensive Care Unit
DOI: 10.1007/s12028-013-9893-3
2013
Cited 17 times
Standards of Scoring, Monitoring, and Parameter Targeting in German Neurocritical Care Units: A National Survey
Optimal management of physiological parameters in neurological/neurosurgical intensive care units (NICUs) is largely unclear as high-quality evidence is lacking. The aim of this survey was to investigate if standards exist in the use of clinical scores, systemic and cerebral monitoring and the targeting of physiology values and in what way this affects clinical management in German NICUs. National survey, on-line anonymized questionnaire. German departments stating to run a neurological, neurosurgical or interdisciplinary neurological/neurosurgical intensive care unit were identified by a web-based search of all German hospitals and contacted via email. Responses from 78 German NICUs were obtained. Of 19 proposed clinical/laboratory/radiological scores only 5 were used regularly by >60 %. Bedside neuromonitoring (NM) predominantly consisted of transcranial Doppler sonography (94 %), electroencephalography (92 %) and measurement of intracranial pressure (ICP) (90 %), and was installed if patients had or were threatened by elevated ICP (86 %), had specific diseases like subarachnoid hemorrhage (51 %) or were comatose (35 %). Although mean trigger values for interventions complied with guidelines or wide-spread customs, individual trigger values varied widely, e.g., for hyperglycemia (maximum blood glucose between 120 and 250 mg/dl) or for anemia (minimum hemoglobin values between 5 and 10 g/dl). Although apparently aiming for standardization in neurocritical care, German NICUs show substantial differences in NM and monitoring-associated interventions. In terms of scoring and monitoring methods, German NICUs seem to be quite conservative. These survey results suggest a need of prospective and randomized interventional trials in neurocritical care to help define standards and target values.
DOI: 10.1016/j.clinph.2016.04.026
2016
Cited 15 times
Changes in electrocorticographic beta frequency components precede spreading depolarization in patients with acute brain injury
Spreading depolarization (SD) occurs after traumatic brain injury, subarachnoid hemorrhage, malignant hemispheric stroke and intracranial hemorrhage. SD has been associated with secondary brain injury, which can be reduced by ketamine. In this present study frequency bands of electrocorticographic (ECoG) recordings were investigated with regards to SDs. A total of 43 patients after acute brain injury were included in this retrospective and explorative study. Relative delta 0.5–4 Hz, theta 4–8 Hz, alpha 8–13 Hz and beta 13–40 Hz bands were analyzed with regards to SD occurrence and analgesic and sedative administration. Higher frequencies, including gamma 40–70 Hz, fast gamma 70–100 Hz and high frequency oscillations 100–200 Hz were analyzed in a subset of patients with a sampling rate of up to 400 Hz. A close association of relative beta frequency and SD was found. Relative beta frequency was suppressed up to two hours prior to SD when compared to hours with no SD. This finding was partially explained by administration of ketamine. Even after removal of all patient data during administration of ketamine, SDs occurred predominantly during times with low relative beta frequency in a patient-independent analysis. Suppression of beta frequency by ketamine or without ketamine is associated with low SD counts. Alteration of beta frequency might help to predict occurrence of SDs in acutely brain injured patients.
DOI: 10.1385/ncc:6:1:30
2007
Cited 20 times
Rapid Geographical Clustering of Wound Botulism in Germany After Subcutaneous and Intramuscular Injection of Heroin
DOI: 10.1007/s00234-010-0719-0
2010
Cited 18 times
Combined interventional stroke therapy using intracranial stent and local intraarterial thrombolysis (LIT)
DOI: 10.1002/ange.201005120
2011
Cited 15 times
pH‐Responsive Release of Acetal‐Linked Melittin from SBA‐15 Mesoporous Silica
Freisetzung im Sauren: Eine pH-labile Immobilisierung des Peptids Melittin im Porensystem eines SBA-15-Wirts über Acetalbrücken ermöglicht die Freisetzung des Peptids durch Absenken des pH-Werts von 7.4 auf 5.5. Die Freisetzung wird anhand der Melittin-induzierten Lyse von Mauserythrozyten demonstriert. Mit dieser Methode könnten neue SiO2-basierte Peptidtransportsysteme für die gezielte Krebstherapie entwickelt werden. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
DOI: 10.1002/ange.201102165
2011
Cited 15 times
Festphasen‐basierte Synthese sequenzdefinierter T‐, i‐ und U‐Form‐Polymere für den pDNA‐ und siRNA‐Transfer
Künstliche Oligoethylenaminosäuren wurden zusammen mit natürlichen Aminosäuren und optional Fettsäuren zur Festphasen-basierten Synthese von Polymeren mit präziser Sequenz, Topologie und Modifikation eingesetzt. Erste Konzeptstudien demonstrieren das große Potenzial solcher Polymere in der Transfektion von pDNA und siRNA.
DOI: 10.1007/s13346-013-0146-y
2013
Cited 14 times
Gene silencing and antitumoral effects of Eg5 or Ran siRNA oligoaminoamide polyplexes
DOI: 10.1097/00004647-200105000-00004
2001
Cited 26 times
Adenosine in Relation to Calcium Homeostasis: Comparison between Gray and White Matter Ischemia
In vitro studies suggest that adenosine may attenuate anoxic white matter damage as an intrinsic protective substance. The authors investigated ischemic alterations of purines in relation to tissue depolarization and extracellular calcium and amino acid concentrations in vivo using microdialysis and ion-selective electrodes in cortical gray and subcortical white matter of 10 cats during 120 minutes of global brain ischemia. Immediately on induction of ischemia, regional cerebral blood flow ceased in all cats in both gray and white matter. The direct current potential rapidly decreased, the decline being slower and shallower in white matter. Extracellular calcium levels decreased in gray matter. In contrast, they first increased in white matter and started to decrease below control levels only after approximately 30 minutes. Adenosine levels transiently increased in both tissue compartments; the peak was delayed by 30 minutes in white matter. Thereafter, levels declined faster in gray than in white matter and remained elevated in the latter tissue compartment. Inosine and hypoxanthine elevations were progressive in both regions but smaller in white matter. Levels of gamma-aminobutyric acid, another putatively protective agent, steadily increased, starting immediately in gray matter and delayed by almost 1 hour in white matter. The delayed and prolonged accumulation of adenosine correlates with a slower adenosine triphosphate breakdown in white matter ischemia and may result in protection of white matter by suspending cellular calcium influx.
DOI: 10.1371/journal.pone.0186607
2017
Cited 12 times
Should preventive antibiotics be used in patients with acute stroke? A systematic review and meta-analysis of randomized controlled trials
Background Infection is a common complication in acute stroke. Whether or not preventive antibiotics reduce the risk of infection or even lead to a favorable outcome and reduction of mortality after a stroke still remains equivocal. This review was performed to update the current knowledge on the effect and possible benefits of prophylactic antibiotic therapy in patients with stroke. Methods A systematic review and meta-analysis of preventive antibiotics`effect on the incidence of infection, favorable outcome (mRS≤2) and mortality in patients with acute stroke is performed with relevant randomized controlled trials. Results Six studies were identified, involving 4125 participants. Compared with the control group, the treated groups were significantly less prone to suffer from early overall infections [RR = 0.52, 95%CI (0.39, 0.70), p<0.0001], early pneumonia [RR = 0.64, 95%CI (0.42, 0.96), p = 0.03] and early urinary tract infections [RR = 0.35, 95%CI (0.25, 0.48), p<0.00001]. However, there was no significant difference in overall mortality [RR = 1.07, 95%CI (0.90, 1.27), p = 0.44], early mortality [RR = 0.99, 95%CI (0.78, 1.26), p = 0.92], late mortality [RR = 1.12, 95%CI (0.94, 1.35), p = 0.21] or favorable outcome [RR = 1.00, 95%CI (0.92, 1.08), p = 0.98]. Conclusion Although preventive antibiotic treatment did reduce the occurrence of early overall infections, early pneumonia and early urinary tract infection in patients with acute stroke, this advantage was not eventually translated to a favorable outcome and reduction in mortality. Future studies are warranted to identify any subgroup of stroke patients who might benefit from preventive antibiotic treatment.
DOI: 10.1007/s12028-009-9301-1
2009
Cited 14 times
Sequential Escalation of Therapy in “Malignant” Cerebral Venous and Sinus Thrombosis
DOI: 10.1016/j.seizure.2009.09.005
2009
Cited 13 times
Epilepsia partialis continua responsive to intravenous levetiracetam
We report on a case of epilepsia partialis continua with rapid response to intravenous bolus administration of levetiracetam. A 60-year-old woman presented with continuous jerking of the right foot and hallux persisting for more than two days. She had a 9-year history of epilepsy due to a left temporoparietal oligodendroglioma with occasional focal seizures clinically presenting as speech arrest, which was treated with levetiracetam and oxcarbazepine administered orally. After hospital admission, the twitching of the foot and toe was refractory to add-on treatment with lorazepam and diazepam but stopped within 15 min after intravenous bolus administration of 2000 mg levetiracetam. This observation suggests that intravenous bolus administration of levetiracetam may be an effective therapeutic option in epilepsia partialis continua.
DOI: 10.1159/000484719
2017
Cited 10 times
Carotid Artery Stenosis Contralateral to Acute Tandem Occlusion: An Independent Predictor of Poor Clinical Outcome after Mechanical Thrombectomy with Concomitant Carotid Artery Stenting
Cerebral ischemic strokes due to extra-/intracranial tandem occlusions (TO) of the anterior circulation are responsible for causing mechanical thrombectomy (MT). The impact of concomitant contralateral carotid stenosis (CCS) upon outcome remains unclear in this stroke subtype.Retrospective analysis of prospectively collected data of 4 international stroke centers between 2011 and 2017. One hundred ninety-seven consecutive patients with anterior TO were treated with MT and acute carotid artery stenting (CAS). Clinical (including demographics and National Institutes of Health Stroke Scale [NIHSS]), imaging (including angiographic evaluation of CCS) and procedural data were evaluated. Favorable clinical outcome was defined as modified Rankin Scale (mRS) ≤2 at 90 days.In 186 out of 197 TO patients preinterventional CT angiography was available for analysis, thereof 49 patients (26%) presented with CCS. Median admission NIHSS and procedural timings did not differ between groups. Reperfusion was successful in 38 out of 49 patients (78%) vs. 113 out of 148 patients (76%) without CCS. In stark contrast, rate of favorable outcome at 90 days differed significantly between groups (22 vs. 44%; p < 0.05). The presence of CCS in TO was associated with an unfavorable clinical outcome independent of age and NIHSS in multivariate logistic regression (p < 0.05). Final infarct volume was significantly larger in CCS patients (100 ± 127 vs. 63 ± 77 cm3; p < 0.05). Neither all-cause mortality rates (25 vs. 17%) nor frequency of peri-interventional symptomatic intracranial hemorrhage differed between groups (7 vs. 6%).For patients with anterior TO undergoing MT with concomitant CAS the presence of CCS >50% is an independent predictor of poor clinical outcome. This most likely cause is due to poorer collateral flow to the affected tissue.
DOI: 10.1016/j.omtm.2017.12.006
2018
Cited 10 times
Exploring Cytotoxic mRNAs as a Novel Class of Anti-cancer Biotherapeutics
New treatments to overcome the obstacles of conventional anti-cancer therapy are a permanent subject of investigation. One promising approach is the application of toxins linked to cell-specific ligands, so-called immunotoxins. Another attractive option is the employment of toxin-encoding plasmids. However, immunotoxins cause hepatoxicity, and DNA therapeutics, among other disadvantages, bear the risk of insertional mutagenesis. As an alternative, this study examined chemically modified mRNAs coding for diphtheria toxin, subtilase cytotoxin, and abrin-a for their ability to reduce cancer cell growth both in vitro and in vivo. The plant toxin abrin-a was the most promising candidate among the three tested toxins and was further investigated. Its expression was demonstrated by western blot. Experiments with firefly luciferase in reticulocyte lysates and co-transfection experiments with EGFP demonstrated the capability of abrin-a to inhibit protein synthesis. Its cytotoxic effect was quantified employing viability assays and propidium iodide staining. By studying caspase-3/7 activation, Annexin V-binding, and chromatin condensation with Hoechst33258 staining, apoptotic cell death could be confirmed. In mice, repeated intratumoral injections of complexed abrin-a mRNA resulted in a significant reduction (89%) of KB tumor size compared to a non-translatable control mRNA.
DOI: 10.1007/s00115-015-4361-2
2015
Cited 9 times
Intensivtherapie des raumfordernden ischämischen Hemisphäreninfarkts
DOI: 10.1007/s00415-023-12016-2
2023
Weaning and extubation failure in myasthenic crisis: a multicenter analysis
DOI: 10.1097/00004647-199907000-00009
1999
Cited 21 times
Breakdown of Calcium Homeostasis in Relation to Tissue Depolarization: Comparison between Gray and White Matter Ischemia
In vitro studies suggest that ischemic injury of cerebral white matter is mediated by nonsynaptic cellular mechanisms, such as Ca 2+ entry into axons through reversal of the Na + -Ca 2+ exchanger. The authors investigated extracellular Ca 2+ concentration in relation to tissue depolarization (direct current potential) in vivo using ion-selective electrodes in cortical gray and subcortical white matter of α-chloralose-anesthetized cats during 120 minutes of global cerebral ischemia. On induction of ischemia, regional CBF, as measured by hydrogen clearance, ceased. The direct current potential decreased rapidly within minutes in gray matter and with little time delay in white matter. Extracellular Ca 2+ concentration decreased just as quickly in gray matter. In white matter, in contrast, extracellular Ca 2+ increased in the first 20 to 30 minutes, and a delayed and much slower decline, compared with gray matter, was observed thereafter, reaching a minimal level only about 60 minutes after occlusion. Our results suggest that smaller and delayed transmembrane shifts of Ca 2+ are correlates of delayed ischemic membrane dysfunction in central white matter tracts, which may be explained by a lack of synaptic mechanisms.
DOI: 10.1159/000091539
2006
Cited 14 times
Early Ischemic Edema on Cerebral Computed Tomography: Its Relation to Diffusion Changes and Hypoperfusion within 6 h after Human Ischemic Stroke
&lt;i&gt;Background:&lt;/i&gt; Brain tissue hypoattenuation on early computed tomography is frequently included in decision making in acute stroke management. However, its pathophysiological counterpart needs further evaluation. &lt;i&gt;Methods:&lt;/i&gt; By comparative imaging with diffusion-weighted imaging and &lt;sup&gt;15&lt;/sup&gt;O-water positron emission tomography we aimed to interpret early (&lt;6 h) hypoattenuation. &lt;i&gt;Results:&lt;/i&gt; In 11 patients, the hypoattenuation corresponded to a decreased proton diffusion (median 115.9% relative DWI value) measured by magnetic resonance imaging and to a severe hypoperfusion (below 12 ml/100 g/ min) assessed by positron emission tomography. The volume of parenchymal hypoattenuation correlated to the tissue with disturbed diffusion (Spearman’s rho = 0.73), but largely underestimated the hypoperfusion below 20 ml/100 g/min. &lt;i&gt;Conclusions:&lt;/i&gt; Early hypoattenuation reflects the coupling of the severity of ischemia and resulting diffusion changes. It allows an estimate of the infarct core but underestimates the penumbral hypoperfusion.
DOI: 10.1007/s12028-009-9303-z
2009
Cited 12 times
A Giant Bilateral Calcified Chronic Subdural Hematoma
DOI: 10.1007/978-1-60761-919-2_32
2010
Cited 10 times
Multifunctional CPP Polymer System for Tumor-Targeted pDNA and siRNA Delivery
Cell-penetrating peptides (CPPs) are a very interesting class of molecules to be introduced in gene and siRNA vectors. They can be used to overcome one of the biggest hurdles in gene and siRNA delivery in vitro and in vivo, the transfer across cell membranes. This chapter describes protocols for the synthesis and biological evaluation of a polylysine-based polymer. In this carrier system, melittin is used as CPP with a high activity to disrupt membranes. pH-Labile masking is applied to render the lytic activity specific for intracellular acidic endolysosomal organelles.
DOI: 10.1159/000477499
2017
Cited 9 times
Incomplete Large Vessel Occlusions in Mechanical Thrombectomy: An Independent Predictor of Favorable Outcome in Ischemic Stroke
Cerebral large vessel occlusion (LVO) in acute ischemic stroke (AIS) may be complete (CLVO) or incomplete (ILVO). The influence of ILVO on clinical outcome after mechanical thrombectomy (MT) remains unclear. We investigated primarily the clinical outcome in patients with AIS due to ILVO or CLVO.Five hundred three consecutive AIS patients with LVO treated with stent-retriever or direct aspiration-based MT between 2010 and 2016 were analyzed. The primary endpoint was favorable clinical outcome (modified Rankin Scale ≤2) at 90 days; secondary endpoints were periprocedural parameters.Forty-nine patients (11.3%) with a median National Institutes of Health Stroke Scale (NIHSS) of 11 presented with ILVO and the remainder presented with CLVO and median NIHSS of 15 (p < 0.001). The median groin puncture-to-reperfusion time was 30 vs. 67 min, respectively (p < 0.001). Successful reperfusion was reached in 47 out of 49 ILVO (95.9%) vs. 298 out of 381 CLVO (78.2%; p < 0.005) with less retrieval maneuvers (1.7 ± 2.2 vs. 3.0 ± 2.5; p < 0.001). The favorable outcome at 90 days was 81% in patients with ILVO vs. 29.1% in CLVO (p < 0.001); respective all-cause mortality rates were 6.4 vs. 28.5% (p < 0.001). Periprocedural complications (6.9%) occurred exclusively in CLVO patients (p < 0.05). ILVO was associated with favorable clinical outcome independent of age and NIHSS in multivariate logistic regression both in the anterior (OR 3.6; 95% CI 1.8-6.9; p < 0.001) and posterior circulation (OR 3.5; 95% CI 1.8-6.9; p < 0.001).AIS due to ILVO is frequent and is associated with a nearly threefold higher chance of favorable clinical outcome at 90 days, independent of age and initial NIHSS compared to CLVO.
DOI: 10.1007/s00115-012-3541-6
2012
Cited 9 times
Umfragestudie „Update Neurointensiv Deutschland 2012“
DOI: 10.1089/hgtb.2017.052
2017
Cited 8 times
Adenovirus Particle Quantification in Cell Lysates Using Light Scattering
Adenoviral vector production for therapeutic applications is a well-established routine process. However, current methods for measurement of adenovirus particle titers as a quality characteristic require highly purified virus preparations. While purified virus is typically obtained in the last step of downstream purification, rapid and reliable methods for adenovirus particle quantification in intermediate products and crude lysates to allow for optimization and validation of cell cultures and intermediate downstream processing steps are currently not at hand. Light scattering is an established process to measure virus particles' size, though due to cell impurities, adequate quantification of adenovirus particles in cell lysates by light scattering has been impossible until today. This report describes a new method using light scattering to measure virus concentration in nonpurified cell lysates. Here we report application of light scattering, a routine method to measure virus particle size, to virus quantification in enzymatically conditioned crude lysates. Samples are incubated with phospholipase A2 and benzonase and filtered through a 0.22 μm filter cartridge prior to quantification by light scattering. Our results show that this treatment provides a precise method for fast and easy determination of total adenovirus particle numbers in cell lysates and is useful to monitor virus recovery throughout all downstream processing.
DOI: 10.1002/ange.201603648
2016
Cited 8 times
A Single Methylene Group in Oligoalkylamine‐Based Cationic Polymers and Lipids Promotes Enhanced mRNA Delivery
Abstract The development of chemically modified mRNA holds great promise as a new class of biologic therapeutics. However, the intracellular delivery and endosomal escape of mRNA encapsulated in nanoparticles has not been systematically investigated. Here, we synthesized a diverse set of cationic polymers and lipids from a series of oligoalkylamines and subsequently characterized their mRNA delivery capability. Notably, a structure with an alternating alkyl chain length between amines showed the highest transfection efficiency, which was linked to a high buffering capacity in a narrow range of pH 6.2 to 6.5. Variation in only one methylene group resulted in enhanced mRNA delivery to both the murine liver as well as porcine lungs after systemic or aerosol administration, respectively. These findings reveal a novel fundamental structure–activity relationship for the delivery of mRNA that is independent of the class of mRNA carrier and define a promising new path of exploration in the field of mRNA therapeutics.
DOI: 10.1159/000319776
2010
Cited 8 times
Systemic Thrombolysis with rt-PA in Patients under 40 Years of Age: A Subgroup Analysis of the Cologne Stroke Experience
&lt;i&gt;Background:&lt;/i&gt; While the application of intravenous systemic thrombolysis (IVT) with rt-PA (recombinant tissue plasminogen activator) in older patients is currently moving into the focus of epidemiological studies, only few data are available regarding the application in young patients ≤40 years. Single-center data of a thrombolysis register were analyzed with respect to safety and efficacy of the treatment of young patients. &lt;i&gt;Methods:&lt;/i&gt; In a retrospective subgroup analysis of 450 patients treated by IVT within a 3-hour time window, patients ≤40 years were identified (n = 20). Clinical data [age, pretherapeutic stroke severity (National Institute of Health Stroke Scale, NIHSS), OTT (onset to-treatment time), rt-PA-dose, DNT (door[-]to[-]needle time), rate of symptomatic intracranial hemorrhages] and medical history were determined. The clinical outcome was assessed by the mRS (modified Rankin Scale). The results were compared to those of patients &gt;40 years (n = 430). &lt;i&gt;Results:&lt;/i&gt; Twenty patients ≤40 years (mean age 32 years) out of 450 patients (4%) were treated by IVT. The percentage of predisposing diseases and vascular risk factors was significantly lower when compared to patients &gt;40 years (p &lt; 0.05). In contrast, the percentage of smokers was significantly higher (55 vs. 24%; p &lt; 0.05). In comparison to patients &gt;40 years, OTT, DNT and NIHSS at admission were not significantly different. After 3 months, 11 of 20 young patients (55%) showed a favorable outcome (mRS 0–1) and 80% were functionally independent (mRS 0–2). In the group of patients &gt;40 years (n = 430), the respective percentages were significantly lower [p &lt; 0.05; 34% (mRS 0–1) and 52% (mRS 0–2), respectively]. Symptomatic intracranial hemorrhages were not observed (in patients &gt;40 years: 4%, p &lt; 0.05). &lt;i&gt;Conclusions:&lt;/i&gt; In comparison to the cohort of patients &gt;40 years, IVT in young patients is safe and leads to a significantly better outcome after 3 months. Our data therefore encourage the use of IVT in young patients.
DOI: 10.1007/s12181-018-0268-z
2018
Cited 8 times
Recommendations for extracorporeal cardiopulmonary resuscitation (eCPR)
2015
Cited 7 times
[Intensive care therapy of space-occupying large hemispheric infarction. Summary of the NCS/DGNI guidelines].
DOI: 10.2337/diab.39.8.938
1990
Cited 15 times
Effect of Medial Arterial Calcification on O2 Supply to Exercising Diabetic Feet
We investigated whether medial arterial calcification (MAC) impairs O2 supply to the exercising foot in diabetic patients with foot lesions. Transcutaneous O2 tension (tcPO2) was monitored at the dorsum of the foot before and after bicycle exercise in 11 diabetic patients with peripheral ischemic vascular disease (PIVD) with or without concomitant existence of MAC, 10 patients with MAC but without PIVD, 10 diabetic control subjects, and 6 nondiabetic control subjects. The mean preexercise tcPO2 level was comparable in these four groups. However, tcPO2 decreased significantly with exercise in feet with PIVD (mean +/- SE -17.9 +/- 2.7%, P less than 0.01, n = 11), regardless of presence or absence of vascular calcification. On the other hand, the value increased significantly with exercise in feet with MAC but without PIVD (21.2 +/- 3.5%, P less than 0.01, n = 10) and in those of diabetic control subjects (14.9 +/- 3.6%, P less than 0.01), respectively. The tcPO2 remained unchanged in the feet of nondiabetic control subjects (1.7 +/- 1.1%). The results suggest that MAC is not associated with reduced O2 supply to the exercising foot in diabetic patients.
DOI: 10.3390/jcm11092555
2022
Cited 3 times
Aneurysmal Subarachnoid Hemorrhage during the Shutdown for COVID-19
The aim was to evaluate hospitalization rates for aneurysmal subarachnoid hemorrhage (SAH) within an interdisciplinary multicenter neurovascular network (NVN) during the shutdown for the COVID-19 pandemic along with its modifiable risk factors. In this multicenter study, admission rates for SAH were compared for the period of the shutdown for the COVID-19 pandemic in Germany (calendar weeks (cw) 12 to 16, 2020), the periods before (cw 6-11) and after the shutdown (cw 17-21 and 22-26, 2020), as well as with the corresponding cw in the years 2015-2019. Data on all-cause and pre-hospital mortality within the area of the NVN were retrieved from the Department of Health, and the responsible emergency medical services. Data on known triggers for systemic inflammation, e.g., respiratory viruses and air pollution, were analyzed. Hospitalizations for SAH decreased during the shutdown period to one-tenth within the multicenter NVN. There was a substantial decrease in acute respiratory illness rates, and of air pollution during the shutdown period. The implementation of public health measures, e.g., contact restrictions and increased personal hygiene during the shutdown, might positively influence modifiable risk factors, e.g., systemic inflammation, leading to a decrease in the incidence of SAH.
DOI: 10.1007/978-3-7091-0651-8_51
2003
Cited 10 times
Identification of malignant brain edema after hemispheric stroke by PET-imaging and microdialysis
Cerebral blood flow (CBF) and extent of irreversible tissue damage as well as the time course of extracellular concentration of amino acids, substrates of energy metabolism, and purine metabolites, intracranial pressure and tissue oxygen tension were assessed in 34 patients with large strokes covering more than 50% of the MCA territory. The results were compared to findings in the experimental model of transient (for 3 hours) MCA occlusion in cats. In the experimental model as well as in the clinical setting development of malignant brain infarcts (due to formation of space occupying brain edema) was predicted by the size of critically hypoperfused tissue and the volume of irreversibly damaged tissue. The course of malignant infarcts was characterized by progressive increase in concentrations of excitatory amino acids, lactate, pyruvate, glycerol, hypoxanthine and in intracranial pressure, while cerebral perfusion pressure and tissue oxygen tension decreased. These results clearly differentiate a malignant from a benign course of large hemispheric infarction. The methods can be used to identify patients at risk for formation of space occupying edema and to select patients who could benefit from invasive therapeutic strategies.
DOI: 10.14581/jer.19008
2018
Cited 6 times
Successful Treatment of Super-Refractory Status Epilepticus with High-Intensity Electroconvulsive Therapy – A Case Report and Review of the Current Literature
Status epilepticus (SE) is a severe neurological condition in which epileptic activity is prolonged or recurring, and the likelihood of spontaneous seizure cessation decreases over time. Evidence on the appropriate treatment regimen in therapy-refractory cases is still sparse. Electroconvulsive therapy (ECT) is known as a last resort treatment for SE due its anticonvulsant properties mediated by an increase in seizure threshold during the course of a treatment series. We examined the effects of ECT in a 61-year-old male patient with new-onset super-refractory SE (SRSE), for whom previous extensive efforts to achieve seizure control had failed. To achieve reliable seizure inductions in ECT concomitantly with an extended anticonvulsant treatment, we established a high-intensity ECT protocol: bitemporal ECT was conducted at a double-dosage setting (200% stimulation energy; equivalent to a mean charge of 1,031 mC) including three seizure stimulations during each treatment session on consecutive days until SRSE termination. After the first course of ECT, temporary seizure cessation was reached but lasted for only several days. A second course of ECT was then initiated, using the identical regimen but followed by tapering sessions every other day. Again, the SRSE terminated and after regaining consciousness the patient could be transferred to an acute rehabilitation facility. SRSE cessation can successfully be achieved by means of high-intensity ECT even after six weeks of prolonged SE and exhausted anticonvulsant pharmacotherapeutic strategies. As controlled clinical trials in the area of SRSE are still lacking, the relative significance of a high-intensity ECT protocol in this clinical setting has yet to be determined.
DOI: 10.1055/s-2005-915623
2006
Cited 8 times
Post-Stroke-Depression
Depression is a frequent and important complication after stroke. The occurrence of a post-stroke-depression (PSD) has a significant impact on the functional and cognitive deficit, on mortality and on quality of life after stroke. In contrast to the clinical importance, PSD is often ignored in routine management of stroke patients and remains often untreated if diagnosed. The diagnostic uncertainty is aggravated by the lack of appropriate diagnostic criteria for PSD in the International Classification of Diseases (ICD-10) used in Germany. For the first time, we present an algorithm, which allows for a standardized examination of stroke patients on the presence of PSD. All stroke patients should be examined initially by a short and simple screening tool and are subjected to more extensive procedures only if PSD is assumed based on the screening result. Furthermore potentials and limitations to convert the diagnosis of PSD into a diagnostic related group (DRG) that is used to calculate the hospital's reimbursement are highlighted. Finally pharmacological treatment options for PSD are discussed.