Clinical features of non-hypertensive lobar intracerebral hemorrhage related to cerebral amyloid angiopathy

Background and purpose: The present study aims to clarify the clinical features of non‐hypertensive cerebral amyloid angiopathy‐related lobar intracerebral hemorrhage (CAA‐L‐ICH). Methods: We investigated clinical, laboratory, and neuroimaging findings in 41 patients (30, women; 11, men) with pathologically supported CAA‐L‐ICH from 303 non‐hypertensive Japanese patients aged ≥55, identified via a nationwide survey as symptomatic CAA‐L‐ICH. Results: The mean age of patients at onset of CAA‐L‐ICH was 73.2 ± 7.4 years; the number of patients increased with age. The corrected female‐to‐male ratio for the population was 2.2, with significant female predominance. At onset, 7.3% of patients received anti‐platelet therapy. In brain imaging studies, the actual frequency of CAA‐L‐ICHs was higher in the frontal and parietal lobes; however, after correcting for the estimated cortical volume, the parietal lobe was found to be the most frequently affected. CAA‐L‐ICH recurred in 31.7% of patients during the average 35.3‐month follow‐up period. The mean interval between intracerebral hemorrhages (ICHs) was 11.3 months. The case fatality rate was 12.2% at 1 month and 19.5% at 12 months after initial ICH. In 97.1% of patients, neurosurgical procedures were performed without uncontrollable intraoperative or post‐operative hemorrhage. Conclusions: Our study revealed the clinical features of non‐hypertensive CAA‐L‐ICH, including its parietal predilection, which will require further study with a larger number of patients with different ethnic backgrounds.