Abstract Body: Introduction: Spontaneous intracerebral hemorrhage (ICH) has heterogeneous etiologies. Brain MRI with and without contrast is usually performed at admission to search for angiogram-negative ICH causes (cerebral amyloid angiopathy [CAA], cavernoma, and malignancy). Another MRI may be repeated after 3 to 6 months to further exclude underlying lesions. This study aimed to evaluate the use of brain MRI for identifying the etiology of lobar ICH in current practice.
Methods: Patients aged 18 to 80 who were admitted with spontaneous supratentorial lobar ICH between September 2016 and March 2023 were included. The etiology of ICH at discharge was reviewed and compared by age groups: 18-49 years, 50-69 years, and 70-80 years. Time to the newly identified etiology by repeated brain MRI after discharge was assessed for undetermined etiology. Descriptive statistics were the primary analysis.
Results: A total of 197 eligible patients were identified. On discharge, a higher proportion of young patients aged 18-49 (32.1%) were found to have a vascular malformation compared to 9.3% and 6.4% for patients aged 50-69 or 70-80 (p=0.001). Probable CAA was the most commonly identified etiology in patients aged 70-80 (43.6%) compared to 5.4% of patients aged 50-69 (p<0.001). Brain malignancy was more commonly found in patients aged 50-69 (25.3%) compared to other age groups (11%, p=0.025).
The etiology remained undetermined for 68 patients on discharge: 28.6%, 44.0% and 28.7% of patients aged 18-49, 50-69 and 70-80, respectively. Among these, 33 (48.5%) had ≥1 brain MRI performed during follow-up, yet only 24 (35.3%) underwent a repeated brain MRI within 6 months of admission (median: 2.2 months; range: 1.0-5.8 months). New etiologies were identified in 8 patients: One brain MRI repeated at 1.9 month detected an underlying AVM in a patient aged 57; Two MRIs repeated around 8 months revealed an underlying glioblastoma in a patient aged 44 and a cavernoma in a patient aged 64; and MRIs performed at a median of 60 months (range: 29-70 months) discovered new microhemorrhages or lobar ICH in 5 patients, leading to a diagnosis of probable CAA.
Discussion Findings confirmed the value of brain MRI for patients with supratentorial lobar ICH during admission. Repeating brain MRI around 3-6 months after the initial MRI had a low rate of detecting underlying lesions for patients with undetermined etiology, yet it should be considered particularly for patients younger than 70 years old.