Spatial Correlates of Dementia and Disability After Intracerebral Hemorrhage

Dementia and disability are highly prevalent after spontaneous intracerebral hemorrhage (ICH). Previous studies categorizing ICH by large anatomic boundaries have demonstrated that lobar ICH is associated with dementia, while ICH in the basal ganglia is associated with disability. This study aims to refine our understanding of the association between ICH location and post-ICH dementia and disability at a voxel level, which could improve the prognostic accuracy of these outcomes and provide mechanistic insights into post-ICH functional outcomes.

In this cohort study, we segmented the ICH lesions from the noncontrast computed tomography scans from 882 patients from the MGH-ICH (Massachusetts General Hospital ICH Study) as the discovery data set and from 146 patients from the Yale-ICH cohort as the validation data set. Using electronic health records and follow-up telephone interviews, incident dementia (International Classification of Diseases, Ninth Revision [ICD-9] codes of dementia or modified telephone interview for cognitive status <20) and disability (modified Rankin Scale score >2) were identified. The median follow-up times of the MGH-ICH and Yale-ICH cohorts were 2.9 (interquartile range, 1.0-5.8) years and 1.0 (interquartile range, 0.6-1.0) years, respectively. Two techniques of lesion symptom mapping were applied on the ICH lesions: sparse canonical correlation analysis for neuroimaging and voxel-based lesion symptom mappings. Dementia conversion after ICH was associated with ICH in the left temporo-occipital region (mean hazard ratio [HR], 3.62 [95% CI, 2.71-4.63]) and left superior longitudinal fasciculus (mean HR, 2.91 [95% CI, 2.40-3.52]). Development of disability after ICH was linked to the right cerebral peduncle (mean HR, 3.10 [95% CI, 2.44-3.94]), right pallidum (mean HR, 2.96 [95% CI, 1.99-4.25]), and right posterior limb of the internal capsule (mean HR, 2.54 [95% CI, 1.88-3.96]).

Specific distribution of ICH lesions is linked to development of dementia and disability after ICH. These insights have the potential to enhance clinical prognostic models for patients with ICH, facilitating more precise predictions of outcomes based on hemorrhage location.