Spatial Correlates of Dementia and Disability After Intracerebral Hemorrhage

Abstract

Background: 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.

Methods and results: 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]).

Conclusions: 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.

Keywords: dementia; disability; intracerebral hemorrhage; voxel‐based lesion symptom mapping.

Figure 1. Patient selection flowchart in the MGH‐ICH cohort.

CT indicates computed tomography; ICH, intracerebral hemorrhage; and MGH‐ICH, Massachusetts General Hospital ICH Study.

Figure 2. ICH lesion probability map.

The value in each voxel represents the proportion of ICH covering the voxel. ICH, intracerebral hemorrhage; A. Voxel weights in SCCAN, B. Voxel P‐value in voxel‐wise Cox regression C. Voxel hazard ratio in voxel‐wise Cox regression.

Figure 3. SCCAN (n=536) and VLSM (n=714) analyses in correlating ICH location with the onset of dementia.

SCCAN indicates sparse canonical correlation analysis for neuroimaging; and VLSM, voxel‐based lesion symptom mappings.

Figure 4. SCCAN (n=353) and VLSM (n=454) analyses in correlating ICH location with the onset of disability.

ICH indicates intracerebral hemorrhage; SCCAN, sparse canonical correlation analysis for neuroimaging; and VLSM, voxel‐based lesion symptom mappings. A. Voxel weights in SCCAN, B. Voxel P‐value in voxel‐wise Cox regression (i.e. VLSM), C. Voxel hazard ratio in voxel‐wise Cox regression (i.e. VLSM).

Figure 5. Illustration of the regions associated with post‐ICH dementia (in red) and disability (in cyan) in VLSM analysis.

ICH indicates intracerebral hemorrhage; PLIC, posterior limb of the internal capsule; and SLF, superior longitudinal fasciculus.