Strategic infarct location for post-stroke cognitive impairment: A multivariate lesion-symptom mapping study

Abstract

Lesion location is an important determinant for post-stroke cognitive impairment. Although several 'strategic' brain regions have previously been identified, a comprehensive map of strategic brain regions for post-stroke cognitive impairment is lacking due to limitations in sample size and methodology. We aimed to determine strategic brain regions for post-stroke cognitive impairment by applying multivariate lesion-symptom mapping in a large cohort of 410 acute ischemic stroke patients. Montreal Cognitive Assessment at three to six months after stroke was used to assess global cognitive functioning and cognitive domains (memory, language, attention, executive and visuospatial function). The relation between infarct location and cognition was assessed in multivariate analyses at the voxel-level and the level of regions of interest using support vector regression. These two assumption-free analyses consistently identified the left angular gyrus, left basal ganglia structures and the white matter around the left basal ganglia as strategic structures for global cognitive impairment after stroke. A strategic network involving several overlapping and domain-specific cortical and subcortical structures was identified for each of the cognitive domains. Future studies should aim to develop even more comprehensive infarct location-based models for post-stroke cognitive impairment through multicenter studies including thousands of patients.

Mapping the contribution and strategic distribution patterns of neuroimaging features of small vessel disease in poststroke cognitive impairment

“…Furthermore, the general strategic distribution patterns of multiple SVD imaging features identified in our study are in line with the studies where only one type of SVD imaging feature was investigated regarding its spatial relationship with poststroke cognitive impairment. Further efforts should aim to include thousands of patients with stroke, as suggested even when AILs are considered alone in a large cohort (with >400 patients),13 to improve the statistical power and generalisability of our findings.…”

“…Specifically, if we define y as the deficits of MoCA scores, then y  = 1 – ( Z – min( Z ))/(max( Z ) – min( Z )), where Z are the MoCA scores (total score and domain scores). This linear transformation helps to get positive predictive weights for the ROI-based lesion features that contribute to MoCA deficits, which is easier for interpretation of the strategic lesion distribution map 13. Here, we used linear kernel rather than non-linear kernel for SVR to retain the ability to plot predictive weights back to brain anatomy 21…”

The Meta VCI Map consortium for meta‐analyses on strategic lesion locations for vascular cognitive impairment using lesion‐symptom mapping: Design and multicenter pilot study

“…For image and lesion data processing, Meta VCI Map promotes the use of the RegLSM image processing pipeline, which was recently developed in a collaborative LSM project between Utrecht and Hong Kong [10]. RegLSM can transform lesion maps to fit onto a standardized brain template.…”

“…Support vector regression (SVR)-based lesion-symptom mapping was performed using a previously published method [10]. Two independent SVR-based analyses were performed: voxel-based LSM (SVR-LSM) and region of interest-based analyses (SVR-ROI).…”

“…Because vascular lesions are not distributed randomly across the brain, some regions are commonly affected, but others that may be relevant for cognition-such as the orbitofrontal lobes in anterior cerebral artery territory infarction [8,9]-are rarely affected. As a consequence, previous studies (e.g., [5,10,11]) found that even with several hundred subjects, large regions of the brain were not affected by vascular lesions and could therefore not be considered in LSM analyses. Thus, it remains difficult to obtain a comprehensive picture of strategic lesion locations for cognitive dysfunction.…”