Generative lesion pattern decomposition of cognitive impairment after stroke

Abstract

SummaryCognitive impairment is a frequent and disabling sequela of stroke. There is however incomplete understanding of how lesion topographies in the left and right cerebral hemisphere brain interact to cause distinct cognitive deficits. We integrated machine learning and Bayesian hierarchical modeling to enable hemisphere-aware analysis of 1080 subacute ischemic stroke patients with deep profiling ∼3 months after stroke. We show relevance of the left hemisphere in the prediction of language and memory assessments, while global cognitive impairments were equally well predicted by lesion topographies from both sides. Damage to the hippocampal and occipital regions on the left were particularly informative about lost naming and memory function. Global cognitive impairment was predominantly linked to lesioned tissue in supramarginal and angular gyrus, the postcentral gyrus as well as the lateral occipital and opercular cortices of the left hemisphere. Hence, our analysis strategy uncovered that lesion patterns with unique hemispheric distributions are characteristic of how cognitive capacity is lost due to ischemic brain tissue damage.

How does hemispheric specialization contribute to human-defining cognition?

“…Further, these patients may ignore and leave untouched food on the left side of the plate as another example of the affected visuo-spatial capacities that are a consequence of damage to the right hemisphere. The proposed double dissociation in the functional relevance of the left hemisphere for language and the right hemisphere for visuospatial awareness and attentional reorientation receives support from a recent multi-site cohort study in >1,000 patients in the early phase after stroke (Bonkhoff et al, 2020; Figure 1).…”