Structural disconnectome mapping of cognitive function in chronic stroke patients

Abstract

AbstractSequalae following stroke represents a significant challenge in rehabilitation treatment. The location and size of focal lesions are only moderately predictive of the diverse cognitive outcome and rehabilitation potential after stroke. One explanation building on recent work on brain networks proposes that the cognitive consequences of focal lesions are strongly associated with perturbations of anatomically distributed brain networks supporting cognitive operations. To investigate the association between post-stroke structural disconnection and cognitive performance, we estimated individual level whole-brain disconnectivity probability maps using lesion maps from 102 stroke patients. Cognitive performance was assessed in the whole sample using Montreal Cognitive Assessment, and a more comprehensive computerized test protocol was performed on a subset (n=82). Multivariate analysis using Partial Least Squares revealed that higher disconnectivity in insular and frontal operculum was associated with poorer MoCA performance, indicating that lesions disconnecting these brain regions are more likely to be associated with global cognitive impairment. Furthermore, our results indicated that disconnection of the inferior frontal gyrus and the frontal orbital cortex is associated with poorer outcome across multiple cognitive domains. These findings demonstrate that the extent and distribution of the brain disconnectome in persons living with stroke sequelae are sensitive to cognitive deficits and support that longitudinal studies assessing the predictive value of brain network connectivity for cognitive outcome following stroke are warranted.