Critical brain regions related to post-stroke aphasia severity identified by early diffusion imaging are not the same when predicting short- and long-term outcome

Abstract

ObjectivesTo identify the critical brain regions associated with 7-days, 3 and 6-months aphasia severity using diffusion-weighted imaging (DWI) in acute post-stroke patients. Materials and methodsWe performed a voxel-based ADC (Apparent Diffusion Coefficient) analysis to identify the critical brain areas correlated with aphasia at the acute (7-days outcome) and chronic stages (3 and 6-months). The location of these areas was compared with the trajectory of the dorsal (the arcuate fasciculus) and the ventral language pathways (the inferior fronto-occipital and the uncinate fasciculi). ResultsDisconnections of the language fasciculi, which were correlated with aphasia outcome, were not the same for the 7-days outcome (disconnection of the ventral stream) and the chronic outcome (3 and 6 months) (disconnection of the dorsal and ventral streams). ConclusionRoutine clinical images can be merged with atlases of anatomical connectivity to provide new insights about the relationship between the lesion location and aphasia severity.