Shared Neuroanatomical Substrates for Co-Occurring Swallowing and Communication Impairments after Acute Stroke.

Introduction: Post-stroke dysphagia and communication impairments occur in two-thirds of acute stroke survivors. Identifying the shared neuroanatomical substrate for related impairments could facilitate the development of cross-system therapies. Our purpose was to elucidate discrete brain regions predictive of the combined presence of dysphagia alongside dysarthria and/or aphasia post-stroke.

Methods: We included 40 right hemisphere stroke (RHS) and 67 left hemisphere stroke (LHS) patients from an acute ischemic stroke cohort with lesions demarcated on diffusion-weighted imaging. We undertook binary non-parametric voxel-lesion symptom mapping with a false discovery rate of p < 0.05 for co-occurring dysphagia, dysarthria, and aphasia (LHS only). If no voxels survived the threshold, a cluster analysis of >20 voxels involving an uncorrected p < 0.01 was applied to identify brain regions associated with the co-occurring impairments.

Results: Cluster analyses revealed that dysphagia and dysarthria were associated with insular and superior temporal gyrus (STG) involvement after RHS and with basal ganglia (BG), internal capsule, and thalamic involvement after LHS. Co-occurring dysphagia, dysarthria, and aphasia were associated with BG, STG, and insular cortex involvement.

Discussion: Our findings highlight the role of the insula and structures of the BG in co-occurrence patterns involving dysphagia, dysarthria, and aphasia. These newly identified biomarkers may inform new rehabilitation therapeutic targets for treating cross-system functions.