Altered Functional Connectivity in Acute Ischemic Post-Stroke Non-Fluent Aphasia Based on fMRI-EEG Multimodal Fusion

This study examined alterations in resting-state and task-state functional connectivity (FC) in patients with acute ischemic post-stroke nonfluent aphasia, using a combined resting-state functional magnetic resonance imaging and visuospatial working memory electroencephalography methodology. We recruited a case group (n =7) of patients with acute ischemic poststroke nonfluent aphasia and a matched healthy control group (n =7) with similar age, sex, and education levels. Resting-state FC analysis revealed significantly reduced bilateral interfrontal FC in patients, but enhanced FC within the executive control network. Task-state FC analysis showed stronger FC increases in the left hemisphere for non-target stimuli and task-averaged states, but in the right hemisphere for target stimuli. Five regions of interest (ROIs) were mapped: right inferior frontal gyrus (ROI1), left frontal gyrus (ROI2), left rolandic operculum (ROI3), left Broca's area (ROI4), and its right-hemisphere homologue (ROI5). In the multimodal FC model of linguistic function subitems, increased F7-C3 connectivity, coupled with decreased ROI2-ROI3 connectivity was associated with enhanced memory and comprehension performance. Concurrent reductions in CP1-P4, ROI1-ROI5, and ROI3-ROI5 connectivity were linked to improvements in visuospatial processing and attention. Enhanced T7-CP1 connectivity paired with reduced ROI2-ROI4 connectivity correlated with improved logical reasoning abilities. Increased CP1-Pz connectivity covaried with enhanced ROI1-ROI4 connectivity, similarly benefiting memory and comprehension subdomains. A multimodal fusion approach examining intra- and interhemispheric FC across resting-state and task conditions, at both local and global scales, in acute nonfluent aphasia patients may elucidate stroke-related neurological deficits and compensatory language mechanisms.