Language reorganization in brain arteriovenous malformations with fiber-based regional functional connectivity

Structure and function changes of language function processing in brain arteriovenous malformations (AVMs) have been investigated, while the alterations of brain connectivity remain unexplored. This study aims to investigate language network reorganization in AVMs using fiber-based regional functional connectivity (FBRFC), which integrates structural and functional information. 34 right-handed patients with left-hemispheric AVMs and 27 healthy controls underwent task-based functional magnetic resonance imaging during three language paradigms: visual synonym judgment, oral word reading, and auditory sentence comprehension. Conventional whole-brain analysis was used for comparison, and patients were categorized into three subgroups to assess lesion location effects on language reorganization. In the oral word reading task, AVMs exhibited significantly increased FBRFC compared to controls in right-hemisphere language-related fiber tracts, including the anterior thalamic radiation, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, superior longitudinal fasciculus temporal part, as well as in bilateral cingulum hippocampus, cingulum cingulate gyrus, and the interhemispheric forceps major. No significant difference was detected in the visual and auditory tasks. Frontal and parietal lesion impairment subgroups demonstrated compensatory FBRFC elevations during the oral task, whereas only the parietal subgroup showed such increase during the auditory task. Conventional FC analysis revealed enhanced FC between the frontal and occipital regions during the oral task, between the parietal and cerebellar regions during the auditory task. These findings provide a structurally informed framework for characterizing pathway-level language network alterations in left-hemispheric AVMs, with exploratory clinical relevance for studying compensatory language organization.