Infiltration of the basal ganglia by brain tumors is associated with the development of co-dominant language function on fMRI

Abstract Studies have shown that some patients with left-hemispheric brain tumors have an increased propensity for developing right-sided language support. However, the precise trigger for establishing co-dominant language function in brain tumor patients remains unknown. We analyzed the MR scans of patients with left-hemispheric tumors and either co-dominant ( n  = 35) or left-hemisphere dominant ( n  = 35) language function on fMRI to investigate anatomical factors influencing hemispheric language dominance. Of eleven neuroanatomical areas evaluated for tumor involvement, the basal ganglia was significantly correlated with co-dominant language function ( p p  = 0.025). While further studies are needed to elucidate the role of the basal ganglia in establishing co-dominance, our results suggest that reactive co-dominance may afford a behavioral advantage to patients with left-hemispheric tumors.