Unsuspected atypical hemispheric dominance for language as determined by fMRI

Purpose: We sought to illustrate the value of functional magnetic resonance imaging (fMRI) in the presurgical assessment of hemispheric dominance for language by means of an illustrative case report. Methods: fMRI with two language paradigms was performed in a right-handed p atient without familial sinistrality suffering from a left frontal focal ep ilepsy. Results: Both fMRI paradigms revealed unequivocally lateralized right hemis pheric activation. Atypical language representation was confirmed by Wada t est. The further presurgical workup could be restricted to subdural strip r ecordings instead of the initially intended grid implantation. After resect ive surgery, no language deficits were apparent. Conclusions: Hemispheric dominance for language should be assessed by fMRI in all patients before surgery in areas potentially relevant for language i n either cerebral hemisphere. fMRI may influence the further diagnostic wor kup and should be performed before other invasive diagnostic procedures.