FUNCTIONAL MRI MEASUREMENT OF LANGUAGE LATERALIZATION IN WADA-TESTED PATIENTS

In this study the Else of functional MRI (fMRI) for measuring language lateralization non-invasively was examined The subjects were seven pa tients with histories of temporal lobe epilepsy who had undergone Wada testing for pre-surgical evaluation. Four patients were left-hemisphe re-dominant and three were right-hemisphere-dominant for language. The y received fMRI scans while they made semantic or perceptual judgments about visually presented words. Regions of the inferior frontal gyrus (pars triangularis and pars orbitalis) and neighbouring orbital corte x, corresponding to portions of Brodmann areas 45, 46 and 47, exhibite d significant increases in activation during semantic relative to perc eptual judgments. Lateralization of the increases in activation were c onsistent with the Wada test assessments of hemispheric language domin ance in each of the seven patients. These results suggest that, in add ition to providing a tool for investigating human cognitive processes, fMRI has significant clinical potential as a non-invasive measure of language lateralization.