Study of hemispheric lateralization of the language regions by functional MRI. Validation with the Wada test.

Language hemispheric dominance can be assessed by the Wada test before temp oral lobectomy, in patients with refractory epilepsy of the mesial temporal lobe. Functional MR is a less invasive technique which recently demonstrat ed the ability to localize some language areas. The aim of this study was t o determine ii functional MR can be:substituted:to the Wada test in the det ermination of language dominance. Seven patients with a refractory epilepsy of the mesial temporal lobe were included. The MR protocol was carried out using a 1.5 T system including 12 axial gradient echo BOLD EPI images. A s emantic-fluency task, interspersed with rest periods, was used as activatio n paradigm. An activation of middle and inferior frontal region was found i n all patients. it predominated in the left hemisphere in 6 cases and in th e right hemisphere in 1 case. The hemispheric and frontal lobe lateralizati on of the functional MR activation was correlated with the hemispheric lang uage dominance as assessed by the Wada test. In conclusion, functional MR i s a promising technique in the determination of language dominance.