OBJECTIVE: To determine concordance rate between functional MRI (fMRI) and Wada test for language lateralization in our cohort of patients with medically intractable epilepsy. BACKGROUND: Preoperative fMRI is a non-invasive test that has been used increasingly in the epilepsy surgery centers to lateralize language. However, concordance rate between fMRI and Wada test has been variable in different studies. We report our local experience. DESIGN/METHODS: Patients with intractable focal epilepsy were studied for language lateralization using fMRI and Wada testing between 2007 and 2014. Three language paradigm tasks were used for fMRI studies: verb generation, sentence completion and naming. fMRI laterality indices were defined as a ratio (L-R)/(L+R) between the number of activated voxels in the left and right ROIs for Brodmann areas 44+45+46+8+9 (Anterior Language Area, ALA) and 22+39+40 (Posterior Language Area, PLA). fMRI and Wada results were divided into the right, left or bilateral hemispheric language dominance. RESULTS: 28 patients (15 men) were studied. Mean age at seizure onset was 19.3±14.57 years, and the mean age at fMRI was 34.8±12.48 years. 17 patients had left temporal epilepsy (TLE), 6 right TLE, 3 bilateral TLE, 1 left frontal and 1 multifocal epilepsy. The concordance rate between Wada and fMRI tests for the ALA and PLA was 68.2[percnt] and 52.2[percnt] for sentence completion; 56[percnt] and 52[percnt] for verb generation and 25[percnt] and 35[percnt] for naming paradigm, respectively. The concordance rate did not improve by combining the activation results of the 3 fMRI paradigms. Bilateral representation in Wada test or fMRI accounted for 68[percnt] of the discordant cases. CONCLUSIONS:Sentence completion and verb generation fMRI paradigms showed greater concordance with Wada test than naming paradigm. The higher discordance between the Wada test and fMRI was related to bilateral results suggestive of less stringent thresholds used for either test. Disclosure: Dr. Massot-Tarrus has nothing to disclose. Dr. Mousavi has nothing to disclose. Dr. Bihari has nothing to disclose. Dr. Hayman-Abello has nothing to disclose. Dr. Hayman-Abello has nothing to disclose. Dr. Mirsattari has nothing to disclose.

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