title: Functional MR imaging in assessment of language dominance in epileptic patients.
abstract: The value of functional MR Imaging (fMRI) in assessing language lateralization in epileptic patients candidate for surgical treatment is increasingly recognized. However few data are available for left-handed patients. Moreover determining factors for atypical dominance in patients investigated with contemporary imaging have not been reported. We studied 20 patients (14 males, 6 females; 9 right handed, 11 left handed) aged from 9 to 48 years, investigated for intractable partial epilepsy. Epileptic focus location was temporal in 14 cases, extratemporal in 6, and lateralized in the left hemisphere in 11/20. Hemispheric dominance for language was evaluated by both Wada test and fMRI using a silent word generation paradigm in all patients. Furthermore, a postictal speech test was performed in 15 patients. An fMRI language lateralization index was calculated from the number of activated pixels (Student's t test, P < 0.0001) in the right and left hemispheres. The Wada test showed a right hemispheric dominance in 8 patients (6 were left handed and 2 right handed) and a left hemispheric dominance in 12 patients (5 were left handed and 7 right handed). These results were concordant with clinical postictal examination in 11/15 patients (73%). Clinical status did not allow a conclusion about hemispheric dominance for the remaining 4 patients. FMRI was concordant with the Wada test in 19/20 cases. For one left-handed patient, fMRI showed bilateral activation, whereas the Wada test demonstrated a right hemispheric dominance. Right language lateralization was significantly correlated with left lateralized epilepsy (P < 0.05) but was not correlated with age at epilepsy onset, early brain injury (before 6 years), and lobar localization of epileptogenic focus. However the lack of a significant relationship between these factors and atypical language lateralization may be related to the small sample size.
authors.affiliation: Service de Radiologie, Hôpital d'Instruction des Armées du Val de Grâce, 74 Boulevard Port Royal, F-75230 Paris, France. sabbah@mail.pf
authors.forename: P
authors.initials: P
authors.lastname: Sabbah
authors.forename: F
authors.initials: F
authors.lastname: Chassoux
authors.forename: C
authors.initials: C
authors.lastname: Leveque
authors.forename: E
authors.initials: E
authors.lastname: Landre
authors.forename: S
authors.initials: S
authors.lastname: Baudoin-Chial
authors.forename: B
authors.initials: B
authors.lastname: Devaux
authors.forename: M
authors.initials: M
authors.lastname: Mann
authors.forename: S
authors.initials: S
authors.lastname: Godon-Hardy
authors.forename: C
authors.initials: C
authors.lastname: Nioche
authors.forename: A
authors.initials: A
authors.lastname: Aït-Ameur
authors.forename: J L
authors.initials: JL
authors.lastname: Sarrazin
authors.forename: J P
authors.initials: JP
authors.lastname: Chodkiewicz
authors.forename: Y S
authors.initials: YS
authors.lastname: Cordoliani
mesh_terms: D000293:Adolescent; D000328:Adult; D000654:Amobarbital; D000849:Anomia / Q000503:physiopathology; D001931:Brain Mapping; D002648:Child; D004292:Dominance, Cerebral / Q000502:physiology*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011932:Reading; D012680:Sensitivity and Specificity; D013067:Speech Perception / Q000502:physiology*; D014705:Verbal Behavior / Q000502:physiology*
chemical_list: D000654:Amobarbital