John Libbey Eurotext

Epileptic Disorders

The Educational Journal of the International League Against Epilepsy

Language tasks used for the presurgical assessment of epileptic patients with MEG Volume 12, numéro 2, June 2010

Centre de Recherche en Neuropsychologie et Cognition, Université de Montréal, Centre de Recherche, Centre Hospitalier Universitaire Sainte-Justine, École d'orthophonie et d'audiologie, Université de Montréal, Neurologie, Centre Hospitalier Universitaire de Montréal (Notre-Dame), Psychology, Bishop's University, Sherbrooke, Quebec
  • Mots-clés : epilepsy surgery, language, magnetoencephalography, localization, lateralization
  • DOI : 10.1684/epd.2010.0314
  • Page(s) : 97-108
  • Année de parution : 2010

Determining the language dominant hemisphere and the intrahemispheric localization of this function are imperative in the planning of neurosurgical procedures in epileptic patients. New noninvasive diagnostic techniques are being developed to reduce the risks associated with more invasive techniques. The aim of this paper is to review the different protocols for lateralizing and/or localizing language functions using magnetoencephalography (MEG), a noninvasive technique. The reviewed studies include control and patient populations using various protocols which employ different expressive and receptive language tasks. The overall findings reveal high concordance between MEG and the intracarotid amobarbital test (IAT). Moreover, MEG allows intrahemispheric localization of receptive and expressive language functions. However, the different language tasks used with MEG, whether receptive or expressive, appear to activate the left temporal more than frontal areas. The best task to assess language comprehension in both adults and children appears to be a word recognition task. A verbal fluency task could be used to test language production in children and a verb generation task in adults.