title: Decreased language laterality in tuberous sclerosis complex: a relationship between language dominance and tuber location as well as history of epilepsy.
abstract: Nearly 90% of patients with tuberous sclerosis complex (TSC) have epilepsy. Epilepsy surgery can be considered, which often requires a presurgical assessment of language lateralization. This is the first study to investigate language lateralization in TSC patients using magnetoencephalography. Fifteen patients performed a language task during magnetoencephalography recording. Cerebral generators of language-evoked fields (EF) were identified in each patient. Laterality indices (LI) were computed using magnetoencephalography data extracted from the inferior frontal as well as middle and superior temporal gyri from both hemispheres between 250 and 550 ms. Source analysis demonstrated a fusiform gyrus activation, followed by an activation located in the basal temporal language area and middle and superior temporal gyri responses, ending with an inferior frontal activation. Eleven patients (73.3%) had left-hemisphere language dominance, whereas four patients (26.7%) showed a bilateral language pattern, which was associated with a history of epilepsy and presence of tubers in language-related areas.
authors.affiliation: Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA. anneg@nmr.mgh.harvard.edu
authors.forename: Anne
authors.initials: A
authors.lastname: Gallagher
authors.forename: Naoaki
authors.initials: N
authors.lastname: Tanaka
authors.forename: Nao
authors.initials: N
authors.lastname: Suzuki
authors.forename: Hesheng
authors.initials: H
authors.lastname: Liu
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Thiele
authors.forename: Steven M
authors.initials: SM
authors.lastname: Stufflebeam
mesh_terms: D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology*; D004827:Epilepsy / Q000150:complications* / Q000453:epidemiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007806:Language Disorders / Q000209:etiology* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D014402:Tuberous Sclerosis / Q000150:complications* / Q000453:epidemiology