title: Noninvasive determination of speech dominance by single magnetic stimulation of the bilateral hand motor cortex.
abstract: Magnetic stimulation of the hand area of the motor cortex in both hemispheres was performed at rest and during reading aloud to observe modulated facilitation of hand muscle motor potentials in 6 right-handed patients, with supratentorial lesions but no motor impairment or aphasia, who had undergone the Wada test to determine speech dominance, showing that 5 were left hemisphere dominant and one was bilateral hemisphere dominant. Motor potentials were facilitated during reading aloud in only the right hand in 3 patients, all left hemisphere dominant, greater in the right hand in one, left hemisphere dominant, and greater in the left hand in one patient, bilateral hemisphere dominant. Based on these results we defined a laterality index which was consistent with the Wada test results. Magnetic stimulation may prove useful for determining cerebral dominance, as our method correlates well with the Wada test, and is safe, convenient, and inexpensive.
authors.affiliation: Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima. hiroshitok@nag.bbiq.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tokimura
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Imamura
authors.forename: Kazunori
authors.initials: K
authors.lastname: Arita
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods*; D001932:Brain Neoplasms / Q000503:physiopathology / Q000601:surgery; D004292:Dominance, Cerebral / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D005910:Glioma / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult