title: Hemispheric asymmetries of early cortical somatosensory evoked potentials revealed by topographic analysis.
abstract: Scalp topography of the early cortical SEPs was analysed in 50 normal right handed subjects. The following hemispheric asymmetries of the potentials were found: 1) The maximal amplitude of N20 was located predominantly at the P electrode after right sided stimulation, but varied between the CP, P and O electrode after left sided stimulation. 2) The N20 amplitudes were higher after right sided stimulation in approximately 70% of the subjects and the P25 and N30 amplitudes were higher after left sided stimulation in again approximately 70% of the subjects. No side difference of amplitudes was found for the subcortical N14. The N20 amplitude and location asymmetries were attributed to an anatomical asymmetry of the somatosensory cortex.
authors.affiliation: Department of Neurology, University Hospital RWTH Aachen, FRG.
authors.forename: H
authors.initials: H
authors.lastname: Buchner
authors.forename: I
authors.initials: I
authors.lastname: Ludwig
authors.forename: T
authors.initials: T
authors.lastname: Waberski
authors.forename: K
authors.initials: K
authors.lastname: Wilmes
authors.forename: A
authors.initials: A
authors.lastname: Ferbert
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011930:Reaction Time