Dipole modelling of median nerve SEPs in normal subjects and patients with small subcortical infarcts.
Somatosensory evoked potentials (SEPs) to median nerve stimulation were analyzed by means of spatio-temporal dipole modelling in 6 normal subjects and 8 patients with small infarcts in the thalamo-cortical radiation or thalamus. The SEPs could be modelled by a tangentially and a radially oriented equivalent dipole in the region of the contralateral cortical hand area and an equivalent dipole located in the region of the brain-stem. In 3 patients with absence or reduction of amplitudes of cortically generated SEP components, the activity of both cortical dipoles was lost or reduced. In 2 patients the frontally recorded SEP component P20 was lost; in one of them the activity of mainly the tangential dipole was reduced.
Franssen
H
H
Department of Clinical Neurophysiology, Academic Hospital Utrecht, The Netherlands.
Stegeman
D F
DF
Moleman
J
J
Schoobaar
R P
RP
D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000503:physiopathology; D002544:Cerebral Infarction / Q000503:physiopathology*; D002648:Child; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000503:physiopathology*; D008875:Middle Aged; D008959:Models, Neurological; D011930:Reaction Time / Q000502:physiology