Journal article
Topographic analyses of somatosensory evoked potentials following stimulation of tibial, sural and lateral femoral cutaneous nerves
Electroencephalography and clinical neurophysiology / Evoked potentials section, Vol.100(1), pp.33-43
1996
DOI: 10.1016/0168-5597(95)00161-1
PMID: 8964261
Abstract
Using topographic maps, we studied the scalp field distribution of somatosensory evoked potentials (SEPs) in response to the stimulation of the tibial (TN), sural (SN) and lateral femoral cutaneous (LFCN) nerves in 24 normal volunteers. Cortical peaks, i.e., N35, P40, N50 and P60 were generally dominant in the contralateral hemisphere for the LFCN-SEP, whereas all peaks except N35 had dominance in the ipsilateral hemisphere for TN- and SN-SEPs. The findings imply that ipsilateral or contralateral peak dominance for the lower extremity SEP is determined by where the cortical leg representation occurs. As a result, mesial hemisphere representation results in peak dominance projected to the hemisphere ipsilateral to stimulation. Representations at the superior lip of the interhemispheric fissure or lateral convexity lead to midline or contralateral peak dominance. These findings also suggest that the paradoxically lateralized P40 is not the result of a positive field dipole shadow generated by the primary negative wave in the mesial hemisphere, but is the primary positive wave, analogous to P26 of the median nerve SEP. Accordingly, contralaterally dominant N35 is likely equivalent to the first cortical potential of N20 in the median nerve SEP. The difference in vector directions of potential fields between N35 and P40 may account for the opposite hemispheric dominance for these peaks in TN- and SN-SEPs.
Details
- Title: Subtitle
- Topographic analyses of somatosensory evoked potentials following stimulation of tibial, sural and lateral femoral cutaneous nerves
- Creators
- Thoru Yamada - Division of Clinical Electrophysiology, Department of Neurology, University of Iowa, College of Medicine, Iowa City, IA 52242, USAMotoko Matsubara - Department of Orthopedic Surgery, Kansai Medical University, Osaka, JapanGen Shiraishi - Department of Orthopedic Surgery, Yamaguchi University, Yamaguchi, JapanMalcolm Yeh - Division of Clinical Electrophysiology, Department of Neurology, University of Iowa, College of Medicine, Iowa City, IA 52242, USAMiyako Kawasaki - Department of Orthopedic Surgery, Kansai Medical University, Osaka, Japan
- Resource Type
- Journal article
- Publication Details
- Electroencephalography and clinical neurophysiology / Evoked potentials section, Vol.100(1), pp.33-43
- DOI
- 10.1016/0168-5597(95)00161-1
- PMID
- 8964261
- NLM abbreviation
- Electroencephalogr Clin Neurophysiol
- ISSN
- 0168-5597
- eISSN
- 1872-6380
- Publisher
- Elsevier Ireland Ltd
- Language
- English
- Date published
- 1996
- Academic Unit
- Neurology
- Record Identifier
- 9984020887202771
Metrics
14 Record Views