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Effect of movement on dipolar source activities of somatosensory evoked potentials
Author(s) -
Valeriani Massimiliano,
Restuccia Domenico,
Di Lazzaro Vincenzo,
Le Pera Domenica,
Tonali Pietro
Publication year - 1999
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/(sici)1097-4598(199911)22:11<1510::aid-mus5>3.0.co;2-z
Subject(s) - somatosensory system , somatosensory evoked potential , neuroscience , scalp , cortical spreading depression , stimulation , tibial nerve , gating , psychology , medicine , anatomy , anesthesia , migraine
The early scalp somatosensory evoked potentials (SEPs) to median and tibial nerve stimulation were recorded at rest and during voluntary movement of the stimulated hand and foot, respectively. Both tibial and median nerve SEP distributions at rest could be explained by four‐dipole models, in which one dipole was activated at the same latency as the subcortical far field and the three remaining dipolar sources were located in the perirolandic region contralateral to the stimulated side. Voluntary movement reduced all cortical dipoles in strength, while the subcortical one remained unchanged, suggesting that the effect of movement occurs above the cervicomedullary junction. In animals, cutaneous inputs are suppressed during movement and we therefore interpreted the depression of activity in the primary somatosensory cortex induced by movement as due to selective “gating” of cutaneous afferents. Because the reduction in strength of the cortical dipoles was generally lower during passive than active movement, both centrifugal and centripetal mechanisms probably contribute to the phenomenon of “gating.” © 1999 John Wiley & Sons, Inc. Muscle Nerve 22: 1510–1519, 1999