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Spinal components of the cerebral somatosensory evoked response in normal man: The “S wave”
Author(s) -
Abbruzzese M.,
Favale E.,
Leandri M.,
Ratto S.
Publication year - 1978
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/j.1600-0404.1978.tb02881.x
Subject(s) - scalp , somatosensory evoked potential , spinal cord , stimulation , somatosensory system , medicine , median nerve , evoked potential , neuroscience , anatomy , audiology , psychology , anesthesia
Responses evoked over the scalp and the neck by median nerve (or finger I) stimulation were concurrently recorded in 10 subjects. It was found that the first component of the cortical SEP consists of a small amplitude polyphasic wave (S wave) which could be recorded bilaterally upon unilateral stimulation. The polarity of the S wave varied according to the reference electrode position, at variance with the P 15 component which remained constantly positive. It is therefore correct to assume that different generators are responsible for these two potentials. The synchrony between the S wave and the cervical response, which is largely spinal in origin, as well as some pertinent experimental data, suggest that the S wave is a far field reflection of activity generated mainly in the cervical dorsal columns. These findings might be relevant to the diagnosis of neurological disorders.