Premium
Responses to electrical stimulation of the median nerve in the human newborn
Author(s) -
Ellis Ron R.,
Ellingson Robert J.
Publication year - 1973
Publication title -
developmental psychobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 93
eISSN - 1098-2302
pISSN - 0012-1630
DOI - 10.1002/dev.420060308
Subject(s) - median nerve , thenar eminence , scalp , sensory threshold , action potential , afferent , stimulation , sensory system , thumb , wrist , audiology , biceps , psychology , medicine , sensation , physical medicine and rehabilitation , electrophysiology , neuroscience , anatomy , cognitive science
Four normal full‐term newborns and 4 adults were stimulated by constant‐current square‐wave pulses to the median nerve at the wrist. Thumb and finger movement thresholds were determined by visual observation and by recording movement potentials from the thenar eminence. Afferent nerve action potential thresholds were determined by recording from the median nerve above the elbow. Subjective sensory thresholds were also determined by verbal report in the adults. Somesthetic evoked responses (SEP) were recorded from the contralateral scalp at movement threshold and 2 times the movement threshold in both infants and adults. The mean afferent nerve action potential threshold of the newborns was 3 times higher than that of the adults. The mean movement thresholds of newborns and adults were not significantly different. The mean action potential threshold was not different from the mean subjective sensory threshold in the adults. The mean action potential threshold was not different from the mean movement threshold in the newborns. Shocks of movement threshold intensity are not always adequate for elicitation of afferent action potentials and SEP's in newborns. In stimulating peripheral nerves to elicit SEP's, the positions of the stimulating electrodes are critical.