Intraoperative recordings of spinal somatosensory evoked potentials to tibial nerve and sural nerve stimulation.
Somatosensory evoked potentials (SSEPs) to stimulation of the tibial nerve at the knee (TN-K) and ankle (TN-A), and the sural nerve at the ankle (SN-A), were recorded from 3 or 4 spinal levels during surgery for scoliosis in 11 neurologically normal subjects. With stimulation of all 3 nerves, the propagation velocity along the spine was nonlinear: it was faster over cauda equina and midthoracic cord than over caudal spinal cord. Over the mid-thoracic cord, TN-K SSEP propagation was faster than that of TN-A and SN-A SSEPs, whereas over the caudal spinal cord these values were similar on stimulation of all 3 nerves. These data suggest that fast conducting second order afferent fiber systems contribute to spinal cord SSEPs evoked by stimulating both mixed and cutaneous peripheral nerves.
Pelosi
L
L
Department of Clinical Neurophysiology, II School of Medicine, University of Naples, Italy.
Caruso
G
G
Cracco
R Q
RQ
Cracco
J B
JB
Balbi
P
P
D000293:Adolescent; D002420:Cauda Equina / Q000502:physiology; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D007430:Intraoperative Care; D008297:Male; D009431:Neural Conduction / Q000502:physiology; D012600:Scoliosis / Q000601:surgery; D013116:Spinal Cord / Q000502:physiology*; D013497:Sural Nerve / Q000502:physiology*; D013979:Tibial Nerve / Q000502:physiology*