Brain evoked potentials to noxious sural nerve stimulation in sciatalgic patients

Publisher Website
Google Scholar
Abstract
S carried out with 8 inpatients affected with a unilateral sciatica resulting from an X-ray identified dorsal root compression from discal origin. The sural nerve was electrically stimulated at the ankle level while BEPs were recorded monopolarly from the vertex. The stimulus intensity eliciting a liminal nociceptive reflex response in a knee-flexor muscle associated with a liminal pain was selected for this study. Both normal and affected side were alternatively stimulated during several conditions of controls and of Lasègue's manoeuvres performed on the normal and on the affected side. Results show that the Lasègue manoeuvre performed on the affected side induced a significant increase in the amplitude of N150-P220; performed on the normal side, this same manoeuvre resulted in a significant decrease of the N150-P220 amplitude. These variations were observed whatever was the side (normal or affected) under sural nerve stimulation. The possible neural mechanisms of these changes and clinical implications of these data are then discussed. Correspondence to: Dr. Jean Claude Wilier, Laboratory of Clinical Neurophysiology, Faculty of Medicine Saint-Antoine, University of Paris VI, 27, rue Chaligny, F 75571 Paris Cedex 12, France. (Received 2 October 1986; accepted 12 December 1986.( © Lippincott-Raven Publishers....