The Effect of Diazepam on Presynaptic Inhibition in Patients with Complete and Incomplete Spinal Cord Lesions

Abstract

SUMMARY:The effect of diazepam on presynaptic inhibition in man has been examined in 5 patients with complete spinal transections and 7 patients with incomplete lesions. The inhibition of the H reflex by vibration applied to the tendo Achilles was used to assess presynaptic inhibition of the la monosynaptic pathway. Diazepam increased this inhibition in the patients with incomplete lesions, but had no significant effect on the inhibition in the patients with complete spinal transections.Evidently diazepam can enhance presynaptic inhibition in man. The effect, however, cannot be demonstrated in patients with longstanding complete spinal lesions possibly because of some alteration in the segmental presynaptic inhibitory mechanism in this group.