Anticonvulsant drugs and spike propagation of motor nerves and skeletal muscle.

The propagation velocity of evoked muscle spikes was measured and normal values are presented. Carbamazepine, phenobarbitone, diazepam, and bromide-containing drugs were tested for their effect on conduction velocity of motor nerve and skeletal muscle fibres. All these drugs caused a decrease in spike propagation, both of motor nerves and skeletal muscle. After discussion of the probable mode and site of action of these drugs, it was supposed that the underlying events- perhaps changes in permeability of excitable membranes during excitation-are an essential factor in the anticonvulsant action of these drugs.