Maximal and minimal motor nerve conduction velocities in amyotrophic lateral sclerosis.

In 15 patients with amyotrophic lateral sclerosis (ALS) and 20 age-matched control subjects, we measured the maximal and minimal motor nerve conduction velocities of the ulnar nerve as well as the action potential amplitude of the abductor digiti minimi muscle. Both maximal and minimal motor nerve conduction velocities in ALS patients were significantly lower than those in the control group. However, the difference between the maximal and minimal conduction velocities in each ALS patient was not statistically different from that in each control subject. The maximal action potential amplitude of the muscle in the ALS patients was significantly smaller than that in the control group.