Abnormalities in central motor pathway conduction in multiple sclerosis.

The technique of scalp stimulation of the motor cortex was used to demonstrate abnormalities in the corticomotoneuron pathway in multiple sclerosis. Unilateral or bilateral delays in corticomotoneuron conduction, dispersion of corticomotoneuron volleys, or both, were shown to occur in such patients. Changes may be seen even in patients with little clinical evidence of corticomotoneuron deficit.