[Analysis of mechanisms of motor disorders in amyotrophic lateral sclerosis (from the results of a tonic vibration reflex study].

In 41 patients with lateral amyotrophic sclerosis the tonic vibrational reflex (TVR) was examined. The H-reflex, the M-response, the stretch reflex, and the maximal spontaneous contraction before and during the Achilles tendon vibration were recorded simultaneously. A relationship between the TVR change and the disease form was revealed, and so was the different character of the change of the spinal reflexes in the presence of vibration. Mechanisms of the changes revealed are discussed with reference to the role of the gamma-system and the intraspinal inhibition in the origin of the motor disturbances characteristic of that disease.