[State of mechanisms regulating muscle tone in amyotrophic lateral sclerosis (clinico-electromyographic study)].

For studying the mechanisms of spasticity electromyographic examinations were carried out in 54 patients suffering from lateral amyotrophic sclerosis at various stages of the disease. At the beginning of the spasticity formation disturbances of the functions of the checking spinal mechanisms and the gamma-system were revealed, while those of alpha-mononeurons (tested by the H-reflex) showed no statistically significant changes. In the late period (pronounced spasticity) disturbances of all the motor systems mentioned were noted. The role of various mechanisms in the development of muscular hypertonicity in lateral amyotrophic sclerosis is discussed.