Functional state of segmental motoneurons in Wilson-Konovalov hepatocerebral dystrophy.

Stimulatory electromyography was used to investigate 12 patients, and chronaximetric investigations were performed in 18. Peak H-potential amplitudes indicated reductions in reflex excitability in the motoneuron pool. The stimulus size required for inducing threshold H-reflexes demonstrated a high level of reflex excitability among those alpha-motoneurons probably involved in generating hyperkinesia. Motor response parameters showed the direct electrical excitability of motor units to be elevated. Changes in H-reflex and M-response parameters demonstrated functional rearrangement of the movement analyzer after stereotaxic surgery. The functional states of the alpha- and gamma-systems are discussed.