[The stretch reflex response in the abductor pollicis brevis muscle in persons with organic and probably functionally conditioned central motor impairment (electromyographic study)].

Stretch reflex responses in the m. abductor pollicis brevis were elicited by percussion with the reflex hammer on the distal digit of the thumb. On the side of spastic hemiparesis the author revealed more marked short-latency and suppression of medium- and late-latency parts of the reflex response. On the side of weak central hemiparesis also the short-latency part of the reflex response was suppressed. In functionally conditioned pareses the author found dishabituation of medium and late latency parts of the reflex response. On the side of the cerebellar lesions there was a relatively higher amplitude of the second part of the medium-latency response. In patients with the diagnosis of definite multiple sclerosis in addition to suppression of medium and late- latency parts of the reflex response there was a typical prolongation their latency.