[Functional nature of the spinal center of the hand muscles in normal subjects and in certain neurologic diseases (according to the results of stimulation electromyography)].

The parameters of the motor and the central responses of the thenar muscles to stimulation of the median nerve in 28 healthy subjects and 85 neurological patients were examined. It was shown that the infracervical alpha-motoneurons responded only to antidromic stimulation (the F-wave was registered). In cerebral pareses monosynaptic transmission from the 1a afferents becomes possible (the central response is similar to the H-reflex): this points to a disturbance of the segmented inhibition. In processes involving the anterior corticospinal tract the F-wave is depressed down to its complete disappearance, i.e. the motoneurons lose their capacity to respond to antidromic stimulation.