Influence of dorsal column stimulation (DCS) on spastic movement disorders.

Dorsal column stimulation in two spastic patients with upper motor neurone disease showed the following effects: 1. The subjective feeling of stiffness decreased. During DCS patients were able to walk longer distances without rest. 2. The ability to perform fast alternating or synchronous "pedal-pressing" foot movements improved by 15%. 3. The threshold of H-reflexes was enhanced up to 12%, and outlasted the end of stimulation by two minutes. 4. The H-reflex amplitude was depressed in relation to intensity and duration of DC-stimulation up to 10 minutes after the end of DCS. 5. A late second facilitatory wave at 300 msec in the curve for H-reflexes conditioned by a short tibial stimulus was inhibited during DCS. Although the hyperexcitability of the H-reflex was dampened significantly during DCS the whole motor disturbance improved only slightly.