Treatment of spasticity by dorsal cord stimulation

Two types of operations can be proposed today in the neurosurgical treatment of spasticity; the destruction of a brain target, a medullary pathway or a nerve root, and electrical stimulation of nervous structures. Striking improvements in voluntary motor control and sensory appreciation were first reported by Cook and Weinstein (1) in 1973, after implantation of a dorsal cord stimulator for intractable back pain in a case of muiltiple scleroris. The favourable effect on spasticity was confirmed later by other groups. Our own experience, with 26 cases tested for a few days with floating electrodes and 11 cases operated on and followed up for more than 3 years, shows that the best results are obtained in cases of medullary spasticity, without complete section of the cord, occurring mainly in multiple sclerosis. Cerebral spasticity did not respond as well. The objective data, measurement of stretch and H-reflexes, support the clinical results. The physiological mechanisms of dorsal cord stimulation on spasticity have not yet been elucidated.