Fifty per cent of patients diagnosed as having multiple sclerosis, primary lateral sclerosis, or hereditary spinocerebellar disorders were observed to have enduring favorable changes in neurological function during the 15 to 27 months they have been followed. The patients who were the least severely disabled were benefitted the most by the stimulation and made the most rapid progress. For example, the patient having only an ataxic or a spastic gait typically was observed to improve faster than the patient having both an ataxic and a spastic gait. The long term effect of electrostimulation of the spinal cord on these patients is unknown. The purpose of the stimulation is to attempt to obtain an improvement in neurological function so that the patient may experience a better life style. It is not thought that the electrical current has any effect on the basic disease process. Electrostimulation over the posterior spinal roots and spinal cord, although not new, has not been used extensively for the treatment of patients with arterial disease. The patients who have responded the most dramatically to electrostimulation are those with vasospastic disorders. A larger percentage of patients showed a greater response to implanted stimulation than to transcutaneous stimulation. Electrostimulation of the nervous system is not designed to replace standard therapeutic measures of treatment of patients with vascular disease, but to supplement them.