Long-term effects of spinal cord stimulation in chronic pain syndromes.

A total of 50 patients with chronic pain syndromes were selected for treatment with spinal cord stimulation. Correct positioning of electrodes was obtained in 44 patients, leading to an initial alleviation of pain in 25 patients. In 6 patients, electrodes (though still effective in 4) had to be removed because of surgical complications within the first 5 months of use. Only 8 patients had at least some beneficial effect lasting for more than 3 years. The long-term results in patients with more severe psychological disturbances were no worse than those of the other patients.