Long-term pain relief during spinal cord stimulation. The effect of patient selection.

We reviewed our experience with spinal cord stimulation (SCS) in treating 116 patients with pain in one or both legs. All these patients were selected for an initial week of trial stimulation by the criteria: pain due to a known benign organic cause, failure of conventional pain control methods and absence of major personality disorders. Selected patients included 78 with the Failed Back Surgery Syndrome (FBSS), in whom proven correlation existed between the clinical picture and the neuroradiological and electromyogram abnormalities. Eighty-four out of 116 selected patients underwent definitive SCS implantation after 1 week of trial stimulation with excellent results (more than 75% pain relief). They were followed clinically every 3 months for a mean follow-up period of 47 months. Forty-five patients (54%) continued to experience at least 50% of pain relief at the latest follow up. Seventy-seven patients (91%) were able to reduce their medication intake and 50 patients (60%) reported an improvement in lifestyle. FBSS patients responded more positively to the trial stimulation than the other patients. However, the later outcome was not affected by patient selection as long-term benefit was similar in all definitive SCS patients irrespective of aetiology.