A Retrospective, Long-term, Third-Party Follow-up of Patients Considered for Spinal Cord Stimulation

The objective of this study was to follow up patients considered for spinal cord stimulation and assess outcomes and patient selection factors associated with outcome. A retrospective study of patients considered for spinal cord stimulation was performed. This included three groups: A) those who did not have a temporary trial of stimulation, B) those who did not go on to have long-term stimulation after a trial, and C) those who did go on to have long-term stimulation after a trial. Patient notes were obtained, a structured telephone interview conducted, and patients returned a questionnaire. VAS scores, percentage pain reduction reported, quality of life reports, Oswestry Disability Index and Hospital Anxiety and Depression Indices were recorded. Fifty-two percent of patients who had long-term stimulation reported 50% or greater pain reduction. In the subset of these patients with the diagnosis of failed back surgical syndrome, 51% reported 50% or greater pain reduction. Significant improvements in VAS, Oswestry Disability Index, and depression were reported pre and post long-term stimulation. There were significant differences in the quality-of-life reports between the patients who received long-term stimulation (who showed a positive outcome) and those who did not (who showed a negative outcome); 80% of patients receiving long-term stimulation reported an improvement in their quality of life. Follow-up of a cohort of patients receiving long-term stimulation demonstrated some reduction of treatment efficacy. Use of a psychological interview aided patient selection, but no other factors showed a correlation with reported pain reduction. No serious adverse effects were demonstrated. A revision rate of 23.5% occured in long-term stimulated patients. We conclude that spinal cord stimulation is an efficacious therapy which is not associated with serious side effects. There is some reduction in therapeutic efficacy over time. Patients deteriorate without treatment.