BMI as a Predictor of Spinal Cord Stimulation Success in Chronic Pain Patients

Background: Spinal cord stimulation (SCS) is an effective method of treating chronic pain. Obese patients are overrepresented in chronic pain cases. We examine the effect of body mass index (BMI) on SCS success. Methods: We prospectively follow outcome measures including visual analog score, Beck Depression Inventory (BDI), McGill Pain Questionnaire, Oswestry Disability Index (ODI), Pain Catastrophizing Scale (PCS), and the Insomnia Severity Index at baseline, six months, and one year postoperatively. Retrospectively, we examined whether our patients with a BMI above the 75th percentile (BMI ≥36.5) had worse outcomes. Results: Our analysis included thoracic and cervical SCS patients—19 with a BMI ≥36.5 and 58 with a BMI <36.5. High BMI patients experienced less BDI improvement at 6 months (T(df) 2.257(36); p = 0.030; 95% CI [4.7%, 87.4%]) and one year (2.74(28); p = 0.011; 95% CI [18.1%, 125.0%]) post-SCS. High BMI patients had less improvement in pain as measured by the PCS at one year (U = 79.5; p = 0.045; 95% CI [−116.0%, 0.0%]). Discussion: Each group experienced successful surgical outcomes. High BMI patients had less BDI improvement at six months and one year and less PCS improvement at one year. These data aid us in counseling our patients preoperatively.