1079 Cervical Spinal Cord Stimulation for Facial Pain: Literature Review and Report of Three Cases

INTRODUCTION: Medically refractory facial pain syndromes are exceedingly difficult to manage. Recent evidence has shown promising results in the use of high cervical spinal cord stimulation for this indication. METHODS: A systematic review was performed according to PRISMA guidelines to include any studies describing primary data regarding cSCS implantation for neuropathic facial pain. Additionally, we performed a retrospective chart review of 3 patients from a single center. End points included % reduction in facial pain from preoperative baseline. A placebo effect was estimated based on review of RCTs on facial pain treatment. Bayesian T-tests were used to test the hypothesis that facial pain improves after SCS placement relative to preoperative baseline and to a greater extent than predicted placebo effect of 30%. Two models were compared for effect size, ??, with a Gauchy distribution prior centered on zero, r=0.707. RESULTS: Seven studies with 39 unique patients met inclusion criteria in addition to three patients from our institution. Of the 42 patients, 2 suffered post-traumatic facial pain, 15 deafferentation pain, 4 postherpetic neuralgia, 1 from multiple sclerosis, and 20 unspecified trigeminal neuropathy. Overall, the mean reduction in pain was 48%. If we assume no placebo effect and attribute all improvement to SCS, Bayes factor is 1.95*10 12 . Controlling for an estimated placebo effect of 30%, Bayes factor is 468. CONCLUSIONS: Overall, these results suggest strong evidence in favor of SCS implantation for neuropathic facial pain. Limitations of this study include limited available data on placebo effect in this population, limited number of patients in this series and inconsistent follow up periods. Future directions include development of multi-center registries to track long-term outcomes and placebo-controlled trials.