title: Occipital nerve stimulation in fibromyalgia: a double-blind placebo-controlled pilot study with a six-month follow-up.
abstract: OBJECTIVE
  The goal of this study is to evaluate the effectiveness of occipital nerve stimulation (ONS) as a surgical treatment for fibromyalgia in a placebo-controlled design.
  
  
  METHODS
  Eleven patients were selected based on the American College of Rheumatology-90 criteria and implanted with an occipital nerve trial-lead stimulator. Baseline scores for pain, mood, and fatigue were acquired, and patients were randomized in a ten-week double-blinded crossover design with placebo and effective subsensory threshold stimulation (no paresthesias). After finalizing the trial, nine patients were implanted permanently; evaluation was performed prior to surgery and at six months after surgery for pain, fatigue, and mood of the number of trigger points and overall morbidity.
  
  
  RESULTS
  Significant results were found during the trial for a decrease in pain intensity (39.74%) on visual analogue scale (VAS; p < 0.001) and pain catastrophizing scale (PCS) during effective stimulation. A total of 9/11 patients responded to trial treatment; however, in two patients, this might be a placebo effect, recognizable due to the study design. Six months after permanent implantation, pain intensity remained decreased (44.01%) on VAS (p < 0.05). Besides the VAS, significant changes were noted for PCS, fatigue (modified fatigue impact scale), the number of trigger points, and overall morbidity (fibromyalgia impact questionnaire). There were no serious adverse events.
  
  
  CONCLUSIONS
  Our data strongly suggest that ONS is beneficial in the treatment of fibromyalgia. The beneficial effects are stable at six months after permanent implantation. Subsensory threshold stimulation is feasible in designing a placebo-controlled trial.
authors.affiliation: Department of Translational Neuroscience, Faculty of Health science and Medicine University Antwerp, Antwerp, Belgium; Department of Neurosurgery, University Hospital Antwerp, Antwerp, Belgium.
authors.forename: Mark
authors.initials: M
authors.lastname: Plazier
authors.forename: Ingrid
authors.initials: I
authors.lastname: Dekelver
authors.forename: Sven
authors.initials: S
authors.lastname: Vanneste
authors.forename: Gaëtane
authors.initials: G
authors.lastname: Stassijns
authors.forename: Tomas
authors.initials: T
authors.lastname: Menovsky
authors.forename: Mark
authors.initials: M
authors.lastname: Thimineur
authors.forename: Dirk
authors.initials: D
authors.lastname: De Ridder
mesh_terms: D000328:Adult; D000339:Affect; D002572:Cervical Plexus / Q000503:physiopathology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004567:Electrodes, Implanted / Q000009:adverse effects; D005221:Fatigue / Q000209:etiology / Q000628:therapy; D005260:Female; D005356:Fibromyalgia / Q000150:complications / Q000523:psychology / Q000628:therapy*; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D059408:Pain Management; D010342:Patient Acceptance of Health Care; D010865:Pilot Projects; D055139:Sensory Gating; D040521:Subcutaneous Tissue; D064232:Visual Analog Scale
keywords: Fibromyalgia; greater occipital nerve stimulation; placebo controlled; six months; subthreshold