Vagus Nerve Stimulation for Treating Adults With Severe Fibromyalgia

Inclusion Criteria: Diagnosis of FMS for at least 2 years, as according to the 1990 guidelines of the American College of Rheumatology (ACR) criteria. In addition, ruling out of any other medical illness to which pain may be attributed. Inadequate relief in FMS pain despite good treatment efforts using standard pharmacological pain management. Only patients who are work-disabled because of FMS pain are eligible for study participation if they are on opioid maintenance therapy. Overall FMS pain at an intensity of 5 or greater on a 0-10 verbally anchored pain intensity scale, on more than 50% of days over a consecutive 7-day period before study entry Has not changed pharmacological and/or non-pharmacological (e.g., yoga, exercise) treatment regimen for the 4 weeks before the first study visit and continues to experience severe pain At least average premorbid IQ, as assessed by the vocabulary subtest of the WAIS-III, which is a standardized, well-validated index of premorbid intellectual function Willing to use an acceptable method of birth control Able to comply with all testing and follow-up visit requirements defined by the study protocol Currently lives within a 2-hour driving commute to the study site Exclusion Criteria: Rheumatologic condition other than FMS Secondary FMS, in which FMS is comorbid with another rheumatologic condition Reports that FMS pain began after a physical trauma In litigation that is associated with FMS condition at study entry Severe lifetime or current diagnosis of psychotic depression, bipolar disorder, schizophrenia, schizoaffective disorder, or other psychotic disorders or has a clear history of other psychiatric illness before the onset of FMS Diagnosed with major depressive disorder and has attempted to commit suicide in the past or has active suicidal ideation Lifetime or current history of dependence or abuse of pain medication or alcohol Treatment with an antipsychotic drug within 3 months of study entry Demonstrated a known placebo response in a previous study Treatment with botulinum toxin or local steroid injection for FMS within 2 months of study entry History of myocardial infarction or cardiac arrest Received general anesthesia within 30 days of implantation surgery Treatment with an investigational drug within a clearance duration of five times the half-life of the investigational drug or within 4 weeks of study entry Currently using another investigational device or drug Significant heart or lung condition currently under treatment and resulting in an American Society of Anesthesiologists (ASA) score greater than III Unilateral or bilateral cervical vagotomy Demand cardiac pacemaker, implantable defibrillator, or other implantable stimulator Any of the following conditions if over the age of 50 years old: cardiac conductance abnormalities, Wolf-Parkinson-White Syndrome, surgical intervention for bradycardia, history of prolonged QT interval, or a history of syncopal or pre-syncopal episodes Likely to require a whole body MRI after VNS system implantation Currently receiving or likely to receive after implantation short-wave diathermy, microwave diathermy, or therapeutic ultrasound diathermy Plans to relocate or move to a location distant from the study site within 1 year of study entry Previously enrolled in this or any other VNS system study Pregnant