Treatment of Fibromyalgia Syndrome Using Low-Intensity Neurofeedback with the Flexyx Neurotherapy System: A Randomized Controlled Clinical Trial


  • Howard M. Kravitz
  • Mary Lee Esty
  • Robert S. Katz
  • Jan Fawcett



Background. Treatment of fibromyalgia syndrome (FMS) remains a clinical challenge. Pain, somatic and cognitive symptoms may be due to neurosensitization involving CNS-activated autonomic and musculoskeletal reactions, associated with EEG abnormalities that may respond to brainwave-based stimulation biofeedback. This study’s objective was to examine the efficacy and safety of a novel EEG neurobiofeedback treatment, the Flexyx Neurotherapy System ® (FNS), and electrophysiological responses in persons with fibromyalgia. Methods. A randomized, double-blind, placebo-controlled clinical trial was conducted in two private practices: a free-standing neurobiofeedback center and a rheumatologist’s office at an academic medical center. Sixty-four participants with FMS (American College of Rheumatology criteria; Wolfe et al., 1990) for at least three years and symptoms for at least 48 months with no recent remission were randomized to treatment. A total of 22 treatment sessions were administered over at least 11 weeks of active (n = 33) or sham (n = 31) FNS therapy. Primary efficacy measures were the Clinical Global Impressions improvement scores, Clinician (CGI-I) and Participant (PGI-I) versions. Secondary outcomes included dolorimetry and tender point count, questionnaires (fibromyalgia symptom scales, CNS Dysfunction Questionnaire, Fibromyalgia Impact Questionnaire, Symptom Checklist-90-R), and EEG activity (delta, alpha, total amplitude). Results. More participants treated with active FNS than with sham improved partially or fully on the CGI-I at session 22 (p = .01) and follow-up (p = .04). The active FNS group had a higher CGI-I full response rate at session 22 (p < .05) but not at one-week post-treatment (p = .07). Significant active versus sham PGI-I responses were not detected (p>.10). There was no significant treatment effect on any secondary outcome measure and no specific symptom improved preferentially with active compared with sham FNS. The most commonly reported side effect was fatigue/tiredness. Pre-treatment delta/alpha EEG amplitude ratio > 1 was associated with PGI-I (but not CGI-I) response independent of treatment group assignment. Conclusion. FNS monotherapy is insufficient for treating chronic, nonremitting FMS.