title: Reduction of pain thresholds in fibromyalgia after very low-intensity magnetic stimulation: a double-blinded, randomized placebo-controlled clinical trial.
abstract: BACKGROUND
  Exposure to electromagnetic fields has been reported to have analgesic and antinociceptive effects in several organisms.
  
  
  OBJECTIVE
  To test the effect of very low-intensity transcranial magnetic stimulation on symptoms associated with fibromyalgia syndrome.
  
  
  METHODS
  A double-blinded, placebo-controlled clinical trial was performed in the Sagrado Corazón Hospital, Seville, Spain. Female fibromyalgia patients (22 to 50 years of age) were randomly assigned to either a stimulation group or a sham group. The stimulation group (n=28) was stimulated using 8 Hz pulsed magnetic fields of very low intensity, while the sham group (n=26) underwent the same protocol without stimulation. Pressure pain thresholds before and after stimulation were determined using an algometer during the eight consecutive weekly sessions of the trial. In addition, blood serotonin levels were measured and patients completed questionnaires to monitor symptom evolution.
  
  
  RESULTS
  A repeated-measures ANOVA indicated statistically significant improvement in the stimulation group compared with the control group with respect to somatosensory pain thresholds, ability to perform daily activities, perceived chronic pain and sleep quality. While improvement in pain thresholds was apparent after the first stimulation session, improvement in the other three measures occurred after the sixth week. No significant between-group differences were observed in scores of depression, fatigue, severity of headaches or serotonin levels. No adverse side effects were reported in any of the patients.
  
  
  CONCLUSIONS
  Very low-intensity magnetic stimulation may represent a safe and effective treatment for chronic pain and other symptoms associated with fibromyalgia.
authors.forename: Ceferino
authors.initials: C
authors.lastname: Maestú
authors.forename: Manuel
authors.initials: M
authors.lastname: Blanco
authors.forename: Angel
authors.initials: A
authors.lastname: Nevado
authors.forename: Julia
authors.initials: J
authors.lastname: Romero
authors.forename: Patricia
authors.initials: P
authors.lastname: Rodríguez-Rubio
authors.forename: Javier
authors.initials: J
authors.lastname: Galindo
authors.forename: Juan
authors.initials: J
authors.lastname: Bautista Lorite
authors.forename: Francisco
authors.initials: F
authors.lastname: de las Morenas
authors.forename: Pedro
authors.initials: P
authors.lastname: Fernández-Argüelles
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D005260:Female; D005356:Fibromyalgia / Q000628:therapy*; D006801:Humans; D055909:Magnetic Field Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017288:Pain Threshold / Q000528:radiation effects*; D055815:Young Adult