A randomized placebo-controlled study of noninvasive cortical electrostimulation in the treatment of fibromyalgia patients.

OBJECTIVE

The aim of this multicenter study was to evaluate the efficacy, safety, and tolerability of noninvasive cortical electrostimulation in the management of fibromyalgia (FM).

DESIGN

A prospective, randomized, double-blind, placebo-controlled design was used. Setting.  Subjects received therapy at two different outpatient clinical locations.

PATIENTS

There were 77 subjects meeting the American College of Rheumatology 1990 classification criteria for FM. Intervention.  Thirty-nine (39) active treatment (AT) FM patients and 38 placebo controls received 22 applications of either noninvasive cortical electrostimulation or a sham therapy over an 11-week period.

OUTCOME MEASURES

The primary outcome measures were the number of tender points (TePs) and pressure pain threshold (PPT). Secondary outcome measures were responses to the Fibromyalgia Impact Questionnaire (FIQ), Symptom Checklist-90 (SCL-90), Beck Depression Inventory-II, and a novel sleep questionnaire, all evaluated at baseline and at the end of treatment.

RESULTS

Intervention provided significant improvements in TeP measures: compared with placebo, the AT patients improved in the number of positive TePs (-7.4 vs -0.2, P<0.001) and the PPT (19.6 vs -3.2, P<0.001). Most secondary outcomes also improved more in the AT group: total FIQ score (-15.5 vs -5.6, P=0.03), FIQ pain (-2.0 vs -0.6, P=0.03), FIQ fatigue (-2.0 vs -0.4, P=0.02), and FIQ refreshing sleep (-2.1 vs -0.7, P=0.02); and while FIQ function improved (-1.0 vs -0.2), the between-group change had a 14% likelihood of occurring due to chance (P=0.14). There were no significant side effects observed.

CONCLUSIONS

Noninvasive cortical electrostimulation in FM patients provided modest improvements in pain, TeP measures, fatigue, and sleep; and the treatment was well tolerated. This form of therapy could potentially provide worthwhile adjunctive symptom relief for FM patients.