Pain reduction using transcranial electrostimulation: a double blind "active placebo" controlled trial.

OBJECTIVE To examine the efficacy of transcranial electrical stimulation a non-invasive method of reducing pain. DESIGN A randomized, double-blind, placebo-controlled trial. SUBJECTS A total of 119 patients with chronic pain. METHODS Patients were treated with either transcranial electrical stimulation or an active placebo device. Short- and long-term follow-ups were evaluated for treatment efficacy with 4 ordinal scale variables: visual analogue scale (pain level), SLEEP (how often does pain disturb sleep), FREQ (frequency of pain) and MED (frequency of use of medications to relieve pain). RESULTS Pain level decreased significantly in the transcranial electrical stimulation-treated group compared with the active-placebo group 3 weeks after the end of treatment (p = 0.0017 between groups). Other parameters did not demonstrate significant differences. Three months after the end of treatment this effect was maintained and other treatment parameters showed similar improvements. CONCLUSION Transcranial electrical stimulation is an effective non-invasive method for pain relief. The active placebo device has a powerful effect on reported pain, which diminishes in the long-term. The involvement of possible neural mechanisms is discussed.