Immediate influence of transcranial electrostimulation on pain and beta-endorphin blood levels: an active placebo-controlled study.

BACKGROUND Stimulation of the antinociceptive system by noninvasive electrical current from electrodes placed on the head is a renewed method of pain relief. METHODS We conducted a randomized, double-blind, placebo-controlled study on 20 chronic back pain patients. They were treated with either transcranial electrostimulation (TCES) or an active placebo device. Pain level and serum beta-endorphin levels were measured before and after treatment. RESULTS beta-Endorphin level increased in seven of the ten patients from the treatment group and did not change in eight of ten patients from control group (P = 0.057 between groups). Pain level decreased in eight treated patients and seven control patients (significant decrease for each group, no significant difference between groups). CONCLUSIONS Transcranial electrostimulation is a nonpharmacologic method of pain relief accompanied or mediated by beta-endorphin release. The comparable degree of the initial clinical response emphasizes the powerful placebo effect on reported pain not mediated by endorphin release. This preliminary study shows that noninvasive electrical stimulation is a safe treatment with a positive effect on beta-endorphin blood levels.