Transcutaneous electrical stimulation (TENS) has been used extensively for many types of pain but only rarely for headache. The object of this study was to judge the efficacy of TENS against placebo. Contrary to popular use, TENS (and placebo) were applied in a rigid manner, probably prejudicial to maximum effectiveness.
62 patients with migraine or muscle contraction headache, or both, were studied using TENS equipment of low amperage and high frequency. One of three modalities was chosen at random for each patient: TENS just above the patient's ability to perceive the stimuli (perceived stimuli), TENS just below the perception threshold (subliminal stimuli), and electrodes applied without electrical stimulation (placebo). Degree of improvement was judged by the patient using a scale of pain from 1 to 10. Following treatment with TENS perceived by the patient, 55% of patients noted improvement as compared to 18% after application of placebo; a significant difference (p < .025 chi-square test). Subliminal TENS was not statistically better than placebo.