Prolonged relief of pain by brief, intense transcutaneous somatic stimulation.

The purpose of this study was to examine the effects of brief, intense transcutaneous electrical stimulations at trigger points or acupuncture points on severe clinical pain. The McGill Pain Questionnaire was used to measure the change in pain quality and intensity produced by stimulation. The data indicate that the procedure provides a powerful method for the control of some forms of severe pathological pain. The average pain decrease during stimulation sessions was 75% for pain due to peripheral nerve injury, 66% for phantom limb pain, 62% for shoulder-arm pain, and 60% for low-back pain. The duration of relief frequently outlasted the period of stimulation by several hours, occasionally for days or weeks. Different patterns of the amount and duration of pain relief were observed. Daily stimulation carried out at home by the patient sometimes provided gradually increasing relief over periods of weeks or months. Control experiments, which included two forms of placebo stimulation, showed that brief, intense electrical stimulation is significantly more effective than placebo contributions. Possible neural mechanisms that underlie these patterns of pain relief by brief, intense stimulation are discussed.