Biofeedback therapy for headache and other pain: an evaluative review.

A survey of the literature is presented in two areas of biofeedback treatment for headache--muscle contraction and migraine--and a variety of miscellaneous pain syndromes. The studies done to date are characterized largely by lack of proper no-treatment or placebo control groups, by confounding biofeedback with a variety of other strategies, or by sample sizes too small to afford any reasonable conclusions about efficacy. There is some evidence that biofeedback works better for muscle contraction headache than false feedback, but it also appears that biofeedback is no more effective than relaxation training. The application of biofeedback to migraine or other pain syndromes remains of unproven value. Investigators seldom attempt to relate empirically their interventions to hypothetical models of pain mechanisms. The potential influence of extraneous factors linked to the therapeutic situation is pervasive in these studies, but examination of their specific roles in symptom reduction is largely missing. Some variables are listed which need to be examined and which may contribute to the alleviation of pain with much less expenditure of clinical resources than that demanded by biofeedback. Perhaps the main contribution of biofeedback has been to highlight such extraneous variables in the pain treatment setting.