Pain
-
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 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.
-
Experimental evidence is reviewed showing that brain and spinal cord serotonergic neurons are involved in nociceptive responses, as well as in the analgesic effects of opiate narcotics. This evidence, based on studies employing pharmacological, surgical, electrophysiological, and dietary manipulations of central nervous system serotonergic neurotransmission, suggests that increases in the activity of brain and spinal cord serotonin neurons are associated with analgesia and enhanced antinociceptive drug potency, whereas decreases in the activities of these neurons correlate with hyperalgesia and diminished analgesic drug potency.