Referred sensations in chronic pain patients.

This clinical note describes an unusual phenomenon of referred sensation reported in a sample of 98 chronic pain patients during electrical stimulation. Thirty-nine percent reported a variety of sensations referred to different parts of the body. Of these, 74% reported the sensations referred to the painful region. Among the sensations were paresthesias, pain, temperature changes, and pressure or constriction. The patients who had referred sensations had lower ratings of depression and had undergone more surgical operations than those who did not report referred sensations. Three case reports of patients with phantom limb pain are presented to illustrate the vividness with which these sensations are experienced. These data suggest that deafferentation due to disease, injury or other lesions of the CNS lead to a hypersensitivity and an increased likelihood of referred pain of long duration.