CHRONIC PAIN IS ASSOCIATED WITH DEFICITS IN INFORMATION-PROCESSING

Beginning with the theoretical premise that pain stimuli are liable to perturb the ordinary dynamical state of the brain, we hypothesized th at individuals in pain may experience impaired information processing. A sample of 19 persons complaining of chronic pain and a comparison s ample of 25 persons having sustained head trauma were obtained by retr ospective chart review. The chronic-pain group consisted of 19 persons whose primary complaint was significant chronic pain, with no known h istory of head trauma or neurologic disorder. The comparison group con sisted of 25 persons who had sustained mild to moderate head traumas. All subjects were administered information processing and motor subtes ts of the Human Performance Measurement System, a computerized set of measures. Both groups obtained mean z scores below the normative mean on all measures except visual digit span. There were no differences be tween groups on motor measures, visual digit span, and visual-spatial memory. On 2 of 6 information-processing tests, pain patients performe d more poorly than head-trauma patients. The results suggest that pain may disrupt cognitive performances which depend on intact speed and c apacity of information processing.