Multidimensional analysis of peak pain symptoms and experiences

Peak pain symptoms and experiences were explored within a group of 243 intractable pain patients seen consecutively at a pain clinic. Using a 5-point scale, patients rated the frequency with which 99 symptom adjectives occurred when their pain was at its worst. Key cluster analysis identified 11 reliable, conceptually clear symptom clusters: Four affective symptom categories, Angry Depression, Diminished Drive, Intropunitive Depression and Anxiety, describing emotional states concomitant with peak pain; two somatic symptom categories, Ecto-Pain and Endo-Pain, describing surface and deep bodily pain, respectively; and five additional symptom categories including Cognitive Dysfunction, Sleep Disturbance, Fatigue, Withdrawal and Disequilibrium. Among the affective symptom clusters, symptoms of Angry Depression were reported to occur frequently by 32% of the patients while only 11% reported the frequent occurrence of Intropunitive Depression. For the somatic symptom clusters, 25 and 52% reported the frequent occurrence of Ecto-Pain and Endo-Pain, respectively. Pain reports measured by Ecto-Pain and Endo-Pain were nearly independent of all other symptom categories. The results suggest that the experiential context of pain differs widely among intractable pain patients. The study derived a Pain Symptom Checklist to measure each symptom cluster as one way to identify coping styles among chronic pain patients.