The interactive computer-based staircase scaling method was used in two experiments, and the continuous track-ball method also was used in two experiments, one delivering 1.4 sec 40 degrees thermal stimuli, the other delivering stimuli ranging from 37 to 53 degrees C. A study evaluating memory of clinical pain magnitude was completed. Two additional studies using the interactive method and the track-ball assessment of 1.4 sec stimuli were initiated during this period, and studies validating a clinical pain questionnaire, and memory for neuropathic and cancer pain also were initiated. The first experiment used the interactive method to examine pain sensitivity in patients with cholestasis, a progressive liver disease. The hypothesis that the pruritus associated with this disease is due to increased levels of endogenous opiates was tested by both examining baseline experimental pain responses and assessing the effect of a challenge by a narcotic antagonist. A final analysis of 20 patients showed no evidence for increased levels of endogenous opiates. The second experiment examined the effects of imipramine and clonidine on the perception of painful thermal stimuli in 60 patients suffering from cardiac pain but without evidence of coronary artery disease. Imipramine reduced the frequency of painful episodes without altering either the painfulness of the episodes or cutaneous pain sensitivity. The third study used the track ball method to assess the effects of fentanyl or placebo on the magnitude and duration of pain sensation evoked by 3-sec thermal stimuli of varying intensity. Magnitude and duration were both related to stimulus intensity, but were independent of each other across subjects. In comparison to placebo, fentanyl reduced both the magnitude and durations of thermally-evoked pain sensations. The fourth study used track-ball assessment of trains of 49 C degrees stimuli to assess the effects of fentanyl on first and second pain sensations. Initial analysis showed that one-half of the subjects can rate both pain components with this method without any instruction about the existence of these two sensations. The fifth study used an at home pain measuring device and a physical therapy session to evaluate the accuracy and pliability of retrospective reports of chronic pain magnitude.
