The Relationship Between Pain Responsiveness And Disease Activity In Fibrositis And Rheumatoid Arthritis

The present research examined the relationship between pain responsiveness and disease activity in patients with the rheumatologic diagnoses of rheumatoid arthritis (R.A.) and fibrositis. Three studies were carried out.;In the first study, 68 R.A. subjects were assessed for levels of disease activity using 7 standard measures, plus the rheumatoid factor titre and the R.A. functional classification. The Basic Personality Inventory was used to measure anxiety, depression, hypochondriasis, and denial. Pain threshold and tolerance levels were taken in each subject using trains of electrical pulses, a constant-pressure algometer, and a variable-pressure dolorimeter. The data were analyzed by multiple regression. The results indicate that pain tolerance is best predicted by levels of disease activity, gender, hypochondriasis and rheumatoid factor titre. Significant differences were found between the sexes on pain responsiveness and disease activity.;One year later, 38 (55%) of the original subjects returned. The same measures, methodology, and analyses were used as on the previous visit. It was found that disease activity and pain responsiveness had decreased between visits. A much clearer pattern of association between the variables was evident. Disease activity was the most important single predictor, in a negative direction, of pain threshold and tolerance levels.;In the third study, 36 patients with the diagnosis of fibrositis completed a 10-week placebo-controlled, randomized double-blind crossover trial of low-dose amitriptyline. Outcome measures were local tenderness (TMS), and pain threshold and tolerance, assessed with the variable-pressure dolorimeter. The other principal measures were, depression, state anxiety, sickness impact, hypochondriasis and pain. The data were initially analyzed using multivariate statistics. Compared to placebo, amitriptyline significantly improved pain, pain threshold, TMS, depression, hypochondriasis and sickness impact. Levels of pain, and pain threshold and the TMS showed a strong negative relationship. A discriminant analysis indicated that pain and the length of symptoms were the most important variables that predicted those who responded to amitriptyline.;This research supports hypervigilance theory which holds that people with chronic pain become more responsive to painful stimuli as a result of their symptoms