Empirically derived chronic pain patient subgroups: the utility of multidimensional clustering to identify differential treatment effects.

The current study used multidimensional clustering to delineate empirically subgroups of chronic pain patients and to compare their responses to interdisciplinary pain rehabilitation. A total of 180 chronic pain patients were used as subjects. They were administered the Sickness Impact Profile (SIP), Medical Examination and Diagnostic Information Coding System (MEDICS) and treatment outcome measures including subjective pain intensity, hours standing and walking, medication usage and work status.

Quantification of biomedical findings of chronic pain patients: development of an index of pathology.

Difficulties in assessing and quantifying the biomedical signs and symptoms that may be related to patients' reports of pain are well recognized. Although there appears to be some consensus among physicians as to the potential utility of examination and diagnostic tests frequently used to evaluate chronic pain patients, little attention has been paid to the reliability of interpreting the results of these procedures. Moreover, the integration of biomedical findings to form a general index of pathology associated with chronic pain has been a difficult problem to solve because not all biomedical procedures used to evaluate pain patients are necessarily relevant or indicated for a specific patient.

Differential utility of medical procedures in the assessment of chronic pain patients.

Physicians are frequently called upon to evaluate patients with chronic pain to (1) establish the etiology, (2) determine the extent of impairment and disability, and (3) prescribe treatment. In many cases, there is little agreement as to what evaluation procedures should be used or how to weight and integrate these findings. Two studies were conducted to determine the domain of procedures pain specialists believe are most important in evaluation and the clinical utility of each.

Learned helplessness and responses to nerve blocks in chronic low back pain patients.

In a double-blind study, 67 chronic low back pain patients received 4 lumbar sympathetic nerve blocks, two given with bupivacaine and two given with saline. It was hypothesized that patients showing evidence of 'learned helplessness,' as measured by dependence on habit-forming medications for the pain, low activity levels, and elevated MMPI scores on Hypochondriasis, Depression and Hysteria would show the least reduction in subjective pain intensity following injections with both bupivacaine and saline. It also was hypothesized that placebo responses would be greatest in patients who had a high educational level, were divorced, and had no pending disability claims.

Treatment outcome in a chronic pain rehabilitation program.

One hundred patients were selected who had completed an outpatient rehabilitation program designed to teach competent coping with chronic pain. Data at follow-up periods averaging 21 months posttreatment indicated statistically significant decreases in subjective pain intensity and increases in activities of daily living with substantial reductions in use of medications for pain. Changes from pretreatment to follow-up were not significantly different among groups of patients with pending, current, or no disability.

Chronic back pain: electromyographic, motion and behavioral assessments following sympathetic nerve blocks and placebos.

Twenty patients with chronic low back pain received 12 lumbar sympathetic injections, in a series of 6 with bupivacaine and a series of 6 with saline. Changes in subjective pain intensity, EMG from paravertebral muscles, joint ranges of mobility, and daily activity levels were measured at multiple intervals throughout treatment and at 3 monthly follow-up intervals. The MMPI was administered before treatment, after treatment and at 3-month follow-up.

Phantom urinary bladder pain--case report.

Phantom urinary phenomena are a relatively rare disease entity. Literature search has revealed only one case following cystectomy, seven cases following spinal cord injury and several other cases in hemodialysis patients. This report presents a case of painful phantom bladder following cystectomy for chronic kidney and urinary tract infection.

Relationship of patient semantic pain descriptions to physician diagnostic judgments, activity level measures and MMPI.

A consecutive sample of chronic pain patients presenting themselves for evaluation was studied. A set of 25 bi-polar adjectives was developed from medical records of previous pain patients' descriptions of their pain. Using the Semantic Differential (S-D) method, each patient rated the extent to which his/her pain was best described by either of the adjective pairs.