Association of Prescribed Medications with Outcomes from Rehabilitation for Musculoskeletal Pain

The lead article for this issue of the Journal of Musculoskeletal Pain [JMP] comes from investigators in Trondheim, Norway (1). The authors proposed to evaluate the association between three classes of controlled medications [centrally-acting analgesics (opioids), anxiolytics, and hypnotics] prescribed for patients involved in institutional rehabilitation programs for musculoskeletal pain with the patient's outcomes from those interventions. Every participant completed the same self-report questionnaire at the beginning and the end of the rehabilitation program. The questionnaires focused on pain, health status, and socioeconomic factors. Linkage of the study subjects to the Norwegian Prescription Database gave the investigators access to the prescribed medications in the three classes of drugs.

The term musculoskeletal pain would represent one manifestation of many specific medical conditions that could benefit from a rehabilitation program. In many cases, pharmacological therapy specific to the relevant diagnosis would have been initiated before the patient was referred for a rehabilitation program. In addition, the individual rehabilitation programs may have differed based on the given diagnosis and its severity, but recall that the focus of this study was upon prescriptions for three specific classes of controlled medications and their relationships to the outcomes resulting from the rehabilitation program.

The investigators evaluated 1564 individuals in rehabilitation programs for musculoskeletal pain and found that 36.4% of the patients [N = 569] were given a prescription for a controlled medication in one of the three monitored classes. If a drug was prescribed, the authors assumed that it was used as directed. Interestingly, they found that the administration of centrally acting analgesics did not predict a good outcome among patients with musculoskeletal pain. Indeed, the prescriptions of hypnotics, and particularly of anxiolytics, were associated with the better outcomes. That being the case, it was surprising that there was no mention of sleep, sleep dysfunction, or insomnia among the authors' measured outcomes. The authors found no relationship between the use of one of the classes of controlled medications and an existing diagnosis of an affective disorder like depression or anxiety.

The second original contribution in this issue, relating to systematic assessment of delayed onset muscle soreness, comes from Joondalup and Brisbane, Australia (2). This study was designed to characterize post-exercise muscle pain when the exercise was intentionally eccentric. Questions answered by this study include the time course of visual analog scale subjective pain resulting eccentric exercise. Does this kind of muscle trauma cause allodynia? If so, does the time course of the resultant allodynia differs from that of the pain? To what extent does the subjective pain correlate with the allodynia? Do muscle pain or tenderness in this condition vary with the examined location in the length of the affected muscle? Finally, which of these measures do the investigators believe most accurately documents post-exercise muscle pain? The reader will be intrigued by the availability of answers to such precise questions. Since the eccentric exercise was experimentally induced unilaterally and consistently involved the no-dominant arm, it would have been interesting to know whether the paired contralateral muscle became symptomatic or developed allodynia to suggest a centrally mediated process. If there was referral to the contralateral unexercised muscle, did the referral more resemble myofascial pain syndrome or complex regional pain syndrome?

A controlled clinical crossover study of the role of experimentally-induced peripheral pain [a form of attentional distraction] on head positioning was conducted in Ulm, Germany (3). The authors use the term cervicocephalic kinaesthesia [CCK] in reference to the proprioceptive, visual, and vestibular control systems that coordinate the positioning of the head by muscles of the cervical spine. In their introduction, the authors outline the development of prior CCK studies, what they contributed to the field, and their limitations. Working with a data management group in Darmstadt, Germany, the investigators tested a virtual reality based method of measuring CCK that utilized the entire range of the subject's neck motion.

Healthy normal males and females were studied with both the painless and the experimentally-induced peripheral pain conditions on two different days with reversal of the sequence on the second day. The subjects wore a helmet with built-in electronics that provided a virtual view of an earth-like sphere moving in relation to other celestial bodies in the same virtual visual field. As the subject followed the focal sphere, the compute-guided tracking system documented the position of the head. The authors describe in good detail their methodology of a static and a dynamic test. The pain stimulus was achieved by an ischemic exercise procedure involving the non-dominant forearm with arterial blood flow obstruction by a cuff on the upper arm. The perceived pain was considered adequate for the purpose of the experiment when the pain visual analog scale was reported to be at least 3.0 cm on a 10.0 cm scale.

The reader may be surprised at the extent of the variability of the measurements between study participant individuals. Review the investigator's data to learn what effect the pain stimulus had on the relative errors in neck/head positioning in the static and dynamic test protocols. Recall that the study subjects were healthy pain-free normal controls. How would they have differed had the patients been experiencing soft tissue pain from neck injury such as whiplash? How likely is this technology to be incorporated into a diagnostic or therapeutic paradigm?

A collaboration between investigators in Samsun and Ankara, Turkey resulted in a report regarding the effects of lower limb amputation on post-amputation pain, functional status, emotional status, and perception of body image (4). The authors indicate that the unique feature of their study is a comparison of the person who has suffered a lower limb amputation [LLA] to healthy normal controls [HNC]. Several self-report instruments were used to assess quality of life, pain, functional status and perception of body image in both comparison groups. The authors also evaluated within group correlations to predict the factors contributing importantly to the compromised quality of life and physical dysfunction of the amputees.

The relationship between the sense of exerted force during quadriceps contraction and proprioception in patients with patellofemoral pain syndrome [PFPS] was investigated by a research group from Tehran, Iran (5). A demographically-matched group of healthy normal controls [HNC] were recruited for control comparisons. The extremity studied was the more painful one. The authors used an isokinetic dynamometer to place the knee at 20 degrees or 60 degrees of flexion and to document the production of 20 and 60 percent of quadriceps maximal voluntary isometric contraction at each angle with visual feedback by an investigator. Then, the subject was asked to estimate and reproduce each of the target forces without visual feedback. Errors in achieving the target force were recorded and analyzed statistically by knee angle and study group. The findings expand what is known about the function of the quadriceps muscle in patients with symptomatic PFPS. The authors point out the importance of quadriceps function to many aspects of life, particularly proprioception, and show how their findings may help to explain compromises of physical function experienced by patients with PFPS.

An interesting case report comes from Bolu and Sakarya, Turkey (7). The authors describe the case of a middle-aged woman who was treated for a displaced right forearm fracture. An internal fixation device was held in place by screws. The three radiographs provided by the authors are instructive. Four months later, she presented with arm pain, swelling, and restricted mobility. One of the screws had caused an enthesopathy at the radial insertion of the biceps brachii muscle tendon. Removal of the screw solved the problem. The reader is encouraged to peruse the case report and view the radiographs. Non-surgeons presented with such a problem of pain and limited motion should wonder what is hidden under that healing scar?

A case report submitted from Ankara, Turkey (8), expands the differential diagnosis of unilateral shoulder pain. In this case, a male presented with unilateral shoulder pain suggesting the diagnosis of Parsonage–Turner Syndrome but the findings from a careful neurologic examination was inconsistent with a simple brachial plexus neuritis. Imaging studies supported comorbidity with multiple sclerosis. This case report highlights the importance of clinical skills in the evaluations of patients with regional pain syndromes.

An interesting Research Ideas paper comes from Mobile, Alabama, USA (9). The authors have found evidence to suggest that compared with fibromyalgia syndrome [FMS] patients eating a traditional western pattern diet, a non-ketogenic, low carbohydrate diet for FMS patients is associate with lower affective distress, higher energy levels, and decreased FMS symptoms in affected middle-aged females. As with other articles included in the Research Ideas section of the JMP, the authors have provided a number of suggestions regarding how further studies could be managed to challenge or to gain support for their hypotheses.

Please note the special interest columns which provide brief reviews of research reports published in other medical journals since the previous issue of the JMP. The topical categories of these reviews are “Fibromyalgia Syndrome” compiled by Michael Spaeth of Munich, Germany; “Myofascial Pain Syndrome” compiled by Jan Dommerholt, of Washington, DC, USA, and Carel Bron of Nijmegen, Netherlands; and “Other Soft Tissue Pain Syndromes” compiled by Thomas J. Romano of Martins Ferry, Ohio, USA.

As always, readers of the JMP are invited to submit original manuscripts for blinded peer review, case reports of general interest, research ideas to promote further investigation, and letters to keep us all informed. The JMP editorial office frequently receives relevant books to be evaluated by and for the benefit of our readers. Book reviewers are allowed keep the featured book after their evaluation report is completed. Readers who would be interested in being a book reviewer for the JMP, please communicate that to the editor [[email protected]].

Potential authors of contributions to the JMP should note that manuscript submissions and all communications between the authors and the JMP staff regarding those manuscripts are to be accomplished online. Point your browser to <http://mc.manuscriptcentral.com/wjmp> for more details.

A recent momentous development has occurred in the life of the JMP after 21 years of continuous publication. The International MYOPAIN Society [IMS] Board of Directors has officially adopted the JMP and will assume responsibility for policy pertaining to it. A Publications Subcommittee of the IMS Board will be making recommendations to the Board regarding personnel and a number of policies. Decisions will be made regarding a rotating JMP editorship, limited advertising in JMP pages, and perhaps some format changes. Rumor has it that IMS membership dues will vary depending on whether the member wishes to receive only an electronic version of the JMP [dues currently $150.00 annually] or both an electronic and a print version [dues currently $200.00 annually]. If you have opinions regarding any of these policies, please submit your letter to the current assistant editor [[email protected]]. If you would like to become a member of the Publications Subcommittee or become an editor of the JMP, please communicate that to the current editor [[email protected]].

The clear mandate for the IMS since its inception has been to perpetuate the international meetings [MYOPAIN] that will now be held every two years in areas where its members live and work. The next International MYOPAIN Meeting will be MYOPAIN 2015, which will be held in Sydney, Australia. This beautiful South Pacific coastal city, with over four million inhabitants, boasts the largest skyline in Australia. Among its assets are strengths in natural beauty, culture, sports, and commerce. Australia was chosen by IMS as the site for this meeting so the IMS can better serve its current and future members in Asia and the Pacific Rim.

Be aware that Regional IMS Chapters are beginning to form. The first to be officially organized was in Thailand. Please contact new IMS Board member Pradit Prateepavanich, MD, PhD, [Department of Rehabilitation Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand, EML: [email protected], [email protected]] if you wish to learn how he started it and how he established a model for perpetual leadership.

The new IMS President is James Fricton, DDS of Minneapolis Minnesota [[email protected]]. He campaigned on a platform of expanded involvement of IMS members in the many functions of their society, so if you would wish to serve a role in IMS leadership, you are welcome to contact him at his email address as listed earlier in this paragraph.

The new IMS administrator is Donna Cameron, CAE, President, Melby, Cameron & Anderson, 23607 Highway 99, suite 2C, Edmonds, WA 98026; [email protected]; http:mcamgmt.com; phone [phone], Fax [phone]. One of Donna's staff members, Amy Phillips, dedicates her time to getting IMS back on a solid foundation of responsible daily operations. The IMS Website is www.myopain.org. Members are urged to pay their dues for 2013 because dues payment makes them eligible to receive the JMP. Dues payment and new member applications can be tendered via the www.myopain.org website. The current IMS Board Chairman is Robert Gerwin, MD, [phone], [email protected]. If you have questions about anything pertaining to IMS, Donna Cameron and Amy Phillips will be able to provide the answers. Communications regarding IMS operations should be directed to Amy Phillips [[email protected]]. This team has just completed a wonderful MYOPAIN meeting in Seattle, Washington. With Ms. Cameron's experienced leadership, we can expect growth and progress on many fronts.