Cognitive Dysfunction in the Fibromyalgia Syndrome

Patients with the fibromyalgia syndrome [FMS] frequently complain about diminished cognitive function. This symptom ranges from misplacing a cell phone to forgetting why one hurridly went from one room to another; from difficulty with focus when reading a book, to frank memory deficits; from frustrating to frightening. Research study suggests that FMS patients perform poorly on several types of cognitive tasks (1), but the evidence of abnormality is more apparent in the setting of distraction or during multitasking experiments. Hill (2) voiced her frustration with FMS-related dyscognition in a peom. The following is one line from that peom: “Yesterday I may have been engaging in great conversation, today I may forget my words, tomorrow I may have forgotten we spoke.”

The causes of cognitive dysfunction in FMS can include chronic pain, medications taken to control pain, chronic loss of restorative sleep, or mood disturbances, but it cannot help to be rapidly losing brain cortical volume as was disclosed by voxel-based brain morphometry (3). That methodology documented the loss of grey matter volume in the brains of FMS patients at a rate that was about ninefold greater than that was seen with healthy normal controls (4,5).

The first research contribution in this issue of the Journal of Musculoskeletal Pain [JMP] comes from Chicago, Illinois, United States (6). The authors began by defining terms. A lexicon is a mental database that houses knowledge of words and their meanings in long-term memory. Most adults have thousands of words in the mental lexicon. Each time a person reads text, word representations are retrieved from lexicon memory. Naming a word is based upon a mental match between a printed string of letters and a memory representation from the lexicon memory. One way of testing a subject's use of this lexicon memory is called “word naming speed.” This information is important because these authors previously observed that people with FMS encounter statistically significant time delays in word naming (7).

In the current paper, the same authors proposed to evaluate a different process called “word generation tasks” that similarly depends on accessing the lexicon. In their controlled oral word association test, subjects were given 60 seconds to orally generate as many words as they could that begin with the letter “F.” In subsequent tests, the letters “A” and “S” become the first letter of the word generation challenge. The purpose of the study is to determine whether people with FMS would exhibit a comparable disadvantage in another measure that depends on the activation of the mental lexicon. The reader is encouraged to carefully review the authors' methodology, study findings, and their interpretations.

The second research contribution to this issue comes from Samsun and Ankara, Turkey (8). The authors proposed to investigate the relationship between FMS and neuropathic pain in male traumatic lower limb amputees. This is indeed a remarkably well-conducted study and should be viewed as a model of its type. These authors have pointed out an observation that probably has been missed for years by clinicians caring for patients who sustained traumatic injury to one or more lower limbs that led to amputation. The truth of their finding is well supported by their data. Forty percent of such amputees met 1990 American College of Rheumatology Research Classification criteria for FMS. Another observation by these investigators that rings true is that the FMS measures did not correlate with the neuropathic measures. These two disorders would appear to be independently comorbid. It is likely that critics of this study will dismiss it on the basis of small sample size and they will be correct in that a larger study is clearly needed. My guess is that amputees in every country of the world will continue to suffer with unrecognized comorbid FMS for years before an even comparable study is actually accomplished. This should be a call to action for some courageous physiatrist or surgeon who has access to patients with traumatic amputations. Repeat this study in another setting with larger numbers and clarify the magnitude of the need. Fibromyalgia is treatable and should not be ignored in any setting.

A study reported from Neuss and Willich–Anrath, Germany evaluated a 12-week, phase II, open-label, randomized, two-dose study of botulinum toxin-A treatment for myofascial pain syndrome [MPS] (9). One hundred sixty-three patients with MPS in the neck and shoulder girdle muscles were treated. Wisely, the authors excluded patients with comorbid FMS. Treated were the four most painful trigger points on each side of the body [eight injection sites in total] without concomitant local anesthetic. Splenius muscle injection was restricted in order to minimize the risk of neck muscle weakness. All the investigators were orthopedic physicians who had specialized in MPS treatment. Readers are directed to the manuscript for the findings in this study.

From Gyeongi-do, Gyeongsangbuk-do, and Seoul, South Korea has come a report regarding the management of lateral epicondylitis (10). The authors drew attention to the paucity of data showing benefit with any intervention for lateral epicondylitis. They then proposed to the use of ultrasonography [US] to identify the nature of the tendinous lesion of the epicondyle and to then determine whether the different classes of lesions recognized would respond differently to extracorporeal shock wave therapy. The reader will appreciate the high-quality US images that were used to stratify the lesions into three groups: as tendinosis of the common extensor tendon origin, tendinosis with calcification, and tendinosis with a tear. The four weekly extracorporeal shock wave therapy sessions were the only interventions used except for gentle stretching and isometric strengthening exercises performed by the patients themselves. The authors used two forms of outcome assessment: 1. Reimaging with US three months after treatment with comparison to the initial study, and 2. A combination of semi-objective and subjective clinical measures of pain, strength, and function administered at baseline, three months, and six months after treatment. The reader is directed to the author's report for the study outcome. Note that US was more likely to identify successful therapy in the stratified groups than were the clinical outcome measures.

Investigators from Chengdu, Sichuan, People's Republic of China reported their experience with a randomized controlled trial of acupuncture using the back-pain-acupoints for chronic low back pain (11). The study was conducted in the Chinese Level II Peacekeeping Hospital in Lebanon between May 2010 and February 2011. In traditional Chinese medicine, several acupoints which lie outside the main meridian can be treated either separately or in addition to the standard acupuncture points that lie within the meridian. The “back-pain-acupoints” are located in the back of hands in the midpoint of the wrist and the near metacarpophalangeal joints, between 2,3 metacarpals and 4,5 metacarpals. In the current study, eligible patients were randomized to treatment with back-pain-acupoints acupuncture, standard acupuncture, or usual care. Fourteen treatments were provided over a span of four weeks. Outcome measures assessing pain and function were subjective questionnaire instruments. Western medicine advocates will be surprised to learn the outcomes of this study, not only because improvement was seen but because the outcomes were different by acupuncture group.

Finally, a systematic review of acupressure for the treatment of body pain comes from Yongin, Daejeon, and Seoul, South Korea (12). Acupressure can be defined as a method of manually stimulating acupuncture points with pressure using fingers, thumbs, elbows, or a device. The purpose of this report is to critically evaluate the evidence for and against acupressure as a treatment for patients with body pain. The authors described their search for relevant medical literature, their selection criteria, their methods of data extraction, and their approach to data synthesis. Of 180 potentially relevant articles, only 4 randomized clinical trials met the inclusion criteria. This review led to some interesting conclusions and suggestions for the directions of future research in this area.

This issue of the JMP is also favored by having five interesting case reports with a lot of supportive medical knowledge. For example, a 61-year-old female developed complex regional pain syndrome type-II following sciatic nerve injury caused by intramuscular injection (13). A bilateral anterior tibial compartment syndrome in a 20-year-old military recruit was attributed to physical exertion (14). The management of pain originating from tardive dyskinesia in a 28-year-old female with cervical dystonia that developed when she was given metoclopramide and promethazine for treatment of chronic migraine headaches (15). Right-sided chest pain was the presenting complaint of a 33-year-old male with a high-thoracic [T1–T2] intradural extramedullary schwannoma (16). And finally, a 37-year-old female presented with left hip area pain and was found to have a lumbosacral plexopathy due to a 2 +  cm multilocular ganglion cyst which was compressing the sciatic nerve between the piriformis muscle and obturator internus muscle (17).

Please note the special interest columns which provide reviews of papers published in other medical journals since the previous issue of the JMP. The topics of these reviews are FMS, MPS, and other soft tissue pain syndromes.

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 to keep the featured book after the evaluation report is completed. Readers who would be interested in being a book reviewer for the JMP, please communicate to the editor. Indeed, there is a good example of such a review in this issue.

Potential authors of contributions to the JMP should note that submissions and all communications between the authors and the JMP staff are to be accomplished online. For more details, visit http://mc.manuscriptcentral.com/wjmp.

The clear mandate of the International MYOPAIN Society [IMS], for which the JMP is the official journal, is to perpetuate the international meeting that is currently held every three years, but moving soon to an every two years schedule. The next international meeting will be MYOPAIN 2013 and will be held in Seattle, Washington, United States. Two years later, the international MYOPAIN 2015 meeting will be held in Australia as the IMS responds to a plan to better serve our Asian members. The IMS website www.myopain.com will offer details as they become available.

Regional IMS Chapters are forming. The first Regional IMS Chapter to be officially organized was in Thailand. Congratulations to them.