Personality Subgroups in the Fibromyalgia Syndrome

It has become increasingly clear that there are subgroups of fibromyalgia syndrome [FMS] patients ([1], [2], [3], [4]). These can differ with respect to comorbidities ([5]), with respect to genetic predisposition ([6], [7], [8], [9]), with respect to response to treatment modalities ([10], [11], [12], [13]), and now we learn from our lead article that the same applies to personality traits as well.

The lead article for this issue of the Journal of Musculoskeletal Pain [JMP] comes from Linköping, Sweden but involves three other sites in Sweden ([14]). Their objectives were to determine whether there are temperament and character differences between FMS and healthy normal controls [HNC], and whether these measures will identify subgroups of FMS patients. The current study ([15]) was conducted with 191 ambulatory female FMS outpatients using the Swedish version of the Temperament and Character Inventory [TCI] ([15]). One of the authors had conducted a previous study ([16]) that addressed the first question using the same instrument and 38 FMS patients matched to HNC, but she concluded that the study needed repetition with a larger sample size. The authors considered the temperament variables to represent heritable traits that program automatic perceptions or responses, while the character traits were considered to be self-concepts acquired through a variety of environmental exposures. The reader is encouraged to review the authors' descriptions of these concepts because they represent a new vocabulary that must be understood to put the findings of the study into context.

With respect to the authors' objective questions, the results of the study say “yes” and “yes” but then what does that mean? The authors offer explanations, insights, and limitations. Now, following a logical sequence, we must wonder whether the contrast of FMS with HNC will be similar when compared with a disease control group also suffering from chronic pain, or even just a chronic illness. There is data available from other studies with this instrument comparing pain patients with HNC ([17], [18], [19]), so it may be possible to answer this question without enrolling new patients. The authors tangentially address this issue in their discussion, but to do it right would require sharing of data between the different studies. It will also be instructive to see analyses from administration of this questionnaire instrument to FMS patients and controls from other ethnic groups, to explore familial patterning, and to see stratification of the subgroups on the basis of symptom severity with respect to a variety of clinical domains including pain, insomnia, depression, anxiety, age, and dyscognition.

From São Paulo, Brazil ([20]) comes a report of a case-controlled study exploring the role of tobacco smoking in FMS. One can't help suspecting that smoking is a factor when seeing a habituated patient with so much pain, insomnia, and distress. The authors' findings may come as a surprise.

From Granada, Spain comes a report ([21]) regarding pressure-pain thresholds in patients with FMS, rheumatoid arthritis [RA], and systemic lupus erythematosus [SLE] compared with HNC. The authors used an electronic dolorimeter and averaged two measurements at each of 24 body sites in each session. Test-retest reliability was assessed with a total of three sessions with each of 65 female volunteers comprising 15–18 subjects in each diagnosis group. Differences were found, so the authors extensively review the relevant literature and discuss their findings.

From Madrid, Spain ([22]) comes a study of the relationship of trigger points [TrPs] to nummular [NH] and chronic tension-type headaches [CTTH]. The authors examined the three muscles of the head for a hyperirritable spot within a taut band, a local twitch response, and referred pain with palpation in HNC contrasted with headache patients. The findings support the distinction of NH as a peripheral primary headache from CTTH as a central primary headache.

From İstanbul, Turkey ([23]) is reported a study of the effect of high power pain threshold ultrasound therapy on the spontaneous electrical activity [SEA] of TrPs and local twitch responses. The question was whether the “ultrasound plus stretching” would be more effective than “dry needling plus stretching” in reducing perceived head pain, improving the range of motion, and reducing the SEA at the TrP in patients with a symptomatic upper trapezius TrP. The sample comprised 10 randomly allocated patients in each treatment group. The findings were reasonably clear despite the small sample size. They will disappoint some readers but not others.

From Ankara and İzmir, Turkey ([24]) comes a study of health-related quality of life among patients with myofascial pain syndrome [MPS]. The authors administered the Nottingham Health Profile to 37 patients with MPS and 40 HNC. The findings clearly distinguished to two diagnosis groups and correlational analysis identified a possible relationship between two variables.

In this issue of JMP we again highlight two synopsis papers from the conference on FMS held in Veldhoven, The Netherlands, in conjunction with the 20th anniversary of the Dutch Fibromyalgia Association on May 12–13, 2006. The overall theme was “Multidisciplinary Treatment of the Fibromyalgia Syndrome.” The speakers were Robert Bennett, Rinie Geenen Karl Henriksson, Kaisa Mannerkorpi, Boudewijn Van Houdenhove, Johan W.S. Vlaeyen, and Muhammad Yunus. The manuscripts resulting from most of those lectures have been peer reviewed and will be included as reviews in the sequential issues of JMP. The first paper in this issue [the third in the series] is by Geenen et al. ([25]), in which she outlines a psychoneuroendocrine perspective on the management of FMS. The second paper is by Henriksson ([26]), in which he describes the transition from clinical and basic science to clinical practice as it applies to FMS.

Readers of JMP are again provided three columns with summaries of the important new developments in soft tissue pain published in other medical journals since the prior issue of JMP. These features not only provide a comprehensive review of what is new in the field, but also allow readers to benefit from illuminating commentary by experts from two continents.

Several book titles are highlighted for the reader's information.

As always, readers of 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. If you would be interested in being a book reviewer for the JMP, please communicate that to the Editor.

The clear mandate of the International Myopain Society [IMS] is to perpetuate the international meeting that is currently held every three years. The most recent International Myopain meeting was held in Washington, DC, USA on August 19–23, 2007. The manuscripts from the invited speakers were published in JMP, volume 16 [1, 2] as a combined special symposium issue. Those who were unable to attend the meeting and wish to jog their memory regarding some aspects of a given presentation would need to see that issue. The IMS staff members are already working on the myriads of details in preparation for the 2010 meeting to be held in Toledo, Spain. The IMS website at http://www.myopain.com will offer details as they become available.