Best practice & research. Clinical rheumatology
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Best Pract Res Clin Rheumatol · Apr 2011
ReviewPeripheral pain mechanisms in chronic widespread pain.
Clinical symptoms of chronic widespread pain (CWP) conditions like fibromyalgia (FM), include pain, stiffness, subjective weakness, and muscle fatigue. Muscle pain in CWP is usually described as fluctuating and often associated with local or generalised tenderness (hyperalgesia and/or allodynia). This tenderness related to muscle pain depends on increased peripheral and/or central nervous system responsiveness to peripheral stimuli, which can be either noxious (hyperalgesia) or non-noxious (allodynia). For example, patients with muscle hyperalgesia will rate painful muscle stimuli higher than normal controls, whereas patients with allodynia may perceive light touch as painful, something that a 'normal' individual will never describe as painful. The pathogenesis of such peripheral and/or central nervous system changes in CWP is unclear, but peripheral soft tissue changes have been implicated. Indirect evidence from interventions that attenuate tonic peripheral nociceptive impulses in patients with CWP syndromes like FM suggest that overall FM pain is dependent on peripheral input. More importantly, allodynia and hyperalgesia can be improved or abolished by removal of peripheral impulse input. Another potential mechanism for CWP pain is central disinhibition. However, this pain mechanism also depends on tonic impulse input, even if only inadequately inhibited. Thus, a promising approach to understanding CWP is to determine whether abnormal activity of receptors in deep tissues is fundamental to the development and maintenance of this chronic pain disorder. ⋯ Most CWP patients present with focal tissue abnormalities including myofascial trigger points, ligamentous trigger points or osteoarthritis of the joints and spine. While not predictive for the development of CWP, these changes nevertheless represent important pain generators that may initiate or perpetuate chronic pain. Local chemical mediators, including lactic acid, adenosine triphosphate (ATP) and cytokines, seem to play an important role in sensitising deep tissue nociceptors of CWP patients. Thus, the combination of peripheral impulse input and increased central pain sensitivity may be responsible for widespread chronic pain disorders including FM.
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Best Pract Res Clin Rheumatol · Apr 2011
ReviewChronic widespread pain: from peripheral to central evolution.
Chronic pain can be classified as localised, regional or widespread, and its high prevalence in the general population seems to increase with age. The majority of cases present with musculoskeletal pain. ⋯ After many years of debate, it is still unclear whether CWP (central sensitisation) is an entirely explainable neurotransmitter-related process or is partially or totally due to individual cognitive experiences and evaluations. The two models (neurochemical and biopsychosocial) also affect our ability to find therapeutic answers.
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Best Pract Res Clin Rheumatol · Apr 2011
ReviewChronic widespread pain in the spectrum of rheumatological diseases.
Fibromyalgia (FM) is a rheumatic disease characterised by musculoskeletal pain, chronic diffuse tension and/or stiffness in joints and muscles, fatigue, sleep and emotional disturbances and pressure pain sensitivity in at least 11 of 18 tender points. There are currently no instrumental tests or specific diagnostic markers, and the characteristic symptoms of the disease overlap those of many other conditions classified in a different manner. FM is often associated with other diseases that act as confounding and aggravating factors, including primary Sjögren's syndrome (pSS), systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). ⋯ The presence of diffuse pain in autoimmune rheumatic diseases compromises the quality of life of the patients, although overall mortality is not increased. A misdiagnosis harms the patients and the community. Rheumatologists should be able to recognise and distinguish primary and secondary FM, and need new guidelines and instruments to avoid making mistakes.
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Best Pract Res Clin Rheumatol · Apr 2011
ReviewTrauma and work-related pain syndromes: risk factors, clinical picture, insurance and law interventions.
In the past decade, major progress has been made in our understanding of fibromyalgia syndrome (FMS). Various triggers have been implicated as contributing to symptom development in FMS when genetically susceptible individuals are challenged. A substantial amount of data points towards the association between trauma and chronic widespread pain/fibromyalgia syndrome (CWP/FMS). ⋯ Furthermore, several persistent local pain conditions may progress to CWP/FMS. These conditions may share a common pathogenic mechanism namely, central sensitisation. Physical trauma and emotional trauma co-exist in many traumatic events and may interact in the pathogenesis of CWP/FMS.
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Best Pract Res Clin Rheumatol · Apr 2011
Future perspectives in generalised musculoskeletal pain syndromes.
This article describes contemporary controversies regarding two categories of soft-tissue pain (STP)--chronic widespread pain and fibromyalgia syndrome. The tone is more editorial than review didactic. It draws upon history to explain current trends that project possible future implications. ⋯ The populations identified by the two criteria are similar but not identical. Misuse of the new criteria could expand fibromyalgia from 2 to 10% of the general population. Avoidance of the term 'fibromyalgia' could return it to the obscurity from whence it came, leaving a much larger problem in its stead.