Fibromyalgia was officially recognised in 1990 when a Multicenter Criteria Committee of the American College of Rheumatology recommended the term be used as a means of classifying patients presenting with chronic widespread pain and tenderness [1].
Pain was considered to be “widespread” when it was experienced in all four quadrants of the body (i.e. on both the left and right sides and above and below the waist).
Tenderness was assessed over 18 specifically chosen tender points. When patients with widespread pain were judged by their clinician to be hypersensitive at 11 or more of these points, the diagnosis of Fibromyalgia could be applied.
Some 20 years later, the criteria for diagnosis were broadened by the introduction of a symptom severity scale score to replace the tender point count. Widespread pain remained a diagnostic criterion [2].
The clinical problem of “RSI” (repetitive strain injury)
In Australia the term “RSI” (repetitive strain injury) came to be broadly applied to all conditions characterised by neck and/or upper limb pain presenting in an occupational context.
“RSI” embraced localised conditions, such as carpal tunnel syndrome, dorsal wrist tenosynovitis, lateral epicondylitis and rotator cuff “tendonitis”, along with poorly understood conditions characterised by diffuse pain felt in the neck, pectoral girdle and arms, often accompanied by positive sensory symptoms, cramp, loss of muscle strength, and vasomotor abnormalities [3,4].
A vigorous medical debate had taken place during the 1980s over the categorization of the sub-group of patients with diffuse pain. On the one side were those who espoused the theory of muscle overuse injury, whilst on the other side were those who argued that those with these conditions were reflecting psychological distress that was manifest as somatic symptoms [5].
However, the homogeneity of presentation of these patients implied not only a common pathophysiology but also one that could be attributed to dysfunction of the nociceptive system itself, consistent with what was then the current definition of “neuropathic” pain. This explanatory model was proposed on the basis of careful clinical observation integrated with current knowledge of mechanisms of nociception [3,6].
Fibromyalgia becomes a regional condition
“The 1980s brought the dreaded “RSI” (repetition strain injury) with interaction between Fibromyalgia Syndrome and the medico-legal system [7].
One of the key proponents in Australia of fibromyalgia, Geoffrey Littlejohn, was keen to extend the construct to subsume these syndromes of less diffuse pain, which were then being called “RSI”. He and his colleagues argued that these conditions were in fact a “subset” of fibromyalgia.
They conjectured: Mechanisms similar to those in generalised fibromyalgia are likely to operate, although to a lesser extent, in patients with primary chronic localised pain or localized fibromyalgia [8].
This reconceptualisation of “primary chronic localised pain” as “regional fibromyalgia” presumed the validity of a parent syndrome.
However this exercise was an example of the logical fallacy known as “begging the question,” and was particularly problematic when the diagnostic credibility of both conditions was being hotly contested.
In the absence of knowledge or theory regarding the pathogenesis of fibromyalgia, these authors nonetheless took a bold step to explain the pathogenesis of local pain that became regional.
To accomplish this, Littlejohn invented the concept of “simple injury to the muscle-tendon unit” but neglected to provide any pathological evidence to support the existence of such an entity:
The majority of patients with the “RSI problem” have a chronic pain syndrome, which, although it may be triggered by a simple injury to the muscle-tendon unit, is not due to persisting tissue damage of injury. Extensive investigations seeking out tissue damage will only show age-related changes which do not explain the diffuse symptoms” [9].
Thus, in summary, “RSI” is seen as a complex pathophysiological pain problem where clinical features may be approached using the paradigm of localised fibromyalgia syndrome” [9].
This step needs to be dissected in order to understand the transmutation of fibromyalgia. A diffuse pain syndrome of unknown pathogenesis was invoked to explain “regional” or “local” apparently similar conditions of allegedly known pathogenesis. There was never a “paradigm” of “localized fibromyalgia syndrome”; it was never proposed that (diffuse) fibromyalgia syndrome could be “triggered by a simple injury to the muscle-tendon unit”.
These assertions were and are entirely conjectural.
Medico-legal implications
Littlejohn’s next contribution was to downplay the nexus between “localised fibromyalgia syndrome” and work-related factors. This strategy was to have important implications for those with the condition who might be seeking workers’ compensation payments, particularly so in New Zealand [10].
Fibromyalgia can also occur as a syndrome of localised or regionalized pain and a low pain threshold. This situation is common after otherwise short-lived “soft tissue” injuries involving spinal areas, particularly in the context of compensation” [11].
Littlejohn defined “low pain threshold” in terms of sensitivity at the arbitrarily chosen “tender points” in fibromyalgia, which he claimed to be “characteristic regions used clinically to define pain threshold” – a circular argument – and that “sensitivity at these points is increased in pain-free subjects, but to an even greater extent in patients with fibromyalgia syndrome.”
But defining “sensitivity” in terms of the stimulus being applied is highly subjective and influenced by contextual effects and, as Littlejohn noted, this diagnostic criterion (along with widespread pain) has not been validated for medicolegal or disability purposes.
Furthermore, he did not produce evidence to support his claim that “low pain thresholds were common” after short-lived “soft tissue injuries” involving spinal areas. Yet again, conjecture was being passed off as established knowledge.
Littlejohn [12] then raised the spectre of psychogenesis:
“The regional features seem to relate to local biomechanical factors around the spine, either postural or secondary to simple strains. When central sensitisation occurs it is likely that central neurophysiological factors, including psychological influences, allow for the amplification of otherwise subclinical spinal reflexes. These in turn cause regional pain, tenderness, muscle tightness and dermatographia.
The concept of “otherwise subclinical spinal reflexes” is yet another of Littlejohn’s conjectures. Furthermore, he failed to explain the mechanism(s) by which “central neurophysiological factors” could be responsible not only for their amplification but also for the various clinical phenomena.
Finally, Littlejohn [13] announced “operational” criteria for a diagnosis of localised fibromyalgia. But in fact they were Littlejohn’s own non-validated criteria [12]:
“Regional pain syndromes are also referred to as localised fibromyalgia. Although no validated classification or diagnostic criteria exist for these condition, operational or clinically useful criteria have been proposed: regional pain and regional lowering of pain threshold, and the presence of sleep disturbance, fatigue, muscular stiffness and emotional distress in the absence of a primary nociceptive cause for pain.”
“Using this model, regional pain syndrome appears to be on a spectrum between the simple self-limited aches and pains of everyday life and persistent musculoskeletal syndromes such as fibromyalgia.”
Littlejohn’s pronouncements are tautological: if regional pain syndrome is in fact localized fibromyalgia syndrome, then it follows that fibromyalgia is generalised regional pain syndrome.
What was achieved?
Where has this transmutation of fibromyalgia taken us? Has any light been shed on diffuse or regional pain syndromes?
Littlejohn attempted to fill gaps in our understanding of “RSI” by interpolating his personal views on Fibromyalgia into the debate. However all he achieved was to introduce circular arguments based on conjecture. How did the guardians of the literature allow that to happen?
John Quintner (Physician in pain medicine and rheumatology)
Milton Cohen (Specialist pain medicine physician and rheumatologist)
References:
1. Wolfe F, Smythe HA, Yunus MB, Bennett RM, Bombadier C, Goldenberg DL, et al. The American College of Rheumatology 1990 criteria for the classification of fibromyalgia. Arth Rheum 1990; 33: 160-172.
2. Wolfe F, Clauw DJ, Fitzcharles MA, Goldenberg DL, Katz RS, Mease P, et al. The American College of Rheumatology preliminary diagnostic criteria fibromyalgia and measurement of symptom severity. Arthritis Care Res 2010; 62-600-610.
4. Cohen ML, Arroyo JF, Champion GD. The relevance of concepts of hyperalgesia to “RSI”. In: Bammer G, ed. Working Paper No. 31. Canberra: Australian National University, 1992.
5. Quintner JL. The Australian RSI debate: stereotyping and medicine. Disabil Rehab 1995; 17(5): 256-262.
7. Reilly P, Littlejohn GO. Fibrositis/fibromyalgia syndrome: the key to the puzzle of chronic pain. Med J Aust 1990; 226-228.
8. Granges G, Littlejohn GO. Pressure pain thresholds in pain free subjects, in patients with chronic regional pain syndrome, and in fibromyalgia syndrome. Arthritis Rheum 1993; 36: 642-646.
9. Littlejohn GO. Key issues in repetitive strain injury. J Musculoskel Pain 1995; 3(2): 25-33.
10. Rankin DB. Viewpoint: the fibromyalgia syndrome: a consensus report. NZ Med J 1999; 112: 18-19.
11. Littlejohn GO. Med J Aust 1996; 165: 387-391.
12. Littlejohn GO. Clinical update on other pain syndromes. J Musculoskeletal Pain 1996: 163-179.
13. Littlejohn GO. Fibromyalgia syndrome and disability: the neurogenic model. Med J Aust 1998; 168(8): 398-401.
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