The diagnosis of fibromyalgia syndrome: UK clinical guidelines – What are the implications from a medicolegal perspective?

Some initial thoughts and musings for expert witnesses and lawyers.

Introduction:

Given that fibromyalgia/fibromyalgia syndrome (FMS), perhaps the most well-known chronic widespread pain condition, is such a complex and ultimately controversial diagnosis, clinical guidance from such an important statutory body as the Royal College of Physicians (RCP) should, as a concept, be a most welcome and long overdue development for the many clinicians across multiple medical specialities to whom these cases commonly present.

Like the RCP guidelines on complex regional pain syndrome (CRPS), first published in 2012 and updated in 2018, it seems inevitable that the use of the RCP guidelines for fibromyalgia will extend into the medicolegal setting. Given that the authors, notably without any preamble or discussion, adopt the premise that fibromyalgia is a biomedical/physical condition, lawyers acting for claimants might well be the first to pop the champagne corks. However, as we all well know, the devil is in the detail, so this article will attempt to identify the key issues and the ways in which this new document might be used within medicolegal practice in years to come.

The majority of pleaded fibromyalgia cases within the medicolegal setting are likely to be claimants with complex chronic pain conditions, so it will be important for lawyers and expert witnesses to note that the RCP guidelines are “especially for patient-facing clinicians who are specialists in areas?other than complex pain conditions” and that the speciality of Pain Medicine was not officially represented on the multi-professional Guideline Development Group (GDG).

RCP Guidance - What fibromyalgia is, and what fibromyalgia is not:

The authors state, “Fibromyalgia syndrome (FMS) is a condition characterised by persistent and widespread pain that is associated with intrusive fatigue, sleep disturbance, impaired cognitive and physical function and psychological distress”.

The reader is advised that fibromyalgia is specifically?not:

• A condition caused by a tendency to experience psychological distress as pain (somatisation).
• A reflection of poor coping.
• A maladaptive reaction to trauma or distress.
• A condition that is “all in the head”.

The clear message presented by the authors being that fibromyalgia is a physical/organic condition and not one that arises out of psychiatric/psychological/emotional factors. Within a medicolegal setting, expert witnesses are, of course, required by the courts to set out a range of opinion, and an important range of opinion is likely to remain, particularly amongst psychiatrists, but also amongst rheumatologists and chronic pain physicians, on these matters.

RCP Guidance - The biological basis of fibromyalgia:

The authors state, “the precise cause of FMS remains?unknown”; “the central issue is?proposed?to be abnormal pain processing within the nervous system”; “pain processing is?complex?and multiple components of the nervous system are involved”; “the exact mechanisms are?unclear” and “the peripheral nervous system?may be?affected in FMS”.

Overall, it is evident that a primary biomedical/physical basis for fibromyalgia has not, or at least not yet, been established. Whilst the authors recognise the potential for immunological elements in fibromyalgia (where research is ongoing), some of the strongest evidence points to the role of the central nervous system, and consequently, primary physical/biological processes and primary psychiatric/psychological processes become much more difficult to disentangle.

The authors refer to “central sensitisation”, which is certainly a concept that has gained a lot of traction particularly over the last decade or so although it is important to recognise that current medical knowledge does not allow for the hypothesis to be confirmed or indeed falsified in clinical practice. Central sensitisation emphasises the role of neurobiology at the expense of sociocultural and psychological contributions and encourages clinicians to concentrate on the neurobiological mechanisms rather than the underlying causes.

Few would argue that depression is a psychiatric/psychological condition (and notably one that is recognised to have close correlates with chronic widespread pain) but depression is also known to be associated with important neurobiological changes such as depleted neurotransmitters within the central nervous system. It does seem likely that what is “biological” or “physical” and what is “psychiatric” or “psychological” will inevitably become increasingly blurred as science advances and our understanding of how the human brain works evolves.

It is of course well recognised that claimants (and their lawyers) and patients alike prefer a physical diagnosis for their somatic complaints to a psychiatric/psychological diagnosis, and a 'physical' diagnosis of fibromyalgia is always likely to be preferred to any psychiatric diagnosis such as Somatic Symptom Disorder.

The authors do acknowledge the widely adopted biopsychosocial model for chronic pain, although the important psychological/psychosocial factors are considered to be secondary to painful fibromyalgia and not primary elements of a complex clinical presentation with chronic widespread pain and other somatic symptoms that lack a demonstrable pathophysiological basis. Just how painful and disabling the fibromyalgia would be in the absence of the secondary psychological and social factors is perhaps an important topic that has yet to be discussed.

Currently, fibromyalgia remains within the Chronic Primary Pain (CPP) category of ICD-11 where there is considerable emphasis on the importance of “emotional distress” and “functional disability”. In ICD-11, CPP is recognised to be a multifactorial condition with biological, psychological and social factors contributing to the pain syndrome and the diagnosis to be appropriate independently of identified biological or psychological contributors “unless another diagnosis would better account for the presenting symptoms”. Another diagnosis might of course be a physical diagnosis, but there is clear scope for it to be a psychiatric diagnosis, such as Somatic Symptom Disorder (with predominant pain).

The authors of the RCP clinical guidelines, do notably recognise “good evidence” that experiencing a stressful life-course or life events such as major physical or psychological trauma increases the risk of developing fibromyalgia, although perhaps not insignificantly in the medicolegal context, any proposed role of medically minor physical trauma, or indeed minor psychological trauma, in causing fibromyalgia, is not identified as evidence based.

Ultimately, it seems likely that the authors’ emphasis on fibromyalgia not being a condition caused by a tendency to experience psychological distress as pain (somatisation) will remain subject to an important range of expert opinion. Psychiatrists recognise that a considerable proportion of individuals diagnosed with fibromyalgia have high levels of distressing somatic and psychiatric symptoms and many of these individuals have abnormal health beliefs and health anxiety as the key drivers in their pain complaints and perception. The psychiatric diagnosis Somatic Symptom Disorder is known to share many common features with fibromyalgia and ultimately, many patients diagnosed with fibromyalgia will also fulfil the key DSM5 criteria for a diagnosis of Somatic Symptom Disorder.

Despite the apparent considerable overlap, the RCP guidance seeks to separate psychiatric diagnoses for presentations of this nature from a physicians’ diagnosis of fibromyalgia. The guidance simply acknowledges that psychiatric conditions are “sometimes considered as possible differentials by patients or clinicians”.

There is a general lack of recognition of the importance of pre-existing psychological vulnerability factors in the guidance. Anxiety and depression do represent important risk factors for presentations of this nature. Childhood adversity is an important risk factor for presentations diagnosed as fibromyalgia, and notably also for somatoform disorders such Somatic Symptom Disorder, in adult life. It is unfortunate that none of this is covered in the RCP guidance.

The authors acknowledge that fibromyalgia can run in families and that it is likely that variants of people’s genetic information increase the risk of developing the condition. High quality twin studies published in peer reviewed journals have certainly shown heritability factors to be important. These twin studies also identify important psycho-affective correlates for chronic widespread pain, with particularly strong correlates with depression. A past history of depression is an important risk factor for a presentation with chronic widespread pain conditions.

The authors also do not discuss the concept of ‘polysymptomatic distress’ (PSD), which is well described in literature published by leading rheumatologists. Polysymptomatic distress recognises the “continuum concept” of fibromyalgia, as well as the fact that many of these individuals have emotional distress and multiple somatic complaints. Literature published on the subject of polysymptomatic distress also concludes that fibromyalgia represents the extreme end of a spectrum of polysymptomatic distress.

In personal injury litigation where a claimant pleads a chronic widespread pain condition such as fibromyalgia and significant associated physical disability, psychiatric expert opinion is frequently important and almost universally sought by the defendant if not by both legal parties involved in the claim. So, it will be important for lawyers and expert witnesses to note that the speciality of Psychiatry was not represented on the RCP Guideline Development Group (GDG).

The absence of any psychiatric representation on the GDG might certainly be seen as surprising given the high rates of mental illness that have been identified in patients with a fibromyalgia diagnosis and the prevalence of established psychiatric formulations for clinical presentations of this nature. However, the ‘How to diagnose’ section of the ‘Information leaflet for clinicians’ states that for fibromyalgia to be diagnosed, “Symptoms cannot be explained by any other conditions”, which perhaps leaves the door open for a psychiatric diagnosis to prevail in these complex chronic widespread pain cases, in a similar way to the fourth diagnostic criterion for CRPS, “There is no other diagnosis that better explains the signs and symptoms”.

In conclusion

Ultimately, it seems highly likely that the longstanding medicolegal debate as to what is biological/physical and what is psychiatric/psychological in these complex chronic pain cases will continue for some time to come!

As is almost universally the case in medicolegal presentations with chronic pain that is more severe, intrusive and disabling than the demonstrated physical pathology would predict, the non-physical elements, such as genuine psychiatric/psychological/emotional factors and other non-medical factors such as inconsistency and exaggeration, will remain of key importance. Until such time when important physical factors are firmly established and effective biological treatments become available, the prevailing non-physical factors will, together with physical rehabilitation focusing on functional restoration, remain a key target for therapeutic intervention.

Article written by: Dr Jon Valentine MB ChB FRCA FFPMRCA FRCP, Consultant in Pain Medicine and Managing Director at Pain Expert Ltd

Dr Jon Valentine, is one of the UK’s leading expert witnesses specialising in chronic pain. He is Managing Director of Pain Expert (a ‘virtual’ medicolegal chambers). He established Pain Expert in 2012 to provide expert witnesses with the comprehensive range of services required to build and maintain a successful medicolegal practice, and also to provide those lawyers seeking to instruct Pain Management specialists in personal injury and medical negligence cases with a reliable source of suitably qualified and experienced Pain Management experts. For more information visit?Pain Expert.

Co-author: Dr Christopher Bass BA MB BChir MA MD?FRCPsych, Consultant in Liaison Psychiatry (Retired).