سندروم خستگی مزمن: برچسب ها، معانی و عوارض

In this month's issue, we report a survey of members of the Association of British Neurologists, which asked if they viewed chronic fatigue syndrome (CFS) as a neurological condition—84% of respondents did not. This is at odds with current classification in ICD-10. We discuss the difficulties of classifying CFS and myalgic encephalopmeylitis (ME), including historical and sociological factors, the pitfalls of the physical/psychological dichotomy and why classification matters to doctors and patients.

In this month's issue, we report a survey of members of the Association of British Neurologists, which asked if they viewed chronic fatigue syndrome (CFS) as a neurological condition — 84% of respondents did not [1]. Conversely, the International Classification of Diseases, 10th Revision (ICD-10) classifies myalgic encephalomyelitis (ME) and CFS under Disorders of the Nervous System, although as our letter points out, it confusingly allows for both neurological and psychiatric coding of CFS but not ME, despite the two being synonymous in the research literature. This is important in the context of ongoing work on the next editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM) and ICD. To help interpret these findings and consider why illnesses may be physical and psychological rather than one or the other, we draw on the history of ME and CFS, focusing on the factors which influenced its classification as a neurological disorder and why classification matters (to patients and doctors). The historical background to the classification of CFS How did CFS come to be classified in the way that it is? The following factors are discussed below: the changing presentation of the disorder, the perceived primacy of medical over psychiatric diagnoses and differences between them, and socioprofessional shifts away from psychological models of illness. The social history of neurasthenia is used to further illustrate some of these factors. ME then and now Before the label and diagnostic criteria for CFS were introduced in 1988 in the UK, the condition was known as ‘ME’. This term was first used to describe an illness outbreak amongst doctors and nurses at the Royal Free Hospital in 1955. Their presentation superficially resembled that of poliomyelitis (paresis, meningism, altered reflexes and nystagmus were recorded), though there were no cerebrospinal fluid abnormalities. ‘Benign myalgic encephalomyelitis’ (ME) was therefore suggested as a diagnosis for this new illness [2]. Clearly, this episode is likely to have contributed to the subsequent view of the World Health Organisation (WHO) that it should be classified as a neurological disorder., These early outbreaks of illness, however, were almost entirely epidemics as opposed to sporadic cases that occur today, as well as featuring different signs and symptoms. In fact, the term ‘benign ME’ is inaccurate and misleading: its course is often not benign but disabling, and ‘encephalomyelitis’, a specific and often lethal neuropathological process, does not occur. The vernacular label ‘ME’ has long since abandoned the prefix ‘benign’ and is little used in the professional literature other than as the compound term ‘CFS/ME’ (e.g., a Pubmed search for myalgic encephalomyelitis in December 2010 yielded 5180 records, of which the first 50 include 21 titles mentioning CFS, including one that mentions CFS/ME, and none which mention ME independently). Neurasthenia, which shares an ICD-10 code with CFS as described above, was prominent in the 19th century and had a very similar presentation. The diagnosis fell out of fashion in the 20th century and is now rare, as least in the English-speaking world. The criteria for neurasthenia (F48.0) overlap almost exactly with those for CFS (Fig. 1 and Fig. 2): one study of 100 consecutive CFS patients found that 97 fulfilled criteria for neurasthenia [3].

British neurologists may not view CFS as a neurological condition in their conceptualisation of the term, but it is also likely that the distinction between physical and mental disorder is unhelpful in this context. Whilst the current classification may not accurately reflect professional consensus (at least in the UK), CFS/ME is in many ways an orphan illness, sitting on the border between medicine and psychiatry. To quote Robert Kendell again: Not only is the distinction between mental and physical illness ill-founded and incompatible with contemporary understanding of disease, it is also damaging to the long-term interests of patients themselves. [12] The drafters of DSM-V and ICD-11 face a challenge [33] and [35]. The current, either neurological or psychiatric, fails. The neurological coding is understandably preferable for many but not all patients, but as this paper suggests, it is not for the majority of neurologists. Evidence supports psychiatric classification with neurasthenia, but this invokes the unhelpful category of symptoms defined by their lack of validation: ‘medically unexplained’. It may also limit engagement with patients, who experience predominantly physical symptoms [36]. In practice, most patients are probably comfortable with psychologically based treatments, provided they are not labelled as ‘psychiatric’. We need a pragmatic solution which allows CFS to exist in a nosological space that is neither one thing nor the other, but promotes open communication between patients and doctors and maximises engagement in evidence-based treatment.