Tag: comment

Chronic fatigue syndrome. ME Association is honest about prognosis

Comment on: Chronic fatigue syndrome: prevalence and outcome. [BMJ. 1994]

 

Editor,-I wish to challenge the assertion by S M Lawrie and A J Pelosi that the prognosis given by some myalgic encephalomyelitis associations is nihilistic. In fact, the figures currently used by the ME Association are in line with the data on chronicity and disability found in various follow up studies of patients, including those of the epidemics of the ’30s, ’40s, and ’50s.

The chronicity of myalgic encephalomyelitis was documented as long ago as 1956 when Sigurdsson and Gudmundsson reported that, of 39 patients involved in the 1948 Icelandic epidemic, only five (1/3%) had recovered completely. Thirty two years later a re-examination of 10 Icelandic patients by Hyde and Bergmann showed that the recovery rate was no more than 20% (two of the 10).

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540204/pdf/bmj00440-0055d.pdf

 

Source: Howes S. Chronic fatigue syndrome. ME Association is honest about prognosis. BMJ. 1994 May 14;308(6939):1299-300. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540204/

 

Chronic fatigue syndrome. Prevalence study overlooked

Comment on: Chronic fatigue syndrome: prevalence and outcome. [BMJ. 1994]

 

Editor,-It is sad that, in an issue in which Tony Delamothe considers biased reporting of the chronic fatigue syndrome, S M Lawrie and A J Pelosi’s editorial on the subject should be so one sided. The editorial’s title mentions the prevalence of the chronic fatigue syndrome, but the editorial fails to mention the most complete British study. In this study all general practices in two health boards were circulated with a questionnaire. There was a 91% response rate, with most respondents (71%) accepting the existence of the chronic fatigue syndrome when a strict definition was used. The doctors reported a prevalence among their patients of 1-3/1000 patients (range 0-3-2/1000 for the 10 areas surveyed). The higher prevalences were found in more populated areas.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540208/pdf/bmj00440-0055a.pdf

 

Source: Ho-Yen DO, Shanks M. Chronic fatigue syndrome. Prevalence study overlooked. BMJ. 1994 May 14;308(6939):1299. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540208/

 

Chronic fatigue syndrome. Immunological findings vary between populations

Comment on: Longitudinal study of outcome of chronic fatigue syndrome. [BMJ. 1994]

 

Editor,-We were interested in Andrew Wilson and colleagues’ paper investigating predictors of the long term outcome of the chronic fatigue syndrome in patients in Australia. We have investigated the association between immune activation and presumed cutaneous anergy in 68 Scottish patients with the syndrome (19 cases conformed to the Centers for Disease Control’s criteria, 18 cases had been diagnosed by a consultant, 28 cases had been diagnosed by a general practitioner, and three patients referred themselves) and 22 family contacts. We assessed delayed hypersensitivity responses (using Multitest antigens and tuberculin skin tests) and evaluated peripheral blood activation markers (CD8, CD38/ CD llb/HLA-DR) using flow cytometry. Patients were classified into three groups on the basis of current severity of illness and mobility.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540184/pdf/bmj00440-0055b.pdf

 

Source: Abbot NC, Spence VA, Lowe JG, Potts RC, Hassan AH, Belch JJ, Beck JS. Chronic fatigue syndrome. Immunological findings vary between populations. BMJ. 1994 May 14;308(6939):1299. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540184/

 

Chronic fatigue syndrome. Self help groups give valuable support

Editor,-Tony Delamothe’s article on myalgic encephalomyelitis was refreshingly objective,’ but this cannot be said of S M Lawrie and A J Pelosi’s editorial.2 Delamothe questions whether “medical journals keep doctors in the dark.”‘ We believe that the editorial was not even handed.

Within two weeks of publication of the article and editorial our paper on self help groups was published.3 Lawrie and Pelosi’s editorial stated, “if an illness is attributed entirely to external sources there will be little scope for self help.”2 Our results were quite different. The Moray Firth myalgic encephalomyelitis self help group has existed for the past seven years and has had one coordinator (AG). A representative sample of members was surveyed by questionnaire in 1988, 1989, and 1992; response rates were 44/53 (83%), 19/34 (56%), and 42/49 (86%) respectively. The results (table) contradict the statement in the editorial.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540186/pdf/bmj00440-0054c.pdf

 

Source: Ho-Yen DO, Grant A. Chronic fatigue syndrome. Self help groups give valuable support. BMJ. 1994 May 14;308(6939):1298-9. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540186/

 

Chronic fatigue syndrome. Preliminary report misrepresented

EDITOR,-We wish to point out an inaccuracy in Tony Delamothe’s review of ME/PVFS and the Press. Delamothe dismissively describes the preliminary report-initially published from our centre as a letter outlining an interesting observation on cerebral hypoperfusion specifically to the brain stem region of patients with myalgic encephalomyelitis-as not worthy of carrying equal weight with every other publication as no further details have been forthcoming since and it was only a 250 word letter. Firstly, further details of the findings were published as abstracts of presentations (refereed) to scientific societies in two specialist journals of nuclear medicine at the same time, giving the report the status of more than merely a letter.

You can read the rest of this letter here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540198/pdf/bmj00440-0054b.pdf

 

Source: Tannock C, Costa DC, Brostoff J. Chronic fatigue syndrome. Preliminary report misrepresented. BMJ. 1994 May 14;308(6939):1298. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540198/

 

Chronic fatigue syndrome. …and study them separately

Comment on: Chronic fatigue syndrome: prevalence and outcome. [BMJ. 1994]

 

Editor,-The struggle over myalgic encephalomyelitis and the chronic fatigue syndrome is not, as S M Lawrie and A J Pelosi suggest, whether they are physical or mental illnesses. Both sides in this debate accept that most illnesses combine organic and psychological factors. The struggle is about methodology and definition and, in particular, how different methodologies and definitions inevitably lead to different findings on the degree to which depression is a perpetuating agent in these conditions.

One side favours studying the chronic fatigue syndrome as a single entity, arguing that there is insufficient knowledge at present to differentiate between different chronic fatigue syndromes. This side prefers Sharpe et al’s broad definition of the syndrome, which includes depressive illness, anxiety disorders, and the hyperventilation syndrome.2 Unsurprisingly, studies that use these criteria find higher levels of depression ) or “psychosocial disorders”-yet another woolly term).

The other side argues that there is sufficient knowledge to distinguish specific chronic fatigue syndromes, particularly the much studied myalgic encephalomyelitis, and that it must be better science in these cases to study such syndromes in their own right. Furthermore, it argues that the study groups used in research based on broadbrush criteria will have been so aetiologically heterogeneous as to invalidate the findings. This side, which includes the national patient organisations, equates myalgic encephalomyelitis with Holmes et als tighter definition of the chronic fatigue syndrome, which focuses more on organic symptoms and, again unsurprisingly, finds lower levels of depression similar to those found in patients with cancer and multiple sclerosis-that is, the levels that might be predicted in any chronic illness.3

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540172/pdf/bmj00440-0054a.pdf

 

Source: Anderson N. Chronic fatigue syndrome. …and study them separately. BMJ. 1994 May 14;308(6939):1298. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540172/

 

Chronic fatigue syndrome. Distinguish between syndromes…

Comment in: Chronic fatigue syndrome and myalgic encephalomyelitis. [BMJ. 1994]

Comment on: Longitudinal study of outcome of chronic fatigue syndrome. [BMJ. 1994]

 

EDITOR,-I note that several people writing in the BMY are still confusing myalgic encephalomyelitis with the chronic fatigue syndrome. I wish to clarify matters. From a scientist’s point of view, the main problem is not the term chronic fatigue syndrome but the various diagnostic criteria that go with it. For instance, the strict Australian definition adopted by Wilson et al is similar to that for myalgic encephalomyelitis.2 As a result, it is reasonably certain that in this article the two names probably refer to the same disease.

The “Oxford” criteria used in Britain, however, are far broader, covering all patients whose severe, unexplained fatigue has been present for at least half of the time and for at least six months. The only other requirements are that the fatigue must have had a definite onset and that it affects both physical and mental functioning. Unlike with the strict Australian definition, no immunological criteria have to be met.2 Moreover, there do not have to be appreciable fluctuations in symptoms still a major criterion for myalgic encephalomyelitis.

In terms of prevalence, a recent study found that 17 of 686 (2-5%) attenders in general practice fulfilled the Oxford criteria for the chronic fatigue syndrome.3 When a further four patients who did not meet the criterion of a definite onset were also included the estimated prevalence increased to 3%. In contrast, the prevalence of myalgic encephalomyelitis rarely exceeds 1-5 per 1000.4

Most patients who fulfil the Oxford criteria suffer not from myalgic encephalomyelitis but from more common conditions, notably depression, anxiety states, sleep disorders, and fibromyalgia. None of these disorders occur in epidemics …

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540201/pdf/bmj00440-0053c.pdf

 

Source: Goudsmit EM. Chronic fatigue syndrome. Distinguish between syndromes… BMJ. 1994 May 14;308(6939):1297-8. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540201/

 

Chronic fatigue syndrome. Role of psychological factors overemphasised

Comment in: Chronic fatigue syndrome and myalgic encephalomyelitis. [BMJ. 1994]

Comment on: Longitudinal study of outcome of chronic fatigue syndrome. [BMJ. 1994]

 

Editor,-In concluding that psychological factors are more important than immunological ones in determining the long term outcome of myalgic encephalomyelitis or the chronic fatigue syndrome Andrew Wilson and colleagues seem overconfident of the validity of their findings. Although the use of self rated measures of outcome is necessary, the validity of the investigators’ treatment of such data is questionable. For example, the five point self rated global illness outcome was dichotomised such that an original response of “not improved at all” was recorded to “worsened”-a decision the investigators fail to justify. It is also dubious whether patients’ recall of their own premorbid psychological state is accurate, given that the average onset was 9 years before recall and the finding that memory of an event is affected by subsequent events.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540179/pdf/bmj00440-0053a.pdf

 

Source: Blatch C, Blatt T. Chronic fatigue syndrome. Role of psychological factors overemphasised. BMJ. 1994 May 14;308(6939):1297. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540179/

 

Lactate responses to exercise in chronic fatigue syndrome

Comment on: Exercise performance and fatiguability in patients with chronic fatigue syndrome. [J Neurol Neurosurg Psychiatry. 1993]

 

We were interested to read the recent account of exercise characteristics in patients with chronic fatigue syndrome by Gibson et al,’ which concluded that there was no abnormality of neuromuscular function in this condition. Patients reached the limits of exercise tolerance at lower heart rates than controls during incremental exercise to exhaustion but their peak work rates and duration of exercise did not differ significantly from the control group, although the total work done (the product of these variables) would appear to have been less; the authors had previously reported that patients with this condition showed a reduction in maximal work rate achieved in such tests.2 Despite this, plasma lactate levels at the end of exercise were as high in the patients as the controls.

In an earlier study using incremental exercise on a treadmill, Riley et a13 had found higher heart rates and increased lactate levels compared with normal controls at submaximal work rates but similarly noted no differences at peak exercise.

We have found that a proportion of patients with chronic fatigue syndrome exhibit abnormally raised lactate levels following steady state exercise at work rates below the anerobic threshold, corresponding to roughly half the peak work rates achieved in the incremental test paradigm.4 It is thus possible that lactate levels in some patients increase more rapidly than normal at lower work rates.

The cause of this apparent ‘left shift’ of the anaerobic threshold is unclear. Neither we nor Gibson et al 2 found evidence of “deconditioning” in terms of cardiac responses to exercise in our patients, and phosphorus spectroscopy of muscle in the syndrome has shown no consistent disturbance of muscle energy metabolism.5 The phenomenon may be of significance in the pathogenesis of “fatigue” in some patients, and it may be premature to conclude that neuromuscular function in all patients is normal, or that the “fatigue” is exclusively “central” in origin. Indeed, it may be presumptuous to consider chronic fatigue syndrome as a unitary entity.

You can read the rest of this comment here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1072952/pdf/jnnpsyc00035-0134b.pdf

 

Source: Lane RJ, Woodrow D, Archard LC. Lactate responses to exercise in chronic fatigue syndrome. J Neurol Neurosurg Psychiatry. 1994 May;57(5):662-3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1072952/

 

Chronic fatigue syndrome: prevalence and outcome

This week’s journal contains two papers from multidisciplinary teams that shed light on syndromes of chronic fatigue and so move us towards resolving the often bitter controversy over myalgic encephalomyelitis. A large community survey by Pawlikowska and colleagues provides estimates of the prevalence of the symptom of fatigue,’ operationally defined chronic fatigue syndrome,2 and self declared (possibly self diagnosed) chronic fatigue syndrome in young and middle aged adults in south east England (p 763).1

They found that fatigue was common, occurred as a continuum, and was highly correlated with emotional distress. Most people attributed their fatigue to social or psychological factors. While 02% of the respondents reported that they had chronic fatigue syndrome, as many as 1% of respondents satisfied several of the criteria for the syndrome. As with many illnesses, the cases were found at the severe end of the continuum of fatigue, without any sharp cut off. Associations of self reported chronic fatigue syndrome with female sex and upper social class confirm what has been found in primary care and hospital studies 34 but are less typical in community surveys.’ 6 Previous studies have consistently identified a strong association between emotional morbidity and chronic fatigue syndrome,7 but this “is inevitable given the similarities of the criteria and the measures used to define them.”‘ Interestingly, the closer cases fulfil the definition of chronic fatigue syndrome the stronger the association with emotional morbidity.

Comment in:

Chronic fatigue syndrome. Prevalence study overlooked. [BMJ. 1994]

Chronic fatigue syndrome. …and study them separately. [BMJ. 1994]

Chronic fatigue syndrome. ME Association is honest about prognosis. [BMJ. 1994]

Comment on: Professional and popular views of chronic fatigue syndrome. [BMJ. 1994]

 

Source: Lawrie SM, Pelosi AJ. Chronic fatigue syndrome: prevalence and outcome. BMJ. 1994 Mar 19;308(6931):732-3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539646/

You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539646/pdf/bmj00432-0006.pdf