Sunday, November 15, 2009

Chronic fatigue syndrome: neurological, psychological or both?

Chronic fatigue syndrome: neurological, psychological or both?

Peter White, Professor of Psychological Medicine, Barts and the London Medical School

A long read but well worth it


Neurology and Psychiatry SpRs Teaching Weekend

12 to 14 December 2008 St Anne's College - Oxford




09:50 Chronic fatigue syndrome: neurological, psychological or both?

Peter White, Professor of Psychological Medicine, Barts and the London
Medical School

The extract I am appending is a summary of Professor Peter Denton White's
presentation (Page 46 of PDF) in which he talks about the taxonomy of CFS
"being a mess".

During his Royal Society of Medicine "CFS" Conference presentation, in
April 2008, White had said, ominously:

"...So ICD-10 is not helpful and I would not suggest, as clinicians, you
use ICD-10 criteria. They really need sorting out; and they will be in due
course, God willing."

See unofficial transcript of part of White's RSM presentation, here, in
which he presents his thoughts on current ICD taxonomy:

Prof Peter White discouraging RSM Conference from using ICD-10:

In an April 2009 paper, co-authored by White, the authors propose a change
to current ICD-10 codings:

Psychological Medicine Preprint "Risk markers for both chronic fatigue and
irritable bowel syndromes: a prospective case-control study of primary

In the section "Implications for Further Research" the authors state that
because the paper finds that:

"These data also suggest that fatigue syndromes are heterogeneous
(Vollmer-Conna et al. 2006), and that CFS/ME and PVFS should be considered
as separate conditions, with CFS/ME having more in common with IBS than
PVFS does (Aggarwal et al. 2006). This requires revision of the ICD-10
taxonomy, which classifies PVFS with ME (WHO, 1992)"


Extract: presentation given at Neurology and Psychiatry SpRs Teaching

Chronic fatigue syndrome: neurological, psychological or both?

Peter White, Professor of Psychological Medicine, Barts and the London
Medical School

Epidemiology of fatigue and CFS

Fatigue is a common symptom in both the community and primary care. When
asked, between 10 and 20 per cent of people in the community will report
feeling abnormally tired at any one time.

At the same time, fatigue is continuously distributed within the community,
with no point of rarity.

Therefore any cut-off is arbitrary and the prevalence will vary by how the
question is asked, the symptom volunteered, and its context. Between 1.5 %
and 6.5 % of European patients will consult their general practitioner with
a primary complaint of fatigue every year, the incidence varying by age and
population. Fatigue is more commonly reported and presented to general
practitioners by women and the middle-aged, and is most closely associated
with mood disorders and reported stress. It does not seem to vary by
ethnicity in the UK, but there is an intriguing paradox in that it is
reported more commonly by those in high income countries, yet is presented
to medical care more often in low income countries.

Prolonged or chronic fatigue is significantly less common than the symptom
of fatigue and it is only in the last 10 years that consensus has emerged
about the existence of a chronic fatigue syndrome (CFS), also called
myalgic encephalomyelitis (ME). CFS is now accepted as a valid diagnosis by
medical authorities in the UK, in the United States of America, as well as
internationally. About one third of patients presenting to their doctor
with six months of fatigue will meet criteria for a chronic fatigue
syndrome. The other two thirds have fatigue secondary to another condition,
most commonly mood and primary sleep disorders. Its primary symptom is
fatigue, both physical and mental, which particularly follows exertion.
Other symptoms agreed in consensual guidelines include poor concentration
and memory, sleep disturbance, headache, sore throat, tender lymph glands,
muscle and joint pain.

There are several criterion based definitions of CFS. These definitions
were derived by consensus and have not been supported by empirical studies,
and continue to be refined. Their utility stems from providing reliable
criteria for research studies, rather than clinical use. The prevalence of
CFS is between 2.5 % and 0.4 % depending on the definition used and whether
comorbid mood disorders are excluded (that is mood disorders that are not
thought to be the primary diagnoses). It is most common in women, the
middle-aged, and ethnic minorities (unlike fatigue) - at least in English
speaking countries.

The diagnosis and classification of CFS

The clinical taxonomy for CFS is a mess. The ICD-10 classification defines
CFS within both the neurology chapter and mental health chapters. Myalgic
encephalomyelitis, the alternative name for CFS, is classified as a
neurological disease (G93.3) (a.k.a. post-viral CFS), whereas neurasthenia
(a.k.a. CFS not otherwise specified) is classified within mental health

[Ed: Note that White does not mention, here, that Chronic fatigue syndrome
is listed in ICD-10: Volume 3, The Alphabetical Index* at G93.3, the same
coding as for Benign myalgic encephalomyelitis, and for Postviral fatigue
syndrome (ICD-10: Volume 1: The Tabular List).]

No comments: