What is CFS/ME and what causes it?
Chronic Fatigue Syndrome/Myalgic Encephalomyelitis is primarily a neurological illness (brain disorder) with variable involvement of other bodily systems including muscles, liver, heart, endocrine or lymphatic glands.
Clinically it is a fluctuating disorder of energy control (fatigue). Symptoms commonly include prolonged recovery from any activity.
Pain is common, especially in muscles and joints. Persistent dizziness and clumsiness may be disabling. Disturbances of brain function occur (eg memory, concentration, sequencing of words and numbers, abnormalities of sensation, balance, vision, hearing, sleep rhythm, temperature, appetite, hormone production and response to stress).
Other symptoms may include irritable bowel, emotional lability and mood fluctuations.
CFS/ME can and does affect all age ranges, from the very young to the elderly. The peak age tends to be between 20 and 40 and the incidence seems higher amongst those in stressful occupations. It is known that female sufferers outnumber males by three to one.
It typically occurs in a vulnerable individual, often at a time of stress, as a consequence of a viral or recurrent viral infection. These include: polio, coxsackie and echo viruses. Secondary infection with another virus such as glandular fever, influenza, mumps, chickenpox and severe stress or excessive exercise may increase the severity at onset.
The consensus view is that the average duration of the illness is four years and up to 20% of sufferers fail to return to previous levels of functioning. The severity of this disorder varies, although some patients are disabled for years.
The National ME Centre was set up originally to see fatigue syndromes of all types. It recognises that chronic fatigue syndrome is an umbrella diagnosis and that the illness content varies from patient to patient. It includes the disorder designated myalgic encephalomyelitis (ME). It recognises therefore the need to advise and recommend very individualised treatment packages. The centre accepts the criteria as described by Fukuda et al (1994) as being suitable for the diagnosis, namely "substantial fatigue newly acquired of greater than six months duration which may be associated with cognitive or neuropsychiatric symptoms". It requires four other symptoms from a list of eight which includes recurrent sore throat, cervical lymphadenopathy (swollen glands), myalgia (muscle pain), headache, impaired memory, multi-joint pain, unrefreshing sleep, post exertional malaise. It excludes medical conditions that can produce fatigue and psychiatric disturbances such as melancholic depression, substance abuse, manic depressive disorders, psychosis and eating disorders.
The definition recognises Idiopathic Fatigue Syndrome - for those who do not fulfil the criteria of chronic fatigue syndrome. These include those with a life long history of fatigue symptoms (Fukuda K, Strauss S, Hickie I, Sharpe M, Dobbins J, Komaroff: the Chronic Fatigue Syndrome: a Comprehensive approach to its definition and Study: Ann. Int. Med 1994; 121; 957-959.
Our concept is that chronic fatigue syndrome (ME) represents a profound disturbance of functioning of the nervous system (brain) and its connections with the immune system and endocrine system (hormone).
Canadian Consensus Document (Bruce M. Carruthers, Majorie I. van de Sande) is recommended and endorsed by Professor L J Findley TD KLJ MD FRCP FACP Clinical Director, The National ME Centre and Dr. Terry Mitchell MA MD FRCPath retired Honorary Consultant The National ME Centre as follows:
"Myalgic Encephalomyelitis/Chronic Fatigue Syndrome is a common illness. Its impact on many sufferers can be profound with intrusive fatigue and multiple symptoms. The secondary burden of the condition is common to all chronic illnesses and includes impoverishment and a significant impact on personal and family life.
We recommend and endorse the Canadian Consensus Document. We regard it as an extremely important contribution to understanding the physical basis of the condition. Future research should be directed to further defining the pathophysiology of the condition together with identifying the sub groups, which undoubtedly exist, with the illness complex currently termed ME/CFS."