What is Myalgic Encephalomyelitis?

Dr Paul Lamden discusses what Myalgic Encephalomyelitis is, including symptoms, diagnosis and treatments  

Recent events with COVID-19 have ignited renewed interest in the range of disorders associated with diverse symptoms, many of which occur apparently as a longer-term response to infections. Myalgic encephalomyelitis (ME) was first recognised over 65 years ago, but many aspects of it remain speculative. The variety of names ascribed to it is a clue to the uncertainty of its aetiology or, indeed, whether all cases have the same cause.

The term ‘myalgic encephalitis’ was first used in the 1950s to reflect the combination of muscle and central nervous system symptoms. Other names subsequently proposed have included chronic fatigue syndrome which, though popular, was felt by many to be dismissive and suggesting someone who is ‘tired all the time’, rather than reflecting the range of symptoms experienced by many sufferers. Other names include post-viral fatigue syndrome for those patients in whom the lingering symptoms are clearly related to a perpetuation of an initial viral illness, but again the disorder may be much more than just persisting fatigue and, most recently, chronic fatigue immune dysfunction syndrome.

The condition more commonly affects women than men (ratio  2:1) and can affect any age, although it seems to occur more frequently in the 20-to-45 age group. When occurring in older people, the symptom profile is often more severe. Features include lack of stamina and fatigue, insomnia, nausea, gastro-intestinal symptoms, dizziness confusion and memory loss, abnormal cardiac rhythms, recurrent viral symptoms and an overarching feeling of exhaustion and debility.  

For the average sufferer, it is commonly the case that no two days are the same, and symptoms may be exacerbated or may abate quite quickly. The variation in the severity and nature of symptoms adds to the difficulty of managing the condition.

Causes

The cause of ME/CFS is not known, although there are a range of opinions. Given the variable nature of the presenting symptoms it is quite possible that the syndrome may be the result of different causes in different people. The most popularly suspected causes are:

1. Viral infections, which may be non-specific or follow an acute episode of glandular fever. For others, typical ME symptoms may persist after COVID-19 or other influenza-type illnesses.
2. Bacterial infections.
3. Associated with an accident or operation.
4. Hormonal disturbances have been implicated, in some cases associated with pelvic pain and disturbances in menstruation.
5. Reduced immunity as a result of diseases which compromise immune function, or those taking drugs which suppress immunity (e.g., cancer drugs or steroids).
6. Family. There are higher rates with first degree relatives, and identical female twins may be up to 40% more likely to both have the disorder.
7. Stress and anxiety have also been implicated but it may be difficult to establish whether the symptoms are the cause of, or the result of, the development of the disorder. There is no doubt that persistent tiredness, the inability to carry out daily activities and the disruption of the normal lifestyle can severely affect mental wellbeing, leading to depression.
8. Stress and anxiety have also been implicated but it may be difficult to establish whether the symptoms are the cause of, or the result of, the development of the disorder.

The prevalence has been estimated to be between two and four per thousand of the population. This would suggest that up to about a quarter of a million people may have the disorder and an average practice of 10,000 patients may have as many as forty sufferers. The number of new cases annually may be about 20,000 in the United Kingdom.

Diagnosis and treatment

The diagnosis of ME/CFS is by the exclusion of other causes for the symptoms. The National Institute for Health and Care Excellence suggests the diagnosis should be considered if the symptoms have a recognised starting point, they persist, are aggravated by exercise, associated with fatigue and exhaustion and other causes have been excluded. The individual will also have one or several other symptoms.

Treatment of the condition depends on the severity of the symptoms and the nature of any co-existing illnesses. It may involve graded exercise with goal-setting to help restore normal activity, although some sufferers are virtually immobilised. Medication may also help and pain killers, muscle relaxants, anti-depressants and other symptom-specific medication may make the individual more comfortable. Cognitive behavioural therapy may be useful in helping the person come to terms with the constraints of the illness and helping to control and overcome symptoms. These measures may be combined with lifestyle advice.

Most people with CFS may be classified into one of four groups. Some sufferers return to normal health after a variable and, sometimes, considerable period of time. The majority have a fluctuating course with exacerbations and remissions, often precipitated by infections, operations or emotional disturbances such as stress. A significant number will have severe and indefinite symptoms which require considerable support, and a small number will show deterioration of variable degree. As with the cause, the reasons for such variable outcomes remain unclear.