Tuesday 7th February 2017
Myalgic encephalopathy (ME) – a complex disorder not fully understood and surrounded by controversy
The terms ME and chronic fatigue syndrome (CFS) are often interchanged or combined (ME/CFS), creating a broad disease category. However, although some of their symptoms overlap, they are two distinct disease entities, with CFS characterised by chronic fatigue and ME characterised by distinctive muscular and neurological symptoms.
A key symptom of ME is post-exertional malaise, usually 24 hours after physical and cognitive exertion, which presents as marked fatigue and weakness, sickness, cognitive dysfunction and symptom flare-up. Affected individuals describe experiencing ‘brain fog’ and pain symptoms, including chronic headaches and myalgia. For many, ME drastically reduces their overall daily functioning levels and poses a significant burden to families and caretakers. Around 25% of sufferers have severe ME and are house or bed bound. They are unable to properly care for themselves, and are often extremely sensitive to light and noise.
There is much that is unknown about ME. The lack of understanding and confusion around ME has centred on the common belief that it is a psychiatric illness. Sufferers can experience scepticism and discrimination from friends, family, health care professionals and employers, who may not see ME as a serious, debilitating condition. Yet, the severity of the physical symptoms of ME are described by the National Institute for Health and Care Excellence (NICE) as being “as disabling as multiple sclerosis, systemic lupus erythematosus, rheumatoid arthritis, congestive heart failure and other chronic conditions.”
The cause of ME is unclear. There may be an inherited genetic susceptibility, and ME is usually triggered by a precipitating factor, which for most people is a viral infection, or occasionally a traumatic event. One theory is that ME patients have an aberrant immune response that fails to ‘switch off’ following resolution of the original infection.
A diagnosis of ME is difficult and made by a process of elimination. There are no biomarkers for ME and an ongoing debate regarding the most appropriate set of diagnostic criteria.
There is no cure for ME. Treatment is aimed at relieving and preventing a worsening of symptoms. Because of its complexity, fluctuating nature and the wide spectrum of symptoms, there is no accepted universal treatment. In addition, there is a wide range of views on how people with ME can be helped. Avoiding overexertion is extremely important and most ME patients find that pacing (listening to their body and finding the right balance between rest and activity) helps them manage their illness.
In 2011, researchers of the PACE trial (Pacing, graded Activity, and Cognitive behaviour therapy; a randomised Evaluation) concluded that exercise and psychotherapy could significantly improve and sometimes cure ME/CFS. The claim has proved controversial and the PACE trial has been heavily criticised for its methodological flaws. Despite this, the results of the PACE trial dominate clinical policy for treatment of ME in the UK and other countries.
In the UK, the NICE guidelines recommend cognitive behavioural therapy (CBT) and/or graded exercise therapy (GET) to treat people with ME. Some patients believe that the NICE recommendations are not fit for purpose, as they reflect the belief that ME is a psychosocial disorder. They believe CBT/GET therapy may even cause additional harm.
ME is estimated to affect 250,000 people in the UK, and around 17 million people worldwide, with women three times more likely to be affected than men.
For a disease that affects so many, there has been under-investment and limited progress in ME research. In recent years, health professionals, researchers and patient groups have raised the profile of ME and improved awareness. Biomedical research is increasing our understanding of the role of mitochondrial function and cytokine production in muscle tissue, immune system involvement and autonomic dysfunction.
Ultimately, the goal is to find a drug treatment that can alter the underlying disease process. In the meantime, early diagnosis together with adequate rest appears to bring the most improvement for ME patients.
Find out more at the ME association: