The 12th of May marks the International Awareness Day for (at least partially) ill-defined or uncertain neurological diseases. The aim of this day is to draw attention to the inadequate understanding of Myalgic Encephalomyelitis (ME) / Chronic Fatigue Syndrome (CFS) and other chronic immunological and neurological diseases (CIND). ME/CFS is a serious, long-term illness.1
The date was chosen in remembrance of Florence Nightingale’s birthday, who was born in 1820 and is considered the founder of modern nursing care. Uncertain neurological diseases and Florence Nightingale are related: From her 30s, she showed symptoms that in retrospect may be attributed to ME/CFS.
ME/CFS seems therefore to have been around for more than 200 years, but the current media presence of the disease is heightened. This is due not least to the fact that the new and likewise uncertain disease “long COVID” shows some similar symptoms to ME/CFS.
According to the IOM 2015 Diagnostic Criteria, ME/CFS is diagnosed if “a substantial reduction of impairment in the ability to engage in pre-illness levels of activity (occupational, educational, social or personal life)”2 has existed for at least six months and is accompanied by fatigue, post-exertional malaise (i.e., a disproportionate aggravation of symptoms after mental or physical exertion) and unrefreshing sleep. In addition, either cognitive impairment or orthostatic intolerance must be present to make the diagnosis.3
Uncertainty persists concerning the aetiology of ME/CFS. Probably the most popular hypothesis regarding underlying causes is an exaggerated immune reaction after a viral infection, especially by human herpes viruses such as the Epstein-Barr virus.4 This overall state of inflammation after a viral infection could also explain why some patients show ME/CFS-like symptoms after a COVID‑19 infection.5 Other hypotheses suppose that a metabolic-endocrine dysfunction and/or psychosocial explanations underlie ME/CFS. Overall, it can be assumed that there is not one underlying cause but a multidimensional aetiology.6
There are also many question marks regarding the best possible treatment of ME/CFS, as currently there is no known curative pharmacological or non-pharmacological therapy.7 Personalised treatment is recommended, including symptom control, control of flare-ups, mobility exercises, diet management and/or cognitive behavioural therapy.8
It is certain that the diagnosis of ME/CFS has a great impact not only in the lives of those affected but also regarding socioeconomic aspects. The prevalence is estimated at 0.89%, with women being affected about 1.5 times more than men.9 The total annual direct and indirect costs of ME/CFS in the U.S. are expected to be between $17 billion and $24 billion.10
These costs can be explained by the low recovery rates of people living with ME/CFS and the high proportion of unemployment among them. It can be assumed that less than 10% of patients recover completely,11 i.e., showing no symptoms and returning to premorbid level of functioning without a need for coping strategies or medications.12 The unemployment rate for ME/CFS patients varies between 35% and 69%,13 which means that about half of those affected are not working. There is evidence that compared to healthy controls, but also to patients with multiple sclerosis, unemployment among people with ME/CFS is significantly higher.14 Unemployment seems to be associated with a delayed diagnosis,15 longer duration of the disease16 and comorbidities such as fibromyalgia, irritable bowel syndrome, depression, or anxiety.17,18,19
A faint glimmer of hope is evident in terms of prognosis regarding mortality. Not only Florence Nightingale reached the impressive age of 90,20 but also generally, there seems to be no significant difference between all-cause mortality rates of ME/CFS patients and the general population.21 Only patients with very severe fatigue may have a higher mortality rate, mainly due to cardiovascular disease.22
Overall, the current prognosis of ME/CFS is not good, not only for those affected but also regarding their insurability. A big factor in this seems to be the uncertainty that accompanies the disease. We therefore support today’s International Awareness Day for ME/CFS and CIND – and emphasise the importance of focusing further research, especially on the aetiology and treatment of ME/CFS.