Myalgic Encephalomyelitis is multi-system disease classified by the World Health Organisation in the chapter on Diseases of the Nervous System at WHO ICD-10 G.93.3, along with with post-viral fatigue syndrome, as benign myalgic encephalomyelitis since 1969.
CFS is a term that was created in the 1980s and is listed in the WHO alphabetical index with a reference back to G.93.3 so according to WHO, it is a colloquial term for a neurological disease.
However, different criteria for both ME (myalgic encephalomyelitis) and CFS (chronic fatigue syndrome) and ME/CFS have been developed in different countries over the years, muddying the waters of diagnosis and treatment. Patients have suffered as a result.
In the UK, CFS/ME has become an umbrella diagnosis for patients whose similar symptoms may have quite different causes, creating confusion for clinicians and researchers alike, and a barrier to useful scientific progress in this important area of human health.
Studies at Dundee and Newcastle Universities found that 40-44% of patients with a diagnosis of CFS/ME were misdiagnosed and some had other, potentially treatable illnesses.
A group of international researchers has now developed a new set of criteria for ME, which can be used for both clinical diagnostic and research purposes – known as the International Consensus Criteria.
Importantly regarding the SMILE study, these criteria are for both adults and children.