Question

Is there a simple reason why the ME Association also uses the term myalgic encephalopathy instead of myalgic encephalomyelitis?

Answer

Many doctors refuse to use the name Myalgic Encephalomyelitis because there is no current clinical evidence (from symptoms or signs) or pathological evidence (from post-mortem or other research) to indicate that people have what doctors and pathologists would regard as an ‘encephalomyelitis' taking place. The term encephalomyelitis refers to the presence of significant and widespread inflammation involving the brain and spinal cord and, while there is some evidence of neuroinflammation (i.e., low level inflammatory changes in some parts of the central nervous system), this is not the same as having an encephalomyelitis.

The ME Association therefore proposed that the name ‘Myalgic Encephalopathy' could be used – as this would be more acceptable to doctors and might help to prevent them from using ‘chronic fatigue syndrome' which has been their preferred alternative (CFS is not a name that we endorse as it doesn't reflect the seriousness of the condition, and is rather like calling dementia, ‘chronic forgetfulness syndrome'). Encephalopathy decribes a serious physical disease process that involves damage to the structure and/or function of the brain. Dr Shepherd would like to point out that we are not trying to remove myalgic encephalomyelitis from everyday use and that he would normally use it when talking to the media.

In light of the 2021 NICE Clinical Guideline on ME/CFS the abbreviated ‘ME/CFS' is now more likely to used in the NHS as the clinical recommendations are implemented and become more widely known. This situation is unlikely to change until research can accurately determine what causes the condition and it is accepted by the medical profession.

In the World Health Organisation's International Classification of Diseases – which provides a central listing and coding for all known diseases – the parent term for ME/CFS is ‘Post-Viral Fatigue Syndrome‘, and within this entry, it includes both ‘Myalgic Encephalomyelitis' and ‘Chronic Fatigue Syndrome', while excluding ‘Fatigue'.

However, SNOMED-CT – the electronic diagnostic coding system used by the NHS – uses ‘Chronic Fatigue Syndrome (disorder)‘ as a parent term. It recognises ‘Myalgic Encepahlomyelitis' and ‘Myalgic Encephalopathy' as acceptable alternatives, but not as separately codable items. It correctly codes the entry under ‘diseases of the nervous system' i.e., neurological which is in line with the WHO ICD (above), but there is a pressing need to change the parent term at least to ME/CFS.

SNOMED-CT also recognises ‘Postviral Fatigue Syndrome (disorder)' which is the parent term used in the World Health Organisation's International Classification of Diseases version 11. However, unlike the WHO ICD, SNOMED-CT does not link PVFS with Myalgic Encephalomyelitis or Chronic Fatigue Syndrome, which seems wrong.

The SNOMED-CT codes should be applied to all patient medical records so it is important that they are correct. It would also enable the NHS to provide more accurate data relating to e.g., ME/CFS prevalence – something it has consistently failed to be able to do – which would help them more accurately plan for healthcare needs. We will continue with our efforts to try and get SNOMED-CT to more accurately reflect the condition as we understand it and for everyone with ME/CFS to have the correct code used in their medical records. This is something that has been raised with the APPG on ME, and separately with the DHSC and NHSE during discussions about the Delivery Plan on ME/CFS.

More information

• The ME Association: Use of the term Myalgic Encephalopathy | October 2010
• We encourage everyone with ME/CFS or who cares for someone with the condition to familiarise themselves with the NICE Guideline and its recommendations. An easy-read version of the guideline has been produced and is available to download for free: An ME Association Summary of the 2021 NICE Clinical Guideline for ME/CFS.
  • Think about the guideline's recommendations and how they might apply to your own situation. Discuss them with your GP or local ME/CFS specialist service. Please let us know how you get on and how the recommendations are received: Feedback@meassociation.org.uk