The following are my criteria, which I based on the work of pioneers such as Gilliam, Ramsay, Parish, Acheson and Dowsett.
1. Generalised or localised muscle fatigue following minimal exertion with prolonged recovery time.2. Neurological disturbances and variable involvement of cardiac and other bodily systems.
3. Impaired circulation.
4. Marked variability of symptoms in the course of a day and from day to day.
5. An extended relapsing course with a tendency to chronicity.
For research purposes, a minimum duration of six months may help to differentiate ME from more common, transient post-viral syndromes.
Dr. Ellen Goudsmit.
Psychologist/Archivist, London.
The emphasis on both fatiguability and central nervous system involvement means that the criteria for ME are consistent with the guidelines for PVFS formulated by Ho-Yen (1993) and the case definitions of CFS developed by Australian researchers (Lloyd et al 1990a) and Walsh and Cunha (1993). They are also similar to the definitions of PVFS adopted by Behan and his colleagues (Behan and Bakheit 1991) and Weir (1991).
The criteria for ME differ from the American and Oxford definitions for CFS in three ways. Firstly, the latter do not require evidence of central nervous system dysfunction.
Secondly, they do not include any references to the fluctuation of symptoms or the close links between symptoms and exertion.
Thirdly, the older CDC criteria place a much greater emphasis on infection-related symptoms such as mild fever, sore throat and tender glands compared to the definitions of ME (Hyde et al 1992).
