Positive move to a new diagnostic, definition

The Psychologist News

Experts from five continents have agreed upon on a new set of 'International Consensus Criteria' for myalgic encephalomyelitis (ME; also referred to as chronic fatigue syndrome or CFS), which they hope will improve clinical diagnosis and research into the condition.

Writing in the Journal of Internal Medicine in July (tinyurl.com/44tvs6v), the 25 co-authors said: 'The primary goal of this consensus report is to establish a more selective set of clinical criteria that would identify patients who have neuroimmune exhaustion with a pathological low-threshold of fatigability and symptom flare in response to exertion. This will enable like patients to be diagnosed and enrolled in research studies internationally under a case definition that is acceptable to physicians and researchers around the world.'

The new criteria are the latest in a series of attempts to nail down the hallmarks of ME/CFS. For example, last year saw a revision to narrow down the Canadian Case Definition, originally published in 2003, which has proved popular with many researchers. Bruce Carruthers, a psychiatrist in private practice in Vancouver, who was lead author on those 2003 criteria is also co-editor of the new International Consensus Criteria.

A key departure from its forerunners by the new International Criteria is that symptoms and signs need not have been present for six months before a diagnosis can be made. 'No other disease criteria require that diagnoses be withheld until after the patient has suffered with the affliction for six months,' the authors said.

However, the cardinal symptom remains 'Post-Exertional Neuroimmune Exhaustion' - a profound loss of energy following exertion, and impaired recovery. Also, the patient must have at least one symptom in each of the following categories: neurocognitive impairments (e.g. pain); immune, gastro-intestinal and genito-urinary impairments (e.g. food sensitivities); and energy production/ transportation impairments (e.g. laboured breathing).

The new criteria also urge that the CFS label be dropped. 'Using "fatigue" as a name of a disease gives it exclusive emphasis and has been the most confusing and misused criterion,' argue Carruthers and his colleagues. 'Fatigue in other conditions is usually proportional to effort or duration with a quick recovery, and will recur to the same extent with the same effort or duration that same or next day. The pathological low threshold of fatigability of ME described in the following criteria often occurs with minimal physical or mental exertion, and with reduced ability to undertake the same activity within the same or several days