Table A1.
Case definitions for the diagnosis of ME/CFS over time.
| Advisor Group, Year | Identifier | Case Definition and Required Symptom(s) |
|---|---|---|
| For Adults | ||
| Holmes et al., 1988 (CDC) [17] | CFS | Major criteria New onset of persistent or relapsing, debilitating fatigue or easy fatigability in a person who has no previous history of similar symptoms, that does not resolve with bedrest, and that is severe enough to reduce or impair average daily activity below 50% of the patient’s premorbid activity level for a period of at least 6 months Minor criteria Mild fever Sore throat Painful lymph node in the anterior or posterior cervical or axillary distribution Unexplained generalized muscle weakness Muscle discomfort or myalgia Prolonged generalized fatigue (≥24 h) after normal level of exercise Migratory arthralgia without joint swelling or redness Neurological complains one or more of: photophobia, transient visual scotomata, forgetfulness, excessive irritability, confusion, difficulty thinking, inability to concentrate, depression Sleep disturbances |
| Sharp et al., 1991 (Oxford) [46] | CFS | Fatigue as the principal symptom A definite onset that is not lifelong The fatigue is severe, disabling, and affects physical and mental functioning The fatigue should have been present for a minimum of 6 months during which it was present for more than 50% of the time Other symptoms may be present, particularly myalgia, mood and sleep disturbance. |
| Fukuda et al., 1994, (CDC) [52] | CFS | Clinically evaluated, “unexplained”, persistent or relapsing fatigue for ≥6 months. Not the result of ongoing exertion Not substantially alleviated by rest Resulting in a substantial reduction in previous activity level. Four or more of the following concurrently present for ≥ 6 months: impaired memory or concentration sore throat tender cervical or axillary lymph nodes muscle pain multi-joint pain new headaches unrefreshing sleep post-exertion malaise |
| London criteria-V2, (Dowsett et al., 1994) [106] | These three criteria must all be present for a diagnosis of M.E./PVFS Exercise-induced fatigue precipitated by trivially small exertion -physical or mental -relative to the patient’s previous exercise tolerance Impairment of short-term memory and loss of powers of concentration, usually coupled with other neurological and psychological disturbances such as emotional lability, nominal dysphasia, disturbed sleep patterns, disequilibrium or tinnitus Fluctuation of symptoms, usually precipitated by either physical or mental exercise |
|
| Canadian Consensus Criteria, (Carruthers et al., 2003) [88] |
ME/PVFS | For a diagnosis of CFS/ME, a patient must meet the following criteria 1–6 and adhere to item 7: Fatigue Post-exertional malaise and/or fatigue Sleep dysfunction Pain Two or more of the following neurological/cognitive manifestations: Confusion Impairment of concentration and short-term memory consolidation Disorientation difficulty with information processing categorizing and word retrieval perceptual and sensory disturbances One or more symptoms from two of the following categories: Autonomic manifestation (e.g., orthostatic intolerance, postural orthostatic tachycardia syndrome, …) Neuroendocrine manifestation (e.g., loss of thermostatic stability, sweating episode, …) Immune manifestation (e.g., tender lymph nodes, recurrent sore throat, …) Illness lasting ≥6 months |
| Revised Canadian Consensus Criteria, (Jason et al., 2010) [107] |
ME/CFS | Definition of Research CFS/ME criteria: Over the past 6 months, persistent or recurring chronic fatigue that is not lifelong and results in substantial reductions in previous levels of occupational, educational, social and personal activities Post-exertional malaise and/or fatigue Unrefreshing sleep or disturbance of sleep quantity or rhythm disturbance Pain (or discomfort) that is often widespread and migratory in nature. At least one symptom from any of the following: Myofascial and/or joint pain (e.g., deep pain, abdomen/stomach pain, or achy and sore muscles. Pain, stiffness, or tenderness may occur in any joint but must be present in more than one joint and lacking edema or other signs of inflammation) Abdominal and/or head pain (e.g., stomach pain or chest pain). Headaches often described as localized behind the eyes or in the back of the head (includes headaches localized elsewhere, including migraines; headaches would need to be more frequent than they were before, which would indicate a new pattern of a new type as compared to headaches previously experienced (i.e., location of pain has changed, nature of pain has changed), or different in severity type as compared to headaches previously experienced by the patient) Two or more of the following neurological/cognitive manifestations: Impaired memory (self-reported or observable disturbance in the ability to recall information or events on a short-term basis) Difficulty focusing vision and attention (disturbed concentration may impair the ability to remain on task, to screen out extraneous/excessive stimuli) Loss of depth perception Difficulty finding the right word Frequently forget what wanted to say Absent-mindedness Slowness of thought Difficulty recalling information Need to focus on one thing at a time Trouble expressing thought Difficulty comprehending information Frequently lose train of thought Sensitivity to bright lights or noise Muscle weakness/muscle twitches At least one symptoms from two of the following categories: Autonomic manifestation: Neurally mediated hypotension, postural orthostatic tachycardia, delayed postural hypotension, palpitations with or without cardiac arrhythmias, dizziness or fainting, feeling unsteady on the feet--disturbed balance, shortness of breath, nausea, bladder dysfunction, or irritable bowel syndrome Neuroendocrine manifestation: Recurrent feelings of feverishness and cold extremities, subnormal body temperature and marked diurnal fluctuations, sweating episodes, intolerance of extremes of heat and cold, marked weight change-loss of appetite or abnormal appetite Immune manifestation: Recurrent flu-like symptoms, non-exudative sore or scratchy throat, repeated fevers and sweats, lymph nodes tender to palpitation--generally minimal swelling observed, new sensitivities to food, odors, or chemicals |
| International Consensus Criteria, (Carruthers et al., 2011) [90] |
ME | Myalgic encephalomyelitis is an acquired neurological disease with complex global dysfunctions. Pathological dysregulation of the nervous, immune and endocrine systems, with impaired cellular energy metabolism and ion transport, are prominent features. Although signs and symptoms are dynamically interactive and causally connected, the criteria are grouped by regions of pathophysiology to provide general focus. A patient will meet the following criteria A. Post-exertional neuro-immune exhaustion (PENEpen’-e): Compulsory This cardinal feature is a pathological inability to produce sufficient energy on demand with prominent symptoms primarily in the neuro-immune regions. Characteristics are as follows:
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