Rare and uncommon symptoms

Rare and uncommon symptoms of myalgic encephalomyelitis (ME) are those not listed the diagnostic criteria, and are more likely to occur or more likely to be problematic in people with severe or very severe ME.

Rare symptoms that can be particularly problematic include:
 * periodic paralysis or partial paralysis
 * chewing swallowing and digesting food
 * seizure-like phenomena, or complete or partial seizures
 * cardiovascular symptoms like heart palpitations
 * nocturnal diarrhea, bladder and bowel control problems
 * blackouts or loss of consciousness

Sensory problems
Sensory problems including noise and light sensitivity (tinnitus, hyperacusis, severe photophobia) are relatively common but may be undercognised; the most commonly used diagnostic criteria do not include any sensory symptoms.

Paralysis
Paralysis is recognized under Motor and Balance symptoms in the Canadian Consensus Criteria (CCC) (Appendix 4). Chewing and swallowing difficulties. Paralysis is not recognized in the International Consensus Criteria, (ICC) but the ion transport and channelopathy impairments that cause it are mentioned in the pathophysiology section, and the response to exercise section.

Chewing and swallowing problems
Chewing and swallowing problems are sometimes caused by paralysis, especially facial paralysis. Some patients are too weak to chew, eat or digest food normally and need a feeding tube. Problems with fine motor control of the hands can also affect eating.

Nocturnal diarrhea
Nightime diarrhea and delayed emptying of the upper gastricintestinal tract were found in some CFS patients, although vomiting was much rarer in the same study. Difficulties with bladder or bowel control have also been identified.

Seizure-like symptoms
Seizure-like symptoms are described as resulting from hypersensitivity to even low levels of a stimulus (to light, noise, chemicals, etc). Seizure-like symptoms are included in the Nervous System symptoms in the Canadian Consensus Criteria (Appendix 4).

Castro-Marrero et al. 2017
Comorbidity in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Nationwide Population-Based Cohort Study
 * 1757 Spanish subjects who met both the 1994 CDC/Fukuda definition and Canadian Consensus Criteria for CFS/ME. Table 2 gives prevelance of each ME/CFS symptom in the Canadian Consensus Criteria

Jason et. al 2014
Examining case definition criteria for chronic fatigue syndrome and myalgic encephalomyelitis
 * 236 patients completed the DePaul Symptom Questionnaire, rating the frequency and severity of 54 symptoms, compared to controls.

de Becker et al. 2010
A definition-based analysis of symptoms in a large cohort of patients with chronic fatigue syndrome 1578 CFS patients fulfilled the Fukuda criteria (called the "CFS group") and 951 (60.3% of the CFS group) fulfilled the Holmes criteria. The Holmes definition was found to be better than the Fukuda at differentiated CFS patients from the patients with Chronic Fatigue without CFS.
 * A study of 2073 patients complaining of chronic fatigue (CF) in Brussels. Table 1 and Table 2 show the how many patients had each symptom according to whether they met the Fukuda criteria, the Holmes criteria or had chronic fatigue without CFS.

Learn more

 * Hummingbird Foundation: Comprehensive list of M.E.Symptoms
 * Supporting people with severe Myalgic Encephalomyelitis - Greg Crowhurst, Nursing Times
 * Supporting someone with Severe ME sufferer: basic information that carers should find-out Greg Crowhurst (2010)
 * Severe M.E. symptoms - 25% Group
 * Severe M.E.: Time to Deliver - Action for M.E.
 * What is M.E? - Invest in M.E. Research