Sleep dysfunction

Sleep dysfunction is nearly universal in ME/CFS patients, although it can take a very wide range of forms. A 2017 study by Davidson, et al, found up to 96.8% of people with CFS report unrefreshing sleep and many describe changes in sleep over the course of their illness.

Some of these sleep dysfunctions include:
 * dysania (a state of finding it hard to get out of bed in the morning; in ME/CFS it can an extended period lasting several hours after awakening)
 * hypersomnia (sleeping too much)
 * hypnagogia (transitional state from wakefulness to sleep during which lucid thought, lucid dreaming, hallucinations and, sleep paralysis can occur)
 * insomnia (difficulty falling asleep, staying asleep, and/or waking up too early in the morning)
 * light sleep (a non-REM stage and the easiest sleep stage to awaken from)
 * myoclonus (an involuntary twitch which occurs when a person is beginning to fall asleep, causing them to jump and awaken)
 * nightmares (a frightening or unpleasant dream)
 * night sweats (excessive sweating while you sleep)
 * sleep phase shifting (a shift in circadian rhythm; a sleep-wake cycle that does not correspond to the day-night cycle)
 * somnolence (sleepiness)
 * unrefreshing sleep (poor-quality sleep that doesn't relieve fatigue)

Prevalence

 * Depending on the criteria used for diagnosis, prevalence can vary greatly.


 * In a 2001 Belgian study, 91.9% of patients meeting the Fukuda criteria and 94.8% of patients meeting the Holmes criteria, in a cohort of 2073 CFS patients, reported sleep disturbances.

Symptom recognition
Sleep dysfunction is a core requirement to meet the diagnostic criteria for ME/CFS according to the 2003 Canadian Consensus Criteria, the 2007 Nightingale definition, and the 2015 Institute of Medicine report.

Sleep dysfunction is an optional symptom in the 1988 Holmes criteria, the 1991 Oxford criteria, the 1994 Fukuda criteria, the 2005 Reeves criteria, the 2007 NICE guidelines, the 2012 International Consensus Criteria, and the 2014 London criteria.

Unrefreshing sleep is required under Systemic Exertion Intolerance Disease (SEID) and Sleep disturbance is a listed under the International Consensus Criteria (ICC).

Sleep dysfunction is not a criteria listed for diagnosis with the 1986 Ramsay definition.

Notable studies

 * 2007, Paradoxical NREMS Distribution in “Pure” Chronic Fatigue Patients: A Comparison with Sleep Apnea-Hypopnea Patients and Healthy Control Subjects (Abstract)
 * 2012, Sleep Abnormalities in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Review (Full Text)
 * 2017, Sleep Quality in Adolescents With Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) (Full text)
 * 2018, Circadian rhythm abnormalities and autonomic dysfunction in patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (Full Text)
 * 2018, The putative role of oxidative stress and inflammation in the pathophysiology of sleep dysfunction across neuropsychiatric disorders: Focus on chronic fatigue syndrome, bipolar disorder and multiple sclerosis (Abstract)
 * 2018, Association of sleep disorders, chronic pain, and fatigue with survival in patients with chronic kidney disease: A meta-analysis of clinical trials via Sleep Medicine

Treatment
Treatment can include sedatives, antidepressants, cannabidiol (CBD), meditation and good sleep hygiene practices.

Amitriptyline may be helpful for improving quality of sleep in individuals with CFS. While originally considered an antidepressant, it is also prescribed at low doses to specifically manage pain and sleep for a number of conditions.