Published: 15 March 2020
Published: 15 March 2020
The rare condition narcolepsy causes persistent tiredness, ‘sleep attacks’ during the day, and in some cases, muscle weaknesses that can cause a person to collapse involuntarily.
Narcolepsy is a chronic neurological condition characterised by recurring periods of excessive sleepiness or lapses into sleep or napping within the same day (American Psychiatric Association 2013). It may also cause cataplexy (sudden involuntary muscle weakness or paralysis) (Brain Foundation n.d.).
Episodes of cataplexy may occur frequently and at any time, often triggered by strong emotions such as fear, anger, excitement or surprise. Attacks may happen during inappropriate moments including eating, talking or driving (Brain Foundation n.d.).
Narcolepsy is rare and estimated to affect about 1 in every 2,000 people, with onset generally during adolescence or early adulthood (though it can develop at any age). Symptoms may develop over a number of years (Sleep Health Foundation 2011).
A normal night of sleep will consist of several sleep cycles, each involving one period of NREM (non-rapid eye movement) sleep, then one period of REM (rapid eye movement) sleep. REM sleep generally begins after the first 60 to 90 minutes of sleep and is the window where dreaming will occur. During REM sleep, the muscles go limp so that the individual does not act out their dreams (NINDS 2019).
A person with narcolepsy, however, will enter REM sleep much earlier than the average person (sometimes within 15 minutes of falling asleep) and may suddenly enter into REM sleep or experience the associated muscle weakness during the day, or while still awake (NINDS 2019; Brain Foundation n.d.).
Narcolepsy is caused by dysfunction of the sleep-wake regulators in the brain, though the reason why they function incorrectly in some people is not completely understood. It is thought that a very low level of the chemical ‘hypocretin’ (which regulates wakefulness) is the cause, as almost all people with narcolepsy who experience cataplexy lack normal levels of hypocretin (NINDS 2019).
However, those with narcolepsy who do not experience cataplexy usually have normal levels of hypocretin (NDIS 2019).
Narcolepsy may be linked to:
(NDIS 2019; Mayo Clinic 2019)
All people with narcolepsy experience excessive sleepiness, but will not necessarily have other symptoms (Sleep Health Foundation 2011). These symptoms may include:
(NINDS 2019; Mayo Clinic 2019; Sleep Health Foundation 2011)
According to the DSM-5, the following criteria should be met in order to diagnose narcolepsy:
(American Psychiatric Association 2013)
Refer to the APA's DSM-5 for the full list of diagnostic criteria: https://www.xyremhcp.com/dsm-5-narcolepsy-diagnostic-criteria
Narcolepsy is usually diagnosed through a combination of methods, including a laboratory test. Because symptoms can vary between people, and most of them (excluding cataplexy) could be falsely attributed to other conditions such as epilepsy, depression or chronic fatigue syndrome, laboratory tests can help rule out these other conditions (Better Health Channel 2014; SNORE Australia 2020).
Some diagnostic methods include:
(Mayo Clinic 2019)
Treating narcolepsy involves controlling the symptoms, as there is no cure for the condition. This may involve medication to help with sleepiness and cataplexy (Sleep Health Foundation 2011). Other strategies that may be helpful in managing symptoms include:
It is extremely important to ensure symptoms are adequately controlled before undertaking activities where sleepiness could be dangerous (e.g. driving). Never drive if you are feeling sleepy (Sleep Health Foundation 2011; SNORE Australia 2020)
Question 1 of 3
How might narcolepsy affect someone’s REM sleep?
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