Narcolepsy

Narcolepsy is a sleep disorder characterised by extreme tiredness and sudden sleep attacks during the day. It may be accompanied by sudden loss of muscle tone or muscle weakness known as cataplexy.

On this page, you can find the following information:

What is narcolepsy?

Narcolepsy is a chronic and disabling sleep disorder. It affects your brain so that messages about when to sleep and when to be awake get confused. This results in uneven and broken sleep during the night and periods of extreme tiredness and sudden attacks of sleep during the day.

There are two main types of narcolepsy. Type 1 is accompanied by cataplexy, a sudden loss of muscle tone or weakening of the muscles that is often triggered by a strong emotion. Narcolepsy that does not include cataplexy is known as type 2 narcolepsy.

A condition called secondary narcolepsy can also occur as a result of damage to the hypothalamus – part of the brain that helps regulate sleep. As well as having symptoms of narcolepsy, people with this may have neurological problems and sleep for long periods (more than 10 hours) at night. Long periods of sleep can also occur for people with type 1 and type 2 narcolepsy. 

Image credit: Canva

Who does it affect?

Women and men are equally affected, and it is thought that about 1 in 2000 people have narcolepsy. It usually starts during the teenage years or early twenties and continues throughout life. This figure may be an underestimate as some people will have it but have not had a diagnosis or have been misdiagnosed as having an emotional or psychological problem.

What are the symptoms of narcolepsy?

Narcolepsy involves a range of symptoms but apart from daytime sleepiness, they don’t apply to everyone with narcolepsy. Symptoms can include:

  • Extreme daytime sleepiness: you may drop off to sleep anywhere and at any time, for a few minutes or up to half an hour. It may be while you are working or talking. These short sleeps seem to refresh you, but you soon feel sleepy again. 
  • Difficulty staying asleep at night: although it may be easy to drop off to sleep you may have problems in staying asleep for longer than a few hours at a time. 
  • Sleep paralysis: a temporary inability to move or talk when you fall asleep or wake up which can last up to several minutes. This is similar to what you normally experience during REM (rapid eye movement) sleep which stops you acting out your dreams. 
  • Hallucinations: vivid and sometimes disturbing dreamlike experiences happening when you are dozing, dropping off to sleep or waking. As they happen when you are still partly conscious it is hard to separate them from reality which can make them especially frightening. If they happen as you go to sleep they are called hypnagogic hallucinations; the ones experienced when waking are called hypnopompic hallucinations. They can happen at the same time as sleep paralysis. 
  • REM sleep changes: If you have narcolepsy, REM sleep (when you dream the most) can happen at any point during the day. Excessive dreaming with motor activity (movement) at night can also happen. 
  • Cataplexy: a loss of muscle tone that can last up to a few minutes at a time and occur a few times a year or up to several times a day for different people. It can result in slurred speech or can cause weakness in most of the muscles in your body. It doesn’t affect your ability to breathe. 
  • Automatic behaviour: being able to keep talking and doing things while half asleep and having no memory of it later. This is likely to happen during familiar activities such as writing/typing or driving.

Narcolepsy might be accompanied by other sleep disorders like obstructive sleep apnoea, restless legs syndrome and insomnia.

What causes narcolepsy?

The cause of narcolepsy is unknown but people with type 1 narcolepsy (with cataplexy) have low levels of a neurochemical called hypocretin which helps to regulate wakefulness and REM sleep. People with autoimmune susceptibilities may be more likely to develop narcolepsy suggesting that the immune system and changes to it may play a role in narcolepsy. More research is required to fully understand why narcolepsy occurs.

How is narcolepsy diagnosed?

If it is not diagnosed and treated narcolepsy can disrupt psychological, social and cognitive function and many aspects of your daily life. Talk to your doctor if you are experiencing extreme daytime sleepiness, especially if you are also dealing with some of the other symptoms of narcolepsy.

Diagnosis is done through clinical assessment and history taking. You may be asked to keep a sleep journal to record your experiences. Medical examination can help to rule out other possible causes for your symptoms as, apart from cataplexy, they may be linked to other conditions. Cataplexy is a specific symptom as it is rarely associated with other diseases.

Two specialised tests are done to diagnose narcolepsy:

  • A polysomnogram (PSG or sleep study) is done to record brain and muscle activity, breathing and sleep patterns overnight.
  • A multiple sleep latency test (MSLT) looks at daytime sleepiness by measuring how quickly you go to sleep and whether you go into REM sleep.

How is narcolepsy treated?

There is no cure for narcolepsy, but some symptoms can be treated with medicines and lifestyle changes. In general, the extreme sleepiness during the day and cataplexy can be controlled with medicines.

  • Modafinil is a wakefulness-promoting agent which helps to reduce daytime sleepiness and improve alertness.
  • Central nervous system stimulants may be prescribed if modafinil isn’t effective. They need to be carefully monitored as they have a number of side effects.
  • Antidepressants (tricyclics and selective serotonin noradrenic reuptake inhibitors) can be effective in controlling cataplexy for many people. They too can have unwanted side effects.

What else can I do to look after myself?

Here are some things you can try to help with your symptoms:

  • Try to maintain good sleep practices including:
    • going to bed and getting up at the same times each day
    • avoiding caffeine, alcohol and heavy meals before bed
    • doing something relaxing before going to bed, eg, a warm bath.
  • Plan to have short naps regularly throughout the day at times when you feel most sleepy.
  • Do some exercise each day.
  • Avoid smoking – particularly at night.
  • Keep yourself safe when you are feeling sleepy during the day – especially when driving.
  • Tell friends and whānau about how you are feeling and ask for help if you need it.
  • If you are feeling anxious, depressed or scared about your condition, consider getting some counselling. Your doctor can refer you to somebody to talk to or you can call Healthline on 0800 611 116. 

It is important that you keep safe, especially with driving. Daytime sleepiness can lead to a greater risk of driving accidents, especially if your symptoms are not being effectively treated.

Supports

Narcolepsy and Overwhelming Daytime Sleep Society (NODSS) private facebook page https://www.facebook.com/groups/280075192188774/

Learn more

The following links provide more information about narcolepsy. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

Narcolepsy and Overwhelming Daytime Sleep Society (NODSS) 
What is narcolepsy? American Thoracic Society 
Narcolepsy sleep health facts Sleep Health Foundation, Australia 
Medical aspects of fitness to drive NZ Transport Agency, NZ 

References

Narcolepsy Mayo Clinic, US, 2020 
Narcolepsy information page National Institute of Neurological Diseases and Stroke (NINDS), US, 2019 
Narcolepsy National Organisation for Rare Disorders (NORD), US, 2017 
Narcolepsy Cleveland Clinic, US, 2020  

Credits: Health Navigator Editorial Team. Reviewed By: Angela Campbell, PhD, Associate Professor & Manager WellSleep Centre, University of Otago, Wellington Last reviewed: 05 Apr 2022