Narcolepsy

What is narcolepsy?

Narcolepsy is lifelong chronic condition characterised by the irresistible urge to nap in the day.

It is relatively rare in childhood, and it is not unusual for the diagnosis to be missed initially. Most children present in their teenage years, but with increased awareness of the subject more children are being recognised earlier.

When a child’s diagnosis is late, their education may suffer as they struggle against an overwhelming urge to sleep. It can often be misunderstood as laziness or difficult behaviour.

Symptoms of narcolepsy

The symptoms of narcolepsy may take many years to appear or they may start all at once.

Excessive daytime sleepiness

This is usually the first, and sometimes the only symptom, despite sufficient sleep length overnight.

As well as feeling tired all of the time, someone with narcolepsy will often fall asleep at unusual or dangerous times (such as when talking to someone or riding a bike). They will feel refreshed after a short nap, but the feeling of sleepiness will recur throughout the day.

Importantly, a child who is fighting an overwhelming desire to sleep will often present with difficult behaviour and appear moody or aggressive.

Concentration is a major difficulty and this can impact on learning.

Cataplexy

Cataplexy can happen with type 1 narcolepsy and involves sudden and brief loss of muscle tone as a response to an emotion, such as commonly anger, surprise or amusement.

This might cause the person to feel weak or to collapse completely. What this means in practice is that children will learn to avoid any situation where they may laugh or get excited. This causes social impairment, and they may be interpreted as behaving in a withdrawn or anti-social way.

Sleep paralysis

Sleep paralysis is the experience of waking from sleep with a brief feeling of being unable to move or talk. Touching the person normally brings one of these episodes to an end. Children may find these frightening.

Hypnagogic and hypnopompic hallucinations

These are dream-like experiences that happen as a child is falling asleep or waking up. Children will describe extremely vivid and often distressing hallucinations.

Some children may recognise that these experiences are bizarre and be reluctant to share their experiences with adults, for fears of thinking they are ‘going mad’. They may present as extreme anxiety about going to bed.

Automatic behaviour

Automatic behaviour is where a child does routine things without being aware or remembering that they are doing so. For example, repeated and prolonged chewing whilst eating, repetitive talking, and illegible writing which makes them get marked down in assessments.

Night waking

Children with narcolepsy commonly wake up during the night or have very restless sleep with sleep-talking or shouting, and this can make daytime sleepiness worse.

Increased appetite and weight gain

Some children have difficult nighttime food cravings, and can also feel less like exercising due to the sleepiness. Weight gain can have an impact on children’s self-confidence.

What causes narcolepsy?

At the moment, we know that narcolepsy is caused by a lack of the chemical ‘hypocretin’ in the brain. This is one of many chemicals that control the delicate balance between waking and sleeping.

In narcolepsy, rapid eye movement (REM) sleep is particularly affected.

While the condition can sometimes run in families, it is not truly a ‘genetic’ condition. It is the predisposition to getting the condition that is inherited. It is unclear what triggers the onset of the narcolepsy in someone with a predisposition.

There is a suggestion that an earlier infective episode may be the trigger, although no single type of infection has been linked to the disease onset.

It does not affect life expectancy or fertility. It is not possible to catch narcolepsy.

How common is narcolepsy?

Narcolepsy in children is a rare disease and based on a global average between 20 and 50 per 100,000 people.

It can happen at any age and most commonly develops between the ages of 10 and late teens in children. Both boys and girls get narcolepsy at the same rate. It is a life-long condition and can affect all aspects of a child’s life.

How does it affect children?

It is likely to impact some children’s ability to engage in:

• more sedentary learning
• retain information
• initiating tasks
• persevering to complete tasks

The excessive daytime sleepiness (EDS) is likely to present as lacking motivation, hinder social relationships and energy to socialise.

Where we should seek help?

To get help, seek a referral from a GP to a sleep specialist where a thorough evaluation and the following investigations may be done:

• 2 actigraph and a sleep diary to monitor sleep and wake over a 2 week period
• detailed study overnight to exclude other underlying sleep disorders
• multiple sleep latency test (MSLT) is 4 to 5 nap opportunities in the day in a sleep laboratory setting, where they will be monitored. This measures sleepiness and looks for REM sleep appearing early during the nap, which is characteristic of narcolepsy
• lumbar puncture to check hypocretin levels
• blood test to look for genetic markers of vulnerability to the condition

Treatment

While there is currently no cure for narcolepsy, it is an area of very active research. It is possible to control most of the symptoms most of the time including:

• medication such as methylphenidate (also used to treat ADHD) can be used to reduce the daytime sleepiness. Cataplexy may be treated with types of medication more commonly used for depression. Many children will be prescribed a combination of medications, which may be taken at different times throughout the day.
• lifestyle changes such as a good sleep routine and are advised to take short planned naps at set times during the day
• dietary advice can be useful where children have food cravings
• education as narcolepsy is a rare condition that most general healthcare professionals and teachers have not previously encountered. Education of the people around the child is essential to ensure that the child receives the right support.