What is narcolepsy?
Narcolepsy is a sleep disorder which causes people to find it difficult to stay awake. In severe cases, sufferers can fall asleep all of a sudden during the day – despite the fact that they have had a good night's sleep. Narcolepsy causes strange sleeping patterns that impact many areas of life, making it difficult to hold down a job, study at school and college or maintain an active social life.
Two main forms of sleep: rapid eye movement (REM) and non-rapid eye movement (NREM). In REM sleep the eyes move fast while the individual is asleep, even though it is the cases that the eyelids are shut. Most dreams occur in REM sleep and although you move in your dreams, your body does not physically move because the body goes limp and hardly moves in REM sleep.
The normal sleep pattern involves a period of NREM after which REM occurs. However, individuals with narcolepsy follow an altered sleep cycle and regularly descend into REM sleep ahead of NREM sleep. Narcolepsy can also cause the period between sleeping and consciousness to have a much less defined quality, which means that people experience actions and sensations normally established in REM when they are awake. Narcolepsy can cause the following:
- Abrupt loss of muscle tone, control and strength: this is known as cataplexy and it can even cause the body to collapse.
- Vivid dreams and hallucinations.
- Inability to speak or move when waking up or going to sleep: this is known as sleep paralysis.
Effects of narcolepsy
Narcolepsy causes people to fall asleep very suddenly and is not restricted to quiet, relaxing times; certain persons with narcolepsy fall asleep at work, when driving or at mealtimes. Narcolepsy increases the risk of:
- Injuries and accidents.
- Problems and difficulties at school, college or in the workplace.
- Problems maintaining a social life.
- Difficulty remembering things.
- A lack of concentration.
There is currently no proper cure for narcolepsy, but there are treatments that can help to ease symptoms and make life more manageable. If not properly treated narcolepsy can have serious and wide-ranging implications for the way an individual lives their life.
What causes narcolepsy?
Studies suggest that narcolepsy is caused by a shortage of a chemical called hypocretin in the brain, which is responsible for stimulating the brain cells and causing alertness and wakefulness. The reason why there is a shortage of hypocretin in some people is not fully understood, but possible causes include:
- Brain injuries or autoimmune conditions which cause brain cells to be lost.
- Hormonal changes in the body.
There is some evidence to suggest that narcolepsy runs in families due to the fact that around 1 in 10 people with cataplexy and narcolepsy have a close family member with the condition.
Who is at risk of narcolepsy?
Narcolepsy has an impact on between 4 and 5 in every 10,000 people in the UK. It is most common at around the ages of 15-30 and slightly more common in men than women. Symptoms may develop gradually or quickly, and many persons subsist with mild symptoms of tiredness for many years before being diagnosed. Narcolepsy is rare in children under the age of five.
Risk factors for narcolepsy include:
- Family history: if you have a close relative with narcolepsy you have a higher risk of developing the disorder.
- Thyroid disorders.
- Autoimmune disorders which cause the body's immune system to attack healthy cells.
What are the symptoms and signs of narcolepsy?
The main symptoms of narcolepsy are feeling tired during the day and sleep attacks (falling asleep all of a sudden). Other symptoms of narcolepsy include:
- Cataplexy: this is an abrupt loss of muscle control and tone while awake.
- Sleep paralysis: a sudden loss of the ability to speak or move whilst going to sleep or waking up.
- Vivid dreams and hallucinations.
Narcolepsy causes excessive tiredness during the day and is often the initial symptom people experience. Some people suffer from sudden desires to sleep during the day, which is known as sleep attacks and usually go on for just a few minutes. In rare cases, sleep attacks can last for longer than an hour. Daytime tiredness can cause:
- A lack of concentration.
- Difficulties thinking and processing information.
- Memory problems.
- Feeling lethargic and lacking energy.
Around three quarters of persons with narcolepsy suffer from cataplexy, which causes the muscles to become weak. Cataplexy is akin to sleep paralysis that happens during REM sleep, but it does not cause unconsciousness. Mild symptoms of cataplexy include:
- Droopy eyelids.
- Difficulty moving the limbs.
- Difficulty gripping.
- Buckling at the knees.
- Nodding the head.
- Difficulty talking.
Severe cataplexy can cause total paralysis and potential falls. Attacks are usually short, go on for less than 2 minutes and can be over in seconds.
Muscle weakness attacks can occur at any time, but certain actions and movements can trigger attacks, including:
- Feeling scared.
- Feeling angry.
- Feeling excited.
In some cases, cataplexy is the first symptom people experience, but in most cases of narcolepsy daytime tiredness is the first sign people notice.
Narcolepsy can result in a sudden loss of movement when they are going to sleep or waking up; they may also lose the ability to speak. During periods of sleep paralysis the individual is still conscious and it can be frightening, even though most attacks only last for a short period of time. Sleep paralysis is comparable to the paralysis experienced during REM sleep, but it does not affect everyone with narcolepsy.
Certain persons with narcolepsy experience vivid dreams and hallucinations when they are waking up or falling asleep. Hallucinations are different to normal dreams as they seem real and include a range of sensations which don't normally feature in dreams. These can be scary and it may be difficult to work out what is real and what is not. Hallucinations can happen with sleep paralysis.
A number of individuals with narcolepsy experience problems staying asleep during the night; disturbed sleep patterns may occur many years after the initial symptoms of narcolepsy become apparent. Other symptoms include carrying out actions or movements without being aware of it (known as automatic behaviour) and may amplify the risk of having an accident. Individuals have no memory of things they have done as a result of automatic behaviour.
Doctors diagnose narcolepsy based on family and medical history, symptoms, test results and physical examination. In most cases, symptoms are usually distinctive enough to reach a diagnosis, but tests may be ordered to verify diagnosis and establish the best course of treatment. Tests can require patients to spend a night under observation.
Family history and symptoms
If your GP thinks you have narcolepsy they will ask you a number of questions about your symptoms and check:
- If you suffer from tiredness during the day.
- If you have ever experience cataplexy (rapid loss of muscle control).
- If you have vivid dreams or hallucinations when you are waking up or falling asleep.
- If you have ever experienced sleep paralysis, which prevents you from being able to speak or move when waking up or falling asleep.
If any of the symptoms listed above are present your GP will need to discuss them in more detail. They will also ask about when the symptoms first appeared and their frequency. A sleep diary may need to be maintained to enable doctors to find out more about your condition. This can help to answer the following questions:
- When do you get up and go to bed?
- How long does it normally take you to get to sleep and how regularly do you wake in the night?
- Do you snore or ever wake up feeling short of breath?
- Do you feel tired during the day and how are you when you wake up?
- Do you doze off during the day or find it difficult to stay awake in the daytime?
Doctors may also ask if you have any close relatives with narcolepsy or other sleep disorders, which may also cause daytime tiredness in such cases.
Your doctor may decide to carry out a physical examination to try and identify possible causes, including:
- Thyroid problems or disorders.
- Drug use.
- Drinking alcohol.
- Other underlying medical problems.
If narcolepsy is suspected your doctor will most likely refer you to a sleep specialist for further tests. The doctor will verify if narcolepsy is present, rule out the condition altogether or diagnose a different sleep disorder based on test results, sleep habits and relevant symptoms. Narcolepsy is generally simpler to diagnose when a patient has more than one symptom.
These can be carried out at a centre for sleep disorders. In some cases, patients are required to stay overnight for observation while they sleep, but some assessments can be carried out in the daytime. There are three main tests used to identify narcolepsy, including:
- Polysomnogram (PSG).
- Hypocretin test.
- Multiple sleep latency test (MSLT).
This test takes place at a sleep centre and during the night. The staff at the centre use instruments to measure the activity of the brain, breathing rate and movement of the body during sleep. Signs to look out for are:
- Going to sleep suddenly.
- Entering REM sleep quickly after going to sleep.
- Waking up frequently during the night.
Multiple sleep latency test
This is usually undertaken during the daytime following a polysomnogram. The MSLT is also known as a 'nap test' because it measures how easily you fall asleep. During the day patients are told to nap every 2-3 hours. The examination records eye movement, brain activity and muscle tone and control using small measuring devices connected to the head. Signs to look out for include:
- Falling asleep quickly in the daytime.
- Going into REM sleep shortly after falling asleep.
This measures the amount of hypocretin in the fluid surrounding the spinal cord, with low quantities of hypocretin being possible indicators of narcolepsy.
Treatment of narcolepsy
There is currently no proper cure for the condition but there are treatments that can ease symptoms. Treatment will be recommended according to the form and symptoms of the condition, with some medicines beneficial for daytime tiredness and others helpful for muscle weakness, cataplexy and hallucinations. Not all medication is effective for individuals with narcolepsy and it may be necessary to try different medicines to identify the most effective one.
Medicines to prevent daytime tiredness
Doctors can prescribe stimulant medicines to prevent daytime tiredness, including:
- Modafinil: this is one of the most recent drugs on the market for narcolepsy. There is the possibility that it will not be enough to alleviate tiredness in all cases of narcolepsy, so it may be prescribed alongside another medicine.
Medicines to prevent other symptoms
Many different anti-depressants treat cataplexy, hallucinations and sleep paralysis. These medicines work by targeting the chemicals inside the brain associated with narcolepsy.
Lifestyle changes can make a significant difference to individuals with narcolepsy and are almost always recommended in tandem with taking medication. Taking short naps during the day may help to prevent tiredness and winding down before bed can help individuals to get a better night's sleep. In order to relax during the evening in time for bed you can try the following:
- Have a bath.
- Read a book or listen to relaxing music.
- Maintain a level of quietness in your bedroom.
- Exercise during the day (not within three hours of going to sleep).
Before going to bed you should avoid:
- Drinking or eating foods that contain caffeine.
- Drinking alcohol.
- Taking certain medications.
Living with narcolepsy
Narcolepsy is a long-term condition with no cure. However, many of the symptoms can be effectively treated with medications and lifestyle changes, and the majority of people can live healthy, normal lives. Narcolepsy can be dangerous and should be managed carefully; if you are operating machinery or driving, for example, narcolepsy can be potentially dangerous. To avoid dangerous situations:
- Avoid being alone, especially at times where there is a high risk of sleep attacks or cataplexy.
- Take steps to make your home or workplace safer.
- Seek help from people around you, including your doctor.
- Take a short nap if you feel tired or at times when sleep attacks are most likely.
- Follow your doctor's advice and stick to the dosage guidelines for prescribed medicines.
The activity of driving can be hazardous for those who have narcolepsy. If you are diagnosed with narcolepsy you should:
- Speak to your doctor about whether it is safe for you to drive.
- Follow your doctor's advice and always take your medication.
- Take a nap before driving.
- Drive with somebody else in the car or take lifts with others.
- Stop on a regular basis if you are driving a long distance.
- Avoid driving at times when you are more liable to experience a sleep attack.
Many persons with narcolepsy are able to work without any problems, although it is often beneficial to try and get a job which offers flexibility so that you can have short naps when required. Talk to your employer about your condition to ensure they understand your symptoms. Steer clear of jobs that have need of driving long distances. There are laws in place to prevent discrimination in the workplace so if you feel that you are being treated unfairly, try to talk to your employer. If this is not beneficial seek advice from an independent adviser.
Narcolepsy can make it difficult to make and maintain friendships and some people find their condition embarrassing. Narcolepsy can contribute to anxiety and depression and some people lack confidence and self-esteem. If you are diagnosed with narcolepsy try to learn as much as possible about your condition and talk to the people around you. Make sure they understand narcolepsy and how they can potentially help you. Emotional support is available from charities and support groups, while professional counselling can also be helpful.
Children of school age
Narcolepsy can cause children to struggle at school as they may find it difficult to concentrate, remember and focus. In some cases, narcolepsy may be confused with learning disabilities or seizure disorders, such as epilepsy. It may also cause some children to try and do activities very quickly if they are tired, which can be confused with hyperactivity.
It is advisable to talk to your child's teacher and other members of staff about their condition, so that they are able to understand your child's behaviour and help them manage better at school. If your child is taking medication you will need to discuss this with their teacher, so that they are able to follow the treatment plan at school.
For women with narcolepsy who are planning to conceive or become pregnant, it is a good idea to speak to their doctor on how narcolepsy may affect the pregnancy and the possibility of having an infant with narcolepsy.
Narcolepsy: key points
- Narcolepsy is a chronic condition which causes people to descend into sleep unexpectedly during the day.
- Narcolepsy can result in an unexpected loss of muscle control and tone (known as cataplexy), the incapacity to speak and move (known as sleep paralysis) and hallucinations and vivid dreams.
- Signs of narcolepsy include accidents and injuries, daytime tiredness, a lack of concentration and difficulties with learning and remembering.
- The initial indicators of narcolepsy usually develop between fifteen and thirty years of age.
- There is no known cure for narcolepsy but there are treatments that can ease symptoms.
- Doctors diagnose narcolepsy according to the symptoms, patient's medical and family history, physical examination and sleep tests.
- Many persons with narcolepsy are able to live a normal life with the help of lifestyle changes and medication.
- The exact source of narcolepsy is unknown; however, it is acknowledged that a shortage of hypocretin contributes to symptoms of narcolepsy. Hypocretin is a chemical found in the brain which brings about wakefulness.