Narcolepsy

• Narcolepsy is characterized by excessive daytime sleepiness and suddenly falling asleep during the day
• The inability to control the onset of sleep has clear implications for safety. Untreated narcoleptics have ten times the automobile accident rate.

Overview of Narcolepsy

Narcoleptics experience daytime sleepiness despite the fact they may be getting sufficient sleep at night. This sleepiness increases to such a point that the person cannot resist the urge to sleep, regardless of what they are doing – driving, in a meeting, or eating for example. The narcoleptic may be asleep for seconds, minutes, or more rarely an hour or more.

Narcolepsy is relatively rare, thought to affect 1 in 2000 Americans. However, many narcoleptics are undiagnosed so the rate may be higher. Most narcoleptics are diagnosed between the ages of 10 and 25, but symptoms can become apparent at any age.

Symptoms of Narcolepsy

Excessive daytime sleepiness is usually the first symptom experienced by narcoleptics. This sleepiness may evolve over time until it becomes debilitating. Sufferers describe an inability to concentrate, extreme tiredness, poor mood, and irritability even after a good night's sleep.

Eventually this tiredness causes the person to suddenly fall asleep, whatever their activity. The duration of the sleep is typically short and the sufferer usually feels refreshed for an hour or more. Automatic behavior syndrome, where the person appears awake but functions without conscious thought, is also common. Just like falling asleep, this has obvious safety consequences.

Cataplexy is experienced by about 70% of narcoleptics, and for about 10% of sufferers is the first symptom to be noticed. Cataplexy is a sudden weakness in the muscles. This could be confined to just muscles in the face or jaw, or could affect many of the muscle groups, causing collapse. It is sometimes misdiagnosed as a seizure, delaying proper treatment. Cataplexy is a distinct symptom, not just falling asleep – in fact the person is fully conscious but unable to respond – a distinction from a seizure. Often the cataplexy is triggered by a strong emotional experience – laughter or fear for example.

Sleep paralysis is also experienced by some narcoleptics – this is an inability to move while falling asleep or waking up. This can be frightening as the sufferer may worry that they are permanently paralyzed. Finally, some sufferers have vivid hallucinations as they fall asleep or wake up. Both sleep paralysis and vivid dreaming are part of the normal sleep cycle called REM sleep, but in the case of narcoleptics the experiences are timed differently, effectively occurring when the person is awake.

Causes of Narcolepsy

The causes of narcolepsy are unknown, but it is clear that the parts of the brain responsible for sleep, and especially REM sleep, are not functioning correctly. There are a number of genes that are typically different in narcoleptics, but the presence of these differences does not always mean that the person will suffer from narcolepsy. Equally, the absence of these gene variations does not mean a person will not suffer from narcolepsy.

In rare cases, brain damage may cause the onset of narcolepsy and it is thought that environmental factors may play a role for some.

Treatment for Narcolepsy

Treatment for narcolepsy is symptomatic – in other words the symptoms are treated, rather than the disease itself. Treatment involves reducing daytime sleepiness and decreasing cataplexic attacks.

For daytime sleepiness, amphetamines have been used for a long time, but have undesirable long term effects. Modafinil is also approved for treating daytime sleepiness and does not have the range of side-effects associated with amphetamines. Some antidepressants are successful in reducing cataplexy, but there are typically side-effects.

Behavioral changes are also important – for example improving nighttime sleep as much as possible and timing naps during the day. Support groups exist and can be very important to the mental well-being of sufferers. If you suspect you have narcolepsy, please discuss your symptoms with your doctor or sleep specialist.