20-22 Underwood Street, Corrimal New South Wales 2518, Australia
Narcolepsy
People with narcolepsy have excessive sleepiness during the day despite adequate sleep duration overnight. The sleepiness may be characterised by an inability to stay awake during passive situations, an irresistible urge to nap or, occasionally, falling asleep in situations where it is inappropriate to do so (such as in meetings, at school or when driving). Many people with narcolepsy find short naps to have a refreshing and restorative effect.
Cataplexy involves a sudden loss of muscle power which is triggered by strong emotion such as laughter. Episodes of cataplexy typically last for up to a couple of minutes, during which time the person is both conscious and awake. Cataplexy does not affect the ability to breathe. Episodes of cataplexy can involve all muscles of the body (resulting in the person to fall over or buckle at the knees) or may only involve only some muscle groups (causing head nodding or jaw sagging, for example).
Many people with narcolepsy also experience other symptoms such as sleep paralysis and hallucinations, although these can occur in other conditions and in some healthy people. Sleep paralysis occurs when someone wakes during the night and is unable to move for a short period of time. Hallucinations can occur at the beginning of sleep (known as hypnagogic hallucinations) and end of sleep (known as hypnopompic hallucinations). People will perceive images, shapes or shadows within their bedroom environment and are often confused as to whether they are dreaming or not.
Narcolepsy occurs in genetically susceptible people. Infections (such as streptococcus and influenza) and some vaccinations have been shown to trigger the onset of narcolepsy. It occurs due to autoimmune destruction of a small group of cells in an area of the brain known as the lateral hypothalamus. These cells normally produce a chemical called hypocretin (also known as orexin), which is very important in both wakefulness and in stabilising the transition between being awake and sleeping.
It affects about 1 person in 2000. Both men and women get narcolepsy. It can occur at any age but most commonly develops in the second decade of life, with a smaller peak at around the age of 40.
There is currently no cure for narcolepsy although symptoms may be controlled with medication. Wake-promoting medications are used to control excessive sleepiness and some antidepressants can be effective in controlling other symptoms such as cataplexy and hallucinations. People with narcolepsy often feel refreshed after short power naps during the day.
It is important to maintain a healthy lifestyle including minimising alcohol and ensuring enough sleep at night. Planned power naps during the day can be effective at reducing sleepiness. Some people with cataplexy are able to ‘flatten’ their emotions to reduce episodes of cataplexy. Driving should be avoided where there is excessive daytime sleepiness or uncontrolled cataplexy. Make family and friends aware of your diagnosis so they can provide support where needed.