Narcolepsy
Narcolepsy is a relatively uncommon condition that affects the nervous system. Persons with narcolepsy - known as narcoleptics - suffer from an uncontrollable desire to sleep and from sudden attacks of sleep that can occur at any time. They can fall asleep in the middle of a conversation, at the wheel of a vehicle or while preparing a meal. Narcoleptics can succumb to sleep episodes lasting anywhere from a few minutes to an hour if left undisturbed. It is, however, easy to wake narcoleptics as they rarely experience deep sleep. Persons with narcolepsy may experience several episodes of sudden onset of sleep a day or only a few episodes a year. Generally speaking, the condition is first noticed in teenagers and young adults.
Causes
The cause of narcolepsy has not yet been determined. There does however, appear to be a genetic factor predisposing family members to this condition. It would also appear that a hormone deficiency (hypocretin) in the brain could also play a role in the development of narcolepsy. Research in this area is ongoing.
Symptoms
The primary symptom of narcolepsy is, without a doubt, excessive daytime sleepiness. Narcoleptics may also experience other symptoms specific to this disorder.
Since narcoleptics do not require more sleep than others, the quality of their sleep at night is often substandard. Their sleep is not as restful and may be interrupted by bouts of insomnia.
Persons with narcolepsy may also suffer from cataplexy, a condition characterized by the loss of voluntary muscle tone. Often triggered by strong emotional reactions (laughter, anger, etc.), cataplexy can affect a single muscle or the entire body. As a result of these emotional reactions, narcoleptics can lose all muscle function, collapse and drop to the ground. This particular symptom has been known to occur before the sudden onset of sleep. Although it may seem serious and frightening at first, sufferers eventually become familiar with the condition and develop measures to help them cope. For example, to prevent an unpleasant fall, they may opt to sit rather than stand during a conversation.
Certain sleep-related problems can also manifest themselves. Narcoleptics may experience temporary but complete paralysis that prevents them from moving for a few seconds. This generally occurs just before drifting off to sleep or upon waking. They may also experience vivid dreams that project into the waking period. Specialists call these hypnagogic hallucinations as they happen while the person is awake and therefore cannot be classified as dreams. These types of hallucinations are primarily visual and sensory.
Diagnosis
Narcolepsy is diagnosed by a physician and, on occasion, by a neurologist or sleep specialist. Symptoms can be highly suggestive of narcolepsy but a multiple-sleep latency test (MSLT), which is conducted in a sleep disorder clinic, is recommended to confirm the diagnosis. This test will measure the time it takes for a person to fall asleep during the day and to reach REM sleep. REM sleep is generally the last period of sleep and is characterized by light sleep during which time the body does not move and when dreaming occurs. During their sleep episodes (in the daytime), narcoleptics typically fall right into REM sleep. This is highly indicative of narcolepsy.
Treatment and Prevention
There is no cure or treatment for narcolepsy. Certain medications, however, can help alleviate and, on occasion, completely bring symptoms under control. Stimulants such as modafinil (Alertec™), methylphenydate (Ritalin™) or amphetamines are commonly used to fight daytime sleepiness. Certain types of antidepressants (ex. imipramine) are also used to fight the symptoms associated with cataplexy, sleep paralysis and hypnagogic hallucinations. Adopting certain healthy habits may also help improve the situation:
- Develop a regular sleep routine - go to bed and get up at the same time - even on weekends.
- Avoid alcohol and nicotine.
- Avoid driving long distances.
- Take short naps throughout the day.
- Practice moderate exercise.