Excessive sleepiness and other sleep symptoms
Narcolepsy is a neurological disorder that affects how the brain controls sleep and wakefulness. It is a chronic, lifelong condition. People with this problem can experience waves of excessive sleepiness despite getting adequate amounts of sleep. There are several characteristic symptoms of narcolepsy (see below). These symptoms can occur all at once, but more commonly develop gradually over a number of years. Not every person with narcolepsy experiences every symptom that is associated with this disorder.
Who gets it?
Narcolepsy occurs in 1 in every 2000 Americans. It can run in families and can occur in all ages, but the symptoms typically begin in the teenage years.
What causes it?
Scientists do not know why people develop narcolepsy, but they have discovered abnormalities in the parts of the brain that control dream sleep. Specifically, there appears to be a deficiency of a brain chemical in patients with narcolepsy that helps control wakefulness.
What are the symptoms?
- Excessive sleepiness – Almost all patients experience this symptom. Sleepiness usually interferes with normal activities like work or school on a daily basis.
- Cataplexy – a sudden, uncontrollable loss of muscle tone that leads to weakness. It is triggered by strong emotions, such as laughter, anger, fear, or surprise. Attacks can occur at any time and can range in severity from a buckling of the knees to slurred speech to total paralysis that results in collapsing. Weakness usually lasts from a few seconds to several minutes. Attacks can occur as rarely as once or twice a year to as often as several times per day.
- Sleep paralysis – temporary inability to move or speak while falling asleep or waking up. Some people experience the frightening sensation of being unable to breathe. These episodes of paralysis usually last a few minutes, and then the person is able to move and speak again normally.
- Hallucinations – vivid, dream-like images that can be frightening and feel real. They are most commonly experienced when drowsy, falling asleep, or upon awakening.
- Disturbed nighttime sleep – People often have difficulty starting and staying asleep. This can make the daytime sleepiness more severe.
- Automatic behaviors – Some people perform activities, such as talking or putting things away, during sleep episodes. They do not remember performing the activities. Generally, the activities are not performed as well as when done while fully awake.
If you or your doctor suspect that you have narcolepsy, it is best to be evaluated by a sleep medicine physician. After a detailed history and physical exam, sleep testing is usually performed to confirm the diagnosis. There are usually two tests needed. They can be completed within a 24-hour period. The first is an overnight sleep study to rule out other sleep disorders that can result in symptoms similar to narcolepsy. The second study occurs the day after the overnight sleep study and consists of measuring the time needed to fall asleep on repeated nap opportunities. If you fall asleep during the nap study, your sleep stages will be analyzed to see if the pattern is consistent with narcolepsy. Certain medications, including over-the-counter and herbal medications, can interfere with sleep study results. It is important for you to discuss all of the medications that you take with your sleep doctor prior to your sleep studies.
There is no cure for narcolepsy, so treatment focuses on the symptoms. Most patients use a combination of medications and lifestyle modifications to improve their quality of life.
- Maintain a regular sleep schedule
- Avoid intentional sleep loss, such as staying up late on weekends
- Avoid alcohol and other central nervous system depressants, as these can worsen sleepiness
- Take short naps (20-30 minutes in length) as needed to minimize the sleepiness
- Use modest amounts of caffeine to promote alertness as needed
- Use extreme caution when operating motor vehicles or other heavy machinery
- Stimulants such as modafinil (Provigil), armodafinil (Nuvigil), methylphenidate (Ritalin), and amphetamine derivatives (Adderall) can diminish sleepiness
- Certain antidepressant medications like venlafaxine (Effexor) and fluoxetine (Prozac) can reduce cataplexy, hallucinations, and sleep paralysis
- Sodium oxybate (Xyrem) is a unique medication that can help reduce sleepiness and cataplexy