What is narcolepsy?
Narcolepsy is a disorder of both impaired wakefulness and impaired sleep. It is often not diagnosed until young adulthood or middle age. It is characterized by excessive daytime sleepiness. Some people will experience this as the need for frequent naps. Some people compensate with taking in large quantities of caffeine. Others will have such severe “sleep attacks” that they will fall asleep uncontrollably, even while talking or eating. People with narcolepsy also have poor nighttime sleep with frequent awakenings and insomnia. They may have vivid dreams, especially in the early morning.
Another symptom which is unique to people with narcolepsy is cataplexy. Cataplexy is the experience of muscular weakness, and usually affects the muscles supporting the head and trunk or chest but sparing the arms and legs. However, it can occur in any muscle group and can even be limited to facial muscles. With cataplexy, the muscle suddenly and unexpectedly loses tone and can become very weak. This is often triggered by emotion, such as laughter, excitement, surprise, or anger. It lasts a few minutes and then spontaneously goes away. In its most severe form, it is also sometimes called “pseudo-seizure,” since these attacks the people are often awake and frightened with an inability to control their head or trunk and collapse to the ground flailing their extremities.
What causes narcolepsy?
Narcolepsy is caused by a lack of hypocretin in the brain, which is thought to help control the onset of sleep and wake. This can be due to having an abnormal at birth (i.e., genetic defect) and can run in families. It may also be caused by other factors and or injury.
How do you test for narcolepsy?
Narcolepsy can be tested for by genetic testing for the loss of the gene which makes hypocretin or by checking hypocretin in the fluid surrounding the brain (cerebrospinal fluid). However, it is usually tested and confirmed by sleep testing, which shows disrupted nocturnal sleep, and abnormal sleep in the daytime (daytime REM sleep).
How is narcolepsy treated?
Narcolepsy can be managed by trying to improve nocturnal sleep and suppress the onset of sleep in the daytime. Medications are frequently used for two purposes, to promote sleep and to promote wakefulness. The newest medication is sodium oxybate, and acts directly on the central nervous system (brain). Other medications include the stimulants, which are used to promote wakefulness and other non-stimulant wake promoting agents (armodafinil). In addition to medications, patients may use caffeine or prophylactic napping also to promote daytime wakefulness. Prophylactic naps consist of brief 15 min naps (limited by an alarm clock) scheduled throughout the day in order to relieve daytime sleepiness.
Can other things mimic narcolepsy?
Many things can mimic narcolepsy, ranging from sleep deprivation to medication side effects to seizures and brain tumors. If you feel that you may have narcolepsy, you should seek further evaluation with a sleep physician.
What if my sleep attacks are provoked by a large carbohydrate meal, salty food, or alcohol?
There is a rare condition called hypokalemic periodic paralysis. It is most commonly seen in Asian people and usually involves muscle weakness at the time the person is waking up from sleep. It is due to a defect in the way that potassium is handled by the body. Avoiding triggers, such as large portions of carbohydrates, salty foods or alcohol may help. Affected persons may also take extra potassium during an attack for relief. There are also medications which may help the body to better maintain potassium as well. Anyone with these symptoms should be evaluated by a physician, as weakness in the respiratory muscles (used to breath) or throat muscles (which keep your airway open) can lead to a fatal attack.
What is Sudden Unexplained Nocturnal Death or SUNDS?
SUNDS refers to Sudden Unexplained Nocturnal Death Syndrome. This occurs in young adults from Southeast Asia (most commonly Laos, Vietnam, and Thailand) who usually have been in the US for little more than one year. People with this syndrome may develop a brief episode of respiratory distress during the middle of the night or early morning while sleeping followed by their heart stopping suddenly and unexpectedly. There may be no prior warnings. However, some people may have warning signs such as recurrent palpitations or fainting episodes. Some patients with this disorder have an inherited heart rhythm problem called Brugada’s syndrome which can be provoked by medications. A cardiologist can evaluate the syndrome on an ECGs (electrocardiograms or heart rhythm tracings). If present, persons with this condition can have a defibrillator placed which may prevent death. A defibrillator is a small device (like a pacemaker) that can shock the heart if a life-threatening rhythm is detected.