“Sleep attacks” that occur in the daytime.
What is narcolepsy?
Narcolepsy is a chronic brain disorder that involves poor control of sleep-wake cycles. People with narcolepsy experience periods of extreme daytime sleepiness and sudden, irresistible bouts of sleep that can strike at any time. Although this condition can appear at any age, it most often begins in adolescence. Narcolepsy affects about one in 2,000 people in the United States and Western Europe. However, the disorder is likely under-diagnosed, particularly in people with mild symptoms.
What causes narcolepsy?
Narcolepsy may have several causes. Most people with narcolepsy have low levels of certain neurotransmitters that help regulate biological processes.
Most cases of narcolepsy are sporadic, meaning the disorder occurs in individuals with no known family history of the disorder.
Other factors appear to play important roles in the development of narcolepsy. Some rare cases are known to result from traumatic injuries to parts of the brain involved in REM sleep, or from tumor growth and other disease processes in the same regions. Infections, exposure to toxins, dietary factors, stress, hormonal changes and alterations in a person's sleep schedule are just a few of the many factors that may contribute to the disease development.
What are the symptoms of narcolepsy?
Narcolepsy is characterized by excessive daytime sleepiness, also known as EDS. Affected individuals feel tired during the day, and several times a day they may experience an overwhelming urge to sleep. “Sleep attacks” can occur at unusual times, such as during a meal or in the middle of a conversation. They last from a few seconds to a few minutes and often lead to a longer nap, after which affected individuals wake up feeling refreshed.
Other than EDS, the most common major symptom is cataplexy, which occurs in about 70 percent of all people with narcolepsy. Cataplexy is a sudden loss of muscle tone while the person is awake that leads to feelings of weakness and a loss of voluntary muscle control. Sleep paralysis and hallucinations are somewhat less common. Only 10 percent to 25 percent of affected individuals, however, display all four of these major symptoms during the course of their illness.
How does Ohio State diagnose narcolepsy?
A clinical examination and exhaustive medical history are essential for diagnosis and treatment. Your physician may ask you to keep a sleep journal noting the times of sleep and symptoms over one to two weeks. Although none of the major symptoms are exclusive to narcolepsy, cataplexy is the most specific symptom and is rarely present outside of narcolepsy.
A physical exam can rule out or identify any other conditions that may be causing the symptoms. A battery of specialized tests, which can be performed in a sleep disorders clinic, is usually required before a diagnosis can be confirmed. These include an overnight sleep study and a multiple sleep latency test that’s conducted during the day.
How does Ohio State treat narcolepsy?
Narcolepsy cannot yet be cured, but some of the symptoms can be treated with medicines and lifestyle changes. Drug therapy should accompany various behavioral strategies according to the needs of the affected individual.
Such behavioral strategies include:
- Short, regularly scheduled naps at times when sufferers tend to feel sleepiest
- Maintaining a regular sleep schedule
- Avoiding alcohol and caffeine for several hours before bedtime
- Avoiding large, heavy meals and smoking just before bedtime
- Engaging in relaxing activities such as a warm bath before bedtime
- Exercising for at least 20 minutes per day at least four to five hours prior to bedtime
Safety precautions, particularly when driving, are particularly important for all persons with narcolepsy. EDS and cataplexy can lead to serious injury or death if left uncontrolled. Suddenly falling asleep or losing muscle control can transform actions that are ordinarily safe, such as walking down a long flight of stairs, into hazards. People with untreated narcoleptic symptoms are involved in automobile accidents roughly 10 times more frequently than the general population. However, accident rates are normal among individuals who have received appropriate medication.