Daytime drowsiness can be caused by several conditions, including sedating medications, chronic illness, or depression. Also among the causes is a chronic sleep disorder known as narcolepsy.
Dr. William Broughton, professor of internal medicine at the University of South Alabama College of Medicine, said that narcolepsy is a sleep disorder characterized by overwhelming daytime drowsiness and sudden attacks of sleep.
Dr. Broughton, who is board certified in sleep medicine, said people with narcolepsy often find it difficult to stay awake for long periods of time, regardless of the circumstances, and it can cause serious disruptions in their daily routine.
For example, those affected may suddenly nod off while working or talking with friends. They may sleep for a few minutes or up to a half-hour before awakening and feeling refreshed, but eventually they fall asleep again.
According to Dr. Broughton, excessive daytime sleepiness usually is the first symptom to appear and is often the most troublesome, making it difficult for the person to concentrate and fully function.
“People with narcolepsy experience sleepiness almost all the time, but some experience worse symptoms than others,” he said. “Some patients diagnosed with narcolepsy experience cataplexy, which is a sudden loss of muscle control that causes paralysis to happen to a person while awake. This can cause numbness in different muscles, and may cause them to fall over.”
Cataplexy can cause a number of physical changes, from slurred speech to complete weakness of most muscles, and may last for a few seconds to a few minutes. Cataplexy is uncontrollable and is triggered by intense emotions, usually positive ones such as laughter or excitement, but sometimes fear, surprise or anger. For example, a person’s head may droop uncontrollably or their knees may suddenly buckle when they laugh. It is something that can occur once a month or twice a day. It varies significantly with no particular pattern, and patients do not necessarily have to have muscle tone issues to suffer from narcolepsy.
“Sleepiness is always a symptom for patients with narcolepsy, but cataplexy may never develop,” he said. “Cataplexy appears to be linked to genetic abnormality, but in other cases people have developed it following a head injury.”
Dr. Broughton explained that when narcoleptics fall asleep, they dream immediately. Some patients can experience a temporary inability to move or speak while falling asleep or upon waking, which is called sleep paralysis. These episodes are usually brief — lasting one or two minutes — but can be frightening. Not everyone with sleep paralysis has narcolepsy, however.
The other symptom of narcolepsy may be hallucinations. Because you may be semi-awake when you begin dreaming, you experience your dreams as reality, and they may be particularly vivid and frightening.
According to Dr. Broughton, the narcolepsy diagnosis is made by testing the patient during a series of naps in a sleep lab. These tests can also help doctors rule out other possible causes of your signs and symptoms. Other sleep disorders, such as sleep apnea, can also cause excessive daytime sleepiness.
“We measure how fast the patient falls asleep over five naps and see if the patient experiences dream sleep,” he said. “If they fall asleep quickly and have dream sleep twice, it is diagnosed as narcolepsy. Then we can further characterize their condition as narcolepsy with or without cataplexy.”
Although narcolepsy is a lifelong illness, Dr. Broughton said he can prescribe medicine to help patients improve their quality of life.
“We can evaluate you and tell you if there is measureable sleepiness, but we can’t cure the disease,” he said. “By taking the sleep tests in our lab we can diagnose the problem and enhance the patient’s quality of life with medication.”
To make an appointment with Dr. Broughton, call (251) 445-9167.