Definition: Defining the Meaning of Narcolepsy
Narcolepsy, also known as hypnolepsy, is a chronic neurological 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. These sleep attacks usually last a few seconds to several minutes.
Narcolepsy is a neurological condition most characterized by Excessive Daytime Sleepiness (EDS), in which a person experiences extreme tiredness, possibly culminating in falling asleep during the day at inappropriate times, such as at work or school.
A narcoleptic will most probably experience disturbed nocturnal sleep, which is often confused with insomnia, and disorder of REM or rapid eye movement sleep. It is one of the dyssomnias. Dyssomnias are a broad classification of sleeping disorder that make it difficult to get to sleep, or to remain sleeping.
The main characteristic of narcolepsy is excessive daytime sleepiness (EDS), even after adequate night time sleep.
A person with narcolepsy is likely to become drowsy or fall asleep, often at inappropriate times and places.
Daytime naps may occur without warning and may be physically irresistible. These naps can occur several times a day. They are typically refreshing, but only for a few hours.
Drowsiness may persist for prolonged periods of time. In addition, night time sleep may be fragmented with frequent awakenings.
Four other "classic" symptoms of narcolepsy, which may not occur in all patients, are;
- sleep paralysis,
- hypnagogic hallucinations,
- automatic behavior.
Narcolepsy can occur in both men and women at any age, although its symptoms are usually first noticed in teenagers or young adults.
It is estimated that as many as 3 million people worldwide are affected by narcolepsy.
In the United States, it is estimated that this condition afflicts as many as 200,000 Americans, but fewer than 50,000 are diagnosed. While the cause of narcolepsy has not yet been determined, scientists have discovered conditions that may increase an individual's risk of having the disorder. Specifically, there appears to be a strong link between narcoleptic individuals and certain genetic conditions.
There is an average 15-year delay between onset and correct diagnosis which may contribute substantially to the disabling features of the disorder.
Cognitive, educational, occupational, and psychosocial problems associated with the excessive daytime sleepiness of narcolepsy have been documented. For these to occur in the crucial teen years when education, development of self-image, and development of occupational choice are taking place is especially damaging. While cognitive impairment does occur, it may only be a reflection of the excessive daytime somnolence.
Diagnosis is relatively easy when all the symptoms of narcolepsy are present, but if the sleep attacks are isolated and cataplexy is mild or absent, diagnosis is more difficult. It is also possible for cataplexy to occur in isolation.
Two tests that are commonly used in diagnosing narcolepsy are the polysomnogram and the multiple sleep latency test (MSLT). These tests are usually performed by a sleep specialist.
- The polysomnogram involves continuous recording of sleep brain waves and a number of nerve and muscle functions during nighttime sleep. When tested, people with narcolepsy fall asleep rapidly, enter REM sleep early, and may awaken often during the night. The polysomnogram also helps to detect other possible sleep disorders that could cause daytime sleepiness.
- For the multiple sleep latency test, a person is given a chance to sleep every 2 hours during normal wake times. Observations are made of the time taken to reach various stages of sleep (sleep onset latency). This test measures the degree of daytime sleepiness and also detects how soon REM sleep begins. Again, people with narcolepsy fall asleep rapidly and enter REM sleep early.
Narcolepsy treatment is tailored to the individual, based on symptoms and therapeutic response.
The time required to achieve optimal control of symptoms may take several months or longer.
Medication adjustments are also frequently necessary, and complete control of symptoms is seldom possible.
While oral medications are the mainstay of formal narcolepsy treatment, lifestyle changes are also important.
The main treatment of excessive daytime sleepiness in narcolepsy is with a group of drugs called central nervous system stimulants such as methylphenidate, racemic amphetamine, dextroamphetamine, and methamphetamine, or modafinil, a new stimulant with a different pharmacologic mechanism.
Narcolepsy Awareness Information
Black is the color of the narcolepsy awareness ribbon. The month of March is Narcolepsy Awareness Month. The second week of March is National Sleep Awareness Week. The second Saturday of March is Narcolepsy awareness day. Sleep Awareness Week is an annual public education and awareness campaign to promote the importance of sleep. The week begins with the announcement of the National Sleep Foundation's Sleep in America poll results and ends with the clock change to Daylight Saving Time, where Americans lose one hour of sleep.
Quick Facts: Narcolepsy
Scientists have confirmed that narcolepsy is caused by the loss of brain neurotransmitters called hypocretin (also known as orexin). These neurotransmitters are involved in the regulation of the sleep/wake cycle as well as other bodily functions such as blood pressure and metabolism.
Narcolepsy can be difficult to diagnose because some of its symptoms, such as chronic fatigue, are common to many conditions. The average time between the onset of symptoms and diagnosis is seven years. Misdiagnosis is common. In a recent study, 60% of patients were initially misdiagnosed. The most common misdiagnosis was depression (almost one third of the patients), followed by insomnia and obstructive sleep apnea. (Patients' Journeys to a Narcolepsy Diagnosis; Lawrence P Carter, PhD, Christine Acebo, PhD, AnnY Kim, MA)
Hallucinations can accompany sleep paralysis and occur when people are falling asleep, waking, or during sleep. Referred to as hypnagogic hallucinations when occurring during sleep onset and as hypnopompic hallucinations when occurring during waking, these images are unusually vivid, seem real, and can be frightening. Most often, the content is primarily visual, but any of the other senses can be involved.
- The prevalence of narcolepsy is about 1 per 2,000 persons.
- Narcolepsy affects both males and female equally and appears throughout the world.
- Narcolepsy with cataplexy is estimated to affect about one in every 3,000 Americans.
- In the United States, it is estimated that narcolepsy afflicts as many as 200,000 Americans, but fewer than 50,000 are diagnosed.
- Narcolepsy can occur in both men and women at any age, although its symptoms are usually first noticed in teenagers or young adults.
- There is strong evidence that narcolepsy may run in families; around 10 percent of people diagnosed with narcolepsy with cataplexy have a close relative with this neurological disorder.