Narcolepsy is a chronic, neurological sleep disorder characterized by excessive daytime sleepiness, abnormal REM sleep, and at times, cataplexy. A person with narcolepsy will experience extreme fatigue and may fall asleep at odd and inappropriate times, such as at work or school. A brief nap is refreshing, but the sleepiness re-occurs a few hours later.
Symptoms of Narcolepsy
In addition to excessive daytime sleepiness, patients may display the following symptoms:
- Cataplexy – a sudden weakening of the muscles, often triggered by a strong emotion, such as laughter, surprise, fear or anger. Cataplexy occurs more frequently during times of stress or fatigue. The cataplectic attack may involve only a slight feeling of weakness and limp muscles (such as sagging facial muscles, loss of arm strength, buckling knees), but it also may result in total collapse or even muscle paralysis. These attacks may last from a few seconds up to thirty minutes.
- Hypnagogic hallucinations – vivid, realistic, sometimes disturbing dreamlike experiences that occur while dozing, falling asleep or upon awakening.
- Sleep paralysis – the temporary inability to talk or move when waking or going to sleep.
- Automatic behavior - a person continues to function or talk while being half asleep, and awakens with no memory of doing these activities.
- Difficulties maintaining sleep – Nighttime sleep is disturbed. Patients often fall asleep rapidly, but are unable to stay asleep for more than a few hours at a time.
Narcolepsy is often mistaken for depression, epilepsy or the side-effects of medication. Symptoms are usually first noticed in teenagers or young adults, though it can occur in men and women of any age, and children as young as 3 years old.
Narcolepsy is often misdiagnosed or not diagnosed at all. The sleepiness may be mistaken for low motivation, laziness, or depression. Attention deficits may lead to a mistaken diagnosis of a learning disability. The hallucinations may be mistaken for psychosis or epilepsy.
The symptoms of narcolepsy, often become severe enough to cause serious disruptions in a person’s social, personal and professional lives and can severely limit activities. Accidental injury is not uncommon.
The Cause of Narcolepsy
In most cases of narcolepsy with cataplexy, the symptoms are caused by a decreased level of the brain chemical, hypocretin.
In cases of narcolepsy without cataplexy, the cause of the symptoms remains unclear.
Diagnosing Narcolepsy
The Sleep Specialists at Iowa Sleep use two main tests to diagnose narcolepsy: the polysomnogram (PSG) and the multiple sleep latency test (MSLT). The PSG continuously records brain waves during sleep, as well as a number of nerve and muscle functions during sleep. The person with narcolepsy will usually fall asleep rapidly, enter REM sleep quickly, and will awaken frequently during the night.
The MSLT gives the person 4 – 5 opportunities to sleep every two hours during normal wake times. This test measures the extent of daytime sleepiness (how fast the patient falls asleep in each nap), and also how quickly REM sleep begins. The MSLT is positive for narcolepsy when the patient falls asleep within 8 minutes, and had at least 2 naps where REM sleep was reached.
Treating Narcolepsy
While there is no cure for narcolepsy, there are prescription and non-prescription treatments available to correct the symptoms. The doctors at Iowa Sleep will help you identify which combination of treatments is best for you.
If you want to learn more about narcolepsy, visit The Narcolepsy Network for additional education and support.
