Narcolepsy is a condition that affects the nervous system. It causes abnormal sleep that can affect a person’s quality of life.
Narcolepsy is a rare chronic condition. Experts estimate it affects about 1 in 2,000 people.
The symptoms of narcolepsy usually begin between the ages of 10 and 25 years, although the condition is often not recognized right away and often misdiagnosed.
Narcolepsy causes significant daytime drowsiness and “sleep attacks,” or overwhelming urges to fall asleep, and poor fragmented sleep at night.
In a majority of cases, it also causes unexpected and temporary loss of muscle control, known as cataplexy. This can be mistaken for seizure activity, especially in children.
Narcolepsy isn’t a deadly disease by itself, but episodes can lead to accidents, injuries, or life threatening situations.
Also, people with narcolepsy can have difficulty maintaining jobs, doing well in school, and have problems maintaining relationships due to the attacks of excessive daytime sleepiness.
Treatments are available to help manage the condition.
There are two types of narcolepsy:
- Type 1 is the most common. It includes a symptom called cataplexy, or sudden loss of muscle tone. People with this type have episodes of extreme sleepiness and cataplexy during the daytime due to low levels of a protein called hypocretin. (Hypocretin is sometimes referred to as orexin.)
- Type 2 is narcolepsy without cataplexy. Usually, people with type 2 narcolepsy have normal levels of hypocretin.
How often and how intensely narcolepsy symptoms occur can vary. Below are common symptoms.
Significant daytime sleepiness
Everyone with narcolepsy has excessive daytime sleepiness (EDS), in which you suddenly experience an overwhelming urge to sleep. EDS makes it difficult to function properly during the day.
Cataplexy is a sudden, temporary loss of muscle tone. It can range from drooping eyelids (referred to as partial cataplexy) to total body collapse.
Laughing and intense emotions, such as excitement and fear, can trigger cataplexy. How often it occurs varies from person to person. It can happen several times per day to once a year.
Sometimes cataplexy may occur later in the disease course, or it may not be known if you take medications that suppress it, such as certain antidepressants.
Poorly regulated rapid eye movement (REM) sleep
REM sleep is the sleep stage when you have vivid dreams with loss of muscle tone. It usually starts about 90 minutes after you fall asleep. REM sleep can happen at any time of day for people with narcolepsy, within about 15 minutes after falling asleep.
Sleep paralysis is an inability to move or speak while falling asleep, sleeping, or waking. Episodes last only a few seconds or minutes.
Sleep paralysis mimics the paralysis seen during REM sleep. It doesn’t affect eye movements or the ability to breathe, though.
Hallucinations when falling asleep
People with narcolepsy may have vivid hallucinations at the same time as sleep paralysis. The hallucinations usually occur when falling asleep or waking up.
Although people with narcolepsy are excessively sleepy during the daytime, they may have difficulty falling asleep at night.
After falling asleep during an activity such as eating or driving, a person with narcolepsy may continue doing that activity for a few seconds or minutes without consciously realizing they’re doing it.
Narcolepsy can also be associated with other sleep conditions, such as:
- obstructive sleep apnea
- restless legs syndrome
Narcolepsy is a chronic condition. Although it doesn’t have a current cure, treatments can help you manage your symptoms.
Medications, lifestyle adjustments, and avoiding hazardous activities can all play a part in managing this condition.
There are several classes of medications doctors use to treat narcolepsy, such as:
- Stimulants. These include armodafinil (Nuvigil), modafinil (Provigil) and methylphenidate (Ritalin). They may improve wakefulness. Although side effects are uncommon, they may include nausea, headache, or anxiety.
- Serotonin-norepinephrine reuptake inhibitors (SNRIs). SNRIs such as venlafaxine (Effexor) can help treat cataplexy, hallucinations, and sleep paralysis. Side effects may include digestion problems, insomnia, and weight gain.
- Selective serotonin reuptake inhibitors (SSRIs). SSRIs such as fluoxetine (Prozac) can also help regulate sleep and improve your mood. However, side effects such as lightheadedness and dry mouth are common.
- Tricyclic antidepressants. These may include amitriptyline and nortriptyline. They may reduce cataplexy, sleep paralysis, and hallucinations. These older medications can have unpleasant side effects, such as constipation, dry mouth, and urinary retention.
- Sodium oxybate (Xyrem). Xyrem is the only treatment approved by the Food and Drug Administration (FDA) to prevent cataplexy and address excessive daytime sleepiness. However, like other medications, there are pros and cons to consider with your doctor. Side effects may include nausea, depression, and dehydration.
- Pitolisant (Wakix). Wakix releases histamines in the brain to decrease daytime sleepiness. It’s been recently FDA-approved to treat narcolepsy. Side effects may include headache, nausea, anxiety, and insomnia.
If you’re experiencing excessive daytime sleepiness or one of the other common symptoms of narcolepsy, talk to your doctor.
Daytime sleepiness is common in many types of sleep disorders. Your doctor will ask you about your medical history and perform a physical exam. They’ll look for a history of excessive daytime drowsiness and episodes of sudden loss of muscle tone.
Your doctor will likely order a sleep study for you as well as several other tests to determine and confirm their diagnosis.
Here are some common sleep evaluations your doctor may order:
- Polysomnogram (PSG) testing requires you to spend the night in a medical facility. Clinicians will monitor you and use electrodes while you sleep to measure your brain activity, heart rate and rhythm, eye movement, muscle movement, and breathing.
- Your doctor will ask you for a detailed sleep history, which may include completing the Epworth Sleepiness Scale (ESS). The ESS is a simple questionnaire. It asks how likely you are to sleep in different circumstances.
- Your doctor may ask you to keep a detailed diary of your sleep pattern for about a week. This sleep record will help show your doctor the correlation between your alertness and your sleep pattern.
- An ActiGraph or other home monitoring system can keep track of how and when you fall asleep. This device is worn like a wristwatch and may be used together with a sleep diary.
- A multiple sleep latency test (MSLT) determines how long it takes you to fall asleep during the day and how quickly you enter REM sleep. This test is often given the day after a PSG. You’ll need to take four to five naps throughout the day, each 2 hours apart.
- Your doctor might use a spinal tap, or lumbar puncture, to collect cerebrospinal fluid (CSF) to measure your hypocretin levels. Hypocretin in CSF is expected to be low in people with type 1 narcolepsy. For this test, your doctor will insert a thin needle between two lumbar vertebrae. However, it’s not commonly done in clinical practice to diagnose narcolepsy.
The exact cause of narcolepsy is unknown. However, most people with type 1 (narcolepsy with cataplexy) have a decreased amount of a brain protein called hypocretin. One of the functions of hypocretin is regulating your sleep-wake cycles.
Scientists think many factors may cause low hypocretin levels. A gene mutation has been identified that causes low levels of hypocretin. It’s believed that this hereditary deficiency, along with an immune system that attacks healthy cells, contributes to narcolepsy.
Other factors, such as stress, exposure to toxins, and infection, also may play a role.
Some of the risk factors for narcolepsy may include the following:
- Family history. If you have a family member with narcolepsy, you’re 20 to 40 times more likely to have the condition.
- Age. People between ages 10 and 30 are more likely to receive a diagnosis with narcolepsy. However, narcolepsy is commonly underdiagnosed or misdiagnosed.
The complications associated with narcolepsy include the following:
- People with narcolepsy also often have depression and anxiety, but it’s not clear whether these are symptoms of narcolepsy or due to its symptoms affecting their quality of life.
- Because of excessive sleepiness and cataplexy, your social life may be affected. For example, you may have difficulty staying awake during social gatherings, or you may lose muscle control when laughing.
- Perhaps because of lower activity levels or a slower metabolism, many people with narcolepsy are overweight. Adults with narcolepsy weigh about 15 to 20 percent more on average than the general population.
- Studies suggest that people with narcolepsy may have an increased risk for suicidal behavior.
To avoid these complications, work closely with your healthcare team to address any symptoms or treatment side effects that concern you.
Here are some steps you can take to make living with narcolepsy easier and safer:
- Tell your teachers and supervisors about your condition in case you do fall asleep at school or work.
- Be aware that some narcolepsy treatments will cause you to test positive for stimulants on drug screens for employment. Talk to your employer in advance to prevent misunderstandings.
- Eat light or vegetarian meals during the day. Don’t eat a heavy meal before important activities.
- Try taking 10- to 15-minute naps after meals.
- Schedule naps throughout the day. This may help you avoid daytime drowsiness.
- Avoid nicotine and alcohol. They can worsen symptoms.
- Exercise regularly. This can help you rest better at night, keep you alert during the day, and help manage your weight.
- Some states may limit driving privileges for people with narcolepsy. Be sure to check with your local department of motor vehicles. They can help keep you from endangering anyone and yourself.
Living with narcolepsy can be challenging. It can be stressful to have episodes of excessive sleepiness, and it’s possible to injure yourself or others during an episode.
But you can successfully manage the condition. By obtaining the correct diagnosis, working with your doctor to find the best treatment for you, and following the above tips, you can continue living a healthy life.