What Is Narcolepsy?
Medically reviewed by Daniel Combs, MD
Narcolepsy is a chronic sleep disorder that interferes with the brain’s ability to control the body’s sleep-wake cycles. It’s commonly referred to as a neurological condition, but it can affect many other parts of the body and limit your ability to function normally.
Narcolepsy isn’t very common; about 1 in every 2,000 people are estimated to have it. The most well-known symptom of narcolepsy is excessive sleepiness that causes you to fall asleep without warning, but there are several other symptoms, too, like hallucinations, cataplexy, and insomnia.
Narcolepsy itself isn’t harmful, but excessive sleepiness can lead to accidents and injuries, and people with narcolepsy are more likely to develop other conditions that negatively affect their health.
There are two primary types of narcolepsy, categorized by whether or not a person has something called cataplexy, a symptom that’s unique to narcolepsy. Cataplexy is characterized as weakness in voluntary muscles after experiencing intense emotions.
Type 1 Narcolepsy
People with type 1 narcolepsy have cataplexy and low levels of hypocretin. Hypocretin, sometimes called orexin, is a neurotransmitter (a brain hormone) that regulates sleep, food intake, and general wakefulness. Hypocretin is produced in an area of the brain called the hypothalamus, which is located behind your eyes.
Type 2 Narcolepsy
People with type 2 narcolepsy experience excessive sleepiness but do not have cataplexy or low levels of hypocretin.
There is also a subtype of this condition called secondary narcolepsy, which is caused by brain injury. People with secondary narcolepsy often have the same symptoms as people with type 1 or 2 narcolepsy but also neurological symptoms.
The most common visual image of narcolepsy is a person suddenly falling asleep while performing another task, unable to control their ability to stay awake. While excessive sleepiness is the top symptom of narcolepsy, it’s not the only one. Other symptoms include:
Excessive daytime sleepiness: Everyone diagnosed with narcolepsy experiences excessive daytime sleepiness; no matter how much sleep they get, or how long it's been since they last slept, people with narcolepsy may never feel refreshed. This sleepiness can lead to “sleep attacks,” or the characteristic symptom of dropping off to sleep without warning, regardless of the environment.
Cataplexy: Cataplexy is the sudden loss of muscle tone. It makes people with type 1 narcolepsy feel weak and unable to control their movements. These episodes are usually preceded by strong emotions, like joy, fear, or anger. Cataplexy can be mild or severe, but most episodes only last a few minutes. Not everyone with narcolepsy has episodes of cataplexy.
Insomnia: Although people with narcolepsy have excessive daytime sleepiness, nighttime sleep is often fragmented and poor. They often don’t sleep well, either failing to stay asleep or can’t fall asleep at all.
Sleep paralysis: People with narcolepsy are more likely to experience episodes of sleep paralysis, a phenomenon where you are cognitively awake but your body remains locked in rapid eye movement (REM) sleep, unable to move for several seconds to minutes. REM sleep is the phase of sleep in which dreams usually occur.
Hallucinations: When falling asleep or waking up, people with narcolepsy may have intense and startling sensory hallucinations.
What Causes Narcolepsy?
Narcolepsy is caused by a combination of factors, including genetics and environmental triggers. Type 1 narcolepsy is typically caused by low levels of hypocretin, but it’s less clear exactly what causes type 2 narcolepsy (since hypocretin levels are usually normal).
People with certain genes are more likely to have low levels of hypocretin, and so are people with certain autoimmune conditions (conditions that cause your immune system to attack itself) or people who have had certain types of infections. The 2009 H1N1 influenza (swine flu) epidemic increased the number of new cases of narcolepsy a significant amount.
Most cases of narcolepsy are sporadic, meaning they do not have a genetic component. Although, type 1 narcolepsy can sometimes (although rarely) run in families. About 10% of people with type 1 narcolepsy report a family member with it as well.
Finally, traumatic brain injuries (TBIs) can also trigger narcolepsy, though this isn’t common, either.
People of any gender are equally as likely to have narcolepsy. Symptoms can begin at any age, though it’s more common to develop narcolepsy in childhood or young adulthood. Some research also shows that narcolepsy may most likely occur between the ages of 15 and 36.
There are a few things that increase your overall risk of developing narcolepsy:
Having an autoimmune disorder
Having a gene variation called HLA-DQB1*06:02
Being a first-degree relative of someone with type 1 narcolepsy
Narcolepsy can be diagnosed using several strategies. A primary care provider may be able to perform these tests and interpret the results, or you may be referred to a sleep medicine specialist or neurologist. They'll use the following methods to assess you:
Physical exam and medical/family history
Evaluation of symptoms (i.e. how often you have excessive daytime sleepiness, whether you experience cataplexy or hallucinations, etc)
Sleep studies, including an overnight polysomnogram to evaluate your vitals while you sleep and a multiple sleep latency test to see how quickly you fall asleep during the day
A cerebrospinal fluid test to measure your hypocretin levels—though this is not mandatory for diagnosis and may or may not be performed
Treatments for Narcolepsy
You can’t cure narcolepsy, but there are medications you can take and lifestyle changes you can adopt to manage your symptoms.
A variety of medications can be used to help manage narcolepsy, depending on the type, cause, and symptoms. These include the following categorizations:
Antidepressants: Serotonin and norepinephrine reuptake inhibitors (SNRIs) or selective serotonin reuptake inhibitors (SSRIs) can help suppress REM sleep and improve symptoms caused by cataplexy, sleep paralysis, and hallucinations. Tricyclic antidepressants can also help with cataplexy.
Stimulants: These drugs stimulate your central nervous system to prevent excessive daytime sleepiness and help you stay awake.
Histamine blockers (histamine 3 receptor antagonists): This type of medication helps block histamines, which can contribute to daytime drowsiness.
Sometimes sodium oxybate, a central nervous system depressant, is prescribed to treat cataplexy in people with type 1 narcolepsy, but this drug is highly regulated and can cause serious side effects.
There are a few non-medication ways to combat the excessive daytime sleepiness, nighttime insomnia, and other symptoms of narcolepsy. Experts recommend maintaining a regular sleep schedule that includes frequent, short naps, avoiding caffeine, alcohol, and heavy meals before bed, exercising daily, and having a calming wind-down routine before going to bed.
Unfortunately, there isn't a way to prevent or cure narcolepsy at this time. However, by following some of the lifestyle recommendations listed above, you can reduce the effect of narcolepsy on your life.
Narcolepsy can occur alongside several other conditions, in some cases causing those other conditions to develop. These include:
Obstructive sleep apnea: Adults and children with narcolepsy are more likely to have sleep apnea, and the crossover in symptoms—particularly excessive daytime sleepiness—can make it hard for people to get the right diagnosis.
Heart disease: Narcolepsy can lead to hypertension and high cholesterol, both of which can affect your heart health, and are tied to a higher risk of stroke and heart attack. One possible reason is because the lower levels of hypocretin common in narcolepsy inhibit the body’s ability to lower its blood pressure during sleep, among other reasons.
Psychiatric conditions: People with narcolepsy are more likely to develop depression and anxiety, partly because of the effects of excessive daytime sleepiness on their quality of life.
Obesity and diabetes: Narcolepsy is associated with a higher body mass index (BMI), in part due to lower levels of hypocretin (which plays a role in regulating food intake). This can not only contribute to obesity but raise your risk of developing diabetes.
Related: BMI Not Always a Good Indicator of Metabolic Health, Study Shows
Living With Narcolepsy
You will always have symptoms of narcolepsy since there’s no way to cure it, but symptoms don’t usually get worse and sometimes improve as you age. Having narcolepsy doesn’t change your life expectancy; it’s important, though, to maintain your health in other ways, especially if your narcolepsy has caused any comorbidities like sleep apnea or hypertension.
People with narcolepsy should consider their safety in the environments where they spend their time, since sleep attacks and episodes of cataplexy can result in injury. Families of school-age children can work with their child’s teachers and administrators to develop a special needs accommodation plan, and adults should discuss their narcolepsy with their employer so they can receive work accommodations under the Americans with Disabilities Act (ADA).
Frequently Asked Questions
At what age does narcolepsy start?
Narcolepsy can start at any age but is most likely to begin in childhood and young adulthood.
Is narcolepsy considered a disability?
In some contexts, yes. Narcolepsy is considered a disability under the Americans with Disabilities Act (ADA), so employers have to accommodate employees with narcolepsy and can’t discriminate on the basis of someone having it.
However, narcolepsy is not recognized by the Social Security Administration (SSA) as a condition that automatically qualifies you to receive disability benefits. I your condition is severe enough to interfere with your ability to work, you’ll have to take extra steps to demonstrate that to government agencies.
What is the life expectancy of someone with narcolepsy?
Narcolepsy itself doesn’t shorten your life expectancy, but accidents and injuries caused by your symptoms (like falling asleep while driving), as well as comorbid conditions like heart disease, can affect your overall health. It’s important to treat both your narcolepsy and any other related health conditions in order to live the longest and healthiest life possible.
For more Health news, make sure to sign up for our newsletter!
Read the original article on Health.