Narcolepsy

What is narcolepsy?

Narcolepsy is listed in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), as a sleep-wake disorder. Per diagnostic criteria, narcolepsy involves repeated periods during which a person has an irresistible urge to sleep, lapses into sleep, or naps over the course of the same day ^[2].

In addition to these sleep episodes, a person with narcolepsy experiences other symptoms, including episodes of cataplexy, during which they lose muscle tone but maintain consciousness. For children, cataplexy involves sudden grimacing or an episode of jaw opening in which the tongue is thrust forward ^[2].

Types of narcolepsy

There are two overarching types of narcolepsy: type 1 and type 2, which are described below ^[3]:

• Type 1 Narcolepsy: Historically called narcolepsy with cataplexy, this form of the condition involves either daytime sleepiness coupled with episodes of cataplexy, or low levels of a hormone called hypocretin. People who experience cataplexy have muscle weakness and loss of muscle control, which is usually triggered by a strong emotion like anger or laughter.
• Type 2 Narcolepsy: Symptoms of this type of narcolepsy are usually less severe, and a person will have normal levels of hypocretin. However, they still experience excessive daytime sleepiness, but often without episodes of cataplexy.

Symptoms of narcolepsy

Common symptoms of narcolepsy are as follows ^[4]:

• Excessive sleepiness
• Experiencing sleep attacks, during which you fall asleep without being able to control it
• Falling asleep while talking to someone, eating, or even while driving
• Waking up feeling refreshed after most sleep attacks
• Having episodes of cataplexy, which involves loss of muscle control and inability to move, often after feeling strong emotions like fear or anger
• Falling and staying paralyzed for several minutes after a severe cataplexy attack
• Experiencing sleep paralysis, which means you cannot move when you are first falling asleep or awakening from sleep
• Falling asleep very quickly (called short sleep onset latency)

Causes of narcolepsy

There is not one single cause of narcolepsy, but rather several risk factors that can increase the likelihood that a person will develop the condition:

• Genetics: Research suggests that certain genes are linked to narcolepsy, and the condition can run in families ^[4].
• Low levels of hypocretin: People with narcolepsy often have low levels of a chemical called hypocretin, which helps us to stay awake. This may be due to an autoimmune reaction that leads to fewer cells available to make the chemical, a lack of which causesdefective signaling ^[4].
• Infections: Some research suggests that being infected with the flu or having unexplained fevers increases the risk of narcolepsy ^[5].
• Stressors: Environmental stressors, such as a significant change in sleeping habits, may lead to narcolepsy ^[5].

Diagnosing narcolepsy

A doctor making a diagnosis of narcolepsy will obtain a medical history from the patient. Narcolepsy is suspected when a patient experiences severe daytime sleepiness. Before diagnosis is made, a doctor will inquire if a patient is consistently getting 6 hours of sleep or more per night. Narcolepsy cannot be diagnosed if a patient consistently sleeps fewer than 6 hours each night ^[1]. 

If narcolepsy is suspected, a polysomnogram, or sleep study is conducted to rule out other sleep disorders and to ensure a patient is sleeping at least 6 hours per night. Next, a doctor will complete a Multiple Sleep Latency Test (MSLT), during which a patient is given the opportunity to nap for 20 minutes. If a patient has narcolepsy, they will take a short amount of time to fall asleep, fewer than 8 minutes on average, and they will rapidly enter REM sleep ^[1]. 

Finally, a doctor will test hypocretin levels to confirm the narcolepsy diagnosis ^[1].

Prevention of narcolepsy

There is no known way to prevent narcolepsy. Instead, a person can learn to manage the condition through quality treatments and self-care.

Treatment for narcolepsy

With treatment, narcolepsy can be manageable. The following treatments are effective for individuals with narcolepsy ^[1] 

• Behavioral Modification:Practicing healthy sleep hygiene and getting an adequate amount of sleep each night can improve narcolepsy. It can also be helpful for narcolepsy patients to schedule 15 to 20 minute naps throughout the day.
• Mental Health Services:Patients with narcolepsy may benefit from counseling and emotional support to help them learn to cope with symptoms. Depression and anxiety are also common among those with narcolepsy, so mental health treatment may be warranted.
• Medications: Narcolepsy medications can make daytime sleepiness and cataplexy more manageable. Common medications used to treat daytime sleepiness in narcolepsy include:
  • Modafinil
  • Armodafinil
  • Stimulant drugs like methylphenidate 

Medications used to treat cataplexy include sodium oxybate, protriptyline, clomipramine, fluoxetine, and venlafaxine as an off-label alternative.

Self-care for narcolepsy

If you live with narcolepsy, there are ways that you can care for yourself to improve your quality of life. Some helpful self-care strategies for narcolepsy include ^[4]: 

• Sleeping in a cool, dark room each night
• Avoiding alcohol, caffeine, and large meals before bed
• Refraining from smoking
• Getting regular exercise to improve night time sleep
• Doing relaxing activities like taking a warm bath before bed
• Telling important people in your life, such as friends, teachers, or employers about your condition, so they are more understanding
• Taking a short nap before activities such as driving

Frequently asked questions about narcolepsy

If you’re looking for information on narcolepsy, the answers to the following questions can also be helpful.

How common is narcolepsy?

The prevalence of narcolepsy depends on the type. For narcolepsy type 1, prevalence  is 14 per 100,000 people. For type 2, prevalence is 65.4 per 100,000 people. The condition is more common in women compared to men and develops most commonly during the teenage years and the early twenties ^[1].

What is the outlook for people with narcolepsy?

Behavioral treatments and medications can make it easier to manage narcolepsy. However, it is a lifelong condition, and there is evidence that it tends to worsen over time. People who have narcolepsy may have a difficult time maintaining employment, and children with narcolepsy often struggle at school ^[1].

Narcolepsy can also cause injuries and accidents, and it may be dangerous to drive or operate heavy machinery if you have this condition ^[4].