Everything You Need to Know About Narcolepsy

You’re sleepy day in and day out, with an uncontrollable urge to sleep at your desk even though you thought you slept well the night before. It could be narcolepsy, a condition in which the sleep-wake cycle isn’t properly controlled. The National Institute of Neurological Disorders and Stroke says that between 135,000 and 200,000 people in the U.S. suffer from this condition each day. What happens in narcolepsy and what can be done about it?

Sleep Disorders Narcolepsy

What is narcolepsy?

Narcolepsy is a condition in which a person has overwhelming sleepiness during the day. Someone with narcolepsy may uncontrollably and unexpectedly fall asleep, even in the middle of activities such as eating or talking. Those with narcolepsy are at high risk of injury when they become sleepy.

Narcolepsy is caused by a disturbance in the natural sleep-wake cycle within the brain, and it can last a lifetime. In addition to daytime sleepiness, people with narcolepsy also have poor sleep at night. They often wake up at night and are unable to go back to sleep. It’s important to note that people with narcolepsy do not necessarily sleep more in 24-hours than those without the condition.

What are the signs and symptoms of narcolepsy?

Since narcolepsy is a disruption of the normal sleep-wake cycle, people with narcolepsy experience problems with sleepiness when awake and problems with wakefulness during sleep. All people diagnosed with narcolepsy have significant sleepiness during the day, and up to a third will have all of the other symptoms listed here.

  • Excessive daytime sleepiness – the hallmark of narcolepsy experienced by all people with the diagnosis

  • Sleep attacks – falling asleep suddenly during the day

  • Cataplexy – muscle weakness triggered by strong emotions like laughter or anger, which may cause the person to collapse. Unlike in seizure, people with cataplexy are fully conscious during an episode.

  • Sleep paralysis – losing the ability to move or speak when waking up or falling asleep

  • Hallucinations when falling asleep – seeing, hearing, or feeling things that aren’t real before sleep

  • Fragmented sleep – frequently waking up during sleep and trouble falling back asleep once awake

What causes narcolepsy?

Narcolepsy symptoms typically develop in people in their teens and twenties. Most people who have narcolepsy Type 1 have a deficiency in hypocretin. This brain hormone helps to control wakefulness and aids in REM sleep regulation. It’s not fully understood why this deficiency occurs, but it may be due to any of the following factors:

  • Family history of narcolepsy – only about 10 percent of people with narcolepsy Type 1 have a close relative with the condition

  • Autoimmune disorders – in which the body’s immune system turns against itself. Researchers believe a combination of genetic or environmental factors may lead to the immune system’s destruction of the brain’s hypocretin

  • Brain damage – in rare cases traumatic brain injury, stroke, or tumors can lead to narcolepsy

Sleep_Disorder_Narcolepsy

Types of Narcolepsy

Tired_at_Work_Narcolepsy

The ICD 10 code for a diagnosis of narcolepsy is G47.4. The diagnosis can be further specified by which type of narcolepsy a person has based on his or her symptoms.

  • Narcolepsy Type 1 – In this form, a person has a combination of at least 3 months of excessive daytime sleepiness plus either cataplexy or low levels of the brain hormone hypocretin-1, or both.
  • Narcolepsy Type 2 – Those with this form will have a constant level of excessive sleepiness for at least 3 months, but they do not experience cataplexy. People with narcolepsy Type 2 have normal levels of the brain chemical hypocretin-1, and they do not have another sleep disorder that explains their symptoms.

Narcolepsy Type 1 is considered the more severe form of the condition, though both can be debilitating and require treatment.

Narcolepsy Tests

A person with excessive sleepiness during the day may be asked to keep track of symptoms using a daily sleep journal. Many of the symptoms of narcolepsy can also be due to other sleep disorders, so a thorough workup and examination are important. However, cataplexy rarely occurs outside of narcolepsy. For someone who has symptoms that are concerning for narcolepsy, the next step towards a diagnosis is to undergo sleep tests with a medical provider at a sleep lab. Two types of sleep tests can help determine a diagnosis of narcolepsy.

This sleep study monitors the brain’s activities, breathing patterns, eye movements, and muscle changes during a night of sleep. People with narcolepsy go into the rapid eye movement stage (REM) of sleep much quicker than healthy sleepers, often within 15 minutes of falling asleep. This test would also show more non-REM light stages of sleep and more spontaneous awakening during sleep in those with narcolepsy.

This test is performed during the day after the polysomnogram test and measures brain activity, muscle and eye movements. During this study, the patient will be in a dark quiet room and have 5 chances to nap up to 15 minutes. A healthy sleeper will fall asleep within 10-15 minutes but will not go into REM sleep during a brief nap. A person with narcolepsy not only falls asleep quicker, on average within 8 minutes, but can enter REM sleep within 15 minutes as well.

In people for whom a sleep study is not an option, doctors can collect a sample of cerebrospinal fluid from the spinal canal to measure the amount of the brain hormone hypocretin-1. In people with narcolepsy Type 1, this hormone level is lower than normal.

Narcolepsy Treatments

While there’s no cure for narcolepsy, doctors have extensive treatment options available.

One key area in improving narcolepsy symptoms is with medications:

  • Nervous system stimulants – reduce daytime sleepiness and promote wakefulness. Medications include modafinil, solriamfetol, pitolisant, methylphenidate, and amphetamines.
  • Cataplexy suppressors – reduce the symptoms of emotion-triggered muscle weakness. Medications include venlafaxine, fluoxetine, clomipramine, and sodium oxybate.

Some people may see an improvement in narcolepsy symptoms by making changes to their lifestyle. Key changes may include:

  • Sticking to a regular sleep schedule as much as possible
  • Scheduling one or two brief naps during the day or before an event
  • Avoiding stimulants before bedtime, including alcohol or caffeine
  • Avoiding sedating medications during the day

In addition to these steps, doctors will work with those who have narcolepsy to ensure they are engaging in activities as safely as possible. This may mean limiting driving to certain lengths of time or to specific times of the day. Reducing hazards at home may also be necessary.

If you suspect you have narcolepsy, see a doctor

There’s no cure for narcolepsy, but treatment may offer some insight and improvement in the quality of life. The key is to seek out help immediately to have a formal diagnosis completed.

Sabina Hoque, MD MPH

Medically Reviewed

Sabina Hoque, MD MPH is a board-certified internal medicine physician with 10 years of clinical experience. In addition, she holds a masters in Public Health and has significant experience in teaching and biostatistics. She enjoys distilling complex medical information for audiences of varying levels of health literacy.

All content published on the HealthySleepGuide.com website is credited for informational purposes only. The information should not substitute as medical advice, diagnosis, or treatment. Always consult your doctor or qualified health professional with any questions regarding your health.