Narcolepsy is a chronic, neurological condition affecting sleep control and wakefulness. This induces irregular sleep at night, and prolonged daytime sleep.
It also features abnormal rapid eye movement (REM) sleep, which may include cataplexy, brief muscle weakness which tone attacks that may cause body collapse.
Narcolepsy can vary from mild to severe in severity. It can have a detrimental effect on social activities, education, work and overall health and wellbeing in extreme cases. For example, a person with narcolepsy can fall asleep while talking or driving at any time.
Symptoms appear to occur in teenage years, or early 1920s and 30s. Men and women are similarly sensitive, and at any given time in the United States it is thought to affect 135,000 to 200,000 people.
Important facts about narcolepsy
Below are a few key points on narcolepsy. More specifics are given in the main article.
- Around 1 in 2,000 people in the United States have narcolepsy.
- The main symptoms are excessive daytime sleepiness and abnormal rapid eye movement (REM) sleep.
- Narcolepsy is the second leading cause of excessive daytime sleepiness after obstructive sleep apnea.
- Symptoms typically begin between the ages of 10 and 30 years.
- Narcolepsy can be treated with medications and lifestyle adjustments.
What is narcolepsy?
Narcolepsy is a hypersomnia, or sleep disorder that is characterized by excessive daytime sleep.
An individual enters the early stage of sleep in a typical sleep cycle, followed by more deep sleep stages for 90 minutes where REM sleep finally occurs.
REM sleep happens in the sleep period within 15 minutes, often intermittently during the waking hours, for people with narcolepsy. Dreams and muscle paralysis occurr in REM sleep.
There are three types of narcolepsy:
- Type 1: Narcolepsy with cataplexy
- Type 2: Narcolepsy without cataplexy, which mainly involves excessive daytime sleepiness
- Secondary narcolepsy: This can result from an injury to the hypothalamus, a part of the brain involved in sleep.
Causes
The exact cause is unclear, but narcolepsy may be an inherited autoimmune disease that results in a hypocretin deficiency, or orexin, a chemical that the brain needs to remain awake. A genetic condition can exist which means it runs in families.
Hypocretin is a neurotransmitter, a chemicals which signal the nerves. It regulates whether we’re asleep or awake by operating on different groups of nerve cells, or brain neurons. It is produced in the area of the brain hypothalamus.
Many individuals with type 1 narcolepsy have this hormone at low levels while those with type 2 do not.
It takes hypocretine to help us stay awake. The brain causes REM sleep phenomena to intrude into regular waking times when there is no avail. As a result, people with narcolepsy experience both severe daytime sleepiness and issues with nighttime sleep.
During an autoimmune disease, the body’s immune system targets itself erroneously and battles healthy cells as if they were alien invaders. Many autoimmune diseases include rheumatoid arthritis, type 1 diabetes and celiac disease.
A brain injury, tumor, or other brain-affecting disease may also lead to narcolepsy.
Symptoms
Excessive daytime sleepiness (EDS) is the distinctive symptom of narcolepsia. Other signs may include cataplexy, hypnagogic hallucinations and sleep paralysis.
Excessive daytime sleepiness (EDS): is a recurrent background sense of sleepiness with a propensity to linger all day long at intervals, sometimes at inconvenient times. Those are also sleep assaults. It may cause brain fog, impaired concentration, reduced strength, lapses in memory, fatigue, and a depressed mood.
Hypnogogic hallucinations: are vivid, often terrifying, hallucinations of the senses that occur when falling asleep. The blend of wakefulness and the dreaming that happens with REM sleep may trigger these.
Cataplexy: is a sudden weakening of the muscles in the jaw, neck and knees. Some people have only slight weakness, like a drop in the head or neck, but some people fall completely to the ground. Strong emotions, such as surprise, laughter, or rage, sometimes cause those episodes. The vulnerability is temporary and will last 2 minutes or less.
Sleep paralysis: is a brief incapacity to move or speak while sleeping or waking. These episodes can last for several minutes, from a few seconds. After the episode ends, people quickly regain their full movement and speaking capacity.
There may also be unconscious behaviors. An individual can momentarily fall asleep but keep on doing the previous activity, such as driving, without being conscious.
Diagnosis
Chronic daytime sleepiness can be due to a variety of factors. Anyone who has an extreme sleepiness will seek a medical assessment to determine the exact cause.
At first, narcolepsy sometimes gets misdiagnosed. It may be confused with a psychological condition, sleep apnea, a symptom of restless legs, or another disease.
To decide whether a person has narcolepsy, it is important to conduct a comprehensive medical and sleep history, physical examination, and sleep tests, such as polysomnography and multiple sleep latency check.
Questions a health care provider can ask about having a history of sleep include:
- Are you sleepy most of the day?
- How many hours are you sleeping at night?
- Do you feel rested on waking?
- Are your naps refreshing?
- Do you experience unusual sensations as you are falling asleep?
- Are you ever unable to move as you fall asleep or when you first awake?
- Do you have muscle weakness or collapse when laughing or angry?
Analysis of the sleep can help validate a narcolepsy diagnosis. The polysomnography is performed in a sleep clinic over night. After polysomnography the multiple sleep latency test is performed a few hours.
Keeping a sleep journal may be diagnostic help.
Treatment
Narcolepsy is often not resolved but medication can help manage the symptoms. Stimulants are able to combat sleepiness. Antidepressants can treat cataplexy symptoms and anomalous REM sleep.
Sleepiness (EDS)
EDS is treated with stimulants resembling amphetamine, such as dexamphetamine, methylphenidate, or modafinil. Because of their low cost, effectiveness and higher efficacy these drugs are first-line therapy.
They’re controlled substances, though. They can lead to tolerance and abuse, with the exception of Modafinil.
Side effects include anxiety, irritability and insomnia. Modafinil has the ability to induce headaches and nausea.
Cataplexy
Antidepressant drugs which suppress REM sleep can lessen the cataplexy.
Clomipramine is for the treatment of narcolepsy. Also useful may be selective serotonin reuptake inhibitors (SSRIs), and selective norepinephrine reuptake inhibitors (SNRIs). Side effects can include dry mouth and constipation, and blurred vision..
Sodium oxybate can relieve EDS, poor sleep in the night and cataplexy. It has no side effects and very little contact with other medicines.
Before any cataplexy is controlled, the individual must avoid any action that may pose a health hazard, such as using machinery or driving.
Treatment can need to be changed as symptoms change.
Living with narcolepsy
Changes in lifestyle can be of benefit. These involve taking care of sleep hygiene, arranging daytime naps and maintaining a daily meal and exercise schedule.
Here are some guidelines for good sleep hygiene:
- Keep a consistent sleep schedule, getting up and going to bed at the same time every day, even on weekends or during vacations.
- Set a bedtime that will allow at least 7 hours of sleep.
- Do not go to bed unless you are sleepy.
- If you do not fall asleep after 20 minutes, get out of bed.
- Establish relaxing bedtime rituals.
- Use your bed only for sleep and sex.
- Make your bedroom quiet and relaxing, with a comfortable, cool temperature.
- Limit exposure to light in the evenings.
- Avoid large meals before bedtime. If you are hungry at night, eat a light, healthy snack.
- Reduce fluid intake before bedtime.
- Exercise regularly and maintain a healthy diet.
- Avoid consuming caffeine in the late afternoon or evening.
- Avoid alcohol.
Nccmed asked Monica Gow, Wake Up Narcolepsy (WUN) co-founder and board member, about the main challenges people are facing with the condition.
She told us:
“People with narcolepsy face many challenges, but the main ones are accurate diagnosis in a timely manner, finding a physician who can effectively manage the narcolepsy and finding the right combination of treatment to allow for daily functioning at the highest possible level considering the medical disorder at hand.”
WUN is a nonprofit organization that promotes research and raises consciousness among people with narcolepsy.
Ms. Gow also told us that: “Friends and family with narcolepsy should be empathetic to loved ones and educate themselves on narcolepsy and all that is associated with it.”
Outlook
Narcolepsy is not healed but prescription drugs and healthy lifestyle habits will help control the disorder.
According to the National Institute of Neurological Disorders and Stroke (NINDS), symptoms sometimes become more extreme within 20 to 30 years of first appearance, but daytime sleepiness may decrease after age 60.
Organizations like WUN will help keep people updated with the new developments. They also invite people to join in the search for a cure by participating in research projects.
