All About Narcolepsy: 6 Warning Signs Plus Diagnosis and Treatment Options

Do you find it difficult to stay awake for long periods—so much so that you often fall asleep during tasks? Does sudden drowsiness interfere with your daily life? Do you experience cognitive dysfunction, hallucinations, or sleep paralysis? If yes, your symptoms might be more than just fatigue. They could be due to a chronic sleep disorder known as narcolepsy.

Person sleeping due to narcolepsy.
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What is Narcolepsy?

Narcolepsy is a chronic sleep disorder characterized by the brain’s inability to regulate the sleep-wake cycle. People with narcolepsy struggle to remain awake for long periods of time. While they may feel rested upon first waking up in the morning, they experience intense episodes of drowsiness throughout the day regardless of circumstances. It is not uncommon to fall asleep in the middle of completing tasks or engaging in the regular activities of life. The disorder is associated with excessive daytime sleepiness, hallucinations, muscle paralysis while asleep, and even cognitive dysfunction.

Narcolepsy Sleeping Patterns

What is the sleep-wake cycle? Why is it so imperative to the sleep patterns in narcolepsy? The sleep-wake cycle is the 24-hour sleep pattern. A normal sleep-wake cycle consists of 16 hours of wakefulness and approximately 8 hours of sleep controlled by the body’s circadian rhythm, which is the internal clock regulated by a portion of the brain.

The body undergoes various stages of quiet sleep (non-REM) and dreaming sleep (REM). Under normal conditions, someone should enter REM sleep within 60 to 90 minutes. However, the transition from non-REM to REM sleep is where the sleep patterns of narcoleptics go awry because the brain does not control muscle movement during sleep as it should. Someone with narcolepsy can enter REM sleep prematurely. As a result, most with narcolepsy sleep in fragments throughout the day and night and act out their dreams from the inability to control muscle movement.

Narcolepsy and the Brain

Hypocretin is a hormone and neurotransmitter that regulates the sleep-wake cycle. The chemical is necessary for arousal and released in the highest quantities during the day. Without hypocretin, REM sleep occurs at the wrong times because neurons in the brain do not receive the appropriate signals to remain alert. The hypothalamus is the only portion of the brain containing neurons that produce hypocretin. Hypothalamic cells in individuals with narcolepsy are damaged. As the cells die off, the nervous system does not have sufficient hypocretin levels to remain awake for long periods of time or to regulate conscious and semi-conscious sleep states.

Symptoms of Narcolepsy

You might be surprised to learn that the symptoms of narcolepsy are more complex than feeling tired or falling asleep at random. The symptoms of narcolepsy drastically interfere with daily life and activities. While the presentation does differ depending on the individual and subtype, many share the same basic narcolepsy symptoms.  

Excessive Daytime Sleepiness

Excessive daytime sleepiness is the main narcolepsy symptom. Ranging from mild to severe, all patients with narcolepsy feel excessively tired during the day throughout normal hours of wakefulness. They struggle to stay away despite sufficient sleep the night before. Some even fall asleep in the middle of tasks such as walking, driving, or cooking.

Cataplexy

Cataplexy describes a loss of muscle tone caused by the inability to regular the sleep-wake cycle. Episodes cataplexy are sudden, lasting one to two minutes, and result in uncontrollable muscle weakness or complete paralysis in the face, limbs, and abdomen. The individual experiencing cataplexy retains full awareness, yet does not have control over their body movements. Strong emotions like excitement, laughter, or anger. Not all people with narcolepsy have cataplexy. This symptom is restricted to type 1 narcolepsy.

Sleep Paralysis

Approximately one-fourth of patients diagnosed with narcolepsy have sleep paralysis. Sleep paralysis is the inability to move or speak while falling asleep or upon waking. It lasts several minutes, but the touch of another individual relieves the episode if it does not resolve on its own.

Like cataplexy, a person with sleep paralysis has full awareness. Sleep paralysis is not physically harmful but is correlated with psychological distress as it is frightening to have little control over the body.

Hallucinations

A hallucination is an act of seeing, hearing, or feeling something that is not there. In the narcolepsy population, hallucinations are similar to dreams but significantly more vivid and intense. When a hallucination occurs while falling asleep, they are called hypnagogic hallucinations. When they happen while waking, they are hypnopompic hallucinations. According to experts at Harvard, the hallucinations associated with narcolepsy are the dreams someone would normally have in REM sleep that occurs while partially awake.  

Automatic Behavior

Automatically behaviors are actions that are unknowingly performed in a state of sleep and wakefulness. Automatic behaviors begin while awake and continue in a semi-sleep state without conscious awareness. The person carrying out the behavior has no recollection of it afterwards. Examples of automatic behaviors are tasks like making coffee, writing, or driving.  

Cognitive Dysfunction

The excessive daytime sleepiness, loss of muscle control, poor nighttime sleep quality, and frightening episodes of sleep paralysis undoubtedly have a cognitive effect. Patients with narcolepsy complain of decreased alertness, “brain fog,” memory impairments, and depression. The latter not only stems from a lack of sleep, but the stress of having a chronic medical condition.

Types of Narcolepsy

Narcolepsy is divided into multiple types. The types of narcolepsy differ depending on the cause, symptoms, and levels of various hormones. Both subtypes include fragmented sleep, hallucinations, and sleep paralysis.

Type 1

Commonly referred to as narcolepsy with cataplexy, type 1 narcolepsy is characterized sudden episodes of loss of voluntary muscle tone triggered by strong emotions. Cataplexy is a key feature, but a sleep study will also confirm excessive daytime sleepiness. Many with type 1 narcolepsy have decreased levels of hypocretin—a brain hormone responsible for arousal and wakefulness.

Type 2

Type 2 narcolepsy is narcolepsy without cataplexy. Patients with this type do not report muscle weakness triggered by emotions or laughter and they have normal levels of hypocretin. Excessive daytime sleepiness is the primary manifestation.  

Secondary Narcolepsy

Secondary narcolepsy is a subtype of narcolepsy resulting from any underlying condition that damages the hypothalamus—the area of the brain which controls the sleep-wake cycle and the body’s circadian rhythm by regulating the production of hypocretin. Conditions causing secondary narcolepsy can include a traumatic brain injury, a brain tumor, encephalitis, or autoimmune disorders like multiple sclerosis (MS). Differentiating secondary narcolepsy from the other narcolepsy types is based upon severe neurological involvement while requiring greater than 10 hours of sleep in addition to excessive daytime sleepiness, cataplexy, sleep paralysis, and hallucinations.

Causes and Risk Factors

  • Age—Narcolepsy frequently develops during adolescence in those between the ages of 15 and 24. However, the disorder has been reported in children and older adults.
  • Family history—Having a family member with narcolepsy increases the chance of developing the disorder. Recent studies hypothesize a genetic predisposition for the body to attack hypocretin producing neurons in the brain’s hypothalamus (Leschziner, 2014). There is also a reported genetic mutation causing low levels of hypocretin that is passed along in families that are currently being studied.  
  • Brain injury—Trauma to the head or a tumor may result in damage to the part of the brain that regulates sleep and wakefulness. These individuals are prone to narcolepsy.
  • Autoimmune disorders—There is a link between narcolepsy and the immune system. Having an autoimmune disorder increases the likelihood of developing narcolepsy, as the immune system mistakenly attacks and damages the area of the brain that produces hypocretin and controls sleep. Common autoimmune disorders include rheumatoid arthritis, lupus, type 1 diabetes, and multiple sclerosis (MS).
  • Infection—Any infection which triggers the immune system in susceptible individuals can cause narcolepsy.

How To Diagnose Narcolepsy

After taking a thorough family and medical history, a physician who suspects a patient has narcolepsy looks for the signs and symptoms of the disorder such as excessive daytime sleepiness, sleep paralysis, hallucinations while falling asleep or waking up, cataplexy, and difficulty focusing. These symptoms are evaluated through the following:

  • Sleep diary—Logging periods of rest and activity provides information on sleeping habits.
  • Epworth Sleepiness Scale—This scale consists of questions about sleep to access sleepiness. Respondents rate their chances of falling asleep in certain situations using a 4-point scale.
  • Actigraph—An actigraph is a device worn around the wrist like a watch and records activity and rest.  
  • Lumbar puncture—To measure levels of hypocretin, a needle is inserted into the spine to retrieve a sample of cerebral spinal fluid (CSF). This is helpful in differentiating the subtype of narcolepsy.

The diagnosis of narcolepsy primarily relies on two sleep studies.

Multiple Sleep Latency Test

The multiple sleep latency test is a sleep study that measures daytime sleepiness. It is divided into five naps with two-hour breaks to determine how quickly someone falls asleep in a calm, quiet environment. Sensors placed on the head, face, and chin measure the state of wakefulness, the sleep stage, and the amount of time to enter REM sleep. The sleep study technician awakes the patient from the nap within 15-minutes. Those with narcolepsy fall asleep fast and enter REM sleep prematurely.  

Polysomnogram

A polysomnogram is an overnight sleep study performed in a medical facility and is used to diagnose sleep disorders by continuously measuring a variety of functions. Electrodes on the scalp record brain waves, along with activity of the heart, eyes, muscle tone, respiration rate, and oxygen levels. The polysomnogram is particularly useful to rule out other sleep disorders that share common symptoms of narcolepsy like apnea or insomnia.  

Treating Narcolepsy

There is no cure for narcolepsy, but the disorder is treatable. Treatment is adjusted based on the patient’s combination of symptoms. With medications, lifestyle changes, and nap therapy, most with narcolepsy can live a normal life.

Medications

A doctor often prescribes medications to manage narcolepsy symptoms. The pharmaceutical options include:

  • Stimulants—Stimulants stimulate the nervous system to combat drowsiness.
  • Selective serotonin reuptake inhibitors (SSRIs)—SSRIs are antidepressants that block the reabsorption of serotonin and increase neurotransmitter levels for the nervous system to transmit the correct signals. For narcolepsy specifically, SSRIs suppress REM sleep. This targets symptoms of cataplexy, hallucinations, and sleep paralysis.
  • Tricyclic antidepressants—Narcolepsy with cataplexy responds favorably to tricyclic antidepressants in low doses. Tricyclic antidepressants are prescribed less frequently due to side effects such as dry mouth, sweating, weight gain, tachycardia, and constipation.
  • Sodium oxybate—In high doses, sodium oxybate is effective at managing excessive daytime sleepiness. It is also beneficial for those who have poor quality nighttime sleep.
Narcolepsy treatment options
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Nap Therapy

Napping seems as if it would be counterproductive for a condition like narcolepsy that leads to drowsiness episodes. However, research by the American Sleep Disorders Association proves brief naps improves excessive daytime sleepiness. The naps beneficial for narcolepsy are timed to last only 20 to 30 minutes and should be limited to two or three times daily. Patients report an increase in alertness for one to three hours. While adapting to nap therapy, some patients exhibited such drastic improvement that they weaned medication dosing for the disorder.

Exercise For Narcolepsy

Experts recommend at least 20-minutes of exercise daily. To improve sleep quality, exercising 4 to 5 hours before bed is optimal. Exercise does not have to be strenuous. Aerobic exercises like swimming, biking, or tennis encourage cardiovascular circulation which reduces episodes of sleepiness. Even incorporating short walks into an exercise routine is helpful for alertness.

Diet For Narcolepsy

Many doctors and patients alike neglect to consider the extent to which dietary adjustments improve symptoms of narcolepsy, especially in combination with medications, exercise, and behavioral strategies. Foods with a high glycemic index inhibit or “turn off” the neurons that stimulate wakefulness and arousal. Because of this, carefully limiting carbohydrates, avoiding processed foods, and consuming specific nutrients for brain function is key to managing the disorder.

Some dietary guidelines for narcolepsy include:

  • Avoid caffeine and alcohol. Both caffeine and alcohol disrupt sleep.
  • Do not eat a heavy meal before bed. Those with narcolepsy typically have poor quality sleep at night. Heavy carbohydrate meals are known to disrupt nighttime sleep.
  • Eat smaller, frequent meals. Consuming large quantities at once is harder for the body to digest, which increases sleepiness. Doctors at John Hopkins suggest for narcoleptics to plan small meals throughout the day with a balance of complex carbohydrates, protein, and fat.
  • Omit processed sugars. The processed sugars found in sodas, baked goods, and candy may increase energy levels initially, but they inevitably lead to a crash.
  • Include healthy fats. Omega 3, 9, and 6 are essential for healthy brain function. Choose leaner fat options like fish, flax seeds, and nuts.
  • Limit high carbohydrate foods. Bread, pasta, and potatoes are foods high in carbohydrates and should be eaten in moderation. High carb foods rapidly increase blood glucose, which is followed by a crash that interferes with energy levels.
  • Lower inflammation with fresh vegetables. Vegetables contain a surplus of vitamins, minerals, and antioxidants that lower inflammation in the body.

References

Leschziner, G, Narcolepsy: a Clinical Review, Pract Neurol 2014; 0:1–9. doi:10.1136/practneurol-2014-000837.

Yoon, S. M., Joo, E. Y., Kim, J. Y., Hwang, K. J., & Hong, S. B. (2013). Is High IQ Protective Against Cognitive Dysfunction in Narcoleptic Patients?. Journal of clinical neurology (Seoul, Korea)9(2), 118–124. https://doi.org/10.3988/jcn.2013.9.2.118