Narcolepsy: Causes, Symptoms, Treatment

Narcolepsy: Causes

The Narcolepsy is a sleep disorder characterized by sudden sleep attacks that occur in any situation and are irresistible. In addition to drowsiness, someone with this disorder experiences cataplexy while awake; a sudden loss of muscle tone.

Cataplexy can last for several seconds to several minutes, and can range from weakness of facial muscles to complete collapse of the body. Two other main features of this disorder are sleeping paralysis and hypnologic hallucinations.


Narcolepsy usually begins between 15 and 25 years, but can appear at any age. In many cases it is not diagnosed and, as a consequence, untreated.

Narcolepsy Causes


Symptoms of narcolepsy

Excessive daytime sleepiness

Daytime drowsiness means that the person with narcolepsy may suddenly fall asleep and fall asleep.

These small naps can last from several seconds to several minutes and can occur several times a day.

This situation can occur even during a good night of rest and usually occurs at inappropriate places and times.

It seems that people with this disorder cannot experience the amount of deep, restful sleep that normal people have.

Although the “siestas” feel like reparative, that sensation of rest only gives for a few hours


In cataplexy, there appears to be a sudden onset of REM or MOR (rapid eye movement sleep).

Normally, before reaching REM sleep they go through 4 previous stages. However, someone with narcolepsy goes directly to REM.

During this stage motor neurons are not stimulated by brain activity and the muscles of the body do not move, which leads to cataplexy.

Sleep paralysis

Sleep paralysis is a sleep disorder that occurs when, in the transition between sleep and wakefulness, you are fully aware of dreams but it is impossible to move.

As this happens when in an intermediate state between sleep and wakefulness, it is possible to have auditory or visual hallucinations that provoke an intense sensation of presence and movement around the body.

Hypnologic hallucinations

A hypnologic hallucination is an auditor, visual or tactile hallucination that occurs shortly before the onset of sleep.

They can be terrifying and very realistic. Examples are flying or the illusion of being trapped in a fire.

Automatic Behavior

It is estimated that up to 40% of people with narcolepsy experience automatic behaviors during dream episodes.

It consists of the person continuing to function (talking, doing things) during the episodes of sleep, but when waking does not remember having been doing those things.

The first symptom that appears in most cases is sudden and excessive daytime sleep.

The other symptoms may begin on their own or in combination a few months after the daytime “naps”.

Approximately 20 to 25% of people with narcolepsy experience the four symptoms.

Daytime drowsiness usually persists throughout life, although sleep paralysis and hypnologic hallucinations are rarer.

Causes of narcolepsy

In humans the narcolepsy dream occurs when you suddenly pass from an awake state to REM sleep, without going through non-REM sleep stages.

During REM sleep, motor neurons in the spine and brain stem produce almost complete agony. This situation occurs in the cataplexy.

Genetic factors

It has been found that the HLA-DQB1 allele of the human HLA-DQB1 gene is found in 90% of patients.

A 2009 study found an association with polymorphisms at the locus of the TRAC gene.

Another locus associated with narcolepsy is EIF3G.

There is a correlation between these individuals and genetic variations in the MHC complex (major histocompatibility complex).

Variations of this complex may increase the risk of an autoimmune response to neuron-producing proteins in the brain.

People with narcolepsy often have a reduced number of neurons that produce the hypo cretin protein, which are responsible for controlling appetite and sleep patterns.

Only between 10,000 and 20,000 brain cells secrete hypo cretin molecules.

Evolutionary factors

Narcolepsy could be an evolutionary atavism; the appearance of ancestral behavior.

According to this theory, REM sleep is the evolution of the defense mechanism known as tonic immobility.

This reflex is also known as animal hypnosis or death simulation, and acts as a last line of defense against a predator. It consists of the total immobilization of the animal.

The neurophysiology and phenomenology of this reaction have some similarities with REM sleep, which may reveal an evolutionary similarity: paralysis, sympathetic activation, changes in thermoregulation, control of the brainstem.


The diagnosis of narcolepsy may require spending the night in a medical center, where a deep sleep @nalysis is performed.

The commonly used methods are:

  • History of sleep: to know how the dream has been given throughout the life of the affected person. The Epworth Drowsiness Scale can be used.
  • Sleep records: The patient may keep a diary in which they record their sleep patterns for 1-2 weeks. You can use an autograph (like a wristwatch), a device that measures periods of activity and rest and offers an indirect measure of how and when you sleep.
  • Polysomnogram: is a test that measures the wake-sleep cycle. It measures brain activity (electroencephalogram), movement of muscles (electroculogram), eye movement (electro-oculogram) and movements of the heart (electrocardiogram). For this test you will spend one night in a medical center.
  • Multiple latency tests: measures how long it takes a person to fall asleep and observes sleep patterns. People with narcolepsy fall asleep soon and pass quickly into REM sleep.
  • Hypo cretin test: Most people with narcolepsy have low levels of hypo cretin. This test measures the levels of hypo cretin in the fluid surrounding the spinal cord.

Diagnostic criteria according to DSM-IV

  1. A) Irresistible repairing sleep attacks that appear daily for a minimum of 3 months.
  2. B) Presence of one or both of the following symptoms:


Recurrent intrastructions of MOR sleep elements in the transition phases between sleep and wakefulness, as indicated by hypnologic or hypnopompic statements or sleep paralysis at the end or at the beginning of sleep episodes.

  1. C) The alteration is not due to the direct physiological effects of a substance or a medical illness.

Treatment of narcolepsy

Although there is no cure for narcolepsy, treatment with medications and changes in lifestyle can help control the symptoms.


  • Stimulants: are drugs that stimulate the central nervous system and are used as a primary treatment to stay awake during the day. Modafinil or armodafinil are often used because they are not as addictive and do not produce the typical ups and downs of other stimulants.
  • Selective serotonin reuptake inhibitors (SSRIs) and nor epinephrine reuptake inhibitors (NRTIs): relieve catheterolytic symptoms, hypnologic hallucinations, and sleep paralysis. They include fluoxetine and venlafaxine. Digestive problems or sexual dysfunctions, among others, can be given as side effects.
  • Tricycle antidepressants: They are effective for cataplexy, although side effects such as dry mouth and dizziness usually occur. Examples are imipramine or clomipramine.
  • Sodium ox bate: it is effective for cataplexy and helps to improve sleep at night. In high doses you can also control sudden sleep during the day.

It is important to consult a doctor before taking any of these drugs, because you may be given interactions with other medications or other conditions such as hypertension or diabetes.

Other drugs such as antihistamines or medication for colds can cause drowsiness.

Treatments currently being studied include: hypo cretin replacement, hypo cretin gene therapy, stem cells, manipulation of body temperature, and immunotherapy.

Changes in lifestyle

Making certain changes in lifestyle can help control the symptoms of narcolepsy:

  • Establish a sleep schedule: try to go to sleep and get up at the same time. Planned naps can prevent sudden naps.
  • Avoiding alcohol, caffeine and nicotine: Coffee, tea and drinks containing caffeine are stimulants and can interfere with sleep if taken in the afternoon. Nicotine is another stimulant that can produce insomnia. Alcohol is a sedative, although it can prevent reaching deep sleep stages and often causes sleep disruption during the night.
  • Do regular exercise: Exercise make you feel more awake during the day and improve sleep at night. In addition, it has many other benefits.
  • Eat a healthy diet: Eat a diet rich in whole grains, fruits, vegetables, low fats and vegetable sources of protein. Avoid heavy meals at night.
  • Avoid dangerous activities: if possible, do not drive, climb or use dangerous machines.
  • Communicate: let the people around you know your condition so they can act if necessary.
  • Relax: The symptoms of narcolepsy can occur during internal emotions, so relaxation techniques can help.

Support groups

People with narcolepsy may suffer from depression, social isolation and disruption of normal functioning.

Finding a psychologist or support group can help you better cope and find social support.

Also Read: Insomnia: Causes, Types, Symptoms, Treatment

Meeting others who have the same problem decreases feelings of isolation and provides social support.

In addition, it may be liberating to share experiences and learn how other people are confronted with symptoms.


  • Interruption of personal relationships: Sleep can produce less desire to have sex or direct problems during sex.
  • Mental health: it may have such influence on life that you may develop disorders such as anxiety or depression.
  • Labor problems: can decrease productivity at work and school performance.
  • Obesity: people with narcolepsy are twice as likely to have possessiveness. Weight gain may be due to lack of activity, hypo cretin deficiency, or a combination of factors.
  • Memory and attention: problems to remember things and concentrate.
  • Physical damage : you run the risk of falling asleep while driving or accidents at home, such as burning when cooking, falling …