NARCOLEPSY: CAUSES, SYMPTOMS, TREATMENT - ECONOMÍA - 2025

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 from several seconds to several minutes, and can range from weakness of the facial muscles to complete collapse of the body. Two other main features of this disorder are sleep paralysis and hypnagogic hallucinations.

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

Symptoms

Excessive daytime sleepiness

Daytime sleepiness is when a person with narcolepsy may suddenly become sleepy and fall asleep. These little "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's rest and often occurs in inappropriate places and times. It seems that people with this disorder cannot experience the amount of deep restful sleep that normal people get.

Although "naps" feel restorative, that feeling of rest only occurs for a few hours.

Cataplexy

In cataplexy there seems to be a sudden onset of REM or REM sleep (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, leading 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 cause an intense sensation of presence and movement around the body.

Hypnagogic hallucinations

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

They can be scary and very realistic. Examples are flying or the illusion of being caught 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 sleep episodes, although upon waking they do not remember having been doing those things.

The first symptom that appears in most cases is sudden and excessive sleep during the day. The other symptoms may begin on their own or in combination a few months after daytime "naps."

About 20-25% of people with narcolepsy experience all four symptoms. Daytime sleepiness tends to persist throughout life, although sleep paralysis and hypnagogic hallucinations are rarer.

Causes

In humans, narcolepsy sleep occurs by suddenly passing from an awake state to REM sleep, bypassing non-REM sleep stages.

During REM sleep, motor neurons in the spine and brainstem produce almost complete atony. This situation occurs in cataplexy.

Genetic factors

The HLA-DQB1 allele of the human HLA-DQB1 gene has been found to be found in 90% of patients.

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

Another locus associated with narcolepsy is EIF3G.

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

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

People with narcolepsy usually have a reduced number of neurons that produce the protein hypocretin, which are responsible for controlling appetite and sleeping patterns.

Only 10,000 to 20,000 brain cells secrete hypocretin molecules.

Evolutionary factors

Narcolepsy could be an evolutionary atavism; the appearance of an ancestor 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 simulation of death, and it works 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 has some similarities to REM sleep, which may reveal an evolutionary resemblance: paralysis, sympathetic activation, thermoregulatory changes, brainstem control.

Diagnosis

The diagnosis of narcolepsy may require an overnight stay in a medical facility, where a thorough sleep analysis is performed.

The methods normally used are:

• Sleep history: to know how the dream has occurred throughout the life of the affected person. The Epworth Sleepiness Scale can be used.
• Sleep logs: The patient can keep a diary in which they write down their sleep patterns for 1-2 weeks. You can use an actigraph (such as a wristwatch), a device that measures periods of activity and rest and provides an indirect measure of how and when you sleep.
• Polysomnogram: it is a test that measures the wake-sleep cycle. It measures brain activity (electroencephalogram), muscle movement (electroculogram), eye movement (electro-oculogram), and heart movements (electrocardiogram). For this test you will spend one night in a medical center.
• Multiple latency test: measures how long a person takes to fall asleep and sleep patterns are observed. People with narcolepsy fall asleep early and move quickly into REM sleep.
• Hypocretin test: most people with narcolepsy have low levels of hypocretin. With this test, hypocretin levels are measured in the fluid that surrounds the spinal cord.

Diagnostic criteria according to DSM-IV

A) Irresistible bouts of restful sleep that appear daily for a minimum of 3 months.

B) Presence of one or both of the following symptoms:

1. Cataplexy
2. Recurrent intrusions of REM sleep elements in the transition phases between sleep and wakefulness, as indicated by hypnagogic or hypnopompic hallucinations or sleep paralysis at the end or beginning of sleep episodes.

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

Treatment

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

Medication

• Stimulants: These are drugs that stimulate the central nervous system and are used as a primary treatment to keep you 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 norepinephrine reuptake inhibitors (SNRIs): relieve symptoms of cateplexy, hypnagogic hallucinations, and sleep paralysis. They include fluoxetine and venlafaxine. Digestive problems or sexual dysfunctions, among others, can occur as side effects.
• Tricyclic antidepressants: They are effective for cataplexy, although side effects such as dry mouth and dizziness often occur. Examples are imipramine or clomipramine.
• Sodium oxybate - It is effective for cataplexy and helps improve sleep at night In high doses it can also control sudden sleep during the day.

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

Other drugs such as antihistamines or cold medication can cause drowsiness.

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

Changes in lifestyle

Making certain lifestyle changes 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.
• Avoid alcohol, caffeine, and nicotine: Coffee, tea, and beverages that contain caffeine are stimulants and can interfere with sleep if taken in the afternoon. Nicotine is another stimulant that can cause insomnia. Alcohol is a sedative, although it can prevent you from reaching deep stages of sleep and often causes sleep disruption at night.
• Get regular exercise: Exercise makes you feel more awake during the day and improves sleep at night. Plus, it has many other benefits.
• Eat a healthy diet: eat a diet rich in whole grains, fruits, vegetables, little fat, and plant sources of protein. Avoid heavy meals at night.
• Avoid dangerous activities: if possible, do not drive, climb or use dangerous machines.
• Communicate: let people around you know your condition so they can act if necessary.
• Relax: Narcolepsy symptoms can occur during internal emotions, so relaxation techniques can help.

Support groups

People with narcolepsy can 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.

Meeting other people who have the same problem reduces feelings of isolation and provides social support. Also, it can be liberating to share experiences and learn how other people cope with symptoms.

Complications

• Disruption of personal relationships: the dream can produce less desire to have sex or direct problems during sexual intercourse.
• Mental health: it can have such an influence on life that disorders such as anxiety or depression can develop.
• Work problems: can decrease productivity at work and school performance.
• Obesity: People with narcolepsy are twice as likely to be obsessed. Weight gain may be due to lack of activity, hypocretin deficiency, or a combination of factors.
• Memory and attention: trouble remembering things and concentrating.

• Physical damage: there is a risk of falling asleep while driving or household accidents, such as burning when cooking, falling…

References

1. "International classification of sleep disorders, revised: Diagnostic and coding manual" (PDF). American Academy of Sleep Medicine. 2001. Retrieved 25 January 2013.
2. "Recent Updates to Proposed Revisions for DSM-5: Sleep-Wake Disorders." DSM-5 Development. American Psychiatric Association.
3. Tsoukalas I (2012). "The origin of REM sleep: A hypothesis." Dreaming 22 (4): 253–283. doi: 10.1037 / a0030790.
4. Gowda CR, Lundt LP; Lundt (December 2014). "Mechanism of action of narcolepsy medications." CNS Spectrums 19 (Supplement 1): 25–33.