Narcolepsy – Causes, Symptoms, Diagnosis and Treatment

Similarly, with other sleep disorders, the exact cause of narcolepsy is unknown. That said, scientists have identified some genes that are associated with this chronic disorder. These particular genes are responsible for the production of brain chemicals that take part in sleep and wake cycle.

Narcolepsy may be caused by low levels of hypocretin (orexin), a neurotransmitter that regulates wakefulness, appetite, and arousal. In addition, hypocretin is vital for control of rapid eye movement (REM) sleep. Several factors may contribute to hypocretin deficiency including gene mutation, stress, autoimmunity, infections, and exposure to toxins.

Not all people with narcolepsy have hypocretin deficiency. Patients with type 1 (narcolepsy with cataplexy) have low levels of hypocretin while those with type 2 (narcolepsy without cataplexy) don’t. Cataplexy is a sudden muscle weakness in the face, neck, and knees. 

Humans need hypocretin to stay awake, but when the concentration of this neurotransmitter lowers the brain allows REM sleep to invade waking period, which is why people with this disorder experience daytime sleepiness and nighttime sleeping problems.

Brain injuries, various diseases, and tumors may also contribute to the development of narcolepsy. Narcolepsy is also associated with restless leg syndrome, sleep apnea, and insomnia.

In normal sleep, cycle REM occurs within 15 minutes and it also happens intermittently during waking hours. We dream when we’re in REM sleep, but this is also the part of the sleep cycle when some people experience paralysis. Numerous factors and disturbances in sleep cycle induce a variety of problems and disorders and narcolepsy is one of them. Below, you can see a brief rundown of the most common symptoms of narcolepsy:

• Cataplexy – a sudden, brief loss of voluntary muscle tone that makes it difficult for an affected person to control their muscles. You may feel a major weakness in your muscles or experience symptoms such as slurred speech, total body collapse among others. Intense feelings and emotions trigger cataplexy. These include laughter, anger, surprise
• Excessive daytime sleepiness (EDS) – this is usually the first and most prominent symptom of narcolepsy. A patient feels incredibly sleepy and tired during the day, but this drowsiness makes it difficult to perform even the simplest activities. People with EDS tend to take frequent naps but find them ineffective. EDS is also linked with poor concentration, weak memory, depressed mood, extreme exhaustion, and overall mental cloudiness
• Sleep paralysis – inability to move and speak while sleeping, falling asleep, or waking. A person hears everything and is awake, but can’t move or say anything. Although it can be scary, sleep paralysis lasts from a few seconds to a few minutes and it doesn’t affect your breathing and other functions. That said, sometimes people who don’t have narcolepsy experience sleep paralysis too
• Hallucinations – remember, narcolepsy involves disturbed REM sleep. As a result, you may dream while you’re partially awake i.e. you’re still not in REM sleep, which can cause hallucinations

If you experience symptoms mentioned above, it’s recommended to schedule an appointment and see your doctor. Don’t wait for symptoms to go away on their own because you won’t know their cause or treatment options to relieve them. The doctor will start by asking you a few questions about medical history followed by a physical exam. To assess sleep quality and make a diagnosis, the doctor may use one (or more) of the following methods:

• Polysomnogram (PSG) – this test requires spending a night in a sleep center in a medical facility. Electrodes are attached to your scalp so the test can measure brain activity, eye movement, muscle movement, heart rate and rhythm, breathing
• Epworth sleepiness scale – a questionnaire where a patient evaluates their own quality of sleep and it also asks how likely you are to fall asleep in a given situation
• Lumbar puncture – used for collection of cerebrospinal fluid in order to measure hypocretin levels
• Multiple sleep latency test – evaluates how long it takes a patient to fall asleep during the day

There is no cure for this sleep disorder and treatment revolves around managing symptoms to improve your quality of life. For example, stimulants are prescribed for EDS while antidepressants are prescribed to address abnormal REM sleep. A medication called Xyrem has been approved for patients with narcolepsy. The drug works to beat daytime sleepiness and promote better sleep at night.

Just like with other disorders, narcolepsy also requires some lifestyle adjustments such as:

• Establish a regular sleep pattern
• Take strategic power naps that last no longer than 20 minutes
• Exercise regularly
• Identify triggers of narcolepsy symptoms, especially EDS, and strive to minimize exposure to them
• Have a relaxing bedtime ritual
• Avoid alcohol and caffeine
• Maintain a healthy diet

Narcolepsy is a serious chronic sleep disorder that can be a result of hypocretin deficiency or it can occur as a consequence of an underlying health condition. There is no cure for narcolepsy, but it can be managed with adherence to doctor-recommended therapy and lifestyle modifications.

Sources:

• Narcolepsy Fast Facts - Narcolepsy Network
• https://www.webmd.com/sleep-disorders/guide/narcolepsy
• Narcolepsy: Causes, symptoms and treatments - MedicalNewsToday

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