We joke about taking a quick snooze when our friends bore us with conversation, but imagine if you were so tired that you really could suddenly fall asleep? Moreover, picture feeling as if you can’t move upon waking or seeing vivid dreamlike hypnagogic hallucinations as you transition from sleep to wake or wake to sleep. Such is the reality of those affected by the sleep disorder, narcolepsy.

Despite the number of hours slept the night before, excessive fatigue can overtake a narcoleptic and affect their concentration, disrupt their nighttime sleep, create extreme irritability and in some cases prevent them from getting a driver’s license.

What is Narcolepsy?

Sleep disorders affect the way you sleep and can harm your health, quality of life, and safety. There are many different types of sleep disorders and narcolepsy, although extremely rare, can significantly impact one’s life without proper treatment.

Narcolepsy is the intrusion of REM sleep into your day. People with narcolepsy experience a strong desire for REM sleep, which is the deepest stage of sleep, and will unexpectedly fall into REM sleep during the day. REM usually occurs one to two hours into sleep. However, those with narcolepsy can enter REM in 15 minutes.

Types of Narcolepsy

There are two types of narcolepsy. Type 1 (previously phrased as narcolepsy with cataplexy) is diagnosed because an individual has low levels of hypocretin, reports bouts of cataplexy, or meets the requirements as indicated by a sleep study.

Type 2 (previously referred by narcolepsy without cataplexy) is diagnosed due to reports of daytime sleepiness yet these patients do not show symptoms of cataplexy. Symptoms of this type are altogether less severe and such patients have normal levels of hypocretin.

A type 2 narcolepsy diagnosis significantly outnumbers type 1 narcolepsy. Although Type 2 narcolepsy is acknowledged in the sleep medicine community, often previously diagnosed type 2 narcoleptics are found later to exhibit symptoms but do not have true narcolepsy. This is because the symptoms mirror other disorders.

Secondary narcolepsy can develop from injury to the hypothalamus. These patients may have severe neurological issues and sleep for longer periods (10 hours per night).

Causes of Narcolepsy

While there are several studies around narcolepsy, the exact cause is still unknown. People who suffer from narcolepsy are usually associated with factors such as age and family history. It typically begins affecting people between 10 and 30 years old, and the risk is 20 to 40 times higher if there’s a family member who also has narcolepsy.

Researchers however have discovered a key connection between hypocretin and narcolepsy. They found people with narcolepsy were missing neurons in the hypothalamus region of the brain. These neurons secrete hypocretin, also known as orexins, which helps regulate sleep and arousal states.

Although researchers identified the absence of hypothalamic neurons that produce the protein hypocretin as a clear indication of narcolepsy, they were unclear about what caused the neurodegeneration. They suspected the deficiency was the result of an autoimmune disorder or mistaken reaction of the immune system. This immune reaction would attack parts of the brain that produce the chemical. Years later in 2018 research was published identifying that autoreactive T cells are responsible for the neuronal loss indicating immune system involvement.

But there are other factors or causes beyond a lack of hypocretin which include:

  • Specific gene alterations.
  • Inheritance pattern with first degree relatives for Type 1 Narcolepsy.
  • Infections, such as streptococcal infection or swine flu.
  • Major psychological stress.
  • Sudden changes in sleep patterns.
  • Hormonal changes.

Signs or Symptoms of Narcolepsy

Narcolepsy is characterized by excessive daytime sleepiness, falling asleep during normal activities, and cataplexy (partial loss of muscle control) while awake.

Cataplexy is the most obvious sign of narcolepsy and is usually accompanied by laughter approximately 80% of the time. If cataplexy occurs, narcolepsy is present as it’s the only sleep disorder that causes cataplexy.

Here are the most common signs of narcolepsy to be aware of:

  • Daytime sleepiness is a hallmark of narcolepsy. Those affected may randomly fall asleep at their desk or while watching television at home. When they wake, they feel refreshed, yet the feelings of lethargy return.
  • Cataplexy, sudden physical changes from slurred speech to weakness of muscles, often accompanied by laughter is linked to narcolepsy.
  • Sleep paralysis. Some people may experience momentary immobility of sleep paralysis.
  • Hypnagogic hallucinations occur as you fall asleep or upon waking. Such visions may be particularly vivid and alarming.
  • REM typically occurs at a later stage of sleep yet those with narcolepsy can transition into the dream stage of sleep within 15 minutes.

Those with narcolepsy may have other sleep disorders such as sleep apnea or restless leg syndrome.

Related:  Sleep Apnea Symptoms: 7 Serious Signs You Might Have Sleep Apnea

How to Figure Out if You Have Narcolepsy

Many symptoms of narcolepsy crossover with other sleep disorders and it’s common to be misdiagnosed with the disorder. True narcolepsy is extremely rare, and in nearly every case is accompanied by cataplexy.

Misdiagnosis can prevent many from getting effective treatment for other disorders which may be causing their symptoms. After 25 years of experience diagnosing and treating sleep disorders, we’ve discovered many people are labeled narcoleptic who in fact don’t have the disorder.

Other factors leading to a misdiagnosis include inadequate sleep, circadian issues, and the fact that depression also mimics narcolepsy.

Is There a Narcolepsy Test?

The most common test used to diagnose narcolepsy is performed by a sleep specialist.  There is no special evaluation or physical exam for narcolepsy outside of the multiple sleep latency test (MSLT) is used to exclude narcolepsy (rather than used to diagnose narcolepsy). MSLT is a daytime nap study to measure how quickly you fall asleep.

Many patients discover their symptoms are caused by other sleep disorders. Other sleep studies, such as a polysomnogram (PSG),  may be performed by professionals at sleep clinics to rule out these other sleep disorders which may be causing REM behavior symptoms that are similar to narcolepsy.

A polysomnogram is an overnight recording of brain and muscle activity, eye movement and breathing. It not only provides information about whether REM sleep occurs early in the sleep cycle, but will also determine if the symptoms result from another condition such as sleep apnea.

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In addition to taking a MSLT you may also have a blood test to find out whether you have a genetic marker known as HLA DQB * 0602, which is associated with narcolepsy. A positive result supports a diagnosis, but doesn’t 100% confirm you have narcolepsy with 30% of people who have the genetic marker don’t have the disorder.

Who Develops Narcolepsy?

Narcolepsy affects men and women equally, and many have symptoms for years before being diagnosed. Narcolepsy can come on suddenly, but also occurs gradually. It’s initially noted in younger people but onset can occur at any age, although it’s rare to see it develop in old age.

There is no cure for narcolepsy, but it can be treated so people function well and have healthy lives.

Many symptoms of narcolepsy crossover with other sleep disorders and it’s common to be misdiagnosed with the disorder. True narcolepsy is extremely rare, and in nearly every case is accompanied by cataplexy.

Is it Possible to Have Narcolepsy and Insomnia At the Same Time?

Yes, there are cases where narcolepsy and insomnia coexist. Some of the additional narcolepsy symptoms include fragmented sleep and insomnia. Individuals who suffer from narcolepsy are very sleepy during the day, but experience difficulties staying asleep at night. Sleep may be interrupted by insomnia and other sleep disorders.

Are Narcolepsy and Sleep Apnea Related?

Sleep apnea and narcolepsy are both chronic sleep disorders, but they are very different conditions.

However, excessive daytime sleepiness (EDS) is one of the most noticeable symptoms of narcolepsy and is shared with sleep apnea.

Sleep apnea occurs when there are partial obstructions (which may cause snoring) or pauses in breathing while sleeping. Narcolepsy is a neurological disorder that prevents the brain from properly regulating sleep-wake cycles.

Although excessive daytime sleepiness (EDS) is a common shared symptom for narcolepsy and sleep apnea, the symptom occurs for very different reasons.

People with sleep apnea experience excessive fatigue or EDS because disordered sleep breathing results in fragmented sleep.

Narcoleptics’ fatigue isn’t caused by fragmented sleep or even a lack of sleep. Generally people with narcolepsy get the same average amount of sleep each night as someone without a sleep disorder.  Instead, narcoleptics can’t regulate their rapid eye movement (REM) sleep which is a restorative stage of sleep.

How Fast Do Narcoleptics Fall Asleep?

It takes an average sleeper about one to two hours to enter REM sleep, but this does not happen with those affected by narcolepsy. As referenced above, a person affected with narcolepsy can enter REM after 15 minutes.

Narcolepsy and REM and NREM Sleep

Sleep stages are divided into rapid eye movement and non-rapid eye movement (REM and NREM). The NREM stage has three substages. The first substage is short, lasting ten minutes. The second substage can last thirty minutes to an hour and the final lasts 20 to 40 minutes.

REM is a deeper stage of sleep, and is typically when dreaming occurs.

For narcoleptics, not only do they fall into deep REM sleep much faster, REM sleep for them can occur at any time of the day.

Narcolepsy Diagnosis

Diagnosing narcolepsy may require multiple tests, especially if cataplexy isn’t present. Cataplexy is considered by many practitioners as the most accurate diagnostic marker of the disease. It worsens with poor sleep and fatigue and often improves with advancing age.

The only subset of patients who are easily diagnosed with narcolepsy are those who are HLA DQB1*06:02 positive and hypocretin deficient. Hypocretin deficiency can be tested by measuring cerebrospinal fluid (CSF) concentrations of hypocretin-1.

For most patients, diagnosis typically begins with a detailed medical history. The sleep specialist will ask questions about your symptoms, sleep patterns, level of sleepiness throughout the day, if you’re experiencing episodes of cataplexy, and other possible symptoms like sleep paralysis. They will also rule out other other causes of sleepiness and investigate

Narcolepsy is a disorder of REM sleep, therefore, patients will also undergo the Multiple Sleep Latency Test (MSLT). This test was developed as a diagnostic tool to identify patients who enter rapid eye movement (REM) sleep quickly once they fall asleep. For diagnostic purposes, when patients receive a mean sleep latency (MSL) it must be equal to or less than eight minutes with at least two sleep onset rapid eye movement periods.

Narcolepsy without cataplexy is a diagnosis of exclusion. Indeed, it is good practice to exclude possible confounding factors for sleepiness and positive MSLTs such as the presence of sleep apnea and circadian abnormalities of sleep deprivation. Many patients discover their symptoms are caused by other sleep disorders.

In practice, some of these factors are often hard to exclude and may coexist in various degrees. The only way to truly exclude other disorders as causal factors is to test for these disorders and observe a therapeutic response.

Narcolepsy Treatments

There is no cure for narcolepsy, but it can be treated so people function well and have healthy lives. Although narcolepsy doesn’t have a cure, some of the symptoms can be treated with medicines and behavioral lifestyle changes.

Some medications and lifestyle changes include:

  • Antidepressants
  • Amphetamine-like stimulants
  • Taking short naps
  • Avoid smoking
  • Avoid caffeine or alcohol before bed
  • Avoid heavy meals right before bedtime
  • Relax before going to bed

Sleep Centers of Middle Tennessee are leading the way to better sleep care, we’re leaders in the field of sleep medicine and aim to help people who have been struggling to get good sleep. We have three different locations in Tennessee to provide you with the best care, located in MURFREESBORO, FRANKLIN, and CLARKSVILLE.

If you suffer from any of the symptoms we have listed or feel related in any way possible to the information we’ve shared, please get in contact with us, we’re here to help you in any way possible.

 

 

 

 

References:

Latorre, D., Kallweit, U., Armentani, E. et al. T cells in patients with narcolepsy target self-antigens of hypocretin neurons. Nature 562, 63–68 (2018). https://doi.org/10.1038/s41586-018-0540-1

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