How to Test for Narcolepsy

Narcolepsy is a rare neurological disorder that causes abnormal sleep patterns that can disrupt a person’s daily life. This sleep disorder has similar symptoms to other medical conditions and is most commonly misdiagnosed as sleep apnea, insomnia, chronic sleep deprivation, and even depression.

Because of this, diagnosing narcolepsy can be hard and it can take years before the patient receives the correct diagnosis and treatment. That’s why medical professionals believe that there are probably more people suffering from narcolepsy than officially diagnosed.

Fortunately, there are medical tests that can successfully diagnose narcolepsy and we’ll discuss them in detail in today’s article. We’ll start by explaining what narcolepsy is and what its symptoms are, as well as the most common treatments. Let’s get into it.

What Is Narcolepsy?

Narcolepsy is a chronic sleep disorder that affects the nervous system and the brain’s ability to regulate the sleep/wake cycle. People who suffer from narcolepsy experience sudden bouts of uncontrollable drowsiness and sleepiness, meaning that they can unwillingly fall asleep at any time of the day while doing everyday activities like working, eating, or talking.

It’s important to note that even though people with a diagnosis of narcolepsy can fall asleep multiple times during the day, they don’t get any more sleep than the general population because their nighttime sleep cycle is fragmented, causing them to wake up several times during the night.

Narcolepsy is considered a rare disorder and it affects both males and females equally. Risk factors may include having a family history of narcolepsy and autoimmune issues. The symptoms of narcolepsy can start at any age, but they most often start between ages 7-25.

Narcolepsy isn’t a dangerous condition in itself, but given the nature of its symptoms, it can inadvertently put the person in danger — for example, if they fall asleep while driving or operating other types of machinery. Additionally, people may also experience difficulties in work, school, and social situations due to excessive sleepiness.

What Are the Symptoms of Narcolepsy?

Narcolepsy is considered a chronic condition whose symptoms will persist through the years. Though they may improve by little over time, it’s unlikely that they’ll disappear completely and will have to be managed with lifestyle changes.

Excessive Daytime Sleepiness

The main symptom that defines narcolepsy is excessive daytime sleepiness (EDS), which makes it difficult to function during the day as it makes you overwhelmingly sleepy to the point where you’ll fall asleep anytime and anywhere.

Cataplexy

Another symptom is cataplexy, which involves a sudden loss of muscle tone that can paralyze parts of the body for a short while. Cataplexy is often triggered by experiencing strong emotions such as fear, excitement, or laughter, and it can manifest with buckling of the knees to complete body collapse.

Other Symptoms

Other symptoms include experiencing hypnagogic hallucinations (seeing or hearing things that aren’t there) and sleep paralysis moments before falling asleep or moments after waking up, as well as automatic behavior, wherein the person falls asleep for several seconds but continues to do whatever they were doing without being aware of it.

Not all people diagnosed with narcolepsy will experience all of these symptoms, though. Excessive daytime sleepiness is the hallmark narcolepsy symptom that all patients experience, while the other symptoms are present in only 10% – 25%.

Finally, it’s important to note that the frequency and severity of the symptoms may vary from person to person. Some will experience only occasional episodes, while others may have more frequent “sleep attacks.”

Types of Narcolepsy

There are two main types of narcolepsy:

Narcolepsy Type 1

Narcolepsy type 1 is the most common type and it’s characterized by excessive daytime sleepiness coupled with cataplexy. People who suffer from this type of narcolepsy have low levels of the neurotransmitter hypocretin-1, also called orexin, which is key in regulating wakefulness, arousal, and appetite.

Narcolepsy Type 2

Previously known as narcolepsy without cataplexy, narcolepsy type 2 induces excessive daytime sleepiness in patients, but typically it doesn’t involve muscle weakness caused by strong emotions. People suffering from narcolepsy type 2 generally have fewer symptoms and have regular levels of hypocretin.

How to Test for Narcolepsy?

Excessive daytime sleepiness can be a symptom of many conditions, but if it’s significantly disrupting your quality of life, you should have it checked out by your doctor. They may ask you about your medical history and perform a clinical examination to rule out other conditions. If your doctor suspects that your symptoms might be related to narcolepsy, they may refer you to a sleep specialist for more thorough tests.

To begin with, the sleep specialist might ask you to keep a sleep journal for a couple of weeks where you’ll track your symptoms. Apart from this, a physical exam should determine whether there is another condition that might be causing the symptoms. It’s important to note that most narcolepsy symptoms may also be indicative of other conditions, except for cataplexy, which is exclusive to narcolepsy.

If all other possible causes are ruled out, your doctor will order a combination of tests which includes the Epworth Sleepiness Scale (ESS) questionnaire, the sleep study, the multiple sleep latency test (MSLT), and a hypocretin level test.

The Epworth Sleepiness Scale (ESS) Questionnaire

The Epworth Sleepiness Scale (ESS) questionnaire is a self-administered questionnaire comprised of eight questions and is often used in diagnosing sleep disorders, including narcolepsy (you can also find the ESS questionnaire online if you’re curious).

The questions are answered on a scale of 0 to 3 and they refer to how likely you are to dose off during different types of activities listed in the questions. If your score is 10 or below, your daytime sleepiness is considered normal. On the other hand, if you score 18 or more, it means your daytime sleepiness is abnormal and should be medically treated.

Sleep Study (Polysomnography)

The sleep study, also known as polysomnography (PSG) requires the patient to stay in a sleep center overnight, which is usually located in a medical facility. The purpose of this test is to monitor their brain waves, body movements, muscle tone, heart rate, and breathing patterns while they sleep. The doctors will observe if there is any brain activity that points towards narcolepsy, such as:

  • Fast falling into REM sleep;
  • Reduced sleep efficiency;
  • Sudden awakenings.

Multiple Sleep Latency Test (MSLT)

А multiple sleep latency test (MSLT) is used to determine how long it takes you to fall asleep and how quickly you enter REM (rapid eye movement) sleep. This test is often employed the day after the polysomnography test to obtain the most accurate results.

For this test, you’ll be asked to take four to five naps in two-hour increments. If it takes you 8 minutes or less to fall asleep each time, you probably have excessive daytime sleepiness. Additionally, if it takes you no more than 15 minutes to enter REM sleep at least twice out of the five napping sessions, you may suffer from narcolepsy.

Hypocretin Level Measurement

In some cases, the sleep specialist will need to check your hypocretin levels, though this test isn’t commonly used for diagnosis. The specialist will need to do a procedure called a lumbar puncture where they’ll collect a sample of cerebrospinal fluid (CBF) from your spine. And as we said earlier, in individuals suffering from narcolepsy type 1 the hypocretin levels are low.

Treatment Options for Narcolepsy

Narcolepsy can’t be completely cured but it can be managed so that the patients’ quality of life isn’t too affected. A combination of the right medications and lifestyle adjustments can produce satisfactory results, although it might be hard to make the changes at first. Of course, everyone is different, so you’ll need to discuss your unique lifestyle with your doctor until you come up with the best treatment plan for you.

Common treatments prescribed to patients with narcolepsy include:

Stimulants

Stimulants are very commonly prescribed for the treatment of narcolepsy because they stimulate the central nervous system and improve wakefulness. Modafinil is one of the better options because it’s effective and has fewer side effects and is less addictive than other stimulants such as methylphenidate or amphetamines. 

However, in cases where modafinil isn’t effective, these stimulants can still be used, but with caution.

Antidepressants

Antidepressant medications such as tricyclics, selective serotonin reuptake inhibitors (SSRIs), and serotonin-norepinephrine reuptake inhibitors (SNRIs) are typically prescribed to improve cataplexy and other narcolepsy symptoms such as sleep paralysis and hallucinations. However, they tend to produce a variety of unpleasant side effects. Alternatively, sodium oxybate may be used, which is effective for daytime sleepiness, but its use is restricted because it’s a strong medication.

Lifestyle Changes

When it comes to lifestyle adjustments the patient will first be advised to keep a consistent sleep schedule. That means going to bed and waking up at the same time every day, including weekends. Short, 20-minute naps throughout the day when you feel the most sleepy can also be helpful, especially after meals.

To feel more energized, try exercising regularly, on a daily basis. It doesn’t have to be strenuous exercise, just a light walk will do if nothing else. It will help you sleep better at night and feel more active during the day.

It’s best to avoid nicotine and alcohol as they may make your symptoms worse. Also, avoid large meals before going to bed as it can make it harder to fall asleep at night.

Finally, it’s very important to avoid driving if you suffer from narcolepsy to avoid putting yourself and others in potential danger.

Final Thoughts

Narcolepsy is a chronic neurological disorder characterized by excessive daytime sleepiness as the main symptom, and cataplexy, hallucinations, and sleep apnea as other less common symptoms. It’s a rare condition that can often go underdiagnosed or misdiagnosed for years because the symptoms can also be indicative of other conditions.

The most commonly performed tests for narcolepsy that also give the most accurate result are the polysomnogram test and the multiple sleep latency test, which are often used in conjunction for diagnosing narcolepsy. The treatment involves taking stimulants and/or sedatives, as well as making lifestyle changes.