Sleep Disorder Guide to Narcolepsy
Not getting enough sleep at night is hard.
But being unable to stop yourself from falling asleep during the day? That’s even harder.
In this sleep disorder guide, we’ll cover the ins and outs of narcolepsy, including causes, symptoms and treatments.
What is Narcolepsy?
Narcolepsy is a chronic neurological sleep disorder that weakens the brain’s ability to control sleep cycles—whether it’s staying awake or falling asleep.
People with narcolepsy are known for their excessive daytime sleepiness (hypersomnia), even if they’ve had a full night’s sleep.
This hypersomnia can cause them to fall asleep at any point in the day. This is especially true in relaxing scenarios, but can happen during any type of everyday activity, like eating, talking or even driving—which is not just inconvenient, but dangerous, too.
Narcolepsy sufferers are also known to have irregular sleep patterns, causing them to wake up several times throughout the night.
Cataplexy (sudden muscle weakness) is another common symptom. It can cause the body to go completely limp.
Sleep paralysis, which is also common among those with narcolepsy, causes total body paralysis while going into or out of sleep.
Narcolepsy and REM Sleep
Narcolepsy is characterized by abnormal rapid eye movement (REM) sleep, which is the dream phase of sleep.
To make sure your body doesn’t try to act out what’s going on in your brain while you dream, your brain tells your body to stay inactive and limp.
For typical sleepers, REM sleep begins after approximately 60 to 90 minutes.
People with narcolepsy go into REM sleep too early: around 15 minutes after falling asleep. The early onset of REM sleep is thought to explain the symptoms of cataplexy and sleep paralysis.
Types of Narcolepsy
There are two different types of narcolepsy:
Type 1 Narcolepsy
Type 1 narcolepsy is characterized by excessive daytime sleepiness (hypersomnia) and either:
- Cataplexy: the sudden loss of muscle control, or
- Low CSF hypocretin-1 levels: a brain chemical that sustains alertness
Type 2 Narcolepsy
Type 2 narcolepsy is characterized by excessive daytime sleepiness without any attacks of cataplexy. The symptoms are typically less severe.
Who Gets Narcolepsy?
Narcolepsy typically starts at a younger age, normally from childhood to young adulthood (ages 7 - 25). That said, narcolepsy has been known to start at any age.
If untreated, narcolepsy can remain a lifelong problem.
Approximately one in 2,000 people suffer from narcolepsy, which translates to about 18,000 Canadians and 135,000 - 200,000 people in the United States.
But doctors believe the condition often goes undiagnosed, so the true numbers are likely higher.
Narcolepsy is not biased towards either gender; men and women are equally affected by narcolepsy.
Causes of Narcolepsy
As with many sleep disorders, the underlying causes of narcolepsy aren’t completely known at this time.
Those who have type 1 narcolepsy (narcolepsy with cataplexy)—which is the more common of the two types—have very low levels of cerebrospinal fluid (CSF) hypocretin. This brain chemical keeps you awake, alert and hungry. The low levels of hypocretin are thought to be the main cause of type 1 narcolepsy.
But what causes low hypocretin levels?
Sleep scientists have identified a few factors that contribute to the condition:
- Autoimmune disorders: An overactive immune system can result in the body mistaking healthy cells or tissue as an infection, causing the body to attack its own cells. Scientists theorize that those with narcolepsy have an overactive immune system that specifically targets the brain cells that contain hypocretin.
- Genetics: Approximately one in 10 people with type 1 narcolepsy has a family member that also suffers from narcolepsy, suggesting there may be a genetic component. However, most instances seem to be one-off cases.
- Brain trauma: In rare cases, low hypocretin levels are due to brain injuries like tumours, diseases or physical damage.
Note: Those who have type 2 narcolepsy tend to have normal hypocretin levels, so the entirety of the condition can’t be explained by this one chemical.
Symptoms of Narcolepsy
Narcolepsy is a chronic condition, meaning it’s a lifelong problem that rarely subsides over time. In most cases, however, symptoms do not necessarily worsen over time, which means it is not degenerative.
According to the National Institute of Neurological Disorders and Stroke, only 10 to 25% of people with narcolepsy will experience all of the following symptoms:
Excessive daytime sleepiness (EDS): Every person with narcolepsy suffers from EDS—the experience of frequent sleepiness—even after getting enough sleep. In contrast to typical feelings of sleepiness that gradually increase over the course of a day, EDS happens in quick bursts known as “sleep attacks.”
- Cataplexy: Cataplexy is a sudden loss of muscle tone that causes a partial or total loss of muscle control. Strong emotions like stress, anger, fear or laughter are known to trigger cataplexy. In some cases, people experience a total body collapse, while in others, it may just involve a slight drooping of the eyes or mouth. Cataplexy also varies widely in frequency—some people experience several attacks a day, while others may only have one or two instances throughout their life.
- Sleep paralysis: Sleep paralysis is similar to cataplexy, but it only happens in the moments before falling asleep or waking up. It involves the inability to move your body or to speak, similar to when you’re in a deep sleep. But throughout sleep paralysis, the person is actually fully awake. This just lasts for a few seconds before falling asleep or when waking up.
- Hallucinations: Hallucinations aren’t as common as the other symptoms, but in severe cases of narcolepsy, people can hallucinate vivid, horrifying images while experiencing sleep paralysis.
- Insomnia: The early onset of REM sleep can cause people with narcolepsy to wake up frequently throughout the night.
Automatic behaviours: In some cases, when a person with narcolepsy falls asleep during a routine daily activity, they may continue to do that activity for a few seconds or minutes even though they are asleep.
Cataplexy is only linked to narcolepsy and is therefore the main clue to diagnosing the condition.
Once you report cataplexy to your doctor, they may ask questions like:
- Do you frequently feel sleepy throughout the day?
- Do you ever experience strange sensations as you fall asleep?
- Do you ever feel unable to move when falling asleep?
- Do you ever experience muscle weakness after laughing or feeling angry?
If you answer yes to any of the above, you may be asked to do the two following sleep tests:
- Polysomnogram (PSG): A PSG measures brain, muscle, respiratory and eye movement activity during sleep. By confirming the early onset of REM sleep, a PSG can differentiate narcolepsy from another disorder. PSGs can be done at a sleep disorder clinic.
Multiple sleep latency test (MSLT): Taken the day after the PSG, an MSLT measures how quickly you are able to fall asleep during the day. You’ll be asked to take five quick naps. Someone with EDS will fall asleep within eight minutes on average over the course of the five naps. If you experience REM sleep within 15 minutes of at least two of the five naps, it’s likely you suffer from narcolepsy.
Most doctors will also request that you keep a sleep journal for 1 - 2 weeks, documenting symptoms, how often they occur and when they occur.
Common Treatments of Narcolepsy
While there is no cure for narcolepsy, medication and proper sleep hygiene can help curb the symptoms:
Medical narcolepsy treatments
The following drug categories are commonly prescribed to treat narcolepsy:
- Stimulants: Most doctors start by subscribing Modanifil, which reduces daytime sleepiness by stimulating the central nervous system. If Modanifil doesn’t work, they may progress to stronger stimulants like methylphenidate.
Antidepressants: Instances of cataplexy can be reduced by antidepressants like tricyclics and selective serotonin or noradrenergic reuptake inhibitors (SSRIs/SNRIs), but can cause high blood pressure and heart rhythm issues.
- Sodium oxybate: While there are associated safety concerns, sodium oxybate is approved for treatment of EDS and cataplexy.
Disclaimer: All of the above-listed medications are available by prescription only and should not be taken without the approval of your doctor.
Natural narcolepsy treatments
In addition to prescription drugs, the following lifestyle changes can improve symptoms of narcolepsy:
- Maintain a consistent sleep and nap schedule
- Exercise at least 20 minutes per day
- Avoid eating close to bedtime
- Quit smoking
- Avoid caffeine and alcohol
- Relax before bed