Your guide to causes, symptoms, treatments and more of this rare sleep disorder.
This article is based on reporting from expert sources including Alon Y. Avidan, MD; Peter A. Fotinakes, MD
Have you ever been so tired that you just fell asleep in the middle of whatever you were doing? We’ve all seen the viral videos of little kids falling asleep in high chairs in mid-meal. But what if that was something that happened to you every day, and you couldn’t seem to control your sleep-wake patterns and always felt so tired you could barely move?
Sounds pretty terrible, doesn’t it? Well, for most people, the occasional bout of daytime sleepiness is related to a poor night or two of sleep and is rectified easily with getting more rest. But for individuals with narcolepsy, this excessive sleepiness and inability to control sleep onset is a lifelong problem that must be carefully managed.
What Is Narcolepsy?
“Narcolepsy is a sleep-related condition that has its origins in the brain,” says Dr. Alon Y. Avidan, professor at the UCLA Department of Neurology and director of the Sleep Disorders Center at UCLA Health. This chronic neurological disorder affects the brain’s ability to control sleep-wake cycles, and disrupts REM sleep, or the period of sleep when dreaming occurs. In short, people with narcolepsy can’t control when they sleep and when they wake. The sleep-wake cycle is disrupted, and this leads to poor sleep at night and excessive daytime sleepiness.
Narcolepsy is considered a rare disorder. The Narcolepsy Network reports that narcolepsy affects an estimated 1 in 2,000 people, or about 200,00 Americans. But just 25% of these individuals have received a diagnosis. Some people with narcolepsy are likely misdiagnosed with depression.
Signs and Symptoms
There are several signs and symptoms associated with narcolepsy, including:
- Excessive daytime sleepiness.
- Sleep attacks.
- Cataplexy.
- Hallucinations.
- Sleep paralysis.
- Sleep-onset REM.
- Brain fog.
- Fragmented sleep.
Excessive Daytime Sleepiness
This is the most common and pervasive symptom of narcolepsy, and it’s not just being tired. “It’s important to emphasize that the daytime sleepiness is pathologic,” Avidan says. “No matter what they do, they’re always sleepy. In the morning. In the afternoon. In the evening. It does not go away.” This debilitating sleepiness prevents the person from engaging in normal daytime activities.
“Although the media often portrays narcoleptics as suddenly flipping in and out of waking/sleep like a light switch, the symptoms usually manifest as extreme sleepiness throughout the waking period that often becomes irresistible,” says Dr. Peter Fotinakes, medical director of the Sleep Disorders Center at St. Joseph Hospital in Southern California. Thus, “narcoleptics experience sleepiness throughout the day, as well as suddenly losing control and falling asleep at inappropriate times.” These individuals are “constantly fighting to remain awake,” he says. This results in disability because the drive to sleep can be so pervasive.
Sleep Attacks
This excessive sleepiness sometimes manifests as suddenly falling asleep, episodes called sleep attacks.
Cataplexy
This sudden loss of muscle tone is typically triggered by intense emotions. Fear, anxiety, anger, excitement and laughter can all trigger episodes of cataplexy, and their frequency varies from person to person. “Cataplexy is unique to narcolepsy and consists of the paralysis of REM sleep appearing after a strong emotion,” Fotinakes says. “Cataplexy may range from feeling as if you’re becoming a rag doll to total paralysis,” and in some people head bobbing, a slack jaw and stuttering may be signs of cataplexy. It usually only lasts for less than a minute, but if it comes at the wrong time, it can be debilitating and dangerous. It’s commonly associated with narcolepsy, but not all narcoleptics experience cataplexy.
Hallucinations
These typically occur upon waking. Called hypnagogic hallucinations, these hallucinations occur because of the REM sleep disruptions associated with narcolepsy. “They will see, hear or feel things that are part of their dreams for a short period after they regain consciousness,” Fotinakes says.
Sleep Paralysis
This also tends to occur when a narcoleptic transitions out of sleep and is also related to the disruption of REM sleep, Fotinakes says. The narcoleptic “literally cannot move a muscle for a few moments after awakening,” he says, but thankfully, breathing is preserved and the person is able to open their eyes and see. Nevertheless, it can be a terrifying feeling to be stranded in bed with sleep paralysis.
Sleep-onset REM
The disrupted REM sleep cycle can lead to narcoleptics experiencing the deep dreaming state of sleep immediately after falling asleep. “Normally, we enter dream sleep between 70 and 120 minutes after falling asleep. Narcoleptics, therefore, often note dreaming after briefly dozing off, during short naps, and experience a greater percentage of dreaming during their nocturnal sleep,” Fotinakes says.
Brain Fog
Another symptom that many narcoleptics feel is a fogginess or trouble remembering and other issues with cognition. This is related to not getting adequate sleep, and it can lead some individuals to operate on a sort of auto-pilot setting, Avidan says. “They might go to the supermarket and start putting things in the cart that they don’t need, in a semi-automatic manner without really thinking about the purpose of the activity.” This constant fogginess can lead to difficulties at work and in interpersonal relationships.
Fragmented Sleep
When narcoleptics do sleep, they’re liable to experience fragmented or interrupted periods of sleep that aren’t restful.
Narcoleptics may also have other associated sleep disorders including:
- Obstructive sleep apnea. People with sleep apnea stop breathing momentarily during sleep, and this causes them to wake up, sometimes hundreds of times a night.
- Insomnia. People with insomnia struggle to fall asleep or stay asleep and often have interrupted and unrestful sleep patterns.
- Restless leg syndrome. People with RLS experience movements in the legs while sleeping which can lead to disrupted and fragmented sleep.
Types
Avidan says there are actually two different types of narcolepsy:
- Type 1: Narcolepsy with cataplexy.
- Type 2. Narcolepsy without cataplexy.
Causes
The National Organization for Rare Disorders reports that type 1 narcolepsy has been linked to low levels of hypocretin in the brain, and that in some individuals, 80% to 90% of hypocretin-producing neurons in the hypothalamus may be lost.
Individuals with type 2 narcolepsy typically have less severe symptoms and normal levels of the brain hormone hypocretin, according to the National Institute of Neurological Disorders and Stroke.
“Narcoleptics experience a loss of hypocretin-producing nerve cells, which reside in an area deep in the center of the brain called the hypothalamus,” Fotinakes explains. Hypocretin is also known as orexin. “Hypocretin is critical in controlling sleep. Although the exact mechanism behind the loss of hypocretin nerve cells is unknown, an auto-immune mechanism is highly suspected.”
Other less frequent potential causes include:
- Exposure to toxins.
- Tumors.
- Strokes.
- Multiple sclerosis.
- Head trauma and concussions.
Symptoms start to become apparent as the population of hypocretin nerve cells falls and the levels of hypocretin levels in the body drop to a critically low level, Fotinakes says.
Risk Factors
The Narcolepsy Network reports that symptoms typically emerge between the ages of 10 and 30, but the condition can develop at any age. NORD notes that there are two peak times for when narcolepsy may present. The first is at about 15 years of age, and the second is at 36 years. It’s unclear why these ages seem to be more common times for the disease to develop.
The National Heart, Lung and Blood Institute reports that genetic, autoimmune and environmental factors – such as exposure to certain chemicals or work enviroments – may also increase risk for developing narcolepsy. The disease sometimes shows up after an upper airway infection or another medical condition, such as a stroke or tumor.
Diagnosis
If it’s suspected that you may have narcolepsy, your doctor will take a thorough medical history and conduct a physical exam. You should keep a sleep diary or journal that documents your symptoms and your sleeping patterns to help your doctor establish what’s going on.
You’ll also undergo sleep testing. A nocturnal polysomnogram will help your doctor rule out other potential sleep disorders that may cause hyper-sleepiness such as sleep apnea. You’ll have to spend the night in a sleep center as your sleep is assessed.
For suspected narcolepsy, you’ll also usually spend the following day at the sleep center to complete another test called the multiple sleep latency test. This test consists of “a series of four or five 20-minute nap periods spaced two hours apart,” Fotinakes says. This test measures “the speed at which a person falls asleep during normal waking hours and screened for sleep-onset REM.”
If sleep testing proves inconclusive, you may undergo an additional test of your hypocretin level in the cerebrospinal fluid. This will require a lumbar puncture (also called a spinal tap), in which a large needle is inserted into the lower back and fluid from the spinal cord is withdrawn and tested. Narcoleptics usually have very low levels or no hypocretin in this fluid.
In the rare instance that you suddenly experience severe daytime sleepiness immediately after sustaining a head trauma, your doctor might also order an MRI to look for signs of injury in the brain that could be contributing to your symptoms, Avidan says.
It’s important to get a firm diagnosis of narcolepsy if you think you might have it because treatments are available and the disease can progress to become truly disabling.
Misdiagnosis
“Given the lifelong nature of narcolepsy and the tendency for misdiagnosis, it’s best to seek out an accredited sleep disorders center and experienced board-certified sleep medicine specialist to confirm the diagnosis,” says Avidan. He adds that some narcoleptics don’t receive a diagnosis because the disease can be mistaken for other issues.
“The primary age in which this condition presents is the teenage years and adolescents up to age 20 or so. This population is particularly vulnerable to sleep deprivation,” and thus symptoms of narcolepsy may be mis-attributed to typical teenage sleep issues or lifestyle choices. “We want to make sure the patient does not suffer from insufficient sleep.” For this reason, Avidan stresses the importance of doing a sleep study and keeping a sleep log so that a correct diagnosis can be made.
Treatments
Although there’s no cure yet for narcolepsy, there are treatments that can help manage and reduce the severity of symptoms .
Stimulants
Stimulant medications promote wakefulness, and modafinil (Provigil) is one of the most widely prescribed for excessive daytime sleepiness. It’s widely used to treat narcolepsy because it seems to have fewer side effects of other stimulants, such as impacts to memory and dependency and withdrawal symptoms.
Over the years, a variety of other medications that promote wakefulness have also been used to treat narcolepsy, including methylphenidate (Ritalin, Methylin), methamphetamine and dextroamphetamine. However, these medications are associated with a variety of unpleasant and problematic side effects, including nervousness, insomnia, irritability and potential dependency.
Drugs to Treat Cataplexy
There are a few drugs, including sodium oxybate or gamma hydroxybutyrate (Xyrem), that can help maintain muscle tone and prevent episodes of cataplexy.
Antidepressants
A variety of antidepressant medications, including fluoxetine (Prozac, Serafem), sertraline (Zoloft), atomoxetine (Strattera) and venlafaxine (Effexor), may also be prescribed. These medications have been found to help with cataplexy, sleep paralysis and hypnagogic hallucinations.
Behavioral Modification
Changing elements of your lifestyle may help promote wakefulness and sleep at the appropriate times. Instituting a bedtime routine along with strictly enforced bedtimes and wake times can help reduce some symptoms. A daily nap may also help with daytime sleepiness. Shift work can be especially difficult for people with narcolepsy, Talk to your doctor about establishing the right sleep schedule to address your issues.
Although we know that the cause of narcolepsy is a loss of hypocretin-producing cells in the brain, replacing that hypocretin hasn’t yet been worked out therapeutically. There’s currently no pill to that you can simply take to replace the missing neurotransmitter. NORD reports that ongoing studies are working to develop gene therapies that could potentially replace the missing hypocretin to effectively “cure” narcolepsy, but such approaches are not available to patients yet.
If in Doubt, Talk to Your Doctor
It’s important to remember that although narcolepsy is not curable, there are ways to manage it. With appropriate treatment, people with narcolepsy can go on to lead normal, fulfilled lives. Avidan tells the story of a young woman he treated who was initially misdiagnosed with depression and was having difficulty in school and being left behind. Eventually, it was discovered that she had narcolepsy and appropriate treatment commenced. “She’s now in law school,” he says, and succeeding in ways that seemed hard to imagine just a few years ago.
The moral of the story, he says, is be sure to “speak with a physician if you’re experiencing daytime sleepiness that’s severe and doesn’t go away despite sufficient sleep.” With appropriate treatment, “we see people flourishing and doing what they’re supposed to be doing.”
