If excessive sleepiness and disrupted sleep-wake cycles are a constant challenge, a narcolepsy diagnosis might be the first step toward relief.
Narcolepsy tends to be widely misunderstood due to media depictions of people with the condition falling asleep randomly or in inappropriate situations. But spontaneous sleeping is a small part of what living with narcolepsy really feels like.
Common signs of the disorder can include constantly feeling tired despite sleeping through the night or experiencing muscle weakness that makes everyday tasks difficult.
But narcolepsy is a manageable condition, and a diagnosis is often the first step to finding a proper treatment plan.
Narcolepsy is a neurological disorder that prevents your brain from regulating sleep-wake cycles. A narcolepsy diagnosis can happen at any stage in life, but most people learn they’re living with the condition before adulthood.
The condition is a subclass of sleep-wake disorders in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) and may impact as many as
There are 5 subtypes of narcolepsy in the DSM-5:
- type 1 narcolepsy (narcolepsy with cataplexy)
- type 2 narcolepsy (narcolepsy without cataplexy)
- secondary narcolepsy (narcolepsy due to an injury to the hypothalamus)
- autosomal dominant cerebellar ataxia, deafness, and narcolepsy
- autosomal dominant narcolepsy, obesity, and type 2 diabetes
Types 1 and 2 narcolepsy tend to be the most common or “primary” types of the condition while the others are rarer.
Narcolepsy is a lifelong condition, but symptoms are manageable with time and the proper treatment plan, though they may never go away.
Excessive daytime sleepiness (EDS) is one of narcolepsy’s five most common symptoms, often referred to as “CHESS,” an acronym for:
- excessive daytime sleepiness (EDS)
- sleep paralysis
- sleep disruption
When you’re in a regulated sleep-wake cycle, your muscles are in a relaxed state as you begin the rapid eye movement (REM) phase.
But when you live with narcolepsy, your brain can’t regulate these processes, and you may experience muscle weakness even while awake.
For some people, cataplexy can be mild. For others, it can cause a state of full-body collapse that makes it challenging to speak, move, or even open your eyes.
It’s often brought on by strong emotions, such as happiness, fear, or anger.
Not everyone who receives a narcolepsy diagnosis will experience cataplexy, but most people with cataplexy live with narcolepsy.
Hallucinations are sensory experiences that happen in the absence of stimuli. You may hear, see, smell, taste, or touch things that aren’t there.
Hallucinations associated with narcolepsy typically occur while falling asleep or waking up. Hallucinations also often accompany another symptom of narcolepsy — sleep paralysis.
Excessive daytime sleepiness (EDS)
EDS is the most common and often the most persistent symptom of narcolepsy.
How EDS presents is unique to each person, but could look like:
- an irresistible urge to nap
- constant drowsiness regardless of your sleep quality the night before
- a spontaneous sleep episode you may experience several times a day
Sleep paralysis is like cataplexy. But it occurs during the changes of the sleep-wake cycle rather than the waking hours.
When you experience sleep paralysis, you might be unable to move or speak for short periods, but you’re fully aware.
A side effect of unregulated sleep-wake cycles is not getting enough sleep at night. Just like being unable to stay awake during the day, you may find that you can’t stay asleep at night.
With narcolepsy, napping during the day doesn’t typically “even out” a sleepless night. You may feel refreshed after sleeping or napping but feel tired later.
Not everyone seeks guidance when they experience sleep disruptions.
You might think it’s just “how you’ve always been” or assume stress is the reason you’re so tired. But any excessive sleepiness can be a reason to speak with a doctor.
If you experience these symptoms during the same day at least several times a week for 3 months or more, you may meet the DSM-5’s diagnostic criteria for narcolepsy:
- lapsing into sleep
- feeling an undeniable need to sleep
These symptoms of excessive sleepiness must be present with at least one of the following:
- multiple cataplexy episodes during a single month
- hypocretin deficiency
- irregular REM and sleep latency periods
What are the causes of narcolepsy?
The exact causes of narcolepsy are unknown, but research suggests several factors may play a role, including:
- brain injuries
- autoimmune disorders
- viral infections
Evidence also indicates that narcolepsy with cataplexy is linked to low levels of hypocretin, a vital chemical in sleep-cycle regulation.
Before receiving a narcolepsy diagnosis, a doctor will first check for other conditions that might be causing your sleep disruptions.
In addition to undergoing a physical evaluation and checking your hypocretin level, you may participate in polysomnogram and multiple sleep latency tests.
Measuring hypocretin, a sleep-regulating brain chemical also known as orexin, is the first step in diagnosing narcolepsy. A shortage of the chemical in the cerebrospinal fluid surrounding the brain and spinal cord often indicates narcolepsy type I.
A lumbar puncture is performed to measure hypocretin. During this procedure, a sample of your cerebrospinal fluid is drawn using a needle.
During the PSG, or sleep study, a healthcare team assesses your sleep overnight at a medical center.
During this process, you’ll sleep as usual, but your healthcare team will monitor:
- brain waves
- eye movement
- other involuntary functions that occur during sleep
Your REM cycles and sleep patterns will be evaluated so that other potential causes of sleep disturbance — like sleep apnea — can be ruled out.
Multiple sleep latency test (MSLT)
The MSLT measures how quickly you fall asleep during the day and how quickly you enter the REM stage. The MSLT is usually performed the day after a PSG.
You may be asked to take a few short naps in 1 day during this test. These naps, separated by about 2 hours, are used to measure EDS. Falling asleep in less than 8 minutes indicates EDS.
Because narcolepsy often causes you to enter REM sleep rapidly, entering REM within 15 minutes in 2 out of 5 naps suggests EDS in the presence of a sleep-wake disorder.
If you frequently feel exhausted or experience uncontrollable sleep episodes and muscle weakness that significantly impact your life, you may have narcolepsy.
Living with narcolepsy can be a challenge, but symptoms can be managed with medication and lifestyle changes.
Finding the proper treatment plan often begins with a diagnosis.
Because a doctor will want to rule out the possibility of other underlying conditions, the first step in diagnosing and treating narcolepsy is often a physical checkup.
Your doctor may then perform specialized tests, such as the polysomnogram (PSG) and the multiple sleep latency test (MSLT), to better understand your sleep.
After a narcolepsy diagnosis, you can work with your doctor and a therapist to design a treatment plan. Finding what strategies work for you may take time and effort, but living a well-balanced life with narcolepsy is possible.