It’s likely you’ve heard of narcolepsy before or seen depictions of it in television and film — but there’s more to this condition than just sudden attacks of sleepiness. Narcolepsy is more common than you may think, and it’s thought that many people who have the disorder go undiagnosed for years (or even forever).
So what exactly is narcolepsy and what are its symptoms?
What is narcolepsy?
Narcolepsy is a chronic neurological disorder that affects your brain’s ability to regulate sleep-wake cycles, causing those who have it to experience sudden irresistible urges to fall asleep. Although approximately 1 in 2,000 people are believed to have narcolepsy, the condition is not always identified immediately and is often misdiagnosed.
There are different types of narcolepsy. Individuals with Type 1 narcolepsy usually have low levels of orexin (a hormone produced by the brain that impacts sleep and various other bodily functions and processes). Cataplexy — a sudden loss of muscle tone — also presents as a symptom of Type 1 narcolepsy.
Those with Type 2 narcolepsy often experience the same “sleep attacks” as individuals with Type 1 narcolepsy, but without cataplexy. Their symptoms tend to be milder than those with Type 1 narcolepsy and they generally have normal levels of orexin.
Secondary narcolepsy can result from an injury to the hypothalamus, an area deep within the brain that helps control sleep. In addition to typical narcolepsy symptoms, individuals with secondary narcolepsy may have neurological problems and sleep for longer (over 10 hours) each night.
Signs of narcolepsy
Typically, signs of narcolepsy usually begin presenting between the ages of 7 and 25 years. Feeling rested after waking up then feeling very tired throughout the day is one of the most common signs of narcolepsy. Interrupted sleep that may involve waking up regularly during the night can also indicate narcolepsy.
In a majority of cases, narcolepsy also causes unexpected and temporary loss of muscle control (cataplexy). This is a symptom that occurs in almost no other medical conditions, and it’s often triggered by sudden, powerful emotions such as fear, anger, or excitement.
Cataplexy attacks range in severity from mild (leading to minor muscle weakness) to severe (resulting in total body collapse during which individuals cannot move or speak). During cataplexy attacks, individuals remain completely conscious — although this can be scary, most episodes last for no longer than a few minutes and typically resolve on their own.
In addition to excessive daytime sleepiness, narcolepsy symptoms can include:
- Sleep paralysis
- Fragmented sleep and insomnia
Although narcolepsy symptoms never completely disappear, they can improve over time. Excessive daytime sleepiness is present in all individuals with narcolepsy but according to the National Institute of Neurological Disorders and Stroke, only 10 to 25 percent of those with narcolepsy will experience all of the other symptoms listed here.
Cause of narcolepsy
It’s believed that narcolepsy may have several causes.
The most common cause of cataplexy in those with narcolepsy is the loss of brain cells that produce orexin, the hormone that encourages wakefulness and regulates REM sleep. It’s unclear what causes this cell loss, but studies suggest that abnormalities in the immune system may be responsible.
Researchers believe that in individuals with narcolepsy, the body’s immune system attacks the brain cells containing orexin due to a combination of genetic and environmental factors.
In rare instances, narcolepsy can develop after traumatic injury to parts of the brain that moderate wakefulness and REM sleep or from other diseases in the same areas.
In order to diagnose narcolepsy, a clinical examination and comprehensive medical history are required. You may be asked to keep a sleep diary chronicling your symptoms before attending a physical exam, which can help rule out or identify other conditions that could be causing symptoms. At a sleep clinic, there are two tests that are used to diagnose narcolepsy:
- Polysomnogram (PSG or sleep study): this is an overnight recording of brain and muscle activity, eye movements, and eye breathing. A polysomnogram can help doctors understand when REM sleep occurs and give them greater insight into patients’ sleep activity
- Multiple sleep latency test (MSLT): this assesses daytime sleepiness by recording how quickly an individual drifts off and whether they enter REM sleep. The MSLT takes place after the PSG — patients are asked to nap at specific intervals and their sleep activity is monitored for further indicators of narcolepsy
In some cases, a doctor may choose to perform a lumbar puncture so they can obtain a fluid sample and test it to ascertain orexin levels.
Treatments for narcolepsy
Some of the symptoms of narcolepsy can be treated through lifestyle changes and excessive daytime sleepiness and cataplexy can be regulated in most with medications.
- Modafinil: a central nervous system stimulant that is less addictive and has fewer side effects than other stimulants
- Amphetamine-like stimulants: if modafinil is not effective, doctors may prescribe amphetamine-like stimulants — but these are less commonly used because of the potential for negative side affects and addiction
- Antidepressants: tricyclics and selective serotonin and noradrenergic reuptake inhibitors are effective in controlling cataplexy
- Sodium oxybate (GHB): this helps regulate excessive daytime sleepiness and cataplexy, but the distribution of this drug is tightly controlled due to safety concerns
The following strategies may be helpful:
- Taking short naps
- Maintaining a regular sleep schedule
- Avoiding caffeine or alcohol before bed
- Avoiding smoking, particularly at night
- Exercising daily
- Avoiding large, heavy meals at night
- Relaxing before bed
Taking safety precautions — especially while driving — is essential for those with narcolepsy. Individuals with untreated symptoms are more likely to be involved in car accidents, but this risk is lowered among those who are taking appropriate medication.
Adults with narcolepsy can often work with employers to adjust their work hours so they can nap when they need to and complete important tasks when they’re most alert. Children and teenagers with narcolepsy should work with their school to establish strategies that accommodate their condition.
Finally, support groups can be a wonderful resource for people with narcolepsy who want to develop better coping techniques.
If you’ve been experiencing symptoms of narcolepsy, don’t allow them to go untreated — consult your doctor for further guidance.