Cataplexy is a brain disorder that causes a sudden and temporary loss of muscle tone and control. (1) The episodes (or “cataplectic attacks”) in most cases are triggered by strong or extreme emotions, including anger, stress, anxiety, fear, a depressed mood, joy, and laughter.
The vast majority of people who experience cataplexy do so as a result of having type 1 narcolepsy, a chronic sleep and neurological disorder in which the brain has trouble properly controlling wake and sleep cycles. In very rare cases, cataplexy has been reported in individuals without narcolepsy. (2)
Living with cataplexy — whether you have narcolepsy or not — is a challenging condition. That’s because you cannot always control your emotions or emotional response, so cataplectic attacks can occur randomly. For some it means being constantly vigilant about how to avoid losing control of their bodies. (3,4,5)
Here are some important things to know about why cataplexy happens, its connection to narcolepsy, and how to manage the potentially debilitating symptom.
Cataplectic Attacks Cause a Sudden Loss of Muscle Control
Cataplexy — episodes of uncontrollable muscle weakness — typically last a few seconds to a few minutes, and can happen as infrequently as a few times a year or as often as a few times a day. They are typically caused by a strong feeling of sadness, excitement, joy, or other emotion, and can cause someone’s knees to buckle, their head to bob, or cause them to fall down if they are standing and lose control of their leg muscles, explains Shelley Hershner, MD, assistant professor of neurology and director of the Collegiate Sleep Clinic at the University of Michigan in Ann Arbor, who has worked on the narcolepsy quality metrics for the American Academy of Sleep Medicine.
Cataplexy is often misdiagnosed as a seizure disorder; but unlike fainting or seizure disorders, people who experience cataplexy are awake and aware of what’s happening — though some may fall asleep after the episode ends. (6)
People who have cataplexy must constantly be on guard to avoid injury. When an episode of cataplexy strikes, an individual may slump, lose his or her grip on something, or fall down. “Some people may avoid swimming, climbing a ladder, or taking a bath,” says Dr. Hershner.
Cataplexy can cause muscle weakness in any part of the body, though cataplexy commonly affects the limbs (hands may drop whatever they’re holding, knees may buckle, legs may collapse) and face (eyelids may droop, jaw may go slack and speech become slurred, the head may nod). The attacks can range from mild, such as a slight drooping of the eyelids, to severe, such as a total body collapse.
People With Narcolepsy Have Cataplexy Because of a REM Sleep Malfunction
The vast majority of cases of cataplexy occur because an individual has type 1 narcolepsy. People with this type of narcolepsy have abnormally low levels of a sleep-wake regulating brain hormone called hypocretin. This error can causes rapid eye movement (REM) sleep to happen at the wrong time. (7)
Most people who are diagnosed with narcolepsy do have cataplexy, too. In some cases, type 2 narcolepsy — the one without cataplexy, which has milder symptoms — may develop into narcolepsy with cataplexy, says Eric Olson, MD, an associate professor of medicine and sleep medicine specialist at the Mayo Clinic in Rochester, Minnesota, and a board member of the American Academy of Sleep Medicine. (8)
Understanding REM sleep — specifically, the way that sleep cycles are disrupted in people with narcolepsy — may help us gain insight into why cataplexy happens in people with narcolepsy. In normal sleep cycles, people go through three stages of non-rapid eye movement (NREM) sleep before entering the REM phase. Each cycle takes about 60 to 90 minutes before repeating throughout the night. But these cycles malfunction in people with narcolepsy. They may enter REM sleep right away when they fall asleep, and then wake up, bypassing the NREM stage; this can occur both during the night as well as the day, blurring the lines between wakefulness and sleep. (9,10)
RELATED: What’s Happening in the Brain During the Stages of Sleep
Another important point: The REM stage of sleep is when dreaming occurs, and when our bodies become paralyzed — a mechanism that is thought to prevents us from acting out our dreams and harming ourselves. In people with narcolepsy, this sleep paralysis associated with REM sleep happens at the wrong time, too, which is why sleep paralysis and vivid hallucinations while falling asleep or waking up can also occur. (11)
Cataplexy episodes resemble that loss of muscle control that naturally happens during REM sleep — but occur when someone is awake rather than during sleep.
Research published in September 2012 in the Journal of Neuroscience suggested that in healthy individuals, positive emotions may lead to muscle weakness (feeling weak with laughter, for instance), but that the brain chemical hypocretin (the one absent in people with narcolepsy) prevents that loss of muscle tone from being anything more than a brief event. (12)
This may help explain why, in people who have narcolepsy with cataplexy, that response is more extreme. More research needs to be done to better understand why and how strong emotions trigger this response to begin with, but recent and continuing discoveries into the role of hypocretin in narcolepsy are significant.
Treatment and Medication Options for Cataplexy
Without proper diagnosis and treatment of narcolepsy, symptoms such as cataplexy can be dangerous and “life-restricting,” notes Dr. Olson. “Someone may stop competing to avoid winning something, or avoid laughing, or even engaging in intercourse,” says Olson.
In short, people affected by cataplexy may learn to modify their behavior and activities to minimize their risk of bringing on an episode, and many end up avoiding situations that may cause cataplexy. These adjustments can be consequential and vastly affect quality of life, such as if someone skips social situations with friends, or avoids driving.
There are drugs that have been shown to be effective in treating cataplexy. There is some evidence that tricyclic antidepressants, such as clomipramine, imipramine, and desipramine, and serotonin reuptake inhibitors (SSRIs) may be helpful for cataplexy, as well as other narcolepsy symptoms. (13) Sodium oxybate (also known as gamma hydrobutate, or GHB, the so-called “date-rape” drug) has also been shown to be effective in treating severe daytime sleepiness as well as cataplexy attacks. (14)
If an individual has very rare episodes of cataplexy, intervention may be unnecessary. But people who experience frequent attacks (or ones that greatly disturb their lives) should discuss medication options with their doctor and consider the potential benefits, as well as possible side effects. For people with severe cataplexy, being able to take medication that can help control attacks may significantly improve social interaction, safety, and overall quality of life.
