- Cataplexy, or sudden muscle weakness that can resemble fainting, may be prompted by strong emotions.
- This symptom isn't serious and mostly occurs with narcolepsy type one — otherwise, it's very rare.
Cataplexy refers to episodes of muscle weakness that typically occur with narcolepsy type one — roughly 75% of people with this sleep disorder experience cataplexy.
But among the general population, this symptom is very rare: It affects less than 1% of people who don't have narcolepsy. Other conditions that may involve this uncommon symptom include Wilson's disease, Niemann-Pick disease type C, and Prader-Willi syndrome.
Cataplexy can resemble fainting, especially if your knees buckle under you. You may suddenly feel weak and have trouble standing or even smiling. But the major difference is that you remain conscious, even if your eyes close.
There's no cure for cataplexy, but medications can help you manage it once you get a proper diagnosis.
Read on to learn the main signs of cataplexy and how to go about treating it.
Signs and symptoms
Cataplexy affects all genders equally. It typically shows up before age 25, but you can experience it at any age.
"Symptoms are consistent across age, but they vary from person to person, from a slight slackening of the facial muscles to falling down," says Dr. David Culpepper, a medical doctor and Clinical Director at LifeMD.
The main symptoms of cataplexy include:
- Abrupt muscle weakness on both sides of the body following heightened emotions — think fear, excitement, stress, and anger
- Sudden inability to move your facial muscles
- Slurred speech
- Double vision
- Trouble focusing your eyes
The sudden muscle weakness from cataplexy can be easily misdiagnosed as a seizure disorder. But since about 10% of people with narcolepsy notice cataplexy as their first symptom, recognizing cataplexy could help you get a diagnosis of narcolepsy sooner.
Note: Cataplexy only affects your skeletal muscles. You'll still breathe during an episode, and your heart will continue to pump blood. In short, it doesn't pose a serious threat to your health.
What causes it?
Experts believe a hormone deficiency may cause this symptom. People who experience cataplexy typically have lower brain levels of hypocretin, a hormone that helps control your sleep and energy levels.
Low levels of this hormone may cause the same muscle weakness during the day you'd otherwise experience while asleep.
However, intense emotions like laughter, sadness, fear, and excitement can all trigger cataplexy.
Nancy Mitchell, a registered nurse at Assisted Living Center, says these emotional triggers vary widely.
"A teen starting high school or college may experience symptoms due to peer pressure or workload, while young adults might experience uncontrollable muscle twitching when overwhelmed with excitement around friends and family," Mitchell says.
So, why do intense emotions result in temporary paralysis? The amygdala and prefrontal cortex in your brain control your emotions — but these regions also connect to your brain's paralysis pathways.
Experts believe your brain may associate intense emotions with paralysis, inadvertently causing cataplexy. Studies in mice show reducing activity in these parts of the brain also reduces cataplexy.
Diagnosis
"Cataplexy mimics symptoms of seizures and brain tumors, so you should visit your clinician to rule out other severe ailments," Mitchell says.
Tell your doctor if you're ever fully conscious when you experience muscle weakness. This information can help them find the right diagnosis, since it's conscious muscle weakness that distinguishes cataplexy from fainting or seizures.
If your doctor does suspect cataplexy, they may refer you to a sleep specialist. Cataplexy is usually preceded by excessive daytime sleepiness, so it's often diagnosed alongside narcolepsy in a sleep center.
For a formal diagnosis, your doctor might also ask you to:
- Keep a sleep journal that tracks your fatigue and other symptoms.
- Spend the night at a sleep center to have your breathing, muscles, and brain activity during sleep monitored via polysomnography.
- Take several supervised naps at a sleep center so specialists can determine how quickly you fall asleep.
Note: If you don't have narcolepsy, your primary care doctor can use blood, urine, or genetic testing to diagnose other causes of cataplexy, like Wilson's disease, Niemann-Pick disease type C, and Prader-Willi syndrome.
Treatment
"There is currently no cure for narcolepsy or cataplexy," Culpepper says.
Still, you do have options to manage and cope with symptoms:
Medication
A combination of prescription medications is the only treatment.
Commonly prescribed medications include:
- Stimulant medications like Modafinil and Adderall to "keep your body alert and muscles active," Mitchell says.
- Antidepressants like solriamfetol or venlafaxine, though experts don't fully understand why these work to improve symptoms.
- Histamine-3 receptor inverse agonists like Pitolisant to increase wakefulness during the day.
Lifestyle changes
Cataplexy can come on pretty suddenly, just like fainting. Injuries are uncommon, but it's still important to keep yourself safe from sudden episodes by making sure you can sit immediately if needed.
"People with cataplexy can try to mitigate their risk of injury by arranging their homes so that fewer obstacles could cause injury," Culpepper says.
You'll likely only have a few seconds to prepare for an episode, so fall-proofing your home in advance can help.
A few other things you can do:
- Arrange your home and office space so you have immediate access to soft chairs and couches.
- Keep your floor clear of objects you might fall on.
- Take naps or lie down as soon as you feel drowsy or lightheaded.
- Break long chores or household tasks into smaller steps so you can sit more easily if needed.
- Sit down before conversations you think might trigger strong emotional responses.
Insider's takeaway
Cataplexy may seem frightening, especially if you suddenly fall and don't know why. But this sudden muscle weakness isn't usually dangerous if you know your emotional triggers and have a safe place to rest.
A doctor or sleep specialist can diagnose cataplexy and its underlying cause and offer guidance on treatment.
Once you have a diagnosis, you can request any accommodations you might need at work and school, like taking naps when necessary and having the option to sit at a moment's notice in case triggers arise.