Cataplexy is a brief, sudden loss of voluntary muscle tone caused by strong emotions like laughter.
Narcolepsy, a sleep disorder that is believed to affect between 135,000 and 200,000 people in the United States, is most often associated with this disease.
Cataplexy occurs during waking hours. In a muscle, a barely visible weakness can occur during a mild attack, such as drooping the eyelids. A more serious episode may result in a complete collapse of the body.
Cataplexy is often misdiagnosed as a seizure disorder although it is a different disorder.
There is no remedy for cataplexy but it can be treated with medications and possible causes modification.
Important facts about cataplexy
Here are a few important points about cataplexy. More details are given in the main article.
- During an episode of cataplexy, an individual is awake but temporarily paralyzed.
- Cataplexy is worsened by fatigue and strong emotion and affects males and females equally.
- Cataplexy is linked to narcolepsy and can occur after suddenly stopping an antidepressant medication.
- Sodium oxybate is approved by the U. S. Food and Drug Administration (FDA) for the treatment of cataplexy
What is cataplexy?
Cataplexy is a sudden loss of muscle control , usually on both sides of the body, caused by emotions that are intense, sometimes pleasing.
Laughter is the most common trigger, but other triggers can include joy, anticipation, frustration, shock, anxiety or an occurrence that is stressful.
Cataplexy is most often associated with narcolepsy but may occur with other unusual disorders such as Niemann-Pick type C disease, Prader-Willi syndrome and Wilson’s disease.
Cataplexy can also be seen in many medical conditions including stroke, multiple sclerosis, head injury and encephalitis.
The length of an attack with cataplexy is brief, typically lasting from a few seconds to a few minutes — usually less than 2 minutes — followed by a rapid return to normal muscle tone and function.
Causes
The REM sleep disassociation hypothesis suggests that cataplexy is the muscle paralysis that normally occurs during REM sleep intruding into waking hours.
The exact underlying cause of this interference is unclear, but a lack of neurons producing hypocretin (also known as orexin) is thought to be a significant contributing factor. Hypocretin is a neurotransmitter involved in sleep / wake cycle, wakefulness promotion,
People with cataplexy have been found to have a certain human leukocyte antigen, variations in T-cell receptors, or dysfunctional immune system responses to certain antigen exposures. It is thought that narcolepsy may be an autoimmune disorder, but more research is needed.
A research published in the 2010 Journal of Clinical Investigation indicated that the hypocretin loss is caused by an autoimmune reaction targeting homologous tribbles 2 (trib 2) autoantigens. This autoimmune response causes the formation of trib 2 antibodies which target and destroy the hypocretin-producing neurons within the brain.
Cataplectic episodes occurrence ranges from less than one per annum to many a day. An individual with cataplexy experiences, on average, one or more episodes per week.
Symptoms
Symptoms of narcolepsy-related cataplexy frequently begin in childhood and young adulthood, between the ages of 7 and 25, but it may start at any time.
Cataplectic attacks can be highly variable. With full body collapse, they can be mild and barely visible, or extreme.
Symptoms of a cataplectic episode may include:
- facial twitching, flickering, or grimacing
- unusual tongue movements
- jaw tremor
- dropping the head or jaw
- knee trembling or buckling
- drooping eyelid
- speech difficulty
A person can collapse, and can not move.
Usually, the episode lasts a few minutes or less, and passes without interruption. It is necessary to ensure, however, that the individual does not hurt himself if they collapse to a fall.
An individual who experiences cataplexy remains alive, can breathe, and can move his or her eyes.
Diagnosis
Tests can help diagnose cataplexy narcolepsy but a diagnosis is often based on the interpretation of events and history by the patient.
An person frequently complains to a doctor about excessive daytime sleepiness (EDS) during waking hours, with a persistent background feeling of sleepiness. The first symptom of narcolepsy is usually EDS. However, if cataplexy occurs with EDS the existence of narcolepsy is probable.
Individuals with EDS or cataplexy signs will see their health-care provider.
The provider would most likely prescribe a sleep study (a polysomnogram) followed by a Multiple Sleep Latency Test (MSLT), a series of five naps that are expected to be taken over the course of a day.
Carrying out the MSLT the day after polysomnography helps physicians to find out if the sleep received the night before has any effect on daytime napping.
Treatment and prevention
There is no cure for cataplexy and treatment includes controlling symptoms with good practices of sleep hygiene and using medicine when appropriate.
In addition, protective measures should be placed in place to avoid serious injury that may result from falls.
Good sleep hygiene practices include:
- keeping a consistent sleep schedule, including getting up and going to bed at the same time every day, even on weekends or during vacations
- striving for at least 7 to 8 hours of sleep, or the amount that normally makes you feel refreshed
- making the bedroom quiet and relaxing and keeping it at a comfortable, cool temperature
- limiting exposure to light in the evenings
- exercising regularly and maintaining a healthful diet
- avoiding a large meal before bedtime and opting for a light, healthful snack if necessary
- avoiding caffeine in the late afternoon or evening
- avoiding alcohol
- scheduling one or more short naps during the day.
The US-approved drug is sodium oxybate at doses between 6 and 9 grams (g) at night. Food and Drug Administration (FDA) for Cataplexy treatment. Sodium oxybate is effective in raising both attack frequency and attack intensity.
Possible side effects include dizziness, headache and nausea. Regardless of the risk of respiratory depression and other important CNS depressant effects, this drug should not be used in combination with alcohol or any other depressant central nervous system (CNS).
Antidepressants are other drugs which can help control the symptoms. Those include venlafaxine, an antidepressant to reuptake serotonin-noradrenaline (SNRI), and tricyclic antidepressants such as clomipramine, imipramine, and desipramine.
Nevertheless, there is substantial evidence to support the use of antidepressants for cataplexy is varied. Similarly, sudden venlafaxine withdrawal can potentially cause rebound cataplexy.
With regard to health, when an person senses the beginning of an episode, injury with cataplexy is very likely.
To help avoid injury from occurring with cataplexy:
- Assess for and be aware of potential dangers such as glass, sharp edges, and heights.
- Practice relaxation and stress management techniques.
- Avoid sleep deprivation.
- Avoid situations that are likely to evoke strong emotions, or prepare ahead of time by sitting down or having a companion nearby.
- Do not drive a car or operate heavy machinery until cleared by a medical provider.
- Enlist the help of significant others and friends, and educate them on the seriousness of the disorder.
Cataplexy is a transient, sudden loss of voluntary muscle control triggered by a strong emotional stimulus such as laughter, or excitement. Narcolepsy almost always leads to cataplexy.
There’s no cure, but education, sleep hygiene habits, and prescription drugs can help people experience improved quality of life with this disease.
