What is Cataplexy?
Cataplexy is a condition characterized by sudden weakening of a muscle associated with a string emotion or emotional sensation.1 It occurs after emotional out-burst such as laughing, crying or feeling angry, and it may be experienced as loss of control over facial expressions. Cataplexy is often associated with narcolepsy; which is a neurological disorder which causes the affected person to feel extremely sleepy during the day. However, it has been estimated that only 1 out of 1000 people may have narcolepsy and the chances of having cataplexy is even lesser. It is important to understand that cataplexy can cause loss of muscle control at wrong time such as driving, which can be quite dangerous.
Symptoms of Cataplexy
The symptoms associated with cataplexy may vary from person to person. In most of the cases, the symptoms are noted during teenage days or during young adult phase such as while entering college, first job etc. It is generally noted during a stressful phase of life. The most common symptoms of cataplexy include:
- Drooping of eyelids
- Jaw dropping
- Head dropping to one side due to weakness in the neck muscles
- Whole body falling to the ground suddenly
- Twitching over various parts of the body without any obvious cause.
A lot of times, cataplexy may be mistaken for seizure attack. However, unlike seizure, the affected individual does not lose his consciousness and he or she is able to remember everything that occurs during the cataplexy episode. While some of these episodes may last for a couple of seconds, some can even last for minutes. Cataplexy occurs after the person experiences a strong emotion such as:
However, these emotional trigger are not constant and can vary with situation and also from individual to individual. If an emotion causes cataplexy during one episode, it may not be the same trigger during the next episode.
Causes of Cataplexy
In case of narcolepsy with cataplexy, the brain may not have adequate orexin (hypocretin); which is a chemical in the brain responsible for keeping us awake and controls the REM (rapid eye movement) sleep cycle. This drop in orexin level causes symptoms of cataplexy. In most of the cases, cataplexy is associated with:
Genetic inheritance or family history of cataplexy
- Brain injury or trauma to the head
- Tumors or other growth near the areas of the brain that controls sleep
- Presence of autoimmune condition
- Infections such as swine flu (caused by H1N1 virus) or side effect of vaccine for H1N1 virus.
Diagnosis of Cataplexy
Diagnosis is often done by a neurologist or a sleep expert. Diagnosis involves obtaining a detailed case history followed by a full physical examination to assess the general health condition of the patient. This is followed by written evaluation such as Epworth Sleepiness Scale or the Stanford Narcolepsy Questionnaire, to get a better understanding of the sleep habits of the person. A sleep study (polysomnogram) may be conducted to evaluate the muscles and brain while sleeping. Other tests include sleep latency test and microscopic study of the fluid collected from around the spinal cord and brain (CSF fluid or cerebrospinal fluid).
Treatment of Cataplexy
Treatment of cataplexy depends of the severity of the condition. It is commonly treated with medicines and life style changes. The most common medications used for treatment of cataplexy include:
- Tricyclic anti-depressants such as Anafranil or Clomipramine
- Selective serotonin uptake reinhibitors or SSRIs such as fluoxetine or venlafaxine
- Sodium oxybate or Xyrem 2
Other medications for cataplexy such as modafil and amphetamines may also be prescribed depending on the symptoms of the patient.
It is important to inform the patients and his family about the side effects of these medications for cataplexy which includes nervousness, mood swings, abnormal heart rhythms, chances of addiction etc.