Cataplexy: Causes, Symptoms, Prevention And Treatment
One of the most characteristic symptoms of narcolepsy are episodes of cataplexy, during which muscles suddenly relax and weakensometimes causing falls and accidents.
In this article we will explore the causes of cataplexy and the treatments that prevent its symptoms, both pharmacological and psychological.
We call “cataplexy” or “cataplexy” the transient episodes of muscle weakness that occur in some people. They are considered an intrusion of the processes that regulate sleep in the waking state, although during cataplexy the person maintains consciousness.
Normally these symptoms occur as a result of intense emotions; For example, it is common for loss of muscle tone to occur when the person laughs a lot, feels afraid, or cries.
Cataplexy episodes They occur almost exclusively in the context of narcolepsyso we can consider them a cardinal symptom of this disease. Cataplexy without narcolepsy is very rare.
What is narcolepsy?
Narcolepsy is a sleep disorder characterized by the appearance of elements of REM (rapid eye movement) sleep while awake. Its most characteristic symptom is sleep attacks that occur despite having rested adequately.
In addition to sleep attacks and cataplexy, other common symptoms of narcolepsy are daytime hypersomnolence, sleep disturbance during REM sleep, and the appearance of hypnagogic hallucinations and sleep paralysis during wakefulness.
Narcolepsy cases do not always include cataplexybut these episodes occur in 70% of narcoleptic people. When there is cataplexy there is practically always a deficiency of the hormone hypocretin, another of the fundamental signs of narcolepsy.
Episodes of cataplexy are brief; Most of the time they last less than two minutes.. They are usually the result of physical exertion or strong emotions, especially if they occur unexpectedly.
Muscle weakness is variable, and may be limited to relaxation of the knees or jaws or involve temporary paralysis of the entire body. This can cause falls or accidents, for example if the person is driving.
Cataplexy episodes should not be confused with sleep attacks that are also characteristic of narcolepsy: during cataplexy the person remains conscious, although if they are in a comfortable position they may feel drowsy and even fall asleep as a result of the relaxation.
Other symptoms that commonly occur during episodes of cataplexy are pronunciation difficulties and visual disturbances, particularly blurred or double vision.
Causes of these alterations
The main cause of narcolepsy and cataplexy is considered to be the presence of low levels of the hormone orexin or hypocretin in the cerebrospinal fluid. Orexin plays a fundamental role in maintaining wakefulness and alertness; its deficit has been related to the REM intrusions typical of narcolepsy.
Specifically, it is believed that episodes of cataplexy are a consequence of the sudden and generalized inhibition of motor neurons at the level of the spinal cord, which causes a loss of muscle control.
Any alteration that reduces orexin levels is likely to cause narcoleptic symptoms such as cataplexy. Thus, These episodes can occur as a consequence of injuries, malformations and brain tumors..
Brain infections, vascular accidents or diseases such as multiple sclerosis can also cause episodes of cataplexy. Damage to the hypothalamus, which secretes hypocretin, is frequently involved in the development of this disorder.
In many cases narcolepsy and cataplexy have a genetic component. In this sense, many experts consider narcolepsy an autoimmune disorder related to the so-called “human leukocyte antigens” (HLA).
Treatment and prevention
The cataplexy It is mainly treated with drugs. The treatment of choice is sodium oxybate, a very safe medication that is also effective in combating daytime sleepiness. Gammahydroxybutyrate has similar effects.
Other drugs used in cases of cataplexy and narcolepsy in general are stimulants, such as modafinil, and antidepressantsparticularly tricyclics and venlafaxine, a selective serotonin and norepinephrine reuptake inhibitor.
Psychology can also contribute to the treatment of cataplexy. In this sense, the interventions focus on the prevention of these episodes by identifying the symptoms that precede them: learning to detect the prodromes of cataplexy is useful to be able to react to them when they begin to occur in the future.
To reduce the symptoms of narcolepsy, including cataplexy and drowsiness, scheduling short daytime naps and maintaining healthy sleep habits is recommended.
