What is cataplexy?

Cataplexy is a sudden disappearance of muscle tone caused by emotional stress or a state of affect, from a subtle weakening of the musculature of the face and neck to a total short-term atony and disabling the ability to hold the body in a certain position. In clinical neurology, cataplexy is considered to be one of the symptoms of such a disease of the nervous system as narcolepsy.

Causes of Cataplexy

Before considering the most important causes of cataplexy, it should be borne in mind that, according to the European Federation of Neurological Societies (EFNS), narcolepsy and cataplexy, more precisely, cataplexy syndrome, is observed in an average of 70-80% of patients with diagnosed narcolepsy - increased drowsiness in daytime time. And this syndrome is not related to the pathology of the musculoskeletal system, but is directly related to the brain and the central nervous system. This is the primary cataplexy (or the Levenfeld-Genneberg syndrome).

Scientific studies of the last 15 years have shown that the periodic inhibition of the transmission of nerve impulses and the instantaneous decrease in muscle tone in this pathology is due to problems with the hypothalamus. The currently accepted version of the etiology of narcolepsy and cataplexy is the inadequate quantity or destruction of hypothalamus cells that produce hypocretin (orexin), a neurotransmitter that regulates the processes of excitation and wakefulness. What exactly leads to the loss of brain cells producing this neuropeptide has not yet been established, but scientists agree on the opinion that this is a genetically transmitted (modified form of the DQB1 0602 gene) pituitary pathology of an autoimmune nature.

According to the second version, cataplexy causes not hypocretin deficiency, but a defect of receptors perceiving it. In general, the neurophysiological mechanism of the development of cataplexy remains unclear, although a certain correlation between the lack of this neurotransmitter and the decrease in the level of such important neurotransmitter hormones as histamine, dopamine, and adrenaline is found. On this basis, this condition could be classified as diencephalic syndromes of a disgormonal nature.

Secondary cataplexy can result from lesions of the hypothalamic region of the brain by tumor formations or metastases of breast, thyroid or lung cancer, due to congenital anomalies of the cerebral vascular system, multiple sclerosis, craniocerebral trauma or infections.

Symptoms of cataplexy

Typical symptoms of cataplexy are expressed in the form of atonic muscle attacks lasting from a few seconds to several minutes, during which a person - due to the disappearance of normal physiological muscle tension - the mandible is hanging down, the head is lowered or tilted, the legs bend at the knee joints "), Hands hang along the body. In most cases, when a cataplectic seizure is caught in a standing position, a person can not restrain himself and falls.

At the same time, the person does not lose consciousness, breathing does not stop, but the heartbeat may slow down; Face turns red, throws into sweat; Speech inarticulate (due to relaxation of mimic and chewing muscles of the face). Vision also deteriorates: double vision (diplopia) and problems with focusing. But hearing and understanding are not violated.

As specialists note, atony can be partial, affecting only the muscles of the face and neck. Symptoms most often occur in adolescence or 20-30 years, in children narcolepsy and cataplexy is diagnosed in less than 5% of cases, the predominant majority of patients are male.

In addition, in the history of patients with cataplexy syndrome there is a short-term loss of muscle tone right after night sleep - the so-called cataplexy of awakening, and there are disturbances in the normal structure of sleep in the form of anxiety, hallucinations when falling asleep and negative emotional coloring of dreams (often all nightmares are dreamed).

Diagnosis of cataplexy

The diagnosis of cataplexy is performed by a neurologist and consists of:

  • Examination of the patient, fixing his complaints and collecting anamnesis;
  • Clarification of all the patient's illnesses and the medications taken by him;
  • Studying the features of night sleep with polysomnography;
  • Setting the level of biological need for sleep by conducting MSLT-testing - a multiple latency test for sleep (conducted no later than two hours after awakening from a night's sleep);
  • Revealing pathological drowsiness (hypersomnia) by questioning according to the Euphord Sleepiness Scale;
  • Electroencephalography (EEG);
  • CT or MRI of the brain.

When making a diagnosis, it is necessary to adhere strictly to diagnostic criteria accepted in neurology, since cataplexy requires differentiation with respect to syncope, epileptic seizures, fall attacks, transient ischemic attacks, vertebral artery syndrome, periodic hyperkaliemic paralysis, acute intermittent porphyria, Thomsen's disease, syndromes Lambert-Eaton and Guillain-Barre, as well as iatrogenic intoxications of the body.

Treatment of cataplexy

To date, the treatment of cataplexy - given the clinical approach to the etiology of the disease - is carried out with drugs that control the manifestation of symptoms. But if cataplexy does not create significant problems for the patient, then no medication is needed.

Despite the lack of medical evidence of the effectiveness of antidepressants in the treatment of this pathology, the European recommendations of EFNS assign antidepressants the main position in the tactics of therapy of cataplexy. According to the appointment of neurologists, you should take Clomipramine - 10-20 mg per day. Also, selective inhibitors of serotonin and norepinephrine and drugs that inhibit serotonin reuptake in nerve endings (SSRIs) can be used. However, all of them, especially antidepressants, have a lot of negative side effects.

Specialists of the American Academy of Sleep Medicine recommend for cataplexy a drug based on the sodium salt of gamma-hydroxybutyric acid - sodium oxybate or sodium oxybutyrate (syrup or solution for oral administration). The main use of this drug is anesthesiology (for non-anional anesthesia), ophthalmology (to improve vision in glaucoma), and in neurology - as a sedative to improve the quality of night sleep. Standard dosage: one tablespoon of syrup or 5% solution before bedtime. The drug undergoes complete biochemical transformation with metabolites in the form of water and carbon dioxide, however a prolonged intake can cause an increased level of potassium in the body.

Because Sodium oxybate can lead to daytime drowsiness, simultaneously stimulant medications are prescribed - in particular, Modafinil (other trade names - Modalert Alertec, Provigil) based on the active substance 2- (diphenylmethyl) -sulfinyl acetamide. The drug is taken once a day (in the morning hours) with diagnosed narcolepsy with frequent attacks of cataplexy. This remedy is contraindicated in patients under 18 years of age, in the presence of psychosis, depression, suicidal thoughts or mania; You should monitor your blood pressure and heart rate.