Narcolepsy — the dream pathology which is characterized by violation of the sequence of phases of a dream and emergence of a phase of a REM sleep during wakefulness. The main symptom of a disease — the attacks of an insuperable dream forcing the patient literally "to fill up on the place". The cataplexy, paralysis of a dream and gipnagogichesky phenomena also belong to signs, typical for a narcolepsy. The basis of diagnostic search is made by the polisomnografiya, the MSLT test and inspections directed to an exception of other types of a gipersomniya. Treatment of a narcolepsy is directed to normalization of a rhythm of a dream and wakefulness, reduction of day drowsiness and manifestations of a cataplexy, improvement of a night dream.
Narcolepsy — seldom found sleep disorder as a gipersomniya (the increased drowsiness) which is shown deterioration of a night dream and emergence of paroksizmalny attacks of falling asleep during active wakefulness. The narcolepsy is possible at any age, but usually it demonstrates during from 15 to 25 years. Frequency of its diagnosing according to various data makes 20-40 cases on 100 thousand persons. In modern medicine the narcolepsy has several synonyms: Zhelino's disease, narkoleptichesky disease, essentsialny narcolepsy.
Etiology and pathogenesis of a narcolepsy
So far the scientific and clinical neurology has no exact data on the reasons and mechanisms of formation of a narcolepsy. The assumption distributed earlier that disorders of regulation of the mode of a dream at a narcolepsy are directly connected with mental deviations and psychological problems is recognized as insolvent today. The theory that the disease is caused by insufficiency of a neurotransmitter responsible for maintenance of a condition of wakefulness is put forward. As similar biologically active agent the hypocretin (orexin) is considered. Deficiency of orexin can be genetically determined or arises at influence of such trigger factors as heavy infections, sharp overfatigue, a craniocereberal trauma, pregnancy, endocrine dysfunction.
According to other theory the narcolepsy can have the autoimmune mechanism of emergence that is confirmed by existence of the abnormal T-lymphocytes which are absent at healthy people, cases after vaccination and its communication with different infectious diseases (flu, measles and so forth).
Is known of pathogenesis of a narcolepsy a little. Similarity of a condition of muscular system at the phenomena of a katapeksiya and sleepy paralysis with its state in a REM sleep phase, and also emergence of a phase of a REM sleep at falling asleep or right after it, allow to make the assumption that the main problem of a narcolepsy consists in untimely emergence of a phase of a REM sleep — its introduction both in a phase of a slow dream, and during wakefulness.
The basis of clinical manifestations of a narcolepsy is made by a gipnolepsiya — an attack (attack) of an insuperable dream (hypnos — a dream, lepsis — an attack). Patients describe this state as very strong drowsiness which is inevitably leading to fall in a dream. Similar attacks develop in a monotonous situation and when performing monotonous actions more often (for example, during listening of a lecture, reading, viewing of the TV). Drowsiness in such situations can be observed also at healthy people. Unlike them at the patient with a narcolepsy of the attack of a dream occur also at the moments of intense activity (at meal, a conversation, driving the car).
Frequency of attacks of a gipnolepsiya considerably varies, their duration can make of several minutes till 2-3 o'clock. It is also simple to wake the person during a narkoleptichesky dream, as well as during usual. After awakening the patient with a narcolepsy, as a rule, feels quite vigorous. However already in a few minutes to it there can be the following attack of a dream. Over time patients adapt to the disease and, having felt characteristic drowsiness, manage to find the place, more or less suitable for a dream.
Along with the gipnolepsiya attacks occurring in the afternoon the narcolepsy is characterized by frustration of a night dream. Bright dreams, frequent interruptions of a night dream, sleeplessness, feeling of a nevyspannost are typical in the mornings. The low-quality night dream leads to decrease in working capacity and an opportunity to concentrate attention, to emergence of day drowsiness and irritability, strengthening of the interpersonal conflicts, developing of depressive neurosis, a syndrome of chronic fatigue.
In the course of falling asleep or before awakening at patients with a narcolepsy gipnagogichesky phenomena — the bright visions, visual and acoustical hallucinations often having the menacing character are possible. These phenomena are similar to the dreams occurring in a REM sleep phase. Normal they are noted at small children, in rare instances — at healthy adults.
At 25% of patients with a narcolepsy sleepy paralysis — the passing muscular weakness which is not allowing the person to make any movements and arising at falling asleep and awakening is observed. Many patients note that during this period they have strong feeling of fear. It is remarkable that muscular hypotonia at sleepy paralysis reminds a condition of skeletal muscles during a REM sleep phase.
Approximately in 75% of cases of a narcolepsy attacks of sudden short-term muscular weakness up to full paralysis are noted — a cataplexy. Usually the cataplexy is provoked by sharp emotional reactions of the patient (surprise, joy, anger, fear, etc.). Muscular weakness can have generalized character, then the patient with a narcolepsy falls as knocked down, or to cover only a part of a body (for example, only a hand or both hands).
Diagnostics of a narcolepsy
Examination of patients with complaints, characteristic of a narcolepsy, as a rule, is conducted by the neurologist. Diagnostic search includes carrying out a polisomnografiya with registration of EEG and the multiple test of latency of a dream (MSLT test). More in-depth study of a dream means of special somnologichesky laboratory is conducted by the somnologist.
Polisomnografiya investigates a night dream for what the patient with suspicion on a narcolepsy should spend the whole night in specially equipped office under observation of the doctor. Polisomnografiya allows to reveal violations of alternation of phases of a dream with increase in frequency and duration of a phase of a REM sleep with the bystry movements of eyeballs and to exclude other possible frustration of a dream (including a syndrome sleepy ).
Carrying out the MSLT test is usually appointed to the day following after a polisomnografiya. During the research the patient is during the day offered to make 5 attempts to fall asleep, the interval between attempts of a dream makes 2-3 hours. Criteria of confirmation of a narcolepsy are: existence not less than two episodes of the confirmed dream and reduction of latent time of approach of a dream up to 5 min.
The definition of the periods of the hidden drowsiness in certain cases allowing to estimate efficiency of the carried-out treatment can be in addition carried out.
It is necessary to differentiate a nakrolepsiya from epilepsy, other types of a gipersomniya: psychophysiological; post-traumatic — the caused postponed ChMT, existence of an intracerebral hematoma; psychopathic — arising against the background of mental frustration (schizophrenia, hysteria); connected with inflammatory (encephalitis, meningitis, arakhnoidit), tumoral or vascular (chronic ischemia of a brain, an aneurysm, an ischemic and hemorrhagic stroke) cerebral diseases, and also with somatic pathology (a hypothyroidism, diabetes, a liver failure, pernitsiozny anemia, etc.). During differential diagnostics consultation of the psychiatrist, an epileptolog, the endocrinologist, infectiologist, gastroenterologist can be required; carrying out oftalmoskopiya, MRT of a brain, duplex scanning, MRA or UZDG of cerebral vessels.
Treatment of a narcolepsy
With a narcolepsy it is recommended to patients to adhere to the constant mode of a dream, i.e. falling asleep and awakening in one and too time. For most of patients the scheme including a 7-8-hour night dream and 2 day dreams lasting from 15 up to 30 min. is the most acceptable. For the purpose of improvement of quality of a night dream it is necessary to avoid reception of heavy food and alcohol, and also food before going to bed. At existence of a narcolepsy it is not necessary to drive transport, to work in dangerous conditions or with any mechanical devices.
Treatment of a narcolepsy with easy or moderate day drowsiness is begun with a modafinil who, stimulating a condition of wakefulness, does not cause euphoria, a syndrome of accustoming and effects of an after-effect. Initial dose of 1 times in the morning. If there is not enough action of a modafinil to stop narcolepsy symptoms for the whole day additional day reception of medicine is allowed.
In cases when the nakrolepsiya badly responds to treatment modafinily, resort to purpose of derivatives of amphetamine: methylphenidate or , methamphetamine. However they have such side effects as tachycardia, excitement, arterial hypertension, accustoming with risk of development of dependence (see Abuse of amphetamine).
Use of tritsiklichesky antidepressants (a klomipramin and an imipramin), inhibitor of the return capture of serotonin helps to reduce cataplexy frequency at patients with a narcolepsy (fluoxetine). In therapy of a narcolepsy are also applied modafinit, methylphenidate and some other medicines. Developments of nasal spray which, according to scientists, will allow patients with a narcolepsy quickly are conducted to fill shortage of a neurotransmitter and by that to avoid gipnolepsiya attacks.
Forecast and prevention of a narcolepsy
The disease is lifelong. Significantly influencing quality of life of patients, the narcolepsy does not cause reduction of its duration. Adequately appointed therapy can reduce considerably manifestations of a narcolepsy, but need of constant administration of drugs leads to manifestation of their side effects.
As today the reasons and mechanisms of emergence of a narcolepsy are for certain not known, its specific prevention cannot be developed.