From Big Medical Encyclopedia

DEVOCALIZATION (synonym oglushennost) — the form of stupefaction which is shown decrease in consciousness and its devastation. The lake meets at the different diseases causing disorders of activity of c. N of page.

The main signs of O. are difficulty a vopriyatiya of external influences owing to increase in an excitation threshold of analyzers, narrowing of judgment of the world around because of delay of thinking and weakening of the analysis and synthesis, passivity and low-mobility of thinking owing to decrease in strong-willed activity, weakening of storing (fixing) of current events with the subsequent amnesia (see). Unlike other conditions of stupefaction (twilight, delirious) at O. there are no productive psychopathological symptoms, e.g. hallucinations, nonsense.

On depth of disturbance of clarity of consciousness distinguish the following degrees of O.: obnubilation, somnolence, sopor and coma. In many cases of O. of border between them are vague.

Obnubilation (Latin obnubilatio misting, obscuring) — «cloudiness of consciousness» — the easiest degree of the Lake. Clear consciousness of the patient is periodically broken short-term, within several seconds, minutes, by easy O.'s condition: perception and judgment of surrounding objects becomes foggy and sketchy, activity of thinking and motility goes down, ability to verbal contact decreases. Stronger external irritants cause temporary clearing of consciousness.

Somnolence (Latin somnolentia drowsiness), patol, drowsiness — deeper and long Lake. Perception of external irritants is considerably complicated: quiet conversation, poorly lit objects of the patient does not perceive and does not react to them; only intensive irritants (a loud conversation, bright light, pain) are perceived, but the reaction to them which is slowed down and is quickly exhausted. Verbal and figurative associations accidental, often sketchy (incoherent), them a little also proceed they slowly. Judgment of surrounding objects and events superficial, their comparison to last life experience is limited that leads to disturbance of recognition surrounding and to disorder of orientation in the place, in time, in a situation. On simple questions and orders to open a mouth, to raise the right hand of the patient reacts; at the same time his speech sluggish, laconic, the movements slow, quickly comes exhaustion; reacts to more difficult questions and instructions inadequately or at all does not react. The patient does not begin a conversation, does not show interest in surrounding, the most part of time passively lies blindly, in a light slumber; the person is relaxed, the movements sluggish. Nek-ry researchers on the level of verbal contact with the patient conditionally allocate easy, average and heavy degree of somnolence.

Sopor (Latin sopor unconsciousness, insensibility) — patol, hibernation, deep devocalization. The patient lies not movably, eyes are closed, the person amimichno, the verbal contact is impossible. Strong irritants (bright light, a strong sound, pain stimulations) cause undifferentiated, the stereotypic protective motor, sometimes not articulated voice reactions.

Coma (grech, a cat a deep sleep), coma — switching off of consciousness (see. Coma ). The patient in such state has no reactions even on the strongest irritants. In initial stages nek-ry unconditional and reflex reactions are possible (pupillary, corneal reflexes, reflexes from mucous membranes), to-rye further disappear.

Also special forms of deep devocalization in the form of an apallichesky syndrome, or an akinetic mutism are allocated (see. Apallichesky syndrome ).

Etiology and pathogeny up to the end are not studied. Lakes can cause various factors: exogenous (alcohol, carbon monoxide gas etc.) and endogenous (e.g., uraemia) intoxication, craniocereberal injuries, intracranial tumors, inflammatory processes and disturbances of blood supply of a brain, etc.

O. comes at decrease in excitability of nervous cells of a cerebral cortex when activity at first of the second, and then first alarm system slows down. Diffusion decrease in cortical activity arises owing to or directly damages of cortical structures, or as considers X. Megun, disturbances of stimulation of bark from a reticular formation.

Treatment it is directed to the basic disease which caused disturbance of activity of a brain. Psychostimulants, napr, amphetamine, and also drugs of metabolic action, napr have auxiliary therapeutic effect, nootropic means (see), glutaminic to - that.

Forecast depends on the nature of a disease, during to-rogo the Lake is observed. Emergence of devocalization testifies to weight of a basic disease. Change of various forms of stupefaction (a delirium, an amentia) by devocalization testifies to the adverse forecast.

Prevention consists in the prevention of heavy injuries of a brain.

See also Consciousness, frustration .

Bibliography: Delgado of X. M. R. Mozg and consciousness, the lane with English, M., 1971; Megrabyan A. A. Personality and consciousness, M., 1978, bibliogr.; Megun G. The awake brain, the lane with English, M., 1965; Saarma Yu. M. and Mekhilane L. S. Psychiatric sindromologiya, Tartu, 1977; With N of e of N of e in with to and y A. V. General psychopathology, Valdai, 1970; Jaspers K. General psychopathology, Chicago, 1964; Lexikon der Psychiatrie, hrsg. v. C. Muller, B., 1973.

Yu. M. Saarma.