From Big Medical Encyclopedia

DIZZINESS — feeling of imaginary rotation of surrounding objects or own body in any of the planes of three-dimensional space, and also feeling of rotation «in the head» (the system, systematized, rotary G.) or feeling of the instability, «falling in a chasm» crumbling under the feet of the soil (not system, unsystematized, oscillatory G.). The listed feelings are expression of disturbance of dimensional orientation and balance. Mistakenly carry to G. feelings of fog, a veil, flashing of front sights before eyes, impression of an illegibility and break of contours of objects.

For the first time G.'s symptom was described in 1799 by J. Morganyi, his experimental studying is begun by Ya. Purkinye in 1820.

Disturbance of interaction of the vestibular, visual analyzers and deep sensitivity jointly providing dimensional orientation is the cornerstone. Can arise as at dysfunction of each of the called systems, and at their diskoordination. As G. is implemented in c. N of page with obligatory participation of vestibular educations, it it is necessary to consider as the specific vestibular phenomenon. Nevertheless it is accepted to divide G. on vestibular when patol, the center is localized in vestibular structures, and not vestibular, arising at pathology in other bodies and systems.

Besides, G. is observed at some anomalies of development (a tower skull, etc.)» can arise at an emotional stress, pregnancy (in connection with an ovarian cycle) etc., as well as at healthy people in transport, on a swing, in the elevator, at rise on height (if to look at the same time down), at watching fast-moving objects. Such feelings at almost healthy people should be considered as manifestation of vestibular instability, to-ruyu usually designate as a vestibulopathy (see. Labyrinthopathy ).

Depending on an alleged cause allocate G. visual, caused by pathology of an organ of sight and the oculomotor device; cardiovascular, at heart diseases; abdominal, at dysfunctions of abdominal organs; cervical, at patol, the processes causing a syndrome of a vertebral artery (see. Barret — Lyeu a syndrome ); otogenic, caused by pathology of an acoustic organ; neurologic, at various diseases of a nervous system, etc.

Vestibular G. meet most often and result from defeat of vestibular structures or impact on them from the outside at a number of somatic, nervous and endocrine diseases when proprioceptive and visual functions are not broken (see. Vestibular symptom complex ). Besides, they can arise uslovnoreflektorno at influence of olfactory, acoustical and visual irritations. Quite often G. are the only display of vestibular pathology.

Vestibular G.' dominance is explained by their emergence in response to the numerous not only specific, but also nonspecific impulses coming to vestibular system. G.'s frequency is caused by a low excitation threshold of a vestibular analyzer on an afferentation), capable to cause G. (lower, than for other its reactions — nistagmenny, vestibulospinalny, vestibulovegetativny), and also late approach of adaptation of a vestibular mechanism to the irritations causing G. (see. Vestibular reactions ).

On character of feelings vestibular G. divide on system, not system and combined. Sometimes distinguish proprioceptive (feeling of the passive movement of own body), tactile, or tactile (feeling of the movement of a motionless support of a body), and visual, (the seeming movement of motionless objects).

Depending on localization patol, process vestibular G. share on peripheral (labyrinth), central and G. with unspecified localization of the center.

Distinguish primary peripheral G. caused by pathology of a middle and inner ear, and secondary (caused), arising at experimental vestibular tests (see. Vestibulometriya ).

Peripheral G. are characterized by lack of signs of defeat of c. N of page. The dizzinesses caused funkts or organic changes at the level of the first neurocyte (a receptor and a nerveroot), more often happen system, usually are followed by vegetative reactions, disturbance of a statics, gait, horizontally ротаторным are quite often combined with a hearing disorder and spontaneous nystagmus (see). At the movement of the head of G. and a nystagmus amplify. During inspection of such patients the harmony of vestibular disturbances comes to light: hearing, vestibular functions suffer, disturbance of vestibulo-spinal reflexes is noted (normal the deviation of a trunk and extremities occurs towards a slow component of a nystagmus).

The central G. — a symptom of dysfunction of the central vestibular area (vestibular nuclei of a trunk of a brain) and overlying vestibular educations. They can be both system, and not system; are followed by vegetative reactions only sometimes. These G. are seldom combined with defeat of hearing. In all cases when the central G. is connected with defeat of vestibular nuclei of a trunk of a brain, it is followed by a spontaneous nystagmus of any character and the direction; it is characteristic that the nystagmus amplifies, and sometimes changes the direction at change of position of a body. If the central G. is connected with defeat of bark, the nystagmus meets seldom, usually small, horizontal, at change of position of a body does not change. Unlike peripheral, the central G. are characterized by a disgarmonichnost of vestibular disturbances.

Proceeding from conditions of emergence of vestibular G., allocate G. depending on a pose (position) including the «dizzinesses of situation» connected both with saving a certain provision, and with change of situation (from horizontal in vertical, at the movement of the head etc.). That and others can be peripheral and central. Peripheral (labyrinth) position G. arises immediately after action of a starting factor, i.e. change of a pose, is followed by a horizontal or horizontally ротаторным spontaneous nystagmus, vegetative reaction and proceeds so far this factor works. The central position G.'s beginning is separated from action of a starting factor by stage of latency, is combined with a slight horizontal spontaneous nystagmus and proceeds at insignificant vegetative reaction or without it.

Depending on G.'s duration divide on instant (several seconds), short-term (minutes, hours) and long (days, weeks).

Is frequent, quite often obligatory, and in certain cases the leading symptom patol, process that defines its diagnostic value.

At an otogenic labyrinthitis the system G. which are quite often followed by nausea and vomiting sharply amplify at any movement of the head. Usually patients lie in a forced pose — a sore ear up since improves such matters or stops.

At Menyer's disease system G. proceeds in the form of rough and heavy attacks (an acute form) or it is less heavy, but it is long (hron, a form). Distinctiveness of this disease — an obligatory combination of system G. to decrease in hearing as cochlear neuritis and with vegetative reactions. As well as at a labyrinthitis, the patient, aiming to reduce G., lies on the healthy party. Menyer's syndrome for the second time developing at some diseases (arterial hypotension, disturbance, blood circulations in system of vertebral and main arteries, multiple sclerosis, etc.), it is characterized by similar G., however, as a rule, without disturbances acoustical functions.

The peripheral G. which are differing in considerable constancy and combined with disturbance of balance, and also a considerable hearing impairment (up to full deafness), are noted at dystrophic processes in nervous elements of an inner ear as a result of action of ototoksichesky antibiotics (streptomycin, Neomycinum, levomycetinum, Monomycinum, etc.). They can develop also after radical a middle ear operation or surgical intervention on a stirrup.

The labyrinthopathy is private manifestation the «lacunar» G. caused by disturbance of blood circulation in an inner ear as a result of a gas embolism. At the same time G. has system character, is followed by a spontaneous nystagmus, feeling of devocalization, loss of balance, eye pain, noise and a ring in ears.

At an arachnoiditis of a mostomozzhechkovy corner arise system and not system long G.

Nevrinoma of the VIII nerve is followed by not system G. in a late stage of a disease; existence of attacks of system G. can form the basis for an exception of the diagnosis of a neurinoma.

The most frequent reason of G. — various forms hron, and acute vascular insufficiency of a brain as a result of atherosclerosis of vessels of a brain, arterial hypertension and hypotension, at atherosclerotic, hypertensive and hypotonic crises and at acute disorders of cerebral circulation.

At patients with atherosclerosis of vessels of different brain of G., preferential not system character, arise upon transition from horizontal position in vertical more often (orthostatic G.) and at the sharp movements. By analogy with age changes of hearing (presbyacusis) they are called if they develop at persons 50 years, presbigolovokruzheniye are more senior.

At a hypertension and arterial hypotension of the complaint to G. quite often are the main. More often not system, but at some patients can proceed as Menyer's syndrome (without changes of hearing). At such patients substantial increase of vestibulovegetativny reactions is noted.

Of various type often are an initial symptom of atherosclerotic, hypertensive and hypotonic crises. At acute disorders of cerebral circulation of G. are especially characteristic in case of pathology in vertebral and basilar vessels; they are observed at 60% of such patients and in most cases appear others nevrol, symptoms much earlier. System instant G. are expressed especially clearly at a heart attack of a trunk of a brain. Are noted often at patients with patol, changes in cervical department of a backbone. If G. at patients with insufficiency of blood supply in system of a vertebral and basilar artery proceeds in the form of menyerovsky crisis, then defeat of a labyrinth and dystrophic changes in a backbone are found in most cases on the same party.

An example of direct dependence of G. on vascular insufficiency of a brain is the symptom complex faint (see).

The hypertensive syndrome can be various G.' reason at tumors and brain injuries. In these cases of G. arises owing to irritation of trunk vestibular structures and is followed by a spontaneous nystagmus. Such G. should be regarded as an all-brain symptom. If G. is result of developments of stagnation (when outflow of an endolymph owing to high intracranial pressure is complicated), the nystagmus usually is absent.

Tumors cause G. of hl. obr. at their localization at the bottom of the fourth ventricle, in a cerebellum and a temporal share of a brain. Tumors of a bottom of the fourth ventricle and cystous tumors of a cerebellum, directly irritating vestibular nuclei, cause the most painful G. which force the patient to look for the pose facilitating his state and are followed by a nystagmus and vomiting. At tumors of a temporal share of a brain of G. sometimes are a harbinger of an epileptic seizure. At a tumor can be system and not system, it is not followed by a hearing disorder if there is no direct Inaction of a tumor on acoustical educations.

G.'s presence is characteristic of the vestibular encephalitis and multiple sclerosis proceeding with defeat of trunk vestibular structures (preferential system G.); for defeat of diencephalic area (not system G. with the increased vegetative reactions); for polusharny encephalitis (G. of any type without vegetative reactions).

(Not system) are the frequent satellite of various neurotic reactions. They differ in big variability, last for years, but do not deprive of patients of working capacity.

As the earliest symptom it is characteristic of aortal insufficiency.

Is a frequent symptom of food intoxication; it is followed by nausea, sometimes vomiting and other dispeptic phenomena. However G. caused by a labyrinthopathy or an acute disorder of cerebral circulation is frequent, take for display of food poisoning.

The overdose of medicamentous means can cause G.: somnolent, neuroplegic, insulin and its drugs, etc.

Treatment shall be directed to elimination of the basic disease which caused G. on decrease in vestibular excitability, on suppression of vegetative reactions and decrease in the general excitability. Atropine and atropinsoderzhashchy drugs (Belloidum, bellaspon, Platyphyllinum), vazodilatator (Nospanum, Stugeronum, Dedalonum), Torecanum in cases when G. is followed by nausea and vomiting are recommended. Apply intranasal novocainic blockade, intravenous (jet and drop) administration of hydrosodium carbonate, vestibular gymnastics. At the same time it is necessary to appoint fortifying means and antihistaminic drugs.

Bibliography The Blagoveshchensk N. S. Otonevrologicheskaya symptomatology in clinic of tumors of a brain, L., 1965, bibliogr.; Kalinovskaya I. Ya. To the current state of a question of dizzinesses, Zhurn, a neuropath, and psikhiat., t. 76, No. 5, page 681, 1976, bibliogr.; Olisov V. S. Labyrinthopathies, L., 1973, bibliogr.; In e h of e n d R. With h. Der Schwindel, Internist (Berl.), S. 455, 1966, Bibliogr.; G o u t e 11 e A. e. a. Une etio-logie possible des vertiges postitionels, J. franc. Oto-rhino-laryng., t. 21, p. 29, 1972; L i n k R. u. P a s with h e r W. Der Schwindel aus otologiseher Sicht, Internist (Berl.), S. 465, 1966, Bibliogr.; P i q u e t J. et Piquet J. Les vertiges, P., 1965.

I. Ya. Kalinovskaya.