Dizziness is one of the most common complaints. Dizziness can be a symptom of a wide variety of neurological and mental illnesses, diseases of the cardiovascular system, eyes and ear. Definition Since patients can call a variety of sensations “dizziness”, when interviewing, it is first necessary to clarify the nature of these sensations. Usually they can be attributed to one of four categories.

•                Vestibular dizziness (true dizziness, vertigo ) is usually caused by damage to the peripheral or central part of the vestibular system. It is manifested by the illusion of movement of one’s own body or surrounding objects. 
•                Fainting and Fainting. These terms denote a temporary loss of consciousness or a sensation of impending loss of consciousness. In a fainting state, increased sweating, nausea, a sense of fear, and darkening in the eyes are often observed . The immediate cause of fainting is a fall in cerebral blood flow below the level necessary to provide the brain. 
  
•                Imbalance is characterized by instability, shaky (“drunk”) gait, but not true dizziness. The reason for this condition is the defeat of various parts of the nervous system, providing spatial coordination. 
  
•                Vague sensations, often described as dizziness, occur with emotional disorders, such as hyperventilation syndrome, hypochondriac or hysterical neurosis , depression. Some patients with complaints of dizziness find it difficult to describe their feelings. In this case, it is advisable to conduct provocative tests.

The two most common causes of vestibular dizziness are: 

•                Vestibular neuronitis and 
•                Benign Positional Dizziness .
   

Vestibular neuronitis (acute peripheral vestibulopathy ).

General information.
Vestibular neuronitis is manifested by a sudden prolonged attack of dizziness, which is often accompanied by nausea, vomiting, imbalance and a sense of fear. Symptoms are worse with head movements or a change in body position. Patients suffer this condition extremely hard and often do not get out of bed. Often marked positional nystagmus. Sometimes there is noise and a feeling of stuffiness in the ear. Hearing is not reduced, and the results of an audiological study remain normal.
There are no focal symptoms indicating damage to the brain stem (paresis, diplopia, dysarthria, impaired sensitivity).
The disease occurs in adults of any age. Acute dizziness usually resolves spontaneously after a few hours, but may recur in the coming days or weeks. Subsequently, residual vestibular dysfunction may persist, manifested by an imbalance, especially pronounced when walking. In almost half the cases, dizziness attacks recur after a few months or years.
The cause of vestibular neuronitis is unknown.
Viral etiology is suspected (as with Bell’s paralysis), but there is no evidence of this. Vestibular neuronitis is a syndrome rather than a separate nosological form.
 

Medicines With severe nausea, drugs are prescribed in suppositories or parenterally. Indications for hospitalization are a pronounced imbalance, as well as persistent vomiting, requiring rehydration .

•                H1-blockers
  a) Mechanism of action. Only H1-blockers that have a central anticholinergic effect ( dimenhydrinate , diphenhydramine , meclosin , cyclizine ) reduce dizziness . b) The main side effect is sedation and sleeping pills. It is more pronounced in dimenhydrinate and diphenhydramine . With severe dizziness, this action is desirable, otherwise meclosin or cyclizine is preferable . H1 blockers can cause anticholinergic effects such as dry mouth or poor accommodation. Meclosin , which has a longer action, is prescribed 1-2 times a day, the rest of the drugs – at least 3 times a day.  
   
•                Anticholinergics that inhibit the activity of the central vestibular structures are also used for dizziness. Currently available patches with scopolamine , releasing into the blood of 0.5 mg of scopolamine in for 72 hours. Sometimes together with scopolamine used promethazine and ephedrine, providing synergistic effect. Side effects of scopolamine are mainly due to the blockade of M- cholinergic receptors , the contraindications to its use are the same as for other M- cholinergic blockers . Scopolamine is prescribed to the elderly with great caution because of the danger of developing psychosis or acute urinary retention.    
•                Phenothiazines are a large group of drugs that have an antiemetic effect. Many of them ( for example, chlorpromazine or prochlorperazine ) reduce vomiting in case of poisoning, but little help with motion sickness and dizziness. In the latter case, promethazine , which also has antihistamine activity , is most effective . By its effect on vestibular dizziness and motion sickness, it is not inferior to other H1-blockers. The drug often causes drowsiness, but much less often than other phenothiazines – extrapyramidal disorders     
•                Sympathomimetics also reduce vestibular dizziness. a) Amphetamines in combination with promethazine or scopolamine are used to prevent dizziness and motion sickness in astronauts. However, amphetamines quickly cause drug dependence, which is why they are not used for vestibular neuronitis . b) Ephedrine enhances the effect of other vestibulolytic drugs. 
   
    
•                Tranquilizers (e.g. diazepam and lorazepam ) are used to reduce the anxiety that often accompanies dizziness. In hydroxyzine, the anxiolytic effect is combined with antihistamine and antiemetic, which makes it especially effective for vestibular dizziness. The usual dose of hydroxyzine for adults is 25-100 mg 3-4 times a day    
•                Duration of treatment. In most cases, drugs are canceled after nausea and dizziness are reduced. Sometimes it is necessary to carry out long-term maintenance therapy.
•                Such a large number of drugs for the treatment of dizziness indicates that none of them has a sufficient effect. The effectiveness of treatment can be increased by combining drugs of various groups ( for example, anticholinergic and sympathomimetics ).