Dizziness is a feeling of imaginary rotation and / or translational movements of the patient in various planes, less often - the illusion of displacement of a stationary environment in any plane. In clinical practice, the term "dizziness" is interpreted much more broadly, therefore, it includes conditions and sensations caused by impaired receipt of sensory information (visual, proprioceptive, vestibular, etc.), its processing. The main manifestation of dizziness is difficulty in orientation in space. Dizziness can have a variety of causes. The task of diagnosis is to identify the etiology of dizziness, which in the future allows you to determine the most effective tactics for its treatment.
Dizziness is a feeling of imaginary rotation and / or translational movements of the patient in various planes, less often - the illusion of displacement of a stationary environment in any plane. In clinical practice, the term "dizziness" is interpreted much more broadly, therefore, it includes conditions and sensations caused by impaired receipt of sensory information (visual, proprioceptive, vestibular, etc.), its processing. The main manifestation of dizziness is difficulty in orientation in space.
Ensuring balance is possible with the integration of the activities of the vestibular, proprioceptive, visual and tactile systems, which are closely related to the cerebral cortex and subcortical formations. Histamine, acting on histamine receptors, plays a crucial role in the transmission of information from the receptors of the semicircular canals. Cholinergic transmission has a modulating effect on histaminergic neurotransmission. Thanks to acetylcholine, it is possible to transfer information from receptors to the lateral vestibular nuclei and the central parts of the vestibular analyzer. It has been proven that vestibulo-vegetative reflexes function due to the interaction of cholin- and histaminergic systems, and histamine- and glutamatergic pathways provide vestibular afferentation to the medial nucleus.
Allocate systemic (vestibular) and non-systemic dizziness. Non-systemic dizziness includes psychogenic dizziness, pre-syncope, imbalance. In some cases, the term "physiological dizziness" may be used. Physiological dizziness is caused by excessive irritation of the vestibular apparatus and occurs as a result of prolonged rotation, a sharp change in speed, and observation of moving objects. It is part of the motion sickness syndrome.
Systemic dizziness is pathogenetically associated with a direct lesion of the vestibular analyzer. Depending on the level of its defeat, central or peripheral systemic dizziness is distinguished. The central one is due to damage to the semicircular canals, vestibular ganglia and nerves, the peripheral one is due to damage to the vestibular nuclei of the brain stem and cerebellum. Within the framework of systemic vertigo, there are: proprioceptive (sensation of passive movement of one's own body in space) and tactile or tactile (sensation of swaying on the waves, lifting or falling of the body, unsteadiness of the soil, moving support under the feet).
Non-systemic dizziness is characterized by a feeling of instability, difficulty maintaining a certain posture. It is based on the mismatch of the activity of vestibular, proprioceptive, visual sensitivity, which occurs at various levels of the nervous system.
Systemic dizziness is observed in 35-50% of patients complaining of feeling dizzy. The occurrence of systemic dizziness is often due to damage to the peripheral part of the vestibular analyzer due to toxic, degenerative and traumatic processes, much less often due to acute ischemia of these formations. Damage to the structures of the brain located above (subcortical structures, brain stem, cerebral cortex and white matter of the brain) most often occurs in connection with vascular pathology, degenerative and traumatic diseases. The most common causes of systemic vertigo are vestibular neuronitis, Meniere's disease, benign paroxysmal positional vertigo, neuroma VIII of the CN pair.
Benign paroxysmal positional vertigo (BPPV) is the most common cause of systemic vertigo. It is based on cupulolithiasis - the formation of calcium carbonate aggregates in the cavity of the semicircular canals, which irritate the receptors of the vestibular apparatus. BPPV is characterized by short-term (up to 1 minute) episodes of intense dizziness (with a change in head position), accompanied by nausea, bradycardia and other autonomic disorders. One of the hallmarks of BPPV is the absence of tinnitus and focal neurological deficit during episodes of dizziness.
Vestibular neuronitis is characterized by attacks of dizziness lasting from several hours to several days. Occurs acutely, often after a bacterial or viral infection. The patient experiences a very intense dizziness, accompanied by severe autonomic disorders. There are no meningeal and focal neurological symptoms. Hearing saved.
Post-traumatic dizziness occurs immediately after a traumatic brain injury. In this case, the presence of focal symptoms of brain damage is not necessary. Post-traumatic dizziness may also occur some time (4-5 days) after a head injury, which may be associated with the formation of a serous labyrinth.
Toxic damage to the vestibular apparatus is a progressive systemic dizziness in combination with impaired coordination of movement associated with the use of aminoglycosides, which can accumulate in the endo- and perilymph.
Meniere's disease - repeated attacks of intense systemic dizziness, accompanied by noise and ringing in the ears, fluctuating hearing loss and severe autonomic disorders. It is based on hydrops - an increase in the volume of endolymph, causing stretching of the walls of the channels of the labyrinth. The duration of dizziness attacks is from several minutes to 24 hours, the frequency is from several times a day to 1 time per year. The attack is accompanied by severe imbalances and autonomic disorders, which can persist for several days after the attack ends. As the disease progresses, hearing decreases (usually unilaterally), but complete hearing loss does not occur.
Temporal lobe epilepsy - repeated unprovoked episodes of systemic dizziness, accompanied by severe autonomic disorders (nausea, pain in the epigastric region, bradycardia, hyperhidrosis, sensation of heat). In addition, visual disturbances and other perceptual disturbances may also be present in the clinical picture.
Balance imbalance can be caused by dysfunction of the vestibular analyzer of various origins. One of the most important distinguishing features is the deterioration of the patient's condition with loss of control of vision (closed eyes). Other causes of imbalance can be damage to the cerebellum, subcortical nuclei, brain stem, multisensory deficit, as well as the use of certain drugs (phenothiazine derivatives, benzodiazepines). In such cases, dizziness is accompanied by impaired concentration, increased drowsiness (hypersomnia). The severity of these manifestations decreases with a decrease in the dose of the drug.
Pre-syncope - a feeling of dizziness, ringing in the ears, "darkening in the eyes", lightheadedness, loss of balance. Psychogenic dizziness is one of the most common symptoms of panic attacks and is one of the most common complaints made by patients suffering from psychogenic disorders (hysteria, hypochondriacal syndrome, neurasthenia, depressive states). Differs in firmness and the expressed emotional coloring.
To diagnose dizziness, a neurologist must first of all confirm the very fact of dizziness, since patients often put a different meaning into the concept of “dizziness” (headache, blurred vision, etc.). To do this, in the process of differential diagnosis between dizziness and complaints of a different nature, one should not prompt the patient to one or another term or offer them to choose from. It is much more correct to hear from him a detailed description of the existing complaints and sensations.
Much attention should be paid to the neurological examination of the patient (the state of CN, detection of nystagmus, coordinating tests, detection of neurological deficit). However, even a full-fledged examination does not always make it possible to determine the diagnosis; for this, observation of the patient in dynamics. In such cases, information about previous intoxications, autoimmune and inflammatory diseases may be useful. A patient with dizziness may need a consultation with an otoneurologist, a vestibulologist and an examination of the cervical spine: X-ray, CT, MRI of the spine.
With the help of CT and MRI of the brain, it is necessary to exclude neoplasms, a demyelinating process, and other structural changes of a congenital and acquired nature. The presence of infectious diseases can be confirmed or denied by the determination of antibodies to suspected pathogens, as well as a complete study of the cellular composition of the blood. In favor of the diagnosis of "Meyer's disease" indicates an improvement in the perception of low frequencies when registering an audiogram. It should also be remembered about the EEG of the brain, which makes it possible to exclude epileptic and paroxysmal activity in the temporal leads. They also conduct a study of the vestibular analyzer: vestibulometry, stabilography, rotational tests, etc.
The choice of tactics for the treatment of dizziness is based on the cause of the disease and the mechanisms of its development. In any case, therapy should be aimed at relieving the patient of discomfort and associated neurological disorders. Therapy of cerebrovascular disorders involves the control of blood pressure, the appointment of antiplatelet agents, nootropics, venotonics, vasodilators, and, if necessary, antiepileptic drugs. Treatment of Meniere's disease involves the appointment of diuretics, limiting the intake of table salt, and in the absence of the desired effect and ongoing bouts of dizziness, they decide on surgical intervention. Treatment of vestibular neuronitis may require the use of antiviral drugs. Since the use of drugs in BPPV,
As a symptomatic treatment of dizziness, vestibulolitics (betahistine) are used. The effectiveness of antihistamines (promethazine, meclozine) has been proven in the case of a predominant lesion of the vestibular analyzer. Of great importance in the treatment of non-systemic dizziness is non-drug therapy. With its help, it is possible to restore coordination of movements and improve gait. It is advisable to carry out the therapy of psychogenic dizziness in conjunction with a psychotherapist (psychiatrist), since in some cases it may be necessary to prescribe anxiolytics, antidepressants and anticonvulsants.
It is known that an attack of dizziness is often accompanied by a feeling of fear, but dizziness, as a condition, is not life-threatening. Therefore, in the case of timely diagnosis of the disease that caused dizziness, as well as its adequate therapy, in most cases the prognosis is favorable.