Vertebrobasilar insufficiency: causes and pathogenesis
Last reviewed: 20.11.2021
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The causes of vertebral-basilar insufficiency
Dizziness can have an ischemic vascular nature, caused by a violation of blood circulation in arteries feeding the inner ear, which leads to labyrinth ischemia. Differential diagnosis of these diseases is extremely important, since only a timely and correctly established diagnosis allows for pathogenetic treatment and prevention of diseases of the inner ear of vascular genesis. Vertigo often occurs on the background of cerebral vascular pathology in patients with arterial hypertension, atherosclerosis, the pathology of the main arteries of the head, vegeto-vascular dystonia, and after myocardial infarction in the presence of various forms of arrhythmias and cirdial pathology.
A significant place in the structure of cerebrovascular diseases is occupied by acute and chronic circulatory disorders in the vertebral-baeylar system, caused by developmental anomalies, stenoses and deformations of the vertebral arteries. Dizziness in these cases occurs in response to ischemia in various parts of the vertebral-basilar system, leading to the defeat of the vestibular analyzer (from the labyrinth to its cortical part).
In clinical practice, it is important to distinguish between peripheral dizziness caused by ischemic damage to the inner ear (labyrinth), the root of the VIII cranial nerve, and central due to ischemia of the vestibular nuclei and conductive pathways. Peripheral dizziness occurs much more often than the central dizziness.
Pathogenesis of vertebral-basilar insufficiency
Given that the anteroposterior artery of the cerebellum participates in the blood supply not only in the anterolateral sections of the trunk, the middle leg of the cerebellum, but also in the inner ear; a change in the intensity of the blood flow along this artery leads to the occurrence of ischemia of the labyrinth and the root of the VIII cranial nerve, vestibular nuclei and vestibular pathways, the development of an attack of dizziness. The clinical signs of a heart attack in the basin of the anterior cerebral artery are described, before the development of which there were recurrent attacks of rotational dizziness. Vertigo appears as an isolated symptom long before the development of an infarct in the basin of the anterior cerebral artery, accompanied by a decrease in hearing, noise in one ear, ataxia. Unilateral auditory and vestibular disorders were confirmed by the results of audiological and vestibulometric research. It is shown that attacks of dizziness, preceding a heart attack, result from ischemia of the inner ear and vestibular nerve.