Arteries of the base of the brain. Blood supply to the brain and spinal cord

The brain system regulates all other structures of the body, maintaining dynamic constancy in the internal environment and the stability of the main physiological functions. That is why the intensity of nutrition in nervous tissue is very high. Next, let's look at how the blood supply to the brain occurs.

General information

At rest, the brain receives approximately 750 ml of blood per minute. This corresponds to 15% of cardiac output. The blood supply to the brain (the diagram will be presented later) is closely related to functions and metabolism. Adequate nutrition of all departments and hemispheres is ensured due to special structural organization and physiological mechanisms of vascular regulation.

Peculiarities

The nutrition of the organ is not affected by changes in general hemodynamics. This is possible due to the presence of various self-regulation mechanisms. Nutrition of the centers of coordination of nervous activity is carried out in an optimal mode. It ensures a timely and continuous supply of all nutrients and oxygen to the tissues. Blood circulation in the brain gray matter differs in greater intensity than in white. It is most intense in children under one year of age. Their nutritional intensity is 50-55% higher than that of adults. In an elderly person it is reduced by 20% or more. About a fifth of the total blood volume is pumped by the vessels of the brain. The centers regulating nervous activity remain constantly active, even during sleep. Control of cerebral blood flow is achieved through metabolic activity in the nervous tissue. With an increase in functional activity, metabolic processes accelerate. Due to this, blood supply to the brain increases. Its redistribution is carried out within the arterial network of the organ. To speed up metabolism and increase the intensity of nerve cell activity, therefore, no additional increase in nutrition is required.

Blood supply to the brain: diagram. Arterial network

It includes paired vertebral and carotid canals. Due to the latter, 70-85% of the hemispheres are supplied with nutrition. The vertebral arteries contribute the remaining 15-30%. The internal carotid canals arise from the aorta. Then they pass on both sides of the sella turcica and the intertwining of the optic nerves. Through a special channel they enter the cranial cavity. In it, the carotid arteries are divided into middle, anterior and ophthalmic. The network also distinguishes between the anterior villous and posterior connecting canals.

Vertebral vessels

They arise from the subclavian artery and enter the skull through the foramen magnum. Then they branch out. Their segments approach the spinal cord and the membrane of the brain. Branches also form the inferior posterior cerebellar arteries. Through connecting channels they communicate with the middle vessels. As a result, a circle of Willis is formed. It is closed and located, accordingly, at the base of the brain. In addition to the Willis, the vessels also form the second circle - Zakharchenko. The site of its formation is the base medulla oblongata. It is formed due to the fusion of branches from each vertebral vessel into a single anterior artery. Similar anatomical diagram circulatory system provides uniform distribution nutrients and oxygen to all parts of the brain and compensates for nutritional disorders.

Venous drainage

Blood channels that collect blood, which is enriched with carbon dioxide, from nerve tissue are presented in the form of jugular veins and sinuses of the dura mater. From the cortex and white matter, movement through the vessels occurs towards the inferior, medial and superolateral surfaces of the hemispheres. An anastomotic venous network is formed in this area. Then it runs through the superficial vessels to the hard shell. A network of deep vessels opens into a large vein. They collect blood from the brain base and internal parts of the hemispheres, including the thalamus, hypothalamus, choroid plexuses of the ventricles, and basal ganglia. The outflow from the venous sinuses is carried out through the jugular canals. They are located on the neck. The superior vena cava is the last link.

Impaired blood supply to the brain

The activity of all parts of the organ depends on the state of the vascular network. Insufficient blood supply to the brain provokes a decrease in the content of nutrients and oxygen in neurons. This, in turn, leads to dysfunction of the organ and causes many pathologies. Poor blood supply to the brain, congestion in the veins leading to the development of tumors, circulatory disorders in the small and large circles and acid-base status, increased pressure in the aorta and many other factors accompanying diseases associated with the activity of not only the organ itself, but also the musculoskeletal system. -motor system, liver, kidneys, provoke lesions in the structure. In response to impaired blood supply to the brain, bioelectrical activity changes. An electroencephalographic study allows us to register and identify this kind of pathology.

Morphological signs of the disorder

Pathological disorders are of two types. Focal signs include infarction, hemorrhagic stroke, and intrathecal hemorrhage. Among diffuse changes small focal disturbances in the substance are noted, with varying degrees of age and character, small organizing and fresh necrotic areas of tissue, small cysts, gliomesodermal cysts and others.

Clinical picture

If the blood supply to the brain undergoes changes, there may be subjective feelings, not accompanied by objective neurological symptoms. These include, in particular:

• Paresthesia.
• Headache.
• Organic microsymptoms without pronounced signs of central nervous system dysfunction.
• Dizziness.
• Disorders of the higher functions of the cortex of a focal nature (aphasia, agraphia and others).
• Disorders of the sensory organs.

Focal symptoms include:

• Movement disorders (impaired coordination, paralysis and paresis, extrapyramidal changes, decreased sensitivity, pain).
• Epileptic seizures.
• Changes in memory, emotional-volitional sphere, intelligence.

Blood circulation disorders, by their nature, are divided into initial, acute (intrathecal hemorrhages, transient disorders, strokes) and chronic, slowly progressive manifestations (encephalopathy, discirculatory myelopathy).

Methods for eliminating disorders

Improved blood supply to the brain occurs after deep breathing. As a result of simple manipulations, more oxygen enters the organ tissue. There are also simple physical exercise, helping to restore circulation. Normal blood supply is ensured if the blood vessels are healthy. In this regard, it is necessary to carry out measures to clean them. First of all, experts recommend reviewing your diet. The menu should contain dishes that help eliminate cholesterol (vegetables, fish, etc.). In some cases, it is necessary to take medications to improve blood circulation. It should be remembered that only a doctor can prescribe medications.

CEREBRAL CIRCULATION- blood circulation through the cerebral vascular system. The blood supply to the brain is more intense than to any other organs: approx. 15% of the blood entering the systemic circulation during cardiac output flows through the blood vessels of the brain (its weight is only 2% of the body weight of an adult). Extremely high cerebral blood flow ensures the greatest intensity of metabolic processes in brain tissue. This blood supply to the brain is also maintained during sleep. The intensity of metabolism in the brain is also evidenced by the fact that 20% of the oxygen absorbed from environment, is consumed by the brain and used for oxidative processes occurring in it.

PHYSIOLOGY

The circulatory system of the brain provides perfect regulation of the blood supply to its tissue elements, as well as compensation for disturbances in cerebral blood flow. The human brain (see) is supplied with blood simultaneously by four main arteries - paired internal carotid and vertebral arteries, which are interconnected by wide anastomoses in the area of ​​the arterial (Willisian) circle of the cerebrum (color. Fig. 4). Under normal conditions, the blood does not mix here, flowing ipsilaterally from each internal carotid artery (see) into the cerebral hemispheres, and from vertebrates - mainly into the parts of the brain located in the posterior cranial fossa.

Cerebral arteries are not elastic, but muscular type vessels with abundant adrenergic and cholinergic innervation, therefore, changing their lumen within a wide range, they can participate in regulating blood supply to the brain.

Paired anterior, middle and posterior cerebral arteries, extending from the arterial circle, branching and anastomosing among themselves, form a complex system of arteries of the pia mater (pial arteries), which has a number of features: branching of these arteries (down to the smallest, diameter 50 microns or less ) are located on the surface of the brain and regulate blood supply to extremely small areas; each artery lies in a relatively wide canal of the subarachnoid space (see Meninges), and therefore its diameter can vary within wide limits; the arteries of the pia mater lie on top of the anastomosing veins. From the smallest arteries of the pia mater radial arteries branch off in the thickness of the brain; they do not have free space around the walls and, according to experimental data, are the least active in terms of changes in diameter when regulating the muscle. There are no interarterial anastomoses in the thickness of the brain.

The capillary network in the thickness of the brain is continuous. Its density is greater, the more intense the metabolism in the tissues, so it is much thicker in gray matter than in white matter. In every part of the brain capillary network characterized by specific architectonics.

Venous blood flows from the capillaries of the brain into the widely anastomosing venous system of both the pia mater (pial veins) and the great cerebral vein (vein of Galen). Unlike other parts of the body, the venous system of the brain does not perform a capacitive function.

More detailed anatomy and histology blood vessels brain - see Cerebrum.

Regulation cerebral circulation carried out perfect physiological system. The effectors of regulation are the main, intracerebral arteries and arteries of the pia mater, which are characterized by specific functions. features.

Four types of regulation of M. to. are shown in the diagram.

When the level of total blood pressure changes within certain limits, the intensity of cerebral blood flow remains constant. Regulation of constant blood flow in the brain during fluctuations in total blood pressure is carried out due to changes in resistance in the arteries of the brain (cerebrovascular resistance), which narrow when total blood pressure increases and expand when it decreases. Initially, it was assumed that vascular shifts were caused by the reactions of the smooth muscles of the arteries to varying degrees of stretching of their walls by intravascular pressure. This type of regulation is called autoregulation or self-regulation. The level of increased or decreased blood pressure, at which cerebral blood flow ceases to be constant, is called the upper or lower limit of autoregulation of cerebral blood flow, respectively. Experimental and wedge studies have shown that autoregulation of cerebral blood flow is in close relationship with neurogenic influences, which can shift the upper and lower boundaries of its autoregulation. The effectors of this type of regulation in the arterial system of the brain are the main arteries and arteries of the pia mater, active reactions of which maintain constant blood flow in the brain when the total blood pressure changes.

Regulation of M. to. when the gas composition of the blood changes is that cerebral blood flow increases with an increase in the CO 2 content and with a decrease in the O 2 content in arterial blood and decreases when their ratio is inverse. The influence of blood gases on the tone of the arteries of the brain, according to a number of authors, can be carried out humorally: with hypercapnia (see) and hypoxia (see), the concentration of H + in the brain tissue increases, the ratio between HCO 3 - and CO 2 changes, which together with other biochemicals, shifts in the extracellular fluid directly affect the metabolism of smooth muscles, causing dilatation) of the arteries. The neurogenic mechanism also plays an important role in the action of these gases on the vessels of the brain, in which chemoreceptors of the carotid sinus and, apparently, other cerebral vessels are involved.

Elimination of excess blood volume in the vessels of the brain is necessary, since the brain is located in a hermetically sealed skull and its excessive blood supply leads to increased intracranial pressure (see) and to compression of the brain. Excessive blood volume can occur when there is difficulty in the outflow of blood from the veins of the brain and when there is excessive blood flow due to dilation of the arteries of the pia mater, for example, during asphyxia (see) and post-ischemic hyperemia (see Hyperemia). There is evidence that the effectors of regulation in this case are the main arteries of the brain, which narrow reflexively due to irritation of the baroreceptors of the cerebral veins or arteries of the pia mater and limit blood flow to the brain.

Regulation of adequate blood supply to brain tissue ensures correspondence between the intensity of blood flow in the microcirculation system (see) and the intensity of metabolism in brain tissue. This regulation occurs when there is a change in the intensity of metabolism in the brain tissue, for example, a sharp increase in its activity, and when there is a primary change in blood flow into the brain tissue. Regulation is carried out locally, and its effector is the small arteries of the pia mater, which control blood flow in negligibly small areas of the brain; the role of smaller arteries and arterioles in the thickness of the brain has not been established. Control of the lumen of effector arteries when regulating cerebral blood flow, according to most authors, is carried out humorally, i.e., through the direct action of metabolic factors accumulating in brain tissue (hydrogen ions, potassium, adenosine). Some experimental data indicate a neurogenic mechanism (local) of vasodilation in the brain.

Types of regulation of cerebral circulation. Regulation of cerebral blood flow when the level of total blood flow changes blood pressure(III) and when there is excessive blood supply to the vessels of the brain (IV), it is carried out by the main arteries of the brain. When the content of oxygen and carbon dioxide in the blood changes (II) and when the adequacy of the blood supply to the brain tissue is impaired (I), small arteries of the pia mater are included in the regulation.

METHODS FOR STUDYING CEREBRAL BLOOD FLOW

The Kathy-Schmidt method allows you to determine blood flow in the entire human brain by measuring the rate of saturation (saturation) of brain tissue with an inert gas (usually after inhaling small amounts of nitrous oxide). Brain tissue saturation is determined by determining the gas concentration in samples venous blood, taken from the jugular vein bulb. This method (quantitative) allows one to determine the average blood flow of the whole brain only discretely. It was found that the intensity of cerebral blood flow in healthy person equal to approximately 50 ml of blood per 100 g of brain tissue per minute.

The clinic uses a direct method to obtain quantitative data on cerebral blood flow in small areas of the brain using the clearance (clearance rate) of radioactive xenon (133 Xe) or hydrogen gas. The principle of the method is that the brain tissue is saturated with easily diffusible gases (133 Xe solution is usually injected into the internal carotid artery, and hydrogen is inhaled). Using appropriate detectors (for 133Xe they are installed above the surface of the intact skull; for hydrogen, platinum or gold electrodes are inserted into any area of ​​the brain) the rate at which brain tissue is cleared of gas is determined, which is proportional to the intensity of blood flow.

Direct (but not quantitative) methods include the method of determining changes in blood volume in superficially located vessels of the brain using radionuclides, which mark blood plasma proteins; in this case, radionuclides do not diffuse through the walls of the capillaries into the tissue. Blood albumins labeled with radioactive iodine have become especially widespread.

The reason for the decrease in the intensity of cerebral blood flow is a decrease in the arteriovenous pressure difference due to a decrease in total blood pressure or an increase in total venous pressure (see), with the main role played by arterial hypotension (see Arterial hypotension). Total blood pressure may drop sharply, and total venous pressure increases less frequently and less significantly. A decrease in the intensity of cerebral blood flow may also be due to an increase in resistance in the vessels of the brain, which may depend on reasons such as atherosclerosis (see), thrombosis (see) or vasospasm (see) of certain arteries of the brain. A decrease in the intensity of cerebral blood flow may depend on the intravascular aggregation of blood cells (see Red blood cell aggregation). Arterial hypotension, weakening blood flow throughout the brain, causes the greatest decrease in its intensity in the so-called. areas of adjacent blood supply, where intravascular pressure drops the most. When certain arteries of the brain are narrowed or occluded, pronounced changes in blood flow are observed in the center of the basins of the corresponding arteries. Of great importance are secondary pathol, changes in the vascular system of the brain, for example, changes in the reactivity of the cerebral arteries during ischemia (constrictor reactions in response to vasodilator effects), unrestored blood flow in the brain tissue after ischemia or spasm of the arteries in the area of ​​blood extravasation, in particular subarachnoid hemorrhages. An increase in venous pressure in the brain, which plays a less significant role in weakening the intensity of cerebral blood flow, may have independent significance when it is caused, in addition to an increase in general venous pressure, by local causes leading to difficulty in the outflow of venous blood from the skull (thrombosis or tumor). In this case, phenomena of venous stagnation of blood in the brain occur, which lead to an increase in blood supply to the brain, which contributes to an increase in intracranial pressure (see Hypertensive syndrome) and the development of cerebral edema (see Edema and swelling of the brain).

Patol, increased intensity of cerebral blood flow may depend on an increase in total blood pressure (see Arterial hypertension) and may be due to primary dilatation (patol, vasodilation) of the arteries; then it occurs only in those areas of the brain where the arteries are dilated. Patol, an increase in the intensity of cerebral blood flow can lead to an increase in intravascular pressure. If the walls of the vessels are pathologically changed (see Arteriosclerosis) or there are arterial aneurysms, then a sudden and sharp increase in total blood pressure (see Crises) can lead to hemorrhage. Patol, an increase in the intensity of cerebral blood flow may be accompanied by a regulatory reaction of the arteries - their constriction, and with a sharp increase in total blood pressure it can be very significant. If the functional state of the smooth muscles of the arteries is changed in such a way that the contraction process is enhanced, and the relaxation process, on the contrary, is reduced, then in response to an increase in total blood pressure, vasoconstriction occurs patol, such as vasospasm (see). These phenomena are most pronounced with a short-term increase in total blood pressure. When the blood-brain barrier is disrupted and there is a tendency to cerebral edema, an increase in pressure in the capillaries causes a sharp increase in the filtration of water from the blood into the brain tissue, where it is retained, resulting in the development of cerebral edema. An increase in the intensity of cerebral blood flow is especially dangerous when exposed to additional factors(traumatic brain injury, severe hypoxia), contributing to the development of edema.

Compensatory mechanisms - mandatory component symptom complex, which characterizes each violation of M. to. In this case, compensation is carried out by the same regulatory mechanisms, which function under normal conditions, but they are more intense.

When total blood pressure increases or decreases, compensation is carried out by changing the resistance in the vascular system of the brain, with the main role played by the large cerebral arteries (internal carotid and vertebral arteries). If they do not provide compensation, then microcirculation ceases to be adequate and the arteries of the pia mater are involved in regulation. With a rapid increase in total blood pressure, these compensation mechanisms may not work immediately, and then the intensity of cerebral blood flow sharply increases with all possible consequences. In some cases, compensatory mechanisms can work very well and even with chronic hypertension, when general blood pressure is sharply increased (280-300 mm Hg) for a significant time; the intensity of cerebral blood flow remains normal and neurol, disturbances do not occur.

When total blood pressure decreases, compensatory mechanisms can also maintain the normal intensity of cerebral blood flow, and depending on the degree of perfection of their work, the limits of compensation may be different in different persons. With perfect compensation, normal intensity of cerebral blood flow is observed when total blood pressure decreases even to 30 mm Hg. Art., while usually the lower limit of autoregulation of cerebral blood flow is considered to be blood pressure not lower than 55-60 mm Hg. Art.

When resistance increases in certain arteries of the brain (during embolism, thrombosis, vasospasm), compensation is carried out due to collateral blood flow. In this case, compensation is provided by the following factors:

1. The presence of arterial vessels through which collateral blood flow can occur. The arterial system of the brain contains a large number of collateral pathways in the form of wide anastomoses of the arterial circle, as well as numerous interarterial macro- and microanastomoses in the system of arteries of the pia mater. However, the structure of the arterial system is individual, and developmental anomalies are not uncommon, especially in the area of ​​the arterial (circle of Willis) area. Small arteries located deep in the brain tissue do not have arterial-type anastomoses, and although the capillary network throughout the brain is continuous, it cannot provide collateral blood flow to neighboring tissue areas if the blood flow into them from the arteries is disrupted.

2. An increase in the pressure drop in the collateral arterial pathways when there are obstacles to blood flow in one or another cerebral artery (hemodynamic factor).

3. Active expansion of collateral arteries and small arterial branches to the periphery from the site of closure of the artery lumen. This vasodilation is, apparently, a manifestation of the regulation of adequate blood supply to the brain tissue: as soon as a deficiency of blood flow into the tissue occurs, a physiological mechanism begins to work, causing dilatation) of those arterial branches that lead to this microcirculatory system. As a result, the resistance to blood flow in the collateral pathways is reduced, which promotes blood flow to the area with reduced blood supply.

The effectiveness of collateral blood flow to the area of ​​reduced blood supply varies from person to person. The mechanisms that ensure collateral blood flow, depending on specific conditions, may be disrupted (as well as other mechanisms of regulation and compensation). Thus, the ability of collateral arteries to expand during sclerotic processes in their walls decreases, which prevents collateral blood flow to the area of ​​impaired blood supply.

Compensation mechanisms are characterized by duality, i.e. compensation for some disorders causes other circulatory disorders. For example, when blood flow in brain tissue that has experienced a deficiency of blood supply is restored, post-ischemic hyperemia may occur, in which the intensity of microcirculation can be significantly higher than the level necessary to ensure metabolic processes in the tissue, i.e., excessive blood perfusion occurs, promoting, in particular, the development of post-ischemic cerebral edema.

On adequate and pharmacological influences, a perverted reactivity of the arteries of the brain can be observed. Thus, the basis of the “intracerebral steal” syndrome is the normal vasodilator reaction of healthy vessels surrounding the focus of ischemia of brain tissue, and the absence of such in the affected arteries in the focus of ischemia, as a result of which blood is redistributed from the focus of ischemia to healthy vessels, and ischemia is aggravated.

PATHOLOGICAL ANATOMY OF CEREBRAL CIRCULATION DISORDERS

Morphol. signs of disturbance of M. to. are revealed in the form of focal and diffuse changes, the severity and localization of which are different and largely depend on the underlying disease and the immediate mechanisms of development of circulatory disorders. There are three main forms of violation

M. to.: hemorrhages (hemorrhagic stroke), cerebral infarctions (ischemic stroke) and multiple different types of small-focal changes in the brain substance (vascular encephalopathy).

Wedge, manifestations of occlusive lesions of the extracranial part of the internal carotid artery in the initial period occur more often in the form of transient disorders of M. K. Nevrol, the symptoms are varied. In approximately 1/3 of cases, there is an alternating optic-pyramidal syndrome - blindness or decreased vision, sometimes with atrophy of the optic nerve on the side of the affected artery (due to discirculation in the ophthalmic artery), and pyramidal disorders on the side opposite to the lesion. Sometimes these symptoms occur simultaneously, sometimes dissociated. The most common signs of occlusion of the internal carotid artery are signs of discirculation in the middle cerebral artery basin: paresis of the limbs of the side opposite to the lesion, usually of the cortical type with a more pronounced defect of the arm. With infarctions in the left internal carotid artery, aphasia often develops, usually motor. Sensory disturbances and hemianopsia may occur. Occasionally, epileptiform seizures are observed.

In heart attacks caused by intracranial thrombosis of the internal carotid artery, which occurs with disconnection of the arterial circle, along with hemiplegia and hemihypesthesia, pronounced cerebral symptoms are observed: headache, vomiting, impaired consciousness, psychomotor agitation; secondary stem syndrome appears.

The syndrome of occlusive lesions of the internal carotid artery, in addition to the intermittent course of the disease and the indicated neurol manifestations, is characterized by a weakening or disappearance of the pulsation of the affected carotid artery, often the presence of a vascular noise above it and a decrease in retinal pressure on the same side. Compression of the unaffected carotid artery causes dizziness, sometimes fainting, and convulsions in healthy limbs.

An occlusive lesion of the extracranial section of the vertebral artery is characterized by “spotty” lesions of various parts of the spinobasilar system: vestibular disorders (dizziness, nystagmus), disorders of statics and coordination of movements, visual and oculomotor disturbances, dysarthria often occur; motor and sensory disorders are less frequently detected. Some patients experience attacks of sudden falling due to loss of postural tone, adynamia, and hypersomnia. Quite often there are memory disorders for current events such as Korsakov's syndrome (see).

When the intracranial part of the vertebral artery is blocked, persistent alternating syndromes of damage to the medulla oblongata are combined with transient symptoms of ischemia of the oral parts of the brain stem, occipital and temporal lobes. In approximately 75% of cases, Wallenberg-Zakharchenko, Babinsky-Nageotte syndromes and other syndromes of unilateral damage to the lower parts of the brain stem develop. With bilateral thrombosis of the vertebral artery, severe swallowing and phonation disorders occur, breathing and cardiac activity are impaired.

Acute blockage of the basilar artery is accompanied by symptoms of predominant damage to the pons with a disorder of consciousness up to coma, rapid development of lesions of the cranial nerves (III, IV, V, VI, VII pairs), pseudobulbar syndrome, paralysis of the limbs with the presence of bilateral patols. reflexes. Autonomic-visceral crises, hyperthermia, and disturbance of vital functions are observed.

Diagnosis of cerebrovascular disorders

The basis for the diagnosis of the initial manifestation of M.'s inferiority is: the presence of two or more subjective signs, often repeated; absence during normal neurol examination of symptoms of organic damage to c. n. With. and detection of signs of general vascular disease (atherosclerosis, hypertension, vasculitis, vascular dystonia etc.), which is especially important, since the patient’s subjective complaints are not pathognomonic for the initial manifestations of vascular inferiority of the brain and can also be observed in other conditions (neurasthenia, asthenic syndromes of various origins). In order to establish a general vascular disease in a patient, it is necessary to conduct a comprehensive wedge and examination.

The basis for the diagnosis of an acute disorder of M. to. is the sudden appearance of symptoms of organic brain damage against the background of a general vascular disease with significant dynamics of cerebral and local symptoms. If these symptoms disappear in less than 24 hours. a transient disorder of M. is diagnosed; in the presence of more persistent symptoms, a cerebral stroke is diagnosed. In determining the nature of a stroke, it is not the individual signs, but their combination that is of key importance. There are no pathognomonic signs for one type of stroke or another. For the diagnosis of hemorrhagic stroke, high blood pressure and a history of cerebral hypertensive crises, sudden onset of the disease, rapid progressive deterioration of the condition, significant severity of not only focal but also general cerebral symptoms, distinct autonomic disorders, early onset of symptoms caused by displacement and compression of the brain stem, are important. rapidly occurring changes in the blood (leukocytosis, neutrophilia with a shift to the left in the leukocyte formula, an increase in the Krebs index to 6 or higher), the presence of blood in the cerebrospinal fluid.

Cerebral infarction is indicated by the development of a stroke during sleep or against the background of weakened cardiovascular activity, the absence arterial hypertension, the presence of cardiosclerosis, a history of myocardial infarction, relative stability of vital functions, preservation of consciousness with massive neurol, symptoms, absence or mild severity of secondary stem syndrome, relatively slow development of the disease, absence of changes in the blood in the first day after a stroke.

Echoencephalography data (see) help in diagnosis - the shift of the M-echo towards the contralateral hemisphere is more likely to speak in favor of intracerebral hemorrhage. X-ray examination of cerebral vessels after administration of contrast agents (see Vertebral angiography, Carotid angiography) for intrahemispheric hematomas reveals an avascular zone and displacement of arterial trunks; In case of cerebral infarction, an occlusive process is often detected in the main or intracerebral vessels; dislocation of the arterial trunks is uncharacteristic. Computed tomography of the head provides valuable information when diagnosing a stroke (see Computer tomography).

Basic principles of therapy for cerebrovascular accidents

With initial manifestations of M.'s inferiority, therapy should be aimed at treating the underlying vascular disease, normalizing the work and rest regime, and using agents that improve the metabolism of brain tissue and hemodynamics.

In case of acute violations of M. to., urgent measures are required, since it is not always clear whether the violation of M. to. will be transient or persistent, therefore, in any case, complete mental and physical rest is necessary. A cerebral vascular attack should be stopped at the earliest early stages its development. Treatment of transient disorders of M. to. (vascular cerebral crises) should primarily involve the normalization of blood pressure, cardiac activity and cerebral hemodynamics with the inclusion, if necessary, of antihypoxic, decongestant and various symptomatic drugs, including sedatives, in some cases they are used anticoagulants and antiplatelet agents. Treatment for cerebral hemorrhage is aimed at stopping the bleeding and preventing its resumption, combating cerebral edema and impairment of vital functions. When treating a heart attack

brain carry out measures aimed at improving blood supply to the brain: normalizing cardiac activity and blood pressure, increasing blood flow to the brain by dilating regional cerebral vessels, reducing vascular spasm and improving microcirculation, as well as normalizing physical-chemical. properties of blood, in particular to restore balance in the blood coagulation system to prevent thromboembolism and to dissolve already formed blood clots.

Bibliography: Akimov G. A. Transient disorders of cerebral circulation, L., 1974, bibliogr.; Antonov I. P. and Gitkina L. S. Vertebro-basilar strokes, Minsk, 1977; B e to about in D. B. and Mikhailov S. S. Atlas of arteries and veins of the human brain, M., 1979, bibliogr.; Bogolepov N.K. Comatose states, p. 92, M., 1962; o n e, Cerebral crises and stroke, M., 1971; Gannushkina I.V. Collateral circulation in the brain, M., 1973; K Dosovsky B. N. Blood circulation in the brain, M., 1951, bibliogr.; K o l t o-vera. N.idr. Pathological anatomy disorders of cerebral circulation, M., 1975; Mints A. Ya. Atherosclerosis of cerebral vessels, Kyiv, 1970; Moskalenko Yu.E. and others. Intracranial hemodynamics, Biophysical aspects, L., 1975; Mchedlishvili G. I. Function of vascular mechanisms of the brain, L., 1968; o N, Spasm of the cerebral arteries, Tbilisi, 1977; Vascular diseases nervous system, ed. E. V. Schmidt, p. 632, M., 1975; Sh m and d t E. V. Stenosis and thrombosis of the carotid arteries and cerebrovascular accidents, M., 1963; Schmidt E. V., Lunev D. K. and Vereshchagin N. V. Vascular diseases of the brain and spinal cord, M., 1976; Cerebral circulation and stroke, ed. by K. J. Ztilch, B. u. a., 1971; Fisher S. M. The arterial lesions underlying lacunes, Acta neuropath. (Berl.), v. 12, p. 1, 1969; Handbook of clinical neurology, ed. by P. J. Vinken a. G. W. Bruyn, v. 11 -12, Amsterdam, 1975; Jorgensen L. a. Torvik A. Ischemic cerebrovascular diseases in an autopsy series, J. Neurol. Sci., v. 9, p. 285, 1969; Olesen J. Cerebral blood flow, Copenhagen, 1974; P u r v e s M. J. The physiology of the cerebral circulation, Cambridge, 1972.

D. K. Lunev; A. N. Koltover, R. P. Tchaikovskaya (pat. an.), G. I. Mchedlishvili (physics., path. physics.).

Blood circulation to the brain is carried out by paired vertebral and carotid arteries. The carotid arterial vessels account for two-thirds of the transported blood, and the vertebral arterial vessels account for the remaining third.

However, the whole picture is made up of:

• Vertebrobasilar system:
• Carotid basin;
• Circle of Willis.

The human brain requires a sufficient supply of resources for its normal functioning. During the period when the brain is inactive, it consumes about 15% of glucose and oxygen from their total amount, and 15% of all blood in the body passes through it. These needs are primarily necessary to maintain the functions of nerve cells and the energy substrate of the brain.

The total human blood flow is approximately 50 ml of blood per minute per 100 g of brain tissue, and does not change during the process. Meanwhile, in children, blood flow rates are 50% higher than in adults, and in older people, these rates decrease by 20%. Under normal conditions, unchanged blood flow indicators are observed when blood pressure fluctuates from 80 to 160 mm Hg. Art.

It is also worth noting that the general blood flow is significantly affected by sudden changes in the tension of oxygen and carbon dioxide in the arterial blood, and the constant blood flow is maintained by a complex regulatory mechanism.

Blood is supplied through 4 large vessels: two internal carotid and two vertebral arteries. The circulatory system includes:

1. Internal carotid arteries

They are branches of the common carotid arteries, and left branch branches off from the aortic arch. The left and right carotid arteries are located in the lateral areas of the neck. The characteristic pulsation of their walls can be easily felt through the skin by simply placing your fingers on the desired point on the neck. Compression of the carotid arteries leads to disruption of blood flow to the brain.

At the level of the upper part of the larynx, the external and internal carotid arteries depart from the common carotid artery. The internal artery penetrates the cranial cavity, where it is involved in supplying blood to the brain and eyeballs, external - nourishes the organs of the neck, face and scalp.

1. Vertebral arteries

These arteries branch from the subclavian arteries, pass to the head through a series of holes in the transverse processes of the cervical vertebrae and subsequently flow into the cranial cavity through the foramen magnum.

Since the vessels that supply the brain branch from the branches of the aortic arch, therefore, the intensity (velocity) and pressure in them are high, and they also have an oscillatory pulsation. In order to smooth them out, when they flow into the cranial cavity, the internal carotid and vertebral arteries form characteristic bends (siphons).

After entering the cranial cavity, the arteries connect with each other and form the so-called circle of Willis (arterial circle). It allows, if the blood supply to any of the vessels is disrupted, to redirect its work to other vessels, which helps prevent disruption of the blood circulation in the brain area. It is worth noting that under normal conditions, blood redistributed among various arteries does not mix in the vessels of the circle of Willis.

3. Cerebral arteries

The anterior and middle cerebral arteries branch from the internal carotid artery, which in turn feed the internal and outer surface cerebral hemispheres, as well as deep brain regions.

The posterior cerebral arteries, which supply the occipital lobes of the cerebral hemispheres, the brainstem and the cerebellum, appear to be branches from vertebrates. From the large cerebral arteries, many thin ones originate, which subsequently plunge into the tissue. Their diameter varies in width and length, therefore they are divided into: short (feeding the cerebral cortex) and long (feeding the white matter).

A high percentage of hemorrhages occur in patients with existing changes in the walls of blood vessels in these particular arteries.

1. Blood-brain barrier

Regulating the transport of substances from the blood capillary to nerve tissue and is called the blood-brain barrier. Under normal conditions, various compounds, such as iodine, salt, antibiotics, etc., do not pass from the blood to the brain. Consequently, medications, which contain these substances, do not have an effect on nervous system person. Conversely, substances such as alcohol, morphine, and chloroform easily pass the blood-brain barrier. This is explained by the intense effect of these substances on the nervous system.

In order to avoid this barrier, antibiotics and a number of other chemical substances, which are used in the treatment of infectious brain pathologies, are injected directly into the cerebrospinal fluid. To do this, a puncture is made in lumbar region spinal column or in the suboccipital area.

Carotid basin

The carotid system includes carotid arterial vessels, which originate from the chest cavity. The carotid system is responsible for the blood supply to most of the head and vision. Upon reaching the thyroid cartilage, the carotid arteries divide into internal and external arterial vessels.

When the functions of these blood vessels are disrupted, blood circulation in the head becomes unstable and gradually decreases, which ultimately leads to the manifestation of diseases such as ischemia, thrombosis or embolism.

The most common provoking factors of these diseases are atherosclerosis or fibromuscular dysplasia, as well as a number of others. However, as a rule, the main pathological factor is vascular atherosclerosis. With impaired metabolism, cholesterol is gradually deposited on the walls of blood vessels, which subsequently forms atherosclerotic plaques, which leads to the blocking of arterial pathways. Over time, these plaques are destroyed, which can lead to thrombosis.

Vertebrobasilar system

This system is formed from the vertebral arteries and the basilar artery, which is formed as a result of the fusion of the vertebral vessels. The vertebral blood vessels originate in the thoracic cavity and pass through the entire bony canal of the cervical vertebrae, reaching the brain.

The basilar (or formerly basilar artery) is responsible for the circulation of the posterior parts of the brain. Common diseases are thrombosis and aneurysms.

Thrombosis occurs as a result of vascular damage, which can be caused by various reasons, from trauma to atherosclerosis. Most negative consequence thrombosis is an embolism, which subsequently develops to thromboembolism. The disease is accompanied by neurological symptoms that indicate damage to the bridge. Also registered acute disorders functions and stagnation of blood in the capillaries, which often leads to stroke.

In the event of an arterial aneurysm, this can lead to possible hemorrhage in the brain and, as a consequence, death of its tissues, which ultimately leads to the death of a person.

Circle of Willis

The circle of Willis includes a network of main arteries of the head and is mainly responsible for supplying blood to the brain tissue. It also consists of paired anterior, posterior and middle cerebral arteries. Depending on the visualization of these vessels, the circle of Willis can be closed (all are visualized) and not closed (when at least one of them is not visualized).

The key goal of the Circle of Willis is compensatory activity. That is, if there is a lack of incoming blood, the circle of Willis begins to compensate for this deficiency with the help of other vessels, which ensures the uninterrupted functioning of the brain.

The appearance of a circle of Willis is not a very common occurrence and is recorded only in 35% of cases. It is often distinguished by its underdevelopment, which is not a pathology, but can lead to a more severe course of certain diseases, since its compensatory functions are not fully realized.

Narrowing of the arteries of the brain, for example, with hypoplasia or with a developing aneurysm, often occurs in the Circle of Willis.

Venous drainage

The outflow of blood from the brain is carried out through a system of superficial and cerebral veins, which subsequently flow into the venous sinuses of the solid MO. The superficial cerebral veins (superior and inferior) collect blood from the cortical part of the cerebral hemispheres and subcortical white matter. In turn, the upper ones flow into the sagittal sinus, the lower ones into the transverse sinus.

Veins located deep in the brain carry out the outflow of blood from the subcortical nuclei, cerebral ventricles, internal capsule and subsequently merge into a large cerebral vein. From the venous sinuses, blood flows out through the internal jugular and vertebral veins. Also, the emissary and diploic cranial veins, which connect the sinus with the external cranial veins, ensure proper provision of blood outflow.

The characteristic features of the cerebral veins include the absence of valves and a large number of anastomoses. The venous network is characterized by the fact that its wide sinuses provide optimal conditions for the outflow of blood and a closed cranial cavity. Venous pressure in the cranial cavity is almost identical to intracranial pressure. This is a consequence high blood pressure inside the skull with venous stagnation and impaired blood outflow from the veins with developing hypertension (neoplastic tumors, hematomas).

The system of venous sinuses includes 21 sinuses (8 paired and 5 unpaired). Their walls are formed by sheets of processes of solid MO. Also, on the cut, the sinuses form a wide lumen in the form of a triangle.

The characteristic sinus connection of the cranial base with the veins of the eyes, face and inner ear may be the cause of developing infection in the sinuses of the dura mater. In addition, when the cavernous or stony sinuses are blocked, a pathology of venous outflow through the ophthalmic veins is observed, resulting in facial and periorbital edema.

Blood supply to the spinal cord

The spinal cord is supplied with blood through the anterior, two posterior and radicular-spinal arteries. The artery localized on the anterior surface originates from two branching vertebral spinal arteries, which subsequently connect and form a single trunk. The two posterior spinal arteries, which arise from the vertebrates, run along the dorsal surface of the spinal cord.

They supply blood only to 2 or 3 upper cervical segments; in all other areas, nutrition is regulated by the radicular-spinal segments, which in turn receive blood from the vertebral and ascending cervical arteries, and below - from the intercostal and lumbar.

The spinal cord has a highly developed venous system. The veins draining the anterior and posterior parts of the spinal cord have a “watershed” approximately in the same place as the arteries. The main venous canals, which receive the blood of the veins from the substance of the spinal cord, run in a longitudinal direction similar to the arterial trunks. At the top they connect with the veins of the base of the skull, forming a continuous venous tract. The veins also have a connection with the venous plexuses of the spine, and through them with the veins of the body cavities.

Arterial pathologies

For normal functioning, the human brain spends great amount resources that are supplied during its circulation. In order to provide these resources, there are 4 paired large vessels located. Also, as we noted earlier, there is a Circle of Willis, in which most of the blood ducts are localized.

It is this element that compensates for the lack of incoming blood during the development of various types, as well as injuries. If one of the vessels does not supply enough blood, then other vessels compensate for this, to which this deficiency is redistributed.

Therefore, the abilities of the Circle of Willis make it possible to replenish the lack of blood, even with two insufficiently functioning vessels, and the person will not even notice any changes. However, even such a well-coordinated mechanism may not cope with the stress that the patient creates on his body.

Most frequent symptoms diseases associated with pathology of the arteries of the head are:

• Headache;
• Chronic fatigue;
• Dizziness.

If the diagnosis is not made in a timely manner, over time, the disease can progress, resulting in damage to brain tissue that occurs with dyscirculatory encephalopathy. This disease is characterized by insufficient blood circulation in a chronic form.

The main reasons for this pathology are atherosclerosis developing in the patient or arterial hypertension. Since these diseases are quite common, the likelihood of developing dyscirculatory encephalopathy is quite high.

Also, the development of pathology can provoke osteochondrosis. This is due to the fact that it causes deformation of the intervertebral discs, which during this pathological process can clamp the vertebral artery, and also, if the circle of Willis does not cope with its functions, the brain begins to experience a lack of necessary elements for its normal functioning. As a result, the process of death of nerve cells begins, which in turn leads to a number of neurological symptoms.

Discirculatory encephalopathy does not decrease over time, but on the contrary, its progressive nature is observed. This creates a high likelihood of developing many serious diseases, such as stroke and/or epilepsy. That is why early examinations and treatment are extremely necessary for pathology of the arterial tracts of the brain.

How to improve cerebral blood flow

It is worth immediately noting that independent use medicines is not allowed, therefore, almost any restoration of cerebral blood flow must take place with the permission of the attending physician. In order to improve cerebral circulation, the doctor may prescribe the following:

• Drugs that prevent platelet aggregation;
• Vasodilators;
• Medicines that prevent blood clotting;
• Nootropics;
• Psychostimulants.

The patient also requires mandatory adjustments to his diet. Therefore, it is recommended to take such products as:

• Plant-based oils (pumpkin, olive, flaxseed);
• Marine and oceanic fish products (trout, tuna, salmon);
• Berries (lingonberries, cranberries);
• Dark chocolate with cocoa content of at least 60%;
• Nuts, flax or sunflower seeds;
• Green tea.

Also, in order to improve blood circulation and prevent various disorders in brain activity, experts additionally advise, first of all, to avoid physical inactivity. An excellent way to do this is through physical exercise, which properly activates blood circulation throughout the body.

In addition, saunas and steam baths have a very good effect. Warming up the body improves blood circulation in the body. A number of products are also highly effective traditional medicine For example, periwinkle, propolis and a number of other mixtures are used that have a positive effect on the condition of blood vessels.

Video

Cerebral circulation is an independent functional system, with its own characteristics of morphological structure and multi-level regulatory mechanisms. In the process of phylogenesis, specific unequal conditions for blood supply to the brain were formed: direct and fast carotid (from the Greek karoo - “putting me to sleep”) blood flow and slower vertebral blood flow, provided by the vertebral arteries. The volume of circulatory deficit is determined by the degree of development of the collateral network, with the most discriminated subcortical areas and cortical fields of the cerebrum lying at the junction of the blood supply basins.

The arterial system of cerebral blood supply is formed from two main vascular territories: carotid and vertebrobasilar.

The carotid basin is formed by the carotid arteries. The common carotid artery on the right side begins at the level of the sternoclavicular joint from the brachiocephalic trunk, and on the left it departs from the aortic arch. Next, both carotid arteries go up parallel to each other. In most cases, the common carotid artery at the level of the upper edge of the thyroid cartilage (III cervical vertebra) or the hyoid bone expands, forming the carotid sinus (sinus caroticus, carotid sinus), and is divided into the external and internal carotid arteries. The external carotid artery has branches - the facial and superficial temporal arteries, which in the orbital area form an anastomosis with the system of internal carotid arteries, as well as the maxillary and occipital arteries. The internal carotid artery is the largest branch of the common carotid artery. When entering the skull through the carotid canal (canalis caroticus), the internal carotid artery makes a characteristic bend with its convexity upward, and then, passing into the cavernous sinus, it forms an S-shaped bend (siphon) with its convexity forward. The permanent branches of the internal carotid artery are the supraorbital, anterior cerebral and middle cerebral arteries, the posterior communicating and anterior villous arteries. These arteries provide blood supply to the frontal, parietal and temporal lobes and participate in the formation of the arterial circle of the cerebrum (Circle of Willis).

There are anastomoses between them - the anterior communicating artery and cortical anastomoses between the branches of the arteries on the surface of the hemispheres. The anterior communicating artery is an important collector connecting the anterior cerebral arteries, and therefore the internal carotid artery system. The anterior communicating artery is extremely variable - from aplasia (“disconnection of the circle of Willis”) to a plexiform structure. In some cases, there is no special vessel - both anterior cerebral arteries simply merge in a limited area. The anterior and middle cerebral arteries have significantly less variability (less than 30%). More often this is a doubling of the number of arteries, anterior trifurcation (joint formation of both anterior cerebral arteries and the middle cerebral artery from one internal carotid artery), hypo- or aplasia, and sometimes islet division of arterial trunks. The supraorbital artery arises from the medial side of the anterior convexity of the carotid siphon, enters the orbit through the optic nerve canal, and on the medial side of the orbit divides into its terminal branches.

Vertebro-basilar basin. Its bed is formed from two vertebral arteries and the basilar (main) artery (a. basilaris) formed as a result of their fusion, which then divides into two posterior cerebral arteries. The vertebral arteries, being branches of the subclavian arteries, are located behind the scalene and sternocleidomastoid muscles, rising to the transverse process VII cervical vertebra, go around the latter in front and enter the canal of the transverse processes formed by the openings in the transverse processes of the VI–II cervical vertebrae, then go horizontally backwards, going around back atlas, form an S-shaped bend with a convexity backward and enter the foramen magnum of the skull. The fusion of the vertebral arteries into the basilar artery occurs on the ventral surface of the medulla oblongata and the bridge above the clivus (clivus, Blumenbach clivus).

The main bed of the vertebral arteries often branches, forming paired arteries that supply blood to the trunk and cerebellum: posterior spinal artery (lower part of the trunk, nuclei of the thin and cuneate fasciculi (Gaull and Burdach)), anterior spinal artery (dorsal parts of the upper part of the spinal cord, ventral parts of the trunk , pyramids, olives), posterior inferior cerebellar artery (medulla oblongata, vermis and rope bodies of the cerebellum, lower poles of the cerebellar hemispheres). The branches of the basilar artery are the posteromedial central, short circumflex, long circumflex and posterior cerebral arteries. Paired long circumflex branches of the basilar artery: inferior anterior cerebellar artery (pons, upper parts of the medulla oblongata, area of ​​the cerebellopontine angle, cerebellar peduncles), superior cerebellar artery (midbrain, quadrigeminal tubercles, base of the cerebral peduncles, area of ​​the aqueduct), labyrinthine artery (area of ​​the cerebellopontine angle, area of ​​the inner ear).

Deviations from the typical variant of the structure of the arteries of the vertebral-basilar basin are common - in almost 50% of cases. Among them are aplasia or hypoplasia of one or both vertebral arteries, their non-fusion into the basilar artery, low connection of the vertebral arteries, the presence of transverse anastomoses between them, and asymmetry of diameter. Options for the development of the basilar artery: hypoplasia, hyperplasia, duplication, the presence of a longitudinal septum in the cavity of the basilar artery, plexiform basilar artery, insular division, shortening or lengthening of the basilar artery. For the posterior cerebral artery, aplasia, duplication when originating from the basilar artery and from the internal carotid artery, posterior trifurcation of the internal carotid artery, origin from the opposite posterior cerebral artery or internal carotid artery, and insular division are possible.

Deep subcortical formations and periventricular areas are supplied with blood by the anterior and posterior villous plexuses. The first is formed from short branches of the internal carotid artery, the latter - from short arterial trunks, perpendicularly extending from the posterior communicating arteries.

The arteries of the brain are significantly different from other arteries of the body - they are equipped with a powerful elastic membrane, and the muscle layer is developed heterogeneously - at the sites of vessel division, sphincter-like formations are naturally found, which are richly innervated and play an important role in the processes of regulating blood flow. As the diameter of the vessels decreases, the muscle layer gradually disappears, again giving way to elastic elements. The cerebral arteries are surrounded by nerve fibers coming from the superior, intermediate (or stellate) cervical sympathetic ganglia, branches from the C1-C7 nerves, which form plexuses in the medial and adventitial layers of the arterial walls.

The venous system of the brain is formed from the superficial, deep, internal cerebral veins, venous sinuses, emissary and diploic veins.

Venous sinuses are formed by splitting the dura mater, which has an endothelial lining. The most constant are the superior sagittal sinus, located along the upper edge of the falx cerebri; the inferior sagittal sinus, located in the lower edge of the falx cerebri; direct sine – continuation of the previous one; the straight and superior flow into the paired transverse sinuses on the inner surface occipital bone which continue into the sigmoid, ending at the jugular foramen and giving blood to the internal jugular veins. On both sides of the sella turcica there are paired cavernous sinuses, which communicate with each other through the intercavernous sinuses, and with the sigmoid sinuses through the petrosal sinuses.

The sinuses receive blood from the cerebral veins. The superficial superior veins from the frontal, parietal, and occipital lobes bring blood to the superior sagittal sinus. The superficial middle cerebral veins flow into the superior petrosal and cavernous sinuses, which lie in the lateral sulci of the hemispheres and carry blood from the parietal, occipital and temporal lobes. Blood enters the transverse sinus from the inferior cerebral veins. The deep cerebral veins collect blood from the choroid plexuses of the lateral and third ventricles of the brain, from the subcortical regions, the corpus callosum and flow into the internal cerebral veins behind pineal gland, and then merge into the unpaired large cerebral vein. The straight sinus receives blood from the great cerebral vein.

The cavernous sinus receives blood from the superior and inferior ophthalmic veins, which anastomose in the periorbital space with tributaries of the facial vein and the pterygoid venous plexus. The labyrinthine veins carry blood to the inferior petrosal sinus.

Emissary veins (parietal, mastoid, condylar) and diploic veins have valves and are involved in providing transcranial blood outflow with increased intracranial pressure.

Syndromes of damage to the arteries and veins of the brain. Damage to individual arteries and veins does not always lead to pronounced neurological manifestations. It has been noted that for the occurrence of hemodynamic disorders, a narrowing of the large arterial trunk by more than 50% or multiple narrowing of the arteries within one or several basins is necessary. However, thrombosis or occlusion of some arteries and veins have distinct specific symptoms.

Disruption of blood flow in the anterior cerebral artery causes motor disorders of the central type contralaterally on the face and limbs (most pronounced in the leg and shallow in the arm), motor aphasia (with damage to the left anterior cerebral artery in right-handed people), gait disturbance, grasping phenomena, elements of “ frontal behavior."

Disruption of blood flow in the middle cerebral artery causes contralateral central paralysis, predominantly of the “brachiofacial” type, when motor disturbances are more severely expressed in the face and hand, and sensory disorders develop - contralateral hemihypesthesia. In right-handed people, when the left middle cerebral artery is damaged, mixed aphasia, apraxia, and agnosia occur.

When the trunk of the internal carotid artery is damaged, the above disorders manifest themselves more clearly and are combined with contralateral hemianopia, disturbances of memory, attention, emotions, and motor disorders, in addition to the pyramidal nature, can acquire extrapyramidal features.

Pathology in the posterior cerebral artery basin is associated with loss of visual fields (partial or complete hemianopia) and, to a lesser extent, with disorders of the motor and sensory spheres.

The most total disturbances are caused by occlusion of the lumen of the basilar artery, manifested by Filimonov's syndrome - the “locked man”. In this case, only the movements of the eyeballs are preserved.

Thrombosis and occlusion of the branches of the basilar and vertebral arteries are manifested, as a rule, by alternating stem syndromes of Wallenberg - Zakharchenko or Babinsky - Nageotte with damage to the posterior inferior cerebellar artery; Dezherina - for thrombosis of the medial branches of the basilar artery; Millard - Gubler, Brissot - Sicard, Fauville - long and short circumflex branches of the basilar artery; Jackson - anterior spinal artery; Benedict, Weber - posterior cerebral artery, posterior villous artery and interpeduncular branches of the basilar artery.

Manifestations of thrombosis of the cerebral venous system, with rare exceptions, do not have a clear topical relationship. If the venous outflow is blocked, then the capillaries and venules of the affected drainage zone swell, which leads to the occurrence of congestive hemorrhages, and then large hematomas in the white or gray matter. Clinical manifestations include general cerebral symptoms, focal or generalized seizures, papilledema, and focal symptoms indicating damage to the cerebral hemispheres, cerebellum, or compression of the cranial nerves and brain stem. Thrombosis of the cavernous sinus can manifest itself as damage to the oculomotor, abducens and trochlear nerves (outer wall of the cavernous sinus syndrome, Foix syndrome). The appearance of a carotid-cavernous anastomosis is accompanied by pulsating exophthalmos. Lesions of other sinuses are less obvious.