Middle cerebral artery: structure, possible pathologies, diagnosis and treatment

The largest vessel that provides blood supply to the human brain is the middle cerebral artery, which transports oxygen with nutrients to most areas of this important organ. Next, we will get acquainted with its structure and possible pathologies that occur when its functioning fails. In addition, we learn how to diagnose and study the work of such an important brain element as the middle artery.

Structure

The middle cerebral artery is the largest of the branches of the internal carotid artery and its direct continuation. It is included in the depth of the lateral groove of the brain and first goes outside, and then up and slightly posteriorly, going to the upper lateral part of the hemisphere. In the direction of its course, it is divided topographically into several parts:

• On the wedge-shaped part - from the site of its beginning to lowering into the lateral groove.
• To the islet part, which goes around the islet and runs in the very depths of the lateral groove.
• On the final part, which leaves the lateral sulcus to the region of the upper lateral surface of the hemisphere.

The wedge-shaped part of the artery is the shortest. After its descent into the lateral sulcus, its distal border is considered the area of ​​discharge of the frontal basal artery. The central anterolateral arteries depart from the wedge-shaped area, which penetrate through the perforated substance, then they are divided into lateral and medial branches, heading upward. Lateral branches supply the outer part of the lenticular nucleus along with the posterior capsule. The medial branches, in turn, approach the internal parts of the pale ball, and in addition, the body of the caudate nucleus.

Middle cerebral artery of the fetus

The main vessels that provide blood to the body of a growing fetus are the uterine and ovarian arteries. Branching into smaller vessels in the direction of the inner layer of the uterus, they are transformed into spiral arteries that carry blood to the intervillous space - this is the place where the mother and baby exchange blood.

What are the parameters in the norm of the middle cerebral artery of the fetus? This is a common question.

The study of blood flow in it is of an applied nature. To determine the indicators of the middle cerebral artery of the fetus, the CDC is used with subsequent Doppler measurements. Normally, in the second and third trimesters of pregnancy, there is a gradual decrease in the vascular resistance index and an increase in the average blood flow velocity.

With fetal hypoxia, centralization of blood circulation is observed, which leads to an increase in speed indicators in the cerebral arteries and, accordingly, a decrease in the resistance index. With its increase, we can talk about intracerebral hemorrhages.

Dopplerometric norms in the middle cerebral artery of the fetus depend on the gestational age. They are listed in the table below.

Vessel separation

The middle cerebral artery is divided into separate branches:

• On the deep branches that go directly from the very beginning of the vessel, providing blood supply to a large proportion of the subcortical areas and a significant portion of the inner capsule.
• But cortical and subcortical. All vascular significant branches that are responsible for the normal blood supply to a larger area of ​​the brain are included in their composition.

The resulting ischemic stroke in the basin of the middle cerebral artery immediately affects the facial expression and the person’s ability to move normally. An artery blockage that has occurred directly affects a person's ability to freely move his upper limbs. Next, we consider the possible pathologies that arise with a violation of the blood flow of the middle cerebral artery.

Possible pathologies

A large part of the brain is supplied with blood by the largest cerebral artery, and very often it happens that various pathologies arise in its pool that cause oxygen depletion of brain tissues in the diet.

Normally, in the middle cerebral artery, blood flow is not impaired.

The most common diseases that affect the internal vascular walls include:

• The appearance of atherosclerotic changes associated with the formation of fatty and cholesterol plaques in the lumen of the arteries.
• The emergence of a different type of embolism.
• The appearance of disorders in the structures of the arteries that lead to aneurysm.
• The development of thrombosis.

Occlusive changes in the carotid arteries can cause the onset of cerebral infarction in the absence of a pronounced painful change in other vessels. But in most situations, cerebral infarction occurs against the backdrop of a combination of diseases, which damage the middle and carotid cerebral artery and its pool.

The appearance of occlusive processes in the artery trunk along with their scale, level and location, as well as the ability to maintain a collateral type of blood supply, paint an overall clinical picture. Moreover, in situations of pathology occurrence above the area of ​​branching of large vessels, a total form of damage to the entire basin of the middle cerebral artery is noted. The pathology located above the branches can affect certain areas of the subcortical part and the site of white matter.

Cerebral infarction and the left branch of the cerebral artery

The following departments are affected by total cerebral infarction:

• The posterior region of the frontal lobe.
• The vast majority of the front and rear convolutions.
• A significant area in the parietal and temporal part.
• The inner capsule along with the semi-oval area.

Damage to the posterior areas of the basin of the right or left middle cerebral arteries is likely only in the presence of a combined disease of the middle artery and its posterior branch. Total heart attack leads to the following disorders in the human body:

• The development of hemiplegia. In this case, patients lose control of their conscious movements of different limbs.
• The occurrence of hemianesthesia. Against this background, the patient may cease to feel certain pain in a particular half of the body.
• The development of hemianopsia. At the same time, there is an absolute impossibility to visually distinguish individual objects in the field of vision.

The resulting stroke within the pool of the left branch of the artery of the brain leads to a serious violation of speech and anosognosia. The patient ceases to really assess the severity of his illness, which often makes it difficult to provide follow-up care.

Ischemic stroke in the basin area of ​​the right middle cerebral artery

Most strokes usually develop in the middle artery basin area. They are characterized by homonymous hemianopsia, which indicates lesions of visual radiance. Eyeballs with a stroke are turned towards the affected hemisphere. Weakness of the facial muscles of the lower region of the face may be noted. In addition, the patient has spastic hemiparesis (while the person’s hands suffer more than his legs). Muscle tone in a paralyzed limb may initially decline, but after a few days spasticity occurs.

What are the other signs of a stroke in the middle cerebral artery basin?

Sometimes a sensitive and motor impairment is limited to contralateral movements of the arm and half of the face, and legs with a torso hardly suffer. In case of damage to the dominant hemisphere, the onset of motor and sensory aphasia is possible. In ischemic stroke of the middle cerebral artery against the background of damage to the parietal lobe of the non-dominant center, a complex violation of sensitivity occurs along with a disturbance in perception. Defeat in the right hemisphere is often accompanied by confusion, and the left by the onset of depression in the later stages of the disease.

Swelling of the brain can cause narrowing and occlusion of one or both of the middle cerebral arteries during a stroke. The consequence of all this is cortical blindness and hemianopsia. With the development of occlusion of the cervical region of the internal carotid artery, blood enters the region of the anterior cerebral artery through the connecting anterior branch from the opposite side. Due to this, a stroke is prevented in the medial surface of the hemisphere and in the frontal lobe. Blood in the region of the posterior cerebral artery comes from the region of the vertebrobasilar system. In this regard, in the presence of occlusion of the carotid internal artery, stroke, as a rule, develops within the basin of the middle cerebral branch.

Possible pathologies: atherosclerosis

Being the largest, this cerebral artery is at risk of pathological atherosclerotic changes. Particularly dangerous is the stenotic syndrome, against which the lumen of the artery can be completely blocked. An anesthetic course of the disease leads to the growth of cholesterol growths along the length, helping to reduce the amount of blood transported to certain areas of the brain.

The growth of lipoid formations on the walls of this artery occurs over a fairly long period. In the vast majority of situations, years pass until the sizes of the plaques become critical and block the normal nutrition of brain regions. At the initial stage of atherosclerosis, plaques can only be found with the use of special diagnostic equipment, and given the fact that patients do not always have pronounced symptoms of the disease, their presence remains hidden for a long time.

The initial stages of atherosclerosis, which affect the large arteries of the brain, are characterized by a slight deterioration in the general well-being of the patient. But in the course of an increase in lipoid deposits, the clinical picture is more pronounced, and against this background, the general symptomatology of the pathology intensifies. A person feels discomfort with a sharp movement of the head, and in addition, with increased loads. Sudden dizziness appears, especially with a sudden decrease in blood pressure.

At this stage, it is extremely important to immediately contact a doctor. Proper diagnosis in combination with the prescribed treatment method will certainly help to avoid the consequences of a stroke in different cerebral hemispheres or a heart attack that affects the entire area of ​​the middle cerebral artery basin along with its collateral network.

In most situations, the initial stages of atherosclerosis are successfully treated with medications that improve the general blood flow in the brain. In addition to prescribing drugs, doctors provide advice on coordinating the patient’s lifestyle with the maximum exception of factors that provoke the number of sclerotic growths. In advanced situations, effective care for the patient is possible only in the hospital surgical departments.

Aneurysms

Any aneurysms of such a site as the middle cerebral artery are a direct consequence of the disease of its walls, in which the norms of the tissue structure are violated. The artery in this case is no longer a triple layer of tissue from the muscles and membranes. Aneurysm includes only one layer of connective tissue, which is not capable of ensuring the full functioning of the artery. When a violation occurs in the structure of the vessel, a protrusion of its walls appears, in which they often rupture with the formation of hemorrhage in the adjacent tissue.

The most dangerous is the ingress of blood into the area of ​​the arachnoid brain space, in which the most serious consequences can occur for patients. The increased risk category includes the male part of the middle-aged population - those who have a hereditary predisposition to the occurrence of structural vascular disorders.

The left and right middle cerebral arteries with aneurysm of the walls are affected in 25% of the total number of blood flow pathologies. In most situations, dilatations along with ruptures of arteries occur in places of bends, in which weakened walls receive excessive dynamic pressure. Symptoms of rupture of cerebral artery aneurysm develop very rapidly, characterized by the presence of such signs:

• Patients complain of the appearance of sudden and severe pain in the head, which is the result of excessive stress, a surge in pressure or severe stress.
• The occurrence of partial aphasia against the background of damage to the left hemisphere of the brain, while paralysis of the upper extremities occurs.
• Convulsive seizures are not excluded, against the background of which the hands can take an unnatural position (in this case we are talking about thalamic arm syndrome).
• Vascular spasms lead to increased headaches, which may be accompanied by nausea and vomiting. At the same time, the pain syndrome can acquire burning sensations.

In twenty percent of cases in patients with rupture of cerebral artery aneurysm, an atypical development of the clinical picture is noted. As a result of all this, the doctor sometimes makes a mistake in making a diagnosis and the patient is placed in a non-core department, so they are late for emergency care regarding him. In this regard, the percentage of patients with disabilities and fatal outcomes with improper treatment is quite high.

Diagnostics

Timely to determine the occurrence of various pathologies of the artery that feeds the brain, the study of its condition within the framework of a specialized medical center will help. Having felt regular changes in well-being, which is expressed by headaches or dizziness, numbness of certain areas of the limbs, or a decrease in the ability to remember elementary things, spasms of certain muscle groups and speech problems, the patient must definitely go to an appointment with a neurologist. The doctor will hear all the patient’s complaints, and he will be prescribed a comprehensive examination of the vessels that feed the brain. For this purpose, various modern techniques can be applied:

• Magnetic resonance imaging allows you to detect atherosclerotic changes on the walls of blood vessels.
• Dopplerometry makes it possible to assess the intensity of blood flow in the artery. Using this type of research, it is possible to study the state of the vessels in the patient.
• Performing radiography. With the help of this examination, the walls of arteries are analyzed, and in addition, acute atherosclerosis is detected along with arterial aneurysms. X-ray images provide an opportunity to receive information about the state of cerebral region of the middle cerebral artery.

Contrast radiography makes it possible to assess the extent of the affected area of ​​the vessel. Thanks to him, the left median cerebral artery is examined, as well as the right one, and in addition, the state of its branches is assessed.

Treatment and support

Timely detection of pathologies of this artery will help in the future to avoid the serious consequences of its diseases. You should not treat changes in your well-being without attention. The fact is that the recurring symptoms of insufficient blood supply to the brain in the form of vasospasm or deterioration of peripheral vision require the immediate assistance of a specialist.

Most pathological processes in the arteries of the brain can be avoided provided that some recommendations are followed. Indeed, a significant proportion of pathologies is a consequence of factors that a person regularly encounters. Their complete exclusion from life helps to avoid the occurrence and development of many vascular diseases. To support the arteries of the brain in a healthy state, a person needs:

• To diversify everyday life with feasible physical activity.
• Ensure no overload by excessive work. You must try to relax properly.
• Quitting smoking and drinking alcohol.
• Monitor your own weight, normalize nutrition.
• Consume plant foods. At the same time, they reduce the consumption of fatty meat dishes.
• In case of detection of sclerotic pathologies in the artery, it is required to carefully observe all the recommendations of a specialist.
  

It is also important to remember that the violation of speed in the middle cerebral artery of blood movement (blood flow) is least likely to be a consequence of past illnesses. In addition, problems with the vessels of the brain are not transmitted to people by inheritance. In most situations, a developing stroke with a heart attack of certain parts of the brain arises as a result of an improper lifestyle, which in modern people is filled with excessive stressful shocks and a frantic rhythm.