Aneurysm of cerebral vessels: symptoms, treatment

Not all changes in the central nervous system can be diagnosed at an early stage. Dangerous and often remaining without due attention pathology is an aneurysm of cerebral vessels. This is the name for a blood-filled protrusion of a portion of the vascular wall. Aneurysm rupture is a life threatening condition, but it can also lead to a variety of disorders during the growth period.

Classification of aneurysms

True aneurysms of cerebral vessels are most often of arterial origin. In form they are saccular (sack-shaped), spindle-shaped and lateral. This depends on the cause and mechanism of the formation of a vascular wall defect. Aneurysms can be mono- and multi-chambered, single and multiple, congenital and acquired

There are also pseudoaneurysms, they are usually post traumatic (including postoperative). In this case, a closed cavity filled with blood forms near the penetrating damage to the vessel. It is limited not by protruding arterial walls, but by neighboring compaction and scarring tissues.

There is also a special type of anomaly of the vascular wall - an aneurysm of the vein of Galen. This is not a single protrusion, but a conglomerate of abnormal vessels located in the subarachnoid space of the brain near the visual hillocks. This pathology is inherent in nature and is due to the presence of multiple malformations.

Aneurysms of intracranial vessels are most often located on the basis of the brain. But it is possible and the defeat of smaller arteries on the surface of the cerebral hemispheres or in the thickness of the brain tissue. Isolate aneurysms of the internal carotid artery, the middle cerebral, anterior cerebral and connective arteries, vessels of the vertebrobasilar basin (Willis circle). In some cases, there are symmetrical defects.

Causes of aneurysms

Defect of the vascular wall with the appearance of protrusion can be congenital, although such an aneurysm can be diagnosed only in adolescence or even in adulthood. This often reveals the malformation - a violation of the development of the circulatory system with an irregularly formed area of ​​the transition of arterioles to venules. If there is a pathology of connective tissue, cerebral aneurysms are often combined with congenital heart defects and major vessels, polycystic kidney disease, systemic diseases. Therefore, the presence of multiple congenital pathologies requires special caution in regard to vascular anomalies.

An aneurysm of the artery wall is also acquired. In this case, it appears during life due to the influence of various factors. These include:

• hypertensive disease, especially with an uncontrolled crisis current;
• atherosclerotic vascular lesion with the development of exfoliating plaques and subsequent thinning of artery walls;
• external compression of blood vessels by various tumors;
• thrombosis and thromboembolism of the arteries, accompanied by an expansion of the site of the vessel before the thrombus;
• brain trauma;
• exposure to radiation, changing the structure and elasticity of tissues;
• a variety of infections with damage to the brain, its membranes and vessels.

Predicting the occurrence of cerebral aneurysms is chronic intoxication: smoking and drug use (especially cocaine).

How aneurysms form

At the initial stages of the formation of an aneurysm in the walls of the vessels, foci of necrosis, fatty degeneration, reduction of the number of elastic fibers or their deformation, displacement and rupture of fibers of the muscle layer. The inner membrane (endothelium) can be rough, inhomogeneous, with areas of atheromatosis, calcification, or ulceration.

All this leads to a decrease in the elasticity and strength of the vessel. As a result, even a normal jerky movement of blood in the arteries can lead to a gradual stretching of their walls in the area of ​​the defect. In this case, there is an almost uniform local expansion of the lumen of the vessel on a certain segment, most often in the area before the thrombus, atherosclerotic plaque or branching of the arteries. This forms a diffuse (spindle-shaped) aneurysm. The structure of the arterial wall in this region is preserved, but there is a pronounced thinning of all its layers and a significant decrease in the ability of muscle fibers to be reduced concentrically.

The dissecting aneurysm has a different developmental mechanism. At the same time, the key points are a violation of the integrity of the endothelium and a tendency to increase blood pressure. As a damaging factor, a disruptive atherosclerotic plaque, microorganisms and their toxins, autoimmune antibodies can act. There are also exfoliating aneurysms of syphilitic origin. Elevated blood pressure promotes the penetration of blood under the damaged endothelium with further separation of tissues. In this case, a hematoma is formed inside the vascular wall, which in time can increase and break out beyond the limits of the vessel or into the lumen of the same artery.

Sacral aneurysms appear at the site of a local vessel defect. Under pressure of blood in the region of breakthrough or lysis of the elastic inner membrane in this region, a gradually growing rounded formation with overstretched and thinned walls is formed.

Sometimes on the vessels of the brain mushroom aneurysms of infectious origin are formed. In this case, damage to the arterial wall by colonies of bacteria and fungi leads to inflammatory infiltration of the vascular wall. Later in these areas, scarring, hyalinization and calcification of tissues occur. Arteries are deformed, and in the area of ​​post-inflammatory defects appear expanding round protrusions on a narrow stalk. They resemble a berry hanging on a vessel, a mushroom or a drop.

Symptoms caused by an aneurysm of the brain

In such patients, the headache can be combined with oculomotor disorders.

Often a person does not suspect about having an intracranial aneurysm before the moment of a vascular catastrophe. Approximately a quarter of patients have small arterial wall formation and do not lead to compression of the nerve structures. It also happens that the symptoms appearing in the aneurysm are not given due attention, they are interpreted as signs of hypertension, atherosclerosis and other diseases. As a result, a person does not pass the required examination.

The appearance of neurological symptoms is associated with the compression of the aneurysm of various neural formations: cranial nerves, areas of the brain, nearby vessels. The most frequent complaint of people with abnormalities of intracranial vessels is headache (cephalgia). It can have different character, localization and intensity. There are migraine-like pains with the seizure of half of the head, pain in the back of the neck, neck or eyeball. The localization of unpleasant sensations depends on the location of the aneurysm. If there is a disturbance of the liquor flow, the hydrocephalic syndrome may develop as a result of an increase in intracranial pressure, accompanied by a diffuse headache with a feeling of pressure on the eyeballs and nausea.

Cephalgia can be combined with signs of compression (compression) of certain cranial nerves or brain areas:

• double vision (diplopia) in the horizontal plane with a violation of the ocular discharge to the outside when the nerve is removed by an aneurysm in the cavernous sinus;
• oculomotor disorders, combined with ptosis, one-sided narrowing of the pupil and a decrease in its response to light arise when the oculomotor nerve with a large aneurysm in the area of ​​the inner carotid and anterior connective arteries, or an aneurysm of the upper choroid artery;
• loss of visual fields caused by compression of the optic nerve or external part of the chiasma with a supraclinic aneurysm of the internal carotid artery or an aneurysm in the bifurcation area of ​​this vessel;
• peripheral paresis of the facial nerve (with lower eyelid lowering, tear production disturbance and expressed facial asymmetry) due to pressure of the aneurysm of the main artery;
• unilateral facial pains with loss of sensitivity when the trigeminal nerve is squeezed by an aneurysm located within the cavernous sinus;
• hemiparesis or hemiplegia with a one-sided pyramidal symptomatology, a sensitivity disorder and a decreased ability arbitrary movements with intracerebral hematoma or syndrome of culling the motor cortex;
• bulbar syndrome with the location of an aneurysm in the posterior cranial fossa;
• various forms of aphasia (speech disorders) and other violations of cortical functions;
• emotional lability, emotional-volitional disorders with a decrease in control of drives or apathy, a mnestic decrease, pseudobulbar syndrome with the defeat of the frontal lobes and the hypothalamus with aneurysms of the anterior cerebral or anterior connective artery, including intracerebral localization.

In some cases, a hallucinatory or convulsive syndrome develops as a result of local irritation of the nervous tissue with an aneurysm.

Than an aneurysm is dangerous

The presence of any aneurysm is associated with a high risk of intracranial bleeding. The rupture of the vascular wall is one of the causes of hemorrhagic stroke and subarachnoid hemorrhage. The clinical picture in this case depends not on the type of aneurysm, but on its location, the volume of blood loss, the involvement of brain tissue and brain envelopes.

At the time of rupture of an aneurysm, a severe headache of high intensity and vomiting without relief usually occur. Possible loss of consciousness. In the following, the level of consciousness is restored or the brain coma develops. Hemorrhage in the subarachnoid space leads to irritation of the meninges, which is manifested by meningeal syndrome. Also there is a reflex spasm of all the vessels of the brain, leading to total ischemia and swelling of the nervous tissue.

The rupture of an aneurysm is often accompanied by focal neurological symptoms. This may be due to the death of neurons in the area of ​​intracerebral hematoma, the effect of a large clot of blood in a massive subarachnoid hemorrhage or developing ischemia due to a shortage of blood flow in the basin of the breakthrough artery. The hemorrhagic period after aneurysm rupture lasts up to 5 weeks, at this stage, the neurological deficit may increase and new symptoms may attach. This is due to a total spasm of arterial arteries, ischemia or the development of complications. Especially dangerous are the breakthrough of blood from the intracerebral hematoma into the ventricles of the brain and the penetration of the swollen nerve tissue into the large occipital foramen or under the nerve of the cerebellum.

Prolonged compression of the aneurysm of the frontal lobes can cause cerebral atrophy in this area. This will lead to an increasing cognitive decline, marked violations of behavior and personal changes. A compression of the aneurysm of the optic nerve will lead to a progressive reduction in vision, which is not amenable to correction.

Diagnosis and treatment

Aneurysms can be detected with angiography with contrast, CT, MRI (with or without angioprogram), transcranial ultrasound. If there is a suspicion of an aneurysm rupture, a contrast agent is not used in the preliminary examination, angiography is performed just before the beginning of the operation. To confirm subarachnoid hemorrhage, indicative spinal puncture with the analysis of cerebrospinal fluid.

If an unexploded aneurysm is detected, operative treatment is performed whenever possible to prevent its spontaneous perforation. The final decision is made by the patient, assessing risks and prospects. A neurosurgeon can use several techniques:

• cupping (excluding an aneurysm from the blood stream with preservation of the vessel), most often clipping of the aneurysm cervix;
• trapping (removal of an aneurysm with the site of the vessel), permissible in the presence of sufficiently developed collaterals in the brain;
• endovascular aneurysm removal, a microsurgical method that does not require transcranial access and allows for the removal of formations even in the depth of the brain tissue.

When forming intracranial hematomas are guided by the patient's condition and the dynamics of neurological disorders. In some cases, expectant management is used, providing sufficient cerebral perfusion pressure, correcting indicators of arterial pressure, electrolyte balance and oxygenation of blood. It is important to eliminate cerebral edema as soon as possible. The operation is performed when the symptoms increase.

To reduce the risk of aneurysm rupture, it is necessary to maintain a stable level of blood pressure, adjust endocrine disorders, avoid the use of alcohol and drugs, neuro-emotional shocks.

TV channel TVC, the program "Doctor I" on the theme "Aneurysm of cerebral vessels":