Arterial aneurysms of the brain are one of the common causes of life-threatening, often fatal intracranial hemorrhages. Artery cial aneurysms are limited or diffuse enlargement of the lumen of the artery or protrusion its wall.
The most common types of aneurysms are:
- so-called saccular aneurysms, having the appearance of a small thin-walled bag, in which you can distinguish the bottom, middle part (body) and neck;
- the rarer forms are spherical,
- fusioform (spindle-shaped) or S-shaped.
The wall of the aneurysm, as a rule, is a plate of scar connective tissue of various thicknesses. The cavity Aneva ism may be blood clots various limitations.
Localization of aneurysms.
The most frequent localization of arterial aneurysms – arte Rhee base of the brain usually in the places of their division and anastomosis . Especially often, aneurysms are localized on the anterior connecting artery, near the discharge of the posterior connecting artery or in the area of the branches of the middle cerebral artery. In 80-85% of cases, aneurysms are located in the system of internal carotid arteries, in 15% – in the system of vertebrates and main arteries.
Causes.
The cause of the formation of arterial aneurysms is established only in a small number of patients. About 4-5% Global Developing aneurysms are due to hit in an artery of the brain of infected emboli . These are the so-called mycotic aneurysms. Atherosclerosis plays an undeniable role in the origin of large spherical and S-shaped aneurysms . The occurrence of saccular aneurysms is associated with congenital inferiority of the arterial system of the brain. Atherosclerosis and hypertension, as well as trauma , play a significant role .
Aneurysms can be:
- single or
- set -governmental.
The clinical picture.
There are two forms Clinically Skog manifestations of arterial aneurysms – apoplectic and OPU – holepodobnuyu . The most common form is the apoplexy With the sudden development of subarachnoid hemorrhage, usually without precursors. Sometimes patients before hemorrhage are concerned about limited pain in the fronto-orbital region, paresis of cranial nerves is observed.
The first and main symptom of aneurysm rupture is a sudden sharp headache. At first, it can have a local character in accordance with the localization of the aneurysm, then it becomes diffuse. Almost simultaneously with the headache occur sick one repeated vomiting, loss of consciousness of varying duration STI. Meningeal syndrome is developing rapidly! sometimes the Supervisory are epileptiform seizures. Often there are mental disorders – from a little confusion and disorientation to severe psychoses. In the acute period – rise in temperature, change in the blood (leukocytosis and moderate shear leukocyte odds mules left) in the cerebrospinal fluid – Blood admixture.
With a rupture of basal aneurysms, cranial nerves are affected, most often oculomotor. With the rupture of the aneurysm, hemorrhage into the substance of the brain ( subarachnoid- parenchymal hemorrhage) can occur, in addition to subarachnoid . Kleene Cesky picture in such cases is supplemented with symptoms of focal brain lesions, which are sometimes difficult to identify due to the severity of brain symptoms.
In the case of blood breakthrough in the ventricles of the brain ( subarachnoid – parenchymal-ventricular hemorrhage) disease Prote repents very hard and rapidly results in death.
Symptoms of brain damage due to rupture of the aneurysm is caused vayutsya not only bleeding in the brain, but also the brain ischemia fuss arising as a result characteristic of subarachnoid hemorrhage ence prolonged spasm of the arteries as the near exploding anevriz we, and at a distance. Revealed by this local nevrologiche skie symptoms often provide substantial assistance in the installed SRI aneurysm localization. More rare complication – the development of normotensive hydrocephalus due to blockade of the blood streamed basal parts of the brain membranes, carrying rezor btsiyu cerebrospinal fluid.
In some cases, arterial aneurysm, slowly withdrawn chivayas cause brain damage and contribute to the emergence of symptoms characteristic of benign tumors of the basal parts of the brain. Symptomatology them varies depending on the localization tion. The most common tumor of the aneurysm with over localize are in the cavernous sinus and chiasmal area.
Aneurysms of the internal carotid artery are divided into track guides groups:
- aneurysms in the cavernous sinus ( infraclinoid – located below the wedge-shaped processes of the Turkish saddle),
- Aneva ism supraclinoid part of the artery,
- near bifurcation aneurysm tion carotid artery
Aneurysms within the cavernous sinus .
Depending on the different localization are three cavernous sinus syndrome sa
- rear, which is characterized by loss of all branches of the triple -border nerve in conjunction with eye movement disorders;
- average – the defeat of I and II branches of the trigeminal nerve and glazodviga -inflammatory disorders; Front – pain and sensory disturbances STI in the innervation zone I branch of the trigeminal nerve and paralysis III, IV and VI nerves.
Large and long-existing aneurysm of the carotid arte Rhee in the cavernous sinus can cause destructive changes of the skull bones, visible on radiographs. With the rupture of aneurysms in the cavernous sinus, there is no hemorrhage in the cranial cavity due to their extradural location.
Aneurysms of the supraclinoid part of the internal carotid artery .
They are disposed near the discharge of the posterior communicating arteries and are characterized, in addition to all of typical symptoms aneurysms subarachnoid hemorrhage, selective lesions SFA zodvigatelnogo nerve in combination with local pain orbitofrontal.
Aneurysms of the carotid bifurcation often cause Naru sheniya of view due to their location in the outer corner of the chiasm.
Aneurysm of the anterior cerebral artery characterized violated niyami psyche, paresis feet, hemiparesis with extrapyramidal change of tone in his hand, due to spasm of the forebrain O arteries and their branches.
Aneurysms of the middle cerebral artery at break causing dissolved develop paresis of extremities opposite, speech disrupt Nij, less sensitivity disorders.
Aneurysms vertebrobasilar system usually present with symptoms of lesion formations posterior fossa (Dizar Tria, dysphagia, nystagmus, ataxia, paresis V and VII nerves, alternating conductive syndromes).
Multiple aneurysms account for about 15% of all Aneva ism. Features of the clinical course are determined by the localization of the aneurysm from which the hemorrhage occurred.
Arteriovenous aneurysm (arteriovenous angiomas, vascular stye malformation or malformations) may also be prichi hydrochloric intracranial hemorrhage. This vascular coils varies a size formed by random weave tortuous and dilated veins and arteries. Their size ranges from a few millimeters to gigantic formations that occupy most of the cerebral hemisphere. Most often they are localized in the fronto-parietal departments.
Arteriovenous aneurysms are a congenital anomaly of cerebral vessels. A characteristic feature of the structure of these Aneva ism – their lack of capillaries, leading to direct shuntirova NIJ arterial and venous blood. Arteriovenous aneurysm distract “the” significant part of the blood, as, Obra such Zom, “parasites brain circulation”.
The main clinical symptoms of arteriovenous aneurysms are intracerebral hemorrhages and epileptiform seizures.
Diagnostics.
Diagnosis of both arterial and arteriovenous aneurysms presents certain difficulties. When recognizing them, anamnestic indications of transferred subarachnoid hemorrhages, transient hemianopsia, ophthalmoplegic migraine, and epileptic seizures are taken into account. Craniography is of great importance, revealing the characteristic thin ring-shaped shadows that have the appearance of petrified aneurysms in the pictures .
Nekoto rye large aneurysm can cause the destruction of the bones of the skull base. EEG is of particular importance.
The final diagnosis of cerebral artery aneurysm, the determination of its location, size and shape are possible only with the help of angiography, which is performed even in the acute period of a stroke. In some cases, computed tomography of the head with contrast enhancement is informative.