Vascular lesions of the brain: causes, symptoms, diagnosis, treatment

Among the vascular malformations of the cerebral arteries, arteriovenous malformations and aneurysms are more common than others.

Arteriovenous malformations (AVM)

Arteriovenous malformations are an interweaving of dilated blood vessels in which the arteries directly flow into the veins. Arteriovenous malformations are more often found at the site of branching of the cerebral arteries, usually within the parenchyma of the brain of the fronto-parietal region, the frontal lobe, the lateral part of the cerebellum or in the vessels of the occipital lobe. Arteriovenous malformations can bleed or directly squeeze the brain tissue, leading to the onset of convulsive syndrome or the development of ischemia. Arteriovenous malformation can be an accidental finding in CT or MPT; KT with contrast enhancement or without reveals arteriovenous malformations larger than 1 cm in diameter. Arteriovenous malformations should be suspected if the patient complains of a sensation of noise in the head. To confirm the diagnosis and assess the operability of arteriovenous malformations, angiography is necessary.

Obliteration of superficial arteriovenous malformations is possible with the use of combined interventions with the use of microsurgery, radiosurgery and endovascular correction. To correct deep and large arteriovenous malformations, but not more than 3 cm in diameter, stereotactic radiosurgery, endovascular methods of treatment (for example, pre-resection embolization or thrombotization through an intra-arterial catheter) or coagulation with a focused proton beam are used.

[1], [2]

Aneurysms

Aneurysms are focal extensions of the arteries. The incidence of aneurysms in the population is approximately 5%. The most common causes of aneurysms are arteriosclerosis, arterial hypertension and hereditary connective tissue diseases (in particular, Ehlers-Danlo syndrome, elastic pseudocanthoma, autosomal dominant polycystic kidney disease). Sometimes septic emboli induce the development of mycotic aneurysms. Cerebral aneurysms usually do not exceed 2.5 cm in diameter, saccular (not spindle-shaped) in shape, sometimes with small multiple protrusions with a thin wall (clusters aneurysm). Most aneurysms are aneurysms of the middle or anterior cerebral arteries or connective branches of the vilious circle, especially in areas of arterial bifurcation. Mycotic aneurysms usually develop distal to the first divergence of arterial branches of the vilizian circle. Many aneurysms are asymptomatic, but in some cases symptoms are noted due to compression of adjacent structures. Oculomotor paralysis, diplopia, strabismus and pain in the orbit can indicate the compression of III, IV, V or VI pairs of cranial nerves. The loss of vision and the bi-temporal defect of the visual fields may indicate the compression of the optic nerve intersection. The entry of blood from the aneurysms into the subarachnoid space causes the symptoms of subarachnoid hemorrhage. Aneurysms do not necessarily provoke a headache before the rupture, however, the preceding rupture of microhemorrhagia may well be a source of headache. Aneurysms are often incidental findings when performing CT or MRI. To verify the diagnosis, angiography or magnetic resonance angiography is necessary. If the size of asymptomatic aneurysm in the area of the cerebral blood supply does not exceed 7 mm, the risk of rupture is considered low and does not justify the risks associated with surgical correction. If the patient has an aneurysm of large size in the area of the blood supply to the posterior cerebral artery, there are symptoms of bleeding or compression of the adjacent brain structures, then an urgent endovascular operation is indicated.

[3], [4], [5], [6], [7], [8]