Morphological and Clinical Consequences of Focal Brain Ischaemia

Overview

The diseases of vessels, mainly of those in brain are one of the most serious problems of the medi-cal practice. The encephalomalacia or cerebral infarctions are usually caused by transient or per-manent obstruction of the brain arteries lumen. Beside local dysfunction of vessels theobstructions could be based on embolic events originating in the heart. Such an obstructions areresulting in global and focal cerebral ischaemias. Arterial occlusion results in cerebral ischaemia and the lack of oxygen (anoxia) which leads to reversible or irreversible injury of the nervous ce-lls in the ischaemic region. The local cell injury or cell death causes attraction of macrophages in-vading into the devitalized tissue within 72 - 96 hours after the beginning of the ischaemia.The aim of this study was to find out the correlation between asymptomatic or symptomaticcourse regarding localisation of the ischaemic lesions in the cerebral tissue.Our anatomical findings were collected from 318 autopsies, and reports on postmortem examina-tions during the period between September-December 1998. The grossing of the brain was carri-ed out by using of Virchow’s method.Atherosclerosis, hypertension, and diabetes mellitus were found to be the main risk factors forthe production of focal cerebral ischaemia. Of those patients with focal cerebral ischaemia athe-rosclerosis had 87.5%, 44.3% were suffering from hypertension, and 25% from diabetes mellitus.The focal ischaemia analysed in this study originated from arterial stenosis or thromboembolicobstructions. We divided the lesions into 3 groups according to their size. The most frequently ap-parent lesions (72%) were the small cysts (0-10 mm in diameter) - lacunae. The majority of them(90%) was found in the basal ganglia. The second group consisted of postmalatic pseudocysts (10-30 mm in diameter), and the third group was represented by encephalomalatic lesions which werelarger than 30 mm.Cerebral ischaemic lesions were present in 27.8% of the studied cases. Nevertheless, more thanthe half (56.8%) of the affected brains (postmalatic pseudocysts, lacunae and malaciae) belongs tothe group of patients who were clinically asymptomatic. The asymptomatic lesions, having negati-ve results in the patient’s history, and the clinical course were localised mainly in the basal gan-glia of both sides and in the frontal part of the right (nondominant) hemisphere.

Key words:
focal cerebral ischaemia, localisation, asymptomacy