FUNDAMENTAL PATHOLOGICAL LESIONS IN VASCULAR DEMENTIA

This review concerns the fundamental cerebral lesions in cases of vasc ular dementia. Extracerebral vascular alterations are dominated by ath erosclerosis with or without thrombosis. In addition, occlusion of ext racerebral arteries can be induced by thrombo-embolism and in rare cas es by other vascular diseases, chiefly arteritis. Intracerebral microa ngiopathies are usually of arteriolosclerotic or hyalinotic types in w hich there is degeneration of smooth muscle cells of the media and dep osition of components of extracellular matrix, chiefly collagens. Agei ng, chronic hypertension, hyperlipidemias and diabetes are important f actors inducing vascular lesions. The vascular lesions, often combined with systemic factors, may produce various ischemic and edematous alt erations of the brain parenchyma. Occlusion and obliteration of arteri es (macroangiopathy) are associated with large infarcts, whereas micro angiopathy may cause lacunar infarcts and some forms of white matter d egeneration. Cases of vascular dementia usually present many types of lesions in the brain parenchyma and its arterial supply. The extent an d location of the injuries differ considerably from case to case. Loca tion o(f the lesions, volume of destroyed tissue, multiplicity and bil ateral occurrence are most important parameters underlying the clinica l manifestations in vascular dementia. A strategic location of a small injury is in some cases of particular importance.