[Vascular dementia].

The term vascular dementia refers to dementia syndromes which are caused by hypoxic-ischaemic brain lesions. Lesions found in vascular dementia such as complete and incomplete infarctions, selective necroses, and others are nonspecific. The characteristics and severity of the clinical syndrome are determined by the size and topography of the ischaemic lesions. Among others, age and pre-existing brain atrophy are risk factors for the development of dementia based on vascular lesions. There is a high comorbidity of Alzheimer's disease and vascular dementia. It can be presumed that ischaemic lesions and Alzheimer-like pathological changes exert additive effects in the manifestation of the clinical dementia syndrome. The diagnostic process follows three steps: 1. presence of a dementia syndrome, 2. presence of cerebrovascular disease, 3. evidence for a relationship between 1 and 2. Present diagnostic criteria, such as "International Classification of Diseases" (ICD-10), "National Institute of Neurological Disorders," "Stroke-Associated Internationale pour la Reserche et l'Enseignement en Neurosciences" (NINDS-AIREN), and "Alzheimer's Disease Diagnostic and Treatment Centers" (ADDTC) describe differing constellations and show little congruence. Estimates of the prevalence depend highly on the set of criteria used. Hence, they differ considerably.