Comments, Opinions, and Reviews Dementia Due to Vascular Disease A Multifactorial Disorder

T he term vascular dementia is generally used to describe the dementias that are thought to be caused by thromboembolic cerebral vascular disease. The dementia has been said to be the result of infarction of a significant amount (100 ml) of brain tissue irrespective of the location of the lesion,a view that seems to conform to the hypothesis of Lashley, who correlated severity of memory loss to the volume of brain tissue damaged or destroyed. Smaller and more localized cerebral infarcts strategically located in anatomic structures (such as the hippocampus, mamillary bodies, thalamus, or basal forebrain-), the functional integrity of which are essential for normal memory function, are also known to cause severe amnestic syndromes if not all the other characteristics of dementia. These lesions are almost invariably in the vascular distribution of the posterior circulation, particularly in the penetrating branches of the posterior communicating arteries or the posterior cerebral arteries. Ischemic lesions in the vascular distribution of the anterior cerebral arteries produce alterations in awareness, memory deficits, and abulia, which, if not classical dementia, are certainly evidence of altered mental status. Similarly, focal lesions in the frontal, temporal, or parietal lobes may produce disturbances in neuropsychological testing that are characteristic for lesions of those anatomic structures and that may conform to broader definitions of dementia even though verbal memory may not be involved. Usually, however, the term vascular dementia and, particularly, multi-infarct dementia (MID) applies to a progressive loss of cognitive functions