Non-Alzheimer Dementias

This chapter deals with the main etiological categories of non-Alzheimer’s Disease pathologies, specifically degenerative dementias, dementias associated with extrapyramidal conditions, vascular dementias, and dementias due to transmissible agents. The prevalence and the incidence of non-Alzheimer dementias vary according to the type of populations that are selected. The diagnosis rests on a triad consisting of focal neuropsychological deficits presenting in a context of dementia, focal cerebral atrophy affecting the temporal and/or frontal lobes, and the typical argyrophilic inclusions. The risk of dementia in association with cerebrovascular pathology is greater than any other known risk factor, including head injuries. The concept of vascular dementia most currently includes all dementias following cerebrovascular accidents whether ischaemic or haemorrhagic in nature. The disease in the majority of cases affects small vessels with subcortical-like deficits, to the extent that vascular dementia often fits the model of subcortical dementia.