[The other dementias: the neuropathology of the non-Alzheimer's disease dementias].

Alzheimer's disease (AD) is one of the most common causes of dementia, but requires neuropathological verification for a definitive diagnosis because there are a number of other neurodegenerative diseases that may present with dementia. Some of these disorders have considerable overlap both clinically and pathologically with AD, while others have distinct clinical and pathological profiles. Vascular dementia and dementia with Lewy bodies (DLB) have the greatest overlap with AD and considerable controversy still surrounds the exact contribution of the non AD pathology to the dementia syndrome. The frontotemporal dementias are loosely united by clinical presentation, but are pathologically heterogeneous and include Pick's disease, dementia lacking distinctive histopathology, motor neuron disease inclusion dementia and corticobasal degeneration (CBD). CBD can be difficult to distinguish from progressive supranuclear palsy, especially when the latter lacks the distinctive gaze palsy. Finally, Creutzfeldt Jakob disease (CJD) may be difficult to distinguish from AD when the symptoms progress at an atypically slow pace. Recently, a new variant of CJD (vCJD) that has been linked to bovine spongiform encephalopathy ('mad cow' disease) has heightened awareness of these prion protein disorders. The neuropathological criteria for the diagnosis of these non AD dementia disorders will be reviewed.