Early onset dementia

Early onset dementia is dementia in which symptoms first appear before the age of 65. The term favored until about 2000 was presenile dementia; young onset dementia is also used.

Early onset dementia may be caused by degenerative or vascular disease, or it may be due to other causes, such as alcohol-related dementia and other inflammatory or infectious processes. Early-onset Alzheimer's disease, vascular dementia and frontotemporal lobar degeneration are the most common forms of early onset dementia, with Alzheimer's accounting for between 30 and 40%. Early onset dementia may also occur, less frequently, in the Lewy body dementias (dementia with Lewy bodies and Parkinson's disease dementia), multiple sclerosis, Huntington's disease and other conditions.