Early onset dementia is

dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

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 Vascular disease is a class of diseases of the blood vessels – the arteries and veins of the circulatory system of the body. Vascular disease is a subgroup of cardiovascular disease. Disorders in this vast network of blood vessels can cause a ra ...

, 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 Vascular dementia (VaD) is dementia caused by problems in the supply of blood to the brain, typically a series of minor strokes, leading to worsening cognitive abilities, the decline occurring piecemeal. The term refers to a syndrome consisting ...

and

frontotemporal lobar degeneration Frontotemporal lobar degeneration (FTLD) is a pathological process that occurs in frontotemporal dementia. It is characterized by atrophy in the frontal lobe and temporal lobe of the brain, with sparing of the parietal and occipital lobes. Common ...

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 Lewy body dementias are two similar and common subtypes of dementia—dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). Both are characterized by changes in thinking, movement, behavior, and mood. The two conditions have sim ...

( dementia with Lewy bodies and

Parkinson's disease dementia Parkinson's disease dementia (PDD) is dementia that is associated with Parkinson's disease (PD). Together with dementia with Lewy bodies (DLB), it is one of the Lewy body dementias characterized by abnormal deposits of Lewy bodies in the brain. ...

multiple sclerosis Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...

Huntington's disease Huntington's disease (HD), also known as Huntington's chorea, is a neurodegenerative disease that is mostly inherited. The earliest symptoms are often subtle problems with mood or mental abilities. A general lack of coordination and an unst ...

and other conditions.

References

Further reading