Alzheimer's disease
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"Alzheimer" redirects here. For other uses, see Alzheimer (disambiguation).
Alzheimer's disease
Classification and external resources

Comparison of a normal aged brain (left) and an Alzheimer's patient's brain (right). Differential characteristics are pointed out.
ICD-10 G30., F00.
ICD-9 331.0, 290.1
OMIM 104300
DiseasesDB 490
MedlinePlus 000760
eMedicine neuro/13
MeSH D000544
Alzheimer's disease (AD), also called Alzheimer disease, Senile Dementia of the Alzheimer Type (SDAT) or simply Alzheimer's, is the most common form of dementia. This incurable, degenerative, and terminal disease was first described by German psychiatrist Alois Alzheimer in 1906. Generally it is diagnosed in people over 65 years of age,[1] although the less-prevalent early-onset Alzheimer's can occur much earlier. An estimated 26.6 million people worldwide had Alzheimer's in 2006; t ...more

Three major competing hypotheses exist to explain the cause of the disease. The oldest, on which most currently available drug therapies are based, is the cholinergic hypothesis, which proposes that AD is caused by reduced synthesis of the neurotransmitter acetylcholine. The cholinergic hypothesis has not maintained widespread support, largely because medications intended to treat acetylcholine deficiency have not been very effective. Other cholinergic effects have also been proposed, for example, initiation of large-scale aggregation of amyloid,[50] leading to generalised neuroinflammation.[51]

In 1991, the amyloid hypothesis postulates that amyloid beta (Aβ) deposits are the fundamental cause of the disease.[52][53] It is a compelling theory because the gene for the amyloid beta precursor (APP) is located on chromosome 21, and people with trisomy 21 (Down Syndrome) who thus have an extra gene copy almost universally exhibit AD by 40 years of age.[54][55] Also APOE4, the m ...more

Not really known

Oldage and senelity