[Alzheimer-type dementia and Down syndrome].

Dementia is seen earlier and more often in patients with Down syndrome (DS) than in the general population. Patients with DS develop neuropathological changes similar to the changes seen in dementia of Alzheimer's type (DAT). The literature concerning DAT in DS is reviewed. The clinical course and differential diagnoses are discussed. Before the diagnosis of DAT is made, treatable causes of dementia should be excluded.