Senile dementia of extreme aging: a common disorder of centenarians.

To study dementia in the extremely aged, I evaluated 40 centenarians with a mean age of 101.6 years (range: 100-107). The group completed 5.8 years of education, on average. Bradyphrenia and bradykinesia were common and most had impaired awareness and concern. The Folstein Mini-Mental State Exam and Washington University's Clinical Dementia Rating Scale indicated moderately advanced dementia in more than half; 4 had a clinical pattern that suggested senile dementia of the Alzheimer's type. A common pattern of dementia emerged consisting of preserved awareness of the environment, normal participation in conversations, mild bradyphrenia and bradykinesia with normal latency to respond to questions and memory impairment with diminished ability to learn new information. They had a constricted universe with limited awareness of events outside their personal sphere; they repeated themes and topics endlessly. This study suggests senile dementia is common in centenarians.