Early Onset Alzheimer Type Dementia More Rapidly Deteriorates than Late Onset Type: A Follow‐up Study on MMSE Scores in Japanese Patients

Abstract

Background:Cognitive function in patients with Alzheimer type dementia (ATD) changes over time, and the rate of progression varies according to reports. An aim of the study is to examine the rate of progression in patients with ATD by the onset of the disease. Methods:Forty patients with early onset dementia at the age of 65 or less and 99 patients with late onset dementia at the age of more than 65 years in whom Mini‐Mental State Examination (MMSE) scores could be followed up for at least 12 months were enrolled and examined retrospectively for changes in MMSE scores over time. Results:It was demonstrated that the rate of decrease in MMSE scores was significantly higher in Alzheimer disease (AD) than in senile dementia of Alzheimer type (SDAT) and that the decrease in MMSE scores was significantly slower in patients with higher initial scores. Conclusion:ATD patients are likely to be classified into AD or SDAT for evaluation of decreased cognitive function. Initial MMSE score and the subtype according to age at onset are important predictors for the progression of intellectual impairment in ATD patients.