VITA: subtypes of mild cognitive impairment in a community-based cohort at the age of 75 years

Background Mild cognitive impairment (MCI) is defined to diagnose prodromal dementia and prodromal Alzheimer dementia, in particular. Objective The main aim of this study is to identify subtypes of MCI in comparison to the frequency of Petersen's MCI-amnestic in an elderly age-cohort. Participants The study is based on the cross sectional data from the Vienna-Transdanube-Aging (VITA) study. The data refer to the age cohort of 592 individuals at age 75 to 76 years who completed extensive neuropsychological examination. Results Dementia was present in 15 subjects (2.5%, CI: 1.4-4.1). 141 subjects (23.8%, CI: 20.4-27.5) of the entire age cohort 75 (n = 592) showed cognitive impairment without dementia concerning one or more cognitive functions (1.5 SD paradigm). These-subjects were assigned to three subtypes of MCI: Selective Memory Impairment: n = 22 (3.7%, CI: 2.35.6), Memory Impairment + Non-Memory Impairment: n = 31 (5.2%, CI: 3.6-7.4) and Non-Memory Impairment: n = 88 (14.9%, CI: 12.1=18.0). Conclusion The frequency of MCI-amnestic, the so-called prestage of AD according to Petersen, was very low (0.5%, CI: 0.1-1.5) compared to the estimated incidence rates of AD at this age. Established criteria of MCI could be modified in order to include a higher percentage of high-risk subjects for later developing Alzheimer dementia. Copyright (c) 2005 John Wiley & Sons, Ltd.