Intraindividual cognitive decline using a brief computerized cognitive screening test
Alzheimer's & Dementia, 04/04/2012
Darby DG et al. – Intraindividual decline in cognitive performance can be detected in otherwise healthy, community–dwelling, older persons, and this may deserve further study as a potential indicator of early Alzheimer’s disease pathology.Methods
- This study evaluated the slopes of cognitive performance over a 12–month period in 263 healthy, community–dwelling, adult volunteers aged ≥50 years.
- Participants completed a brief computerized battery of cognitive tests (CogState) at baseline and during 3–, 6–, 9–, and 12–month follow–up assessments.
- Linear mixed models were used to estimate age–adjusted mean slopes and 95% confidence intervals of change for each of the cognitive measures.
- By defining age–adjusted mean slopes, and 95% confidence intervals for a measure of episodic memory, individuals with greater than expected decline (equal to or lower than the fifth percentile level of decline) were identified.
- From these, four individuals completed a full medical, neurologic, and neuropsychological evaluation, with none of them fulfilling criteria for mild cognitive impairment, but three (75%) having positive amyloid–positron emission tomographic scans.