Intraindividual cognitive decline using a brief computerized cognitive screening test

• Published in: Alzheimer's & dementia Vol. 8; no. 2; pp. 95 - 104
• Main Authors: Darby, David G, Pietrzak, Robert H, Fredrickson, Julia, Woodward, Michael, Moore, Lynette, Fredrickson, Amy, Sach, Jack, Maruff, Paul
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2012
• Subjects: Aged; Aged, 80 and over; Alzheimer disease; Alzheimer's disease; Aniline Compounds; Cognition; Cognition Disorders - diagnosis; Cognition Disorders - diagnostic imaging; Cognitive ability; Cognitive decline; Cognitive impairment; Cognitive performance; Community living; Confidence intervals; Dementia disorders; Diagnosis, Computer-Assisted - methods; Disease Progression; Female; Follow-Up Studies; Humans; Male; Memory; Memory, Episodic; Middle Aged; Neurodegenerative diseases; Neurology; Neuropsychological Tests; Outcome Assessment (Health Care); Pathology; Positron-Emission Tomography; Preclinical diagnosis; Residence Characteristics; Thiazoles; Time Factors; Cognitive decline; Cognition; Preclinical diagnosis; Alzheimer disease; Memory
• ISSN: 1552-5260; 1552-5279
• DOI: 10.1016/j.jalz.2010.12.009

Abstract Background Progressive intraindividual decline in memory and cognition is characteristic of dementia and may be useful in detecting very 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. Results 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. Conclusions 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.