Intraindividual cognitive decline using a brief computerized cognitive screening test

Alzheimer's & Dementia, 04/04/2012

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.

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.

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