title: Intraindividual cognitive decline using a brief computerized cognitive screening test.
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.
authors.affiliation: CogState Ltd, Melbourne, Victoria, Australia. ddarby@cogstate.com
authors.forename: David G
authors.initials: DG
authors.lastname: Darby
authors.forename: Robert H
authors.initials: RH
authors.lastname: Pietrzak
authors.forename: Julia
authors.initials: J
authors.lastname: Fredrickson
authors.forename: Michael
authors.initials: M
authors.lastname: Woodward
authors.forename: Lynette
authors.initials: L
authors.lastname: Moore
authors.forename: Amy
authors.initials: A
authors.lastname: Fredrickson
authors.forename: Jack
authors.initials: J
authors.lastname: Sach
authors.forename: Paul
authors.initials: P
authors.lastname: Maruff
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000814:Aniline Compounds; D003072:Cognition Disorders / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D061212:Memory, Episodic; D008875:Middle Aged; D009483:Neuropsychological Tests; D017063:Outcome Assessment, Health Care; D049268:Positron-Emission Tomography; D012111:Residence Characteristics; D013844:Thiazoles; D013997:Time Factors
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000814:Aniline Compounds; D013844:Thiazoles