Nonepisodic memory deficits in amnestic MCI.
OBJECTIVE
To (a) compare patients with amnestic Mild Cognitive Impairment (MCI), mild Alzheimer disease (AD), and a group of healthy elderly persons on nonepisodic memory measures; (b) examine which measures are independent of level of education in the groups studied.


BACKGROUND
Episodic memory impairment is a cardinal feature of preclinical AD. However, a number of other cognitive measures are also sensitive to the preclinical stage of AD and deficits in multiple domains characterize AD several years before clinical diagnosis.


METHODS
Patients with amnestic MCI (N=31), patients with mild probable AD (N=15), and healthy elderly controls (N=27) were compared on nonepisodic memory tasks measuring fluid intelligence, working memory, processing speed, verbal fluency, and visual-perceptual and motor functions. Amnestic MCI patients were selected based on clinical criteria and a subgroup was also selected based on psychometric criteria.


RESULTS
Multivariate analyses of covariance, controlling for the effects of age, education, and sex, showed that fluid intelligence, working memory, processing speed, semantic fluency, visual-perceptual function, and complex motor function were significantly worse in the MCI than the elderly control group. Working memory, processing speed, semantic fluency, and complex motor tasks were significantly worse in the mild probable AD than the MCI group. The analyses were corroborated using the psychometrically derived MCI group.


CONCLUSIONS
(a) Performance on multiple nonepisodic memory measures is affected in the preclinical stage of AD, indicating that broad cognitive impairment characterizes that stage. (b) Complex motor tasks were independent of level of education in our sample, and may have practical utility in the early detection of dementia.
Economou
Alexandra
A
Department of Psychology, School of Philosophy, University of Athens, Athens, Greece. aoikono@psych.uoa.gr
Papageorgiou
Sokratis G
SG
Karageorgiou
Clementine
C
Vassilopoulos
Dimitrios
D
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D000647:Amnesia / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D000704:Analysis of Variance; D016022:Case-Control Studies; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000145:classification / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D008875:Middle Aged; D011594:Psychometrics; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012660:Semantics; D012720:Severity of Illness Index; D012737:Sex Factors; D014706:Verbal Learning / Q000502:physiology