Subcortical lacunes are associated with executive dysfunction in cognitively normal elderly.
OBJECTIVE
The relationship between subcortical ischemic vascular disease (SIVD) and cognition in normal elderly is unclear, in part because of methodological inconsistencies across studies. To clarify this relationship, the current study investigated a well characterized cognitively normal elderly sample (>or=55 years) with quantitative MRI and psychometrically robust neuropsychological measures within a multivariate model. Converging evidence suggests that SIVD selectively impairs frontal-executive tasks by disrupting frontal-subcortical circuits. We therefore hypothesized that MRI markers of SIVD would be selectively associated with worse executive functioning.


METHODS
We studied 94 participants who were cognitively and functionally normal. Volumetric measures of white matter signal hyperintensity (WMH), subcortical lacunes, hippocampal volume, and cortical gray matter were obtained to predict performance on composite measures of executive functioning and episodic memory.


RESULTS
Hierarchical regression demonstrated that after controlling for demographic variables, MMSE, and total intracranial volume, the total number of subcortical lacunes was the only significant predictor, with a greater number of lacunes associated with poorer executive performance. Hippocampal volume best predicted episodic memory performance.


CONCLUSIONS
Results suggest that SIVD in the form of silent lacunes corresponds to poorer executive functioning even in otherwise normal elderly, which is consistent with the hypothesis that SIVD preferentially disrupts frontal-subcortical circuits. The clinical importance of these findings is highlighted by the fact that 33% of the normal elderly participants in this study had lacunar infarcts.
Carey
Catherine L
CL
Department of Psychiatry, University of California, San Diego, 150 W. Washington, 2nd Floor San Diego, CA 92103, USA. ccarey@ucsd.edu
Kramer
Joel H
JH
Josephson
S Andrew
SA
Mungas
Dan
D
Reed
Bruce R
BR
Schuff
Norbert
N
Weiner
Michael W
MW
Chui
Helena C
HC
D000368:Aged; D000369:Aged, 80 and over; D020520:Brain Infarction / Q000473:pathology* / Q000523:psychology; D002540:Cerebral Cortex / Q000473:pathology; D003071:Cognition; D003072:Cognition Disorders / Q000473:pathology* / Q000523:psychology; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D011594:Psychometrics