White matter hyperintensities and subclinical infarction: associations with psychomotor speed and cognitive flexibility.
OBJECTIVE
We examined white matter hyperintensity volume (WMHV) and subclinical infarction (no history of clinical stroke; SI) in relation to performance on tests of sequencing, cognitive flexibility, and sensorimotor ability.


METHODS
The Northern Manhattan Study includes a stroke-free community-based sample of Hispanic, Black, and White participants. A subsample (n=656) has undergone measurement of WMHV, SI, and neuropsychological testing. Linear regression was used to examine WMHV and SI in relation to performance on tests of sequencing as measured by Color Trails 1, cognitive flexibility as measured by Color Trails 2, and sensorimotor ability as measured by Grooved Pegboard, using generalized estimating equations (GEE) to account for the correlation among the cognitive tests and other covariates.


RESULTS
Considering performance on the tests of sequencing, cognitive flexibility, and sensorimotor ability simultaneously using GEE, WMHV and subclinical infarction were each associated with worse cognitive performance globally. There was a threshold effect for WMHV with those in the upper quartile performing significantly worse on the tests of cognitive flexibility and sensorimotor ability. Those with frontal SI performed worse on the test of cognitive flexibility and those with deep SI, worse on the test of sequencing.


CONCLUSIONS
Both SI and WMHV were associated with globally worse cognitive performance. Participants with WMH affecting more than 0.75% of cranial volume had significantly slower performance on a task of cognitive flexibility and sensorimotor ability than those in the lowest quartile. The effects of SI on cognitive performance varied by location.
Wright
Clinton B
CB
Division of Stroke and Critical Care, Department of Neurology, College of Physicians and Surgeons of Columbia University, NI-Room 640, 710 W168th Street, New York, NY 10032, USA. cbw7@columbia.edu
Festa
Joanne R
JR
Paik
Myunghee C
MC
Schmiedigen
Alexis
A
Brown
Truman R
TR
Yoshita
Mitsuhiro
M
DeCarli
Charles
C
Sacco
Ralph
R
Stern
Yaakov
Y
D000368:Aged; D002544:Cerebral Infarction / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D003071:Cognition; D015331:Cohort Studies; D005260:Female; D006801:Humans; D049292:Leukoaraiosis / Q000175:diagnosis*; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D012720:Severity of Illness Index; D013997:Time Factors