title: Subcortical hyperintensities impact cognitive function among a select subset of healthy elderly.
abstract: Previous studies have examined the impact of subcortical hyperintensities (SH), a proxy measure of cerebrovascular disease, on the cognitive abilities of otherwise healthy older adults. However, there remains a limited understanding as to what extent this MRI marker of pathological processes explains the decline in specific cognitive functions that occur nearly ubiquitously with advanced age, especially in relation to other age-related imaging markers. In the present study we compared cognitive abilities between a sample of 53 older healthy adults (age range=50-79) and a sample of 53 younger adults (age range=21-40). As expected, the older group performed significantly worse on most cognitive measures compared to the younger group. Frontal volume and total grey matter volume were also significantly reduced among the older individuals compared to the younger individuals. SH volume was consistently associated with cognitive function in older adults, though, this relationship was evident only for a relatively small subset of older individuals with the most severe SH. These data suggest that the relationship between SH and cognition in the elderly is driven by a subset of individuals who may be in the earliest stages of vascular cognitive impairment. Further, the findings suggest that cognitive aging is largely determined by factors other than SH for most older adults.
authors.affiliation: Brown Medical School, Centers for Behavioral and Preventive Medicine, Department of Psychiatry and Human Behavior, 1 Hoppin Street, Providence, RI 02903, USA. rpaul@lifespan.org
authors.forename: Robert H
authors.initials: RH
authors.lastname: Paul
authors.forename: Omar
authors.initials: O
authors.lastname: Haque
authors.forename: John
authors.initials: J
authors.lastname: Gunstad
authors.forename: David F
authors.initials: DF
authors.lastname: Tate
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Grieve
authors.forename: Karin
authors.initials: K
authors.lastname: Hoth
authors.forename: Adam M
authors.initials: AM
authors.lastname: Brickman
authors.forename: Ronald
authors.initials: R
authors.lastname: Cohen
authors.forename: Kelly
authors.initials: K
authors.lastname: Lange
authors.forename: Angela L
authors.initials: AL
authors.lastname: Jefferson
authors.forename: Kristin L
authors.initials: KL
authors.lastname: MacGregor
authors.forename: Evian
authors.initials: E
authors.lastname: Gordon
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000473:pathology* / Q000502:physiology*; D002552:Cerebral Ventricles / Q000473:pathology; D003071:Cognition / Q000502:physiology*; D015140:Dementia, Vascular; D003710:Demography; D005260:Female; D005625:Frontal Lobe / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007360:Intelligence / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011930:Reaction Time / Q000502:physiology; D014705:Verbal Behavior / Q000502:physiology; D014888:Wechsler Scales / Q000706:statistics & numerical data