@article {830, title = {Subclinical brain magnetic resonance imaging abnormalities predict physical functional decline in high-functioning older adults.}, journal = {J Am Geriatr Soc}, volume = {53}, year = {2005}, month = {2005 Apr}, pages = {649-54}, abstract = {

OBJECTIVES: To determine whether severity of subclinical brain magnetic resonance imaging (MRI) abnormalities predicts incident self-reported physical impairment or rate of decline in motor performance.

DESIGN: Longitudinal analysis, average follow-up time: 4.0 years.

SETTING: Cardiovascular Health Study (CHS).

PARTICIPANTS: CHS participants with modified Mini-Mental State Examination (3MS) score of 80 or greater, no self-reported disability, no history of stroke, and at least one assessment of mobility (n=2,450, mean age=74.4).

MEASUREMENTS: Brain MRI abnormalities (ventricular enlargement, white matter hyperintensities, subcortical and basal ganglia small brain infarcts), self-reported physical impairment (difficulty walking half a mile or with one or more activities of daily living), and motor performance (gait speed, timed chair stand).

RESULTS: After adjusting for demographics, cardiovascular risk factors, and diseases, risk of incident self-reported physical impairment was 35\% greater for those with severe ventricular enlargement than for those with minimal ventricular enlargement, 22\% greater for those with moderate white matter hyperintensities than for those with minimal white matter hyperintensities, and 26\% greater for participants with at least one brain infarct than for those with no infarcts. Those with moderate to severe brain abnormalities experienced faster gait speed decline (0.02 m/s per year) than those with no MRI abnormalities (0.01 m/s per year). Further adjustment for incident stroke, incident dementia, and 3MS score did not substantially attenuate hazard ratios for incident self-reported physical impairment or coefficients for decline in gait speed.

CONCLUSION: Subclinical structural brain abnormalities in high-functioning older adults can increase the risk of developing physical disabilities and declining in motor performance.

}, keywords = {Activities of Daily Living, Aged, Aged, 80 and over, Brain, Female, Follow-Up Studies, Gait, Humans, Incidence, Magnetic Resonance Imaging, Male, Proportional Hazards Models, Psychomotor Disorders, Risk Factors, United States}, issn = {0002-8614}, doi = {10.1111/j.1532-5415.2005.53214.x}, author = {Rosano, Caterina and Kuller, Lewis H and Chung, Hyoju and Arnold, Alice M and Longstreth, William T and Newman, Anne B} } @article {1049, title = {Association between lower digit symbol substitution test score and slower gait and greater risk of mortality and of developing incident disability in well-functioning older adults.}, journal = {J Am Geriatr Soc}, volume = {56}, year = {2008}, month = {2008 Sep}, pages = {1618-25}, abstract = {

OBJECTIVES: To determine whether, in well-functioning older adults, a lower score on the Digit Symbol Substitution Test (DSST) and slower gait are associated with greater risk of mortality and of developing incident disability independent of other risk factors, including brain structural abnormalities (white matter hyperintensities, brain infarcts, ventricular enlargement) and whether the combination of varying levels of DSST score and gait speed are associated with a greater risk of mortality and disability than low DSST or slow gait alone.

DESIGN: Observational cohort study.

SETTING: Community.

PARTICIPANTS: Three thousand one hundred fifty-six (43\% men, 29\% black, mean age 70.4) participants in the Cardiovascular Health Study (CHS), free from stroke and physical disability and with a modified Mini-Mental State Examination (3MS) score of 80 or higher.

MEASUREMENTS: Total mortality and incident disability (self-report of any difficulty performing one or more of the six activities of daily living) ascertained over a median follow-up time of 8.4 years.

RESULTS: By the end of follow-up, 704 participants had died and 1,096 had incident disability. In Cox proportional hazards models adjusted for age, sex, race, education, cardiovascular disease, and brain magnetic resonance imaging abnormalities, lower DSST score and slower gait remained significantly associated with greater risk of mortality and of incident disability. Mortality rates were higher in those who had both low DSST score (<27 points) and slow gait (speed <1.0 m/s) than in those who had only low DSST score, only slow gait, or neither (rates per 1,000 person years (p-y): 61.2, 42.8, 20.8, and 16.3, respectively). A similar risk gradient was observed for incident disability (82.0, 57.9, 47.9, and 36.0/1,000 p-y, respectively).

CONCLUSION: In well-functioning older adults, low DSST score and slow gait, alone or in combination, could be risk factors for mortality and for developing disability, independent of other risk factors, including measures of brain integrity.

}, keywords = {Activities of Daily Living, Aged, Aged, 80 and over, Analysis of Variance, Atrophy, Brain, Brain Diseases, Cause of Death, Cohort Studies, Disability Evaluation, Discrimination Learning, Female, Gait, Humans, Male, Memory, Short-Term, Mobility Limitation, Neuropsychological Tests, Pattern Recognition, Visual, Psychometrics, Psychomotor Performance, Risk Factors}, issn = {1532-5415}, doi = {10.1111/j.1532-5415.2008.01856.x}, author = {Rosano, Caterina and Newman, Anne B and Katz, Ronit and Hirsch, Calvin H and Kuller, Lewis H} }