An estimated 65 percent of ischemic stroke survivors experience cognitive impairment and decline. However, little is known about the varying roles of cognitive risk and protective factors before, during and after stroke.
To address that gap in knowledge, scientists at Wake Forest Baptist Medical Center examined changes in cognitive function surrounding ischemic stroke in older women over an eight year period. The retrospective study analyzed data from 159 participants, ages 65 to 79, in the National Institutes of Health’s Women's Health Initiative Memory Study (WHIMS).
Cognitive function was examined in three phases: three years prior to ischemic stroke; at the time of ischemic stroke; and up to three years after ischemic stroke. At each of these phases, the researchers examined how women’s characteristics were related to cognitive functions such as memory, attention and verbal fluency. The findings are published in the June online issue of the journal Aging, Neuropsychology, and Cognition.
“We found that how individual factors like higher body mass index (BMI), hypertension, low optimism and higher physical function are related to cognitive function varies over the time course of the ischemic stroke,” said corresponding author Leslie Vaughan, Ph.D., assistant professor of public health sciences at Wake Forest Baptist.
For example, the team found that a higher BMI, presence of hypertension, lower optimism and higher physical function were all associated with significantly greater decreases in cognitive function at the time of stroke.
After ischemic stroke, however, there was significantly less cognitive decline in women with the exact same characteristics, Vaughan said.
This study has implications for improving cognitive function after ischemic stroke. Based on these findings, interventions could be designed to target modifiable risk and protective factors, and to identify individuals likely to receive the greatest benefit.
For instance, women who have lower BMI or lower physical function at the time of stroke may experience greater rates of cognitive decline in the years following their stroke. These may be individuals that doctors recommend for specific rehabilitative interventions.
Vaughan said that further research also is needed on the role of psychological factors such as optimism and depression in cognitive decline after stroke, especially in older women, to develop better psychosocial interventions.
Co-authors of the study are Cheryl Bushnell, M.D., and Mark A. Espeland, Ph.D., of Wake Forest Baptist, and Christina L. Bell, M.D., of the University of Hawaii.
WHIMS was funded by the National Heart, Lung and Blood Institute, HHSN-268-2004-6-4221C, through the initial follow-up period, WHIMS-ECHO is funded by the National Institute on Aging, HHSN-271-2011-00004C, and the WHI program is funded by the National Heart, Lung and Blood Institute, U.S. Department of Health and Human Services.
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Marguerite Beck: marbeck@wakehealth.edu, 336-716-2415