The findings point to the need for better long-term follow-up care for the nation's 7 million stroke survivors, including therapy to retain or even regain cognitive ability, the study says. Funded by the National Institute for Neurological Disorders and Stroke and the National Institute on Aging and using data from 23,572 Americans aged 45 years or older from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, the new research also includes scientists from the University of Alabama at Birmingham and Indiana University.
According to the National Stroke Association, about one third of stroke survivors will develop memory problems. These memory problems can be so severe that they interfere with normal functioning and are then classified as dementia, which is more common in older stroke survivors (http://www.stroke.org/we-can-help/survivors/stroke-recovery/post-stroke-conditions/cognition/memory-loss).
While the participants had no history of cognitive impairment when they entered the study in the mid-2000s, they were tested in terms of their memory and thinking ability at the beginning of the study and at regular intervals afterwards. They were monitored two times per year for acute stroke events, and suspected strokes were confirmed by study physicians. During a period of 6 to 10 years, 515 of the participants had a stroke, and researchers compared their test results with the others in the study. The researchers had information on the ways in which stroke survivors' memory and thinking ability changed over time before the stroke, enabling them to separate the declines in brain function traced to aging from declines in brain function traced to stroke. The latter included "declines in global cognition, new learning and verbal memory early after stroke as well as accelerated and persistent declines in global cognition and thinking ability over the years after the event", the report says.
Levine concludes, "Stroke is common, costly, and disabling, and cognitive decline is a major cause of disability in stroke survivors. Yet cognitive decline after stroke has not received enough attention. We hope these findings will shine a spotlight on stroke survivors' long-term cognitive needs."