New York, Jul 8 (IANS): Those who survive a stroke may experience accelerated and persistent decline in memory and thinking ability over several years after the event, say a study.

Problems with memory and thinking ability after a stroke keep getting worse for years, and happen faster than normal brain ageing, showed the the findings published in the Journal of the American Medical Association.

"We found that stroke is associated with cognitive decline over the long-term," said lead author Deborah Levine from University of Michigan Medical School in the US.

"That is, survivors had accelerated and persistent declines in memory and thinking ability during the years after stroke -- even after accounting for their cognitive changes before and early after the event," Levine noted.

The study involved 23,572 Americans aged 45 years or older.

They were monitored twice a year for acute stroke events. Suspected strokes were confirmed by study physicians using medical records.

Over the next six to 10 years, 515 of them had a stroke, and researchers compared their test results with those from the 23,057 who remained stroke-free.

In their study, stroke was associated with declines in cognition, new learning, and verbal memory early after stroke as well as accelerated and persistent declines in cognition and thinking ability over the years after the event.

"Our results suggest that stroke survivors warrant monitoring for mounting cognitive impairment over the years after the event," Levine noted.