Bilingual patients were twice as likely as those who spoke one language to have normal cognitive functions after a stroke, according to a new study. Findings were reported Nov. 19 in the American Heart Association journal Stroke.
Past research has found bilingualism might delay the onset of Alzheimer’s disease. “People tend to think of Alzheimer’s as the only cause of dementia, but they need to know that stroke is also an important cause,” senior investigator Subhash Kaul, DM, developer of the stroke registry at Nizam’s Institute of Medical Sciences in Hyderabad, India, said in a news release.
In the new study, researchers reviewed the records of 608 patients in the NIMS stroke registry in 2006-13. More than half the patients were bilingual, defined in the study as speaking two or more languages. To ensure results weren’t because of bilinguals having a healthier lifestyle, researchers took into account other factors such as smoking, high blood pressure, diabetes and age.
• About 40% of bilingual patients had normal cognitive functions after a stroke, compared to about 20% of single language patients.
• Bilinguals performed better on poststroke tests that measured attention, and ability to retrieve and organize information.
• Surprisingly, there was no difference between bilinguals and those who spoke one language in the likelihood of experiencing aphasia, a disorder that can cause difficulties in speaking, reading and writing, after a stroke.
“The advantage of bilingualism is that it makes people switch from one language to another, so while they inhibit one language, they have to activate another to communicate,” lead author Suvarna Alladi, DM, a neurology professor at NIMS, said in the release.
“The combined vocabulary of bilinguals can make it more difficult for them to find specific words. This may explain what appears to be a surprising result,” study co-author Thomas Bak, MD, of the University of Edinburgh in United Kingdom, said in the release.
The study’s results may not be universally applicable to all bilingual people, according to researchers. Hyderabad is a multicultural city in which many languages commonly are spoken, including Telugu, Urdu, Hindi and English.
“Constantly switching languages is a daily reality for many residents of Hyderabad,” Alladi said in the release. “The cognitive benefit may not be seen in places where the need to function in two or more languages isn’t as extensive.”
People who speak only one language shouldn’t necessarily begin learning another one, Kaul noted.
“Our study suggests that intellectually stimulating activities pursued over time, from a young age or even starting in mid-life, can protect you from the damage brought on by a stroke,” Kaul said in the release.
On average, someone in the U.S. suffers a stroke every 40 seconds, according to the American Heart Association’s 2015 Statistical Update.
Other co-authors are Shailaja Mekala, PhD; Amulya Rajan, MA; Jaydip Ray Chaudhuri, DM; Eneida Mioshi, PhD; Rajesh Krovvidi, DM; Bapiraju Surampudi, PhD; and Vasanta Duggirala, PhD. The Indian Council of Medical Research funded the study.
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