The key to communication for some speech-impaired stroke patients may be learning to sing their words and phrases.
The technique—called melodic intonation therapy—was devised more than three decades ago, but a recent study to evaluate the therapy found that it produced dramatic improvements in 12 patients with aphasia, a deficit in language that results from a stroke on the left side of the brain. This language deficit affects about 20 percent of all stroke survivors. Patients undergoing the therapy learn to sing useful phrases such as “I am hungry” while tapping a rhythm with their left hands.
In the new study, presented at a medical conference in late February, patients who received this training in daily 90-minute sessions for 15 weeks improved and maintained their verbal abilities for up to a month after the therapy ended, says Gottfried Schlaug, M.D., a neurology professor at Harvard Medical School and Beth Israel Deaconess Medical Center who headed the study. He presented his findings at the annual meeting of the American Association for the Advancement of Science.
Each of the patients had suffered a serious stroke that left them unable to speak coherently, he tells Bulletin Today, “and all had tried other therapies—and nothing worked.” He plans a larger study of the therapy, which he says could benefit some 70,000 stroke patients a year who suffer from this kind of speech problem.
Why the singing therapy appears to work in stroke patients is unknown. But one theory is that the method works because the left side of the brain is engaged with speech and the right side with music.
“If you get a stroke in the left hemisphere, according to this hypothesis, you become aphasic and can’t produce words because the left hemisphere, although damaged, retains dominance for producing language,” says Martin L. Albert, M.D., professor of neurology at Boston University School of Medicine. Often the stroke patients know exactly what they want to say but can’t find the words. It’s as if they’re trying to express themselves in a foreign language they don’t know.
Learning to sing the words essentially “shifts the dominance” to the right side of the brain—the “singing” side of the brain—so language can be released, Albert explains. Albert was not involved in Schlaug’s study, but he devised the therapy in the 1970s after he and other clinicians observed that some stroke patients who were no longer able to talk could still sing.
Since Albert’s discovery, there have been individual case studies of the therapy, but few larger studies, Schlaug says.
Tapping with the left hand not only helps the patients to keep rhythm, it also improves right-brain hearing and motor systems, and helps control facial movements, he adds.
Sid Kirchheimer covers consumer and health issues for the AARP Bulletin.