image of brain
© Agence France-Presse
A computer image mapping parts of the brain. US scientists have restored speech to stroke victims by getting them to sing words instead of speaking them, a leading neurologist said here Saturday.

San Diego, California - US scientists have restored speech to stroke victims by getting them to sing words instead of speaking them, a leading neurologist said.

Gottfried Schlaug, an associate professor of neurology at Beth Israel Deaconess Medical Center and Harvard Medical School, showed a video of a patient with a stroke lesion on the left side of the brain who was asked to recite the words of a birthday song.

The patient could not comply, and merely repeated the letters N and O.

But when Schlaug asked him to sing the song while someone held the patient's left hand and tapped it rhythmically, the words "happy birthday to you" came out clear as day.

"This patient has meaningless utterances when we ask him to say the words but as soon as we asked him to sing, he was able to speak the words," Schlaug told reporters at the annual meeting of the American Association for the Advancement of Science (AAAS).

Another patient was taught to say, "I am thirsty" by singing, while another who suffered a large lesion on the left side of the brain and had tried various, ultimately unsuccessful therapies for several years to try to regain the power of speech was taught to say his address.

Images of the brains of patients with stroke lesions on the left side of the brain -- which is typically used more for speech -- show "functional and structural changes" on the right side of the brain after they have undergone this form of therapy through song, called Music Intonation Therapy (MIT).

Although medical literature has documented the phenomenon of people who are unable to speak being able to utter words when singing, Schlaug was the first to run a randomized clinical trial of MIT, with a view to gaining acceptance of the therapy in the medical field.

"You don't need to be a trained singer to do this. We want to teach caregivers to do MIT because the treatment is very long and expensive," said Schlaug.

MIT treatment can last for 14-16 years, and involves sessions of an hour and a half a day, five days a week.

But the benefits of the therapy are usually permanent, and two thirds of patients who have undergone MIT with Schlaug added more words to their spoken vocabulary after their therapy had ended than the 100 words they were "taught" to say in therapy.

Exactly how MIT works is not clear, but another study presented at the AAAS meeting by Aniruddh Patel of the Neurosciences Institute showed that grammatical processing of language and music overlaps in the brain.

Schlaug said music helps parts of the brain that usually do not engage with each other when a person speaks, to do so.

"Music-making is a multisensory experience that simultaneously activates several systems in the brain and links and loops them together. It engages many regions of the brain," he said.

Tapping the patient's hand gently on the table "might serve as a pacemaker for the motor articulatory system in the brain," said Schlaug.

"Combining motor activity with sound might facilitate speech."

In the United States, MIT could potentially help up to 70,000 nonverbal stroke victims to retrieve the ability to speak, according to the neurologist.