Today at Brown

Foreign accent syndrome (FAS) is a rare and odd phenomenon: Following a stroke or a brain injury, patients speak with a mysterious and nonspecific foreign accent – or so it sounds to a layperson’s ear. (Hear an example of FAS speech.)

Professor of Cognitive Science and Linguistics Sheila Blumstein and her lab team were among the first to study the syndrome. They quantified speech patterns characteristic of the syndrome using acoustic analyses of the patient’s speech. Recently Blumstein, a former dean of the College and interim Brown president, studied an unusual case that presents new insights into FAS.

With Kathleen Kurowski, assistant professor of of cognitive science and linguistics (research) at Brown, and researchers at Beth Israel Deaconess Medical Center in Boston, Blumstein examined the case of a patient whose stroke in the left frontal cortex had produced the foreign accent syndrome. Later, the woman suffered a second stroke in the right cerebellum, and her accent disappeared.

Blumstein recently spoke about the quirky case, which the researchers presented in the August issue of Neurology.

Now that the patient can speak normally, how did you find out what happened to her to resolve the syndrome?

We were fortunate to have available to us recordings of this patient over a period of time. It turned out that her daughter had telephone messages left by her mother. We thus had access to recordings of the patient when she was totally normal, just before her first stroke; after the first stroke that produced the foreign accent syndrome; prior to her second stroke; and right after her second stroke, which resulted in a loss of FAS.

What did you do next?

We went to (Beth Israel Deaconess Medical Center) and interviewed her for an hour, recording her speech. This was approximately four years after the second stroke. We acoustically analyzed a number of speech parameters in all of the recordings. It gave us a lot of time points where we were able to determine whether she had FAS originally and then examine whether the FAS resolved after her second stroke.

And it had resolved. She had FAS after the first stroke, and her speech patterns were within normal limits after the second stroke.

What happened inside her brain to cause, and then resolve, this disorder?

It brings up a very interesting phenomenon called restorative, paradoxical functional facilitation. The term, originally identified by the neurologist Narinder Kapur, proposes that the activity of the brain is a complex combination of excitatory and inhibitory patterns in neural systems. With a brain injury, the balance of excitatory and inhibitory gets affected.

This study supports his hypothesis. The cerebellum is involved in speech production and in particular rhythm and timing of speech output. It looks as though damage to the right cerebellum may have disinhibited the left cerebellum to help resolve the motor speech problem that the patient in the study had with FAS.

Was this simply an interesting case, or something on which to build future research?

With respect to FAS it may speak to the role of the cerebellum in such processing. Up until now most people have focused on the cortex and damage to the anterior frontal regions in producing foreign accent syndrome. So that’s one issue.

What’s the other issue?

The second issue is that it does reemphasize and reaffirm the notion that lesions don’t just result in the loss of function. In rare occasions, they may actually result in improved performance, presumably because there is a change in the balance of excitatory and inhibitory connections. There aren’t many examples in literature of this type of phenomenon.