A Biological Basis for Stuttering
July 23, 2001 -- People who stutter aren't weird or crazy -- they just have different brains. A groundbreaking study shows that areas of the brain important for speech look different in stutterers than in fluent speakers.
Stuttering seems funny to those who speak fluently. But for those who suffer from the speech disorder, it means emotional anguish and social rejection. Treatment requires intensive speech therapy, sometimes in combination with medications -- and not all stutterers respond.
Now a research team led by Anne L. Foundas, MD, of the Tulane University Health Science Center in New Orleans, finds the speech and language centers in the brains of persistent stutterers differ from those of fluent people. Moreover, there are differences among stutterers that may explain why not everyone responds to the same treatments.
"It is very difficult to develop treatments that work for everyone who stutters," Foundas tells WebMD. "Under the umbrella of this clinical disorder there are ... brain differences. If you can figure out who falls into which group, you could target therapy to the right people."
The Foundas team took a big step toward this goal by using a sophisticated MRI tool to get pictures of the brains of 16 adults with stuttering that had persisted from childhood into adulthood, and 16 nonstuttering adults. They found that the stutterers' brains were more likely to have unusual features -- scattered all along the speech/language areas of the brain.
There was no single difference that accounted for the stuttering. This raises the possibility that there may be different kinds of stuttering depending on which part of the brain is affected.
The brain differences weren't necessarily defects, even though they appear to be responsible for speech disorders.
"If you think about the human brain, there is a tremendous amount of variation between individuals," Foundas says. "When people looked at Einstein's brain, it was highly unusual. Maybe this was responsible for his brilliant thinking -- but he was also dyslexic. So if a person stutters, they may have another gift."
David B. Rosenfield, MD, director of the Stuttering Center/Speech Motor Control Laboratory at Baylor College of Medicine, in Houston, praises the work of the Foundas team. He agrees that the brain differences that make a person a stutterer are not brain defects.