By Andrea Estrada

For an adult who stutters, the mere act of introducing himself or herself is enough to cause sweaty palms, heart palpitations, and worse.

Stuttering affects more than 3 million people in the United States, occurring most frequently in children as their language skills begin to develop. Children generally outgrow the disorder, but it can become a chronic problem for the roughly 1 percent who carry it into adulthood. Adult onset of the disorder also can occur, usually due to a brain injury, mental illness, or a drug overdose.

Stuttering is one of the most commonly known speech disorders but the most difficult to treat effectively, especially in adults. At present, no cure for the disorder exists.

That may change due to a large scale, five-year study currently being conducted by Roger Ingham, professor of speech and hearing, to evaluate a protocol he developed to treat adults who stutter. Supported by a $2.5-million grant from the National Institute on Deafness and Other Communication Disorders, the study marks the second phase of clinical trials to determine the treatment’s efficacy.

The first was completed successfully in 2001 with a group of five subjects. Each of the five speakers in the initial study achieved and maintained stutter-free and natural-sounding speech when tested 12 months after completing the program.

As many as 50 adults are participating in the second study, which began last summer and takes place at the Research Imaging Center at the University of Texas Health Science Center in San Antonio, where Ingham is currently an adjunct professor. The treatment is being evaluated in conjunction with brain imaging, specifically, positron emission tomography (PET). It is part of a collaboration between Ingham and Peter Fox, director of the imaging center. Ingham directs the activity and monitors the participants’ progress via the Internet.

Ingham’s treatment protocol, called Modifying Phonation Intervals (MPI), uses a software program he developed in association with former staff members in the Department of Speech and Hearing, and his wife, Janis, who is also a professor in the department.

“People who stutter cannot control rapid onset and offset of particularly short intervals of phonation,” said Ingham. “The treatment trains the stutterer to alter his or her custom of speech to avoid those short intervals.”

According to Ingham, recent imaging studies on adults who stutter have revealed unusual regional fluxes in cerebral blood flow during stuttered speech, particularly in the brain’s right hemisphere. These findings have intensified the search for a dysfunctional neurological system that might be functionally related to stuttering.

The treatment protocol takes about 18 months to complete. During that time patients receive five sets of PET scans so researchers can examine changes in the regions of the brain believed connected to stuttering behavior.

“We’re looking at what neural changes accompany treatment and, more specifically, what neural changes occur in people for whom it’s helpful and for whom it isn’t,” said Ingham. “We’re looking to see whether critical regions of the brain are changed.”