For Some With Parkinson's, Surgery Can Improve Speech, Study Finds

December 15, 1999

GAINESVILLE — When Parkinson’s Disease sufferer James Stuebe underwent brain surgery last year, he was overjoyed it nearly eliminated the tremors in his right arm and hand.

But the surgery also had another beneficial effect: It improved his voice.

“I felt I was speaking in a monotone that was quite noticeable before I had the surgery, and I was told the volume of my voice was tapering off at the end of sentences,” he said. “I think I’ve got most of the color back in my voice that I had before.”

Stuebe, 66, a retired motorcycle dealership service manager in Gainesville, is one of several patients to experience speech improvements as a result of the surgery known as pallidotomy, according to the results of a new study by a team of University of Florida researchers. While pallidotomy is widely known to reduce or eliminate the tremors often associated with Parkinson’s, the study is the first to offer scientific evidence it can also raise the volume of patients’ voices, said Geralyn Schulz, lead researcher and a UF assistant professor of communications sciences and disorders.

“It’s exciting to know that something is helpful for at least one of the speech symptoms,” said Schulz, whose paper on the study recently was accepted for publication in the Journal of Voice, a leading national journal on speech and voice issues.

More than 1.5 million Americans suffer from Parkinson’s Disease, a degenerative neurological disorder that reduces the ability to control muscles, resulting in tremors, slow movement and rigidity. About 80 percent of Parkinson’s patients also experience speech and voice problems, including reduced volume, slurring and slowed speech. People with Parkinson’s include actor Michael J. Fox, country singer Johnny Cash and U.S. Attorney General Janet Reno.

Pallidotomy is a type of surgery that permanently destroys a small area deep inside the brain of Parkinson’s sufferers that sends out too many “stop” signals to other parts of the brain that control movement. These signals cause tremors and slow down movement in muscles, including the muscles of the vocal chords and respiratory system, which results in an inability to speak with sufficient volume. Doctors began experimenting with the surgery, which involves drilling a hole in the skull and sending a probe deep in the brain, in the 1930s. But the technique was pushed aside in the 1960s by the use of the drug l-dopa, which led to more dramatic improvements. Recently, however, pallidotomy and other surgical techniques have returned to fashion because some patients who use anti-Parkinson’s drugs for years develop severe side effects.

In her study, Schulz found that seven of 12 Parkinson’s patients with mild speech volume problems improved following pallidotomy surgery, a statistically significant 58 percent. Other tests of patients with moderate or severe volume problems, however, failed to show improvements following surgery.

“The take-home message seems to be, If you’re going to perform the pallidotomy from a speech perspective, the time do it is when your problems are still mild,’” Schulz said.

She added that preliminary results show pallidotomy surgery also may have other benefits for people with mild voice problems, including reducing slurring problems. She plans to look at those issues in more depth in future studies, she said.

The other members of the research team are Melvin Greer, professor of neurology, and William Friedman, professor of neurological surgery, both at the UF College of Medicine. All three researchers are members of the UF Brain Institute. The pallidotomy program at the UF Health Science Center was funded in part by the National Parkinson’s Foundation.