Feb. 25, 2003 -- For people with Parkinson's disease, talking can be a struggle or even embarrassing when a whisper comes out as a shout. But a new speech therapy technique may help these patients by teaching them to speak "loud and low" rather than shouting to get their message across.
Two studies in the Feb. 11 issue of Neurology show that a classic speech therapy technique can actually reprogram the brain to help Parkinson's patients speak more effectively, and a new modification of this technique can further improve their speaking abilities.
Researchers say about 89% of people with Parkinson's disease have speech and voice symptoms, but only 3% to 4% of them receive speech treatment. Most people with Parkinson's have soft voices because the disease makes it harder to force the necessary amount of air through the larynx or voice box to produce a normal speaking volume, and the vocal cords are often weakened and don't vibrate adequately to produce sound.
Although drugs and surgery may improve other symptoms of Parkinson's, these treatments usually do little to improve speech problems.
In the first study, researchers found evidence that a voice treatment frequently used to improve speech in Parkinson's patients produced tangible changes in the brain in areas associated with motor skills.
Researchers from the University of Texas Health Science Center at San Antonio compared PET brain scans in Parkinson's patients before and after a month of intensive voice and loudness training using the Lee Silverman method, which teaches patients to "speak loud, think shout." They found a shift in brain activity that suggested a change from more effortful speech to a more automatic form of speech production.
Although this method makes speech of Parkinson's patients easier to hear, it can also make their voices less intelligible and overly high-pitched and loud.
In the second study, researchers from the Institute of Neurology at the University of Nijmagen in the Netherlands found that refining the Lee Silverman method by instructing patients to "think loud, think low" not only improved the loudness of their speech but also enhanced the quality of their voice by easing tension in the larynx.
The study compared the two methods and found that both treatments produced the same increase in loudness, but the modified technique limited the rise in vocal pitch and prevented strained or pressed-sounding speech.
SOURCE: Neurology, Feb. 11, 2003.