Parkinson's disease is a chronic degenerative neurologic disorder commonly associated with tremors, a shuffling walk and a flat facial expression. Less well known is the effect Parkinson's disease has on the voice.
Almost 90 percent of patients diagnosed with Parkinson's disease have some voice deterioration. Family and friends will often notice the symptoms before the patient does.
Patients often have a quiet voice, frequently have to repeat themselves to be heard and can mumble, stutter and deal with hoarseness. Individuals with Parkinson's disease also often have trouble swallowing.
Although medications and deep brain stimulation can improve gait and help reduce tremor, these treatments rarely produce direct benefits for the voice. However, intense therapy with a speech pathologist who specializes in voice and swallowing disorders can facilitate a recovery.
Research has shown the "gold standard" for voice therapy in patients with Parkinson's disease is a technique known as the Lee Silverman Voice Treatment, which has proven to increase vocal loudness, help speech intelligibility, increase facial expression and improve swallowing.
These sessions require high-effort (but not strenuous) vocal exercise. Sessions are one hour daily, four days a week, over the course of a month, and with ongoing use of the techniques taught in therapy the results have been shown to last up to two years.
Because individuals with Parkinson's disease are usually not aware of how quietly they are speaking, therapy involves getting the patient to focus on a simple target, and to maintain that focus during communication in and out of the clinic.
As patients progress in therapy, the length and complexity of their speech increases, as does their loudness. Practice is intense, one-on-one and geared toward home and social interaction. Training includes simple, frequently used phrases so the improved voice becomes automatic while building endurance.
I encourage patients to call family members, and often this will be their first phone conversation in some time. The positive feedback becomes fuel for the patient to work hard, as they recognize improvement.
Any individual diagnosed with Parkinson's disease may benefit from this treatment. It also has been shown to improve speech quality in disorders like multiple sclerosis, cerebral palsy and multiple systems atrophy. Regardless of disease progression, benefits can be obtained; it is rarely too late to introduce therapy and improve quality of life.
Rebecca L. Hancock is a speech pathologist for the University of Kentucky Clinical Voice Center.