Speech and voice impairments are common among those living with Parkinson’s. As many as 90% of people with Parkinson’s experience difficulties such as “hypophonia” (soft speech) or a more monotone, raspy or breathy voice (Duffy, 2005). Speech can become less intelligible and can make communication difficult, especially if paired with decreased facial expressions (facial masking). It comes as no surprise that speech and voice impairments can impact quality of life.
Why is there voice impairment in Parkinson's?
As Parkinson’s progresses, changes in the vocal cords occur---the technical name is “vocal folds”. The muscle of the vocal cord becomes thinner and less taut. The vocal cords do not vibrate as they should, and a gap develops between the cords. If vocal cords do not fully close, air escapes through this gap and softness or hoarseness can result.
Addressing these difficulties, Dr. Olga Klepitskaya and her team at the University of Colorado, funded by the Davis Phinney Foundation in 2016, investigated the effect of an injectable gel to improve closure of the vocal cord gap. They wanted to learn:
- Will this treatment increase closure and decrease the effort needed to talk?
- Will people experience improved loudness, voice quality, intelligibility and quality of communication?
Known as “vocal fold augmentation”, this technique was first described by a doctor in 1911 as a treatment for vocal cord paralysis. Over the last 100 years, this treatment developed into an office-based procedure with a variety of approved materials for injection for voice disorders. Generally, this treatment is safe and effective; yet, it is not widely-used among those living with Parkinson’s.
Dr. Klepitskaya and her team recruited 29 people living with Parkinson’s (average age 73) to receive a short-acting injection (carboxymethylcellulose gel). This injection can last up to three months. Participants then completed questionnaires about their perceptions of their own voice about a month after treatment.
Unique to this study, researchers also recorded participants talking so that independent raters could judge the voice quality. Finally, researchers used a small camera that passed through the nose and down the vocal cords to assess the ability of the vocal cords to close.
Closure improved approximately 16% after one month. Voice judgments by independent raters also showed that severity, breathiness and loudness scores all improved after one month.
Dr. Klepitskaya and her team will continue to track these participants and assess their voice and speech. This research team is also recruiting these participants to receive another longer-acting type of injection (calcium hydroxyapatite paste) and then tracking these participants for two more years to examine the impact of that type of treatment.
While the speech and voice impairments that often accompany Parkinson’s can impact communication and affect quality of life, work to identify and refine treatments continues to make progress. As research builds a case for this type of treatment, perhaps it will become more wide-spread and help people live well today.
For Further Reading
Hypophonia in Parkinson’s disease: Neural correlates of voice treatment revealed by PET
Speech and Voice Impairments in Individuals with PD
Speak easy: 6 tips for improving speech in Parkinson’s patients
Comparison of Intelligibility Measures for Adults With Parkinson's Disease, Adults With Multiple Sclerosis, and Healthy Controls
The Harvard Sentences and the Lists