Study: Parkinson’s Patients Speak 60% Less Than Healthy Peers
People with Parkinson’s disease verbally communicate less than those without the neurodegenerative disorder, according to a recent study that discovered that patients speak about 60% less than their healthy peers.
Apart from the tremors and movement issues associated with Parkinson’s, the disease also can disrupt aspects of a person’s speech, including volume, rhythm, and intonation. Such difficulties in speaking lead those with Parkinson’s to rate themselves as being worse at conversing compared with their counterparts without the disease, according to researchers.
Now, a new quantitative study shows that, in fact, patients speak for fewer minutes each day than those without Parkinson’s.
“In some cases, a person with Parkinson’s will hesitate to speak or pause when speaking, leading even attentive listeners to jump in or talk over that person,” according to a press release from the University of Nebraska-Lincoln. Angela Dietsch, PhD, an associate professor in the university’s department of special education and communication disorders, conducted the study with Jeff Searl, PhD, director of the undergraduate program in communicative sciences and disorders at Michigan State University.
The study reporting their findings is titled “Daily Phonatory Activity of Individuals With Parkinson’s Disease,” published in the Journal of Voice. The two researchers investigated the amount of phonatory activity — also called phonation or voicing, but basically, how people speak — among Parkinson’s patients compared with those without the disease.
The team looked at 30 age- and sex-matched individuals, half diagnosed with Parkinson’s and using dopaminergic medications — commonly used medicines to replace the dopamine lacking in Parkinson’s patients — and half without the disease, who served as the control group.
All participants were asked to wear vocal monitors — specifically, the VocaLog vocal monitor — for three days while going about their daily lives. The monitor measures the number of one-second windows in which the sound is increased over zero and then reports that relative to how long the monitor is worn. That allows for the determination of %PA, or percentage of phonatory activity, which essentially quantifies how much time people speak.
This method gets around the usually used questionnaires, in which participants often overestimate their speaking time.
The Voice Handicap Index score — a self-reported measure in which patients report how much their voice disorder impacts their quality of life — also was assessed.
Results showed that patients with Parkinson’s had, on average, 54 fewer minutes per day in which they spoke, resulting in about 60% less speaking than those without Parkinson’s. Those with Parkinson’s had 11.1% phonatory activity over the course of the three days, while those without the disorder had an activity of 18.6%.
Additionally, the Voice Handicap Index was found to directly correlate with the amount of speaking the patients did. Those who scored themselves higher on the index, meaning they had less quality of life due to a higher impact of vocal issues, tended to speak less than those who scored themselves lower.
Overall, “the results indicate that PwPD [people with Parkinson’s disease] engaged in less verbal communication in their daily environment compared to adults without Parkinson’s disease,” the researchers wrote. “The findings support reports in the literature indicating that PwPD often have reduced communication participation.”
Furthermore, the team believes that the percent of phonatory activity may be a useful measure to assess communication changes in patients with Parkinson’s disease, as a way to evaluate both disease progression and treatment.
“Measures such as %PA could serve as a quantifiable metric in future studies,” the researchers concluded.