Pitt Researchers Identify a Cause of Pneumonia Common In Parkinson’s Disease Patients

Impaired coordination between breathing and swallowing may be the underlying cause of aspiration pneumonia in patients with Parkinson’s disease, researchers from the University of Pittsburgh School of Medicine report in a recent issue of the journal Dysphagia.

At least half of all Parkinson’s patients report having difficulty swallowing and a higher percentage show swallowing abnormalities on X-ray tests. Aspiration pneumonia, a leading cause of death for individuals with Parkinson’s, often develops as a complication of mealtime swallowing problems, leading to the inhalation of food and drink. The high prevalence of swallowing problems and risk of aspiration pneumonia in these patients may be largely a result of flawed breathing and swallowing patterns, according to the researchers.

The findings, which mark a significant step toward preventing aspiration pneumonia in patients with Parkinson’s, indicate that swallowing problems may be respiratory-based as well as neuromuscular-based, helping to explain why Parkinson’s medications do not consistently help to improve swallowing function.

“Most Parkinson’s patients don’t know they have swallowing problems—even though aspiration pneumonia often is a severe complication of the disease—and Parkinson’s drugs most often do not improve these patients’ swallowing function,” said Roxann Diez Gross, principal investigator and assistant professor in the Department of Otolaryngology at the University of Pittsburgh School of Medicine. “Now that we know the respiratory system may play an important role in swallowing problems in patients with Parkinson’s disease, we can develop therapies to help these patients recoordinate breathing and swallowing patterns to improve swallowing function and possibly avoid aspiration pneumonia,” said Gross, who also is a speech-language pathologist and director of the Swallowing Disorders Center in the otolaryngology department.

Gross, an expert in swallowing and its disorders, has begun to incorporate this and other research into therapies for Parkinson’s patients at the Swallowing Disorders Center, which is under the medical direction of Ricardo Carrau, a Pitt professor of otolaryngology, and Bridget Hathaway and Libby Smith, both assistant professors of otolaryngology.

Gross currently sees Parkinson’s patients with swallowing disorders, and, thus far, she has been able to stop aspiration instantly in some patients after quickly teaching them how to recoordinate their breathing and swallowing patterns.

While the underlying cause of swallowing problems in Parkinson’s has not been well understood, prior research has found that healthy adults swallow most often during exhalation and that exhalation regularly follows the swallow, even when a swallow occurs during inhalation. Gross’ study looked at 25 Parkinson’s patients and a control group of healthy adults, all between ages 51 and 84, as they swallowed standardized portions of pudding and cookies. While participants from both groups spontaneously ate, researchers measured their nasal airflow and respiratory movement to determine where swallowing took place in the respiratory cycle. This data was then blinded and analyzed; results found the Parkinson’s patients inhaled during and after swallowing significantly more often than the healthy adults. Also, the Parkinson’s patients swallowed at low-lung volumes more often than the healthy adults.
This research was performed at the University Drive location of the VA Pittsburgh Healthcare System and was funded by the Department of Veteran’s Affairs Research and Rehabilitation Merit Review Program.