Pharyngeal Area Changes in Parkinson's Disease and Its Effect on Swallowing Safety, Efficiency, and Kinematics.

Pharyngeal area can increase as a function of normal healthy aging and muscle atrophy. These increases in pharyngeal area can negatively affect swallowing function in healthy older adults (HOA). However, the presence of pharyngeal area changes and their effects on swallowing function in Parkinson's disease (PD) remain unknown. Therefore, we compared the pharyngeal area of people with PD to HOA to determine if pharyngeal area changes were present in PD above and beyond what is seen in HOA. Within PD, we also evaluated if and how an increase in pharyngeal area affects swallowing kinematics, swallowing safety, and swallowing efficiency. A secondary analysis of videofluoroscopic swallow studies was completed comparing 41 HOA and 40 people with PD. Measures of pharyngeal area, swallowing kinematics, swallowing safety (penetration/aspiration), and swallowing efficiency (residue) were analyzed. An analysis of covariance (ANCOVA) was used to determine if pharyngeal area was significantly different between the HOA and PD groups while controlling for age, sex, and height. Regression analyses were used to examine if and how pharyngeal area influenced swallowing kinematics, swallowing safety, and swallowing efficiency in PD. Pharyngeal areas were significantly larger for people with PD when compared to HOA (p = .008). An increase in pharyngeal area was associated with less pharyngeal constriction (p = .022), shorter duration of airway closure (p = .017), worse swallowing safety (p < .0005), and worse swallowing efficiency (p = .037). This study revealed that pharyngeal areas are larger in people with PD when compared to HOA, and that this increase in pharyngeal area is associated with maladaptive changes to swallowing kinematics, residue, and penetration/aspiration. These findings support the notion that pharyngeal muscle atrophy may be exacerbated in PD above and beyond what is seen in normal, healthy aging group. Results from this study highlight the need to consider pharyngeal muscle atrophy as a source for swallowing dysfunction in PD, and as a potential treatment target for swallowing rehabilitation.