Objective: To assess if silent aspiration is a risk factor for respiratory infection in patients with Parkinson's disease (PD).
Method: From February 2006 to June 2006, 19 PD patients with diurnal sialorrhea were evaluated by swallow videofluoroscopy (VF). Two patients moved away and contact with them was lost. The other patients were divided into two groups according to the presence or absence of penetration/aspiration and were followed up for 1 year. During this period, patients were assessed for airway infections, hospital admissions, weight loss, use of nasoenteral or gastric tube and to detect cases of death.
Results: Silent laryngeal penetration or silent aspiration (SLP/SA) was observed in four patients. During the follow up period, three of the four patients with SLP/SA developed respiratory infection, and one of the 13 patients who did not show SLP/SA had airway infection (RR=9.75, 95% CI: 1.36-69.65). Two patients with SLP/SA developed airway infection and died, and there were two deaths in the group who had not been diagnosed for SLP/SA, one due to cardiac arrest and the other related to pancreatic cancer.
Conclusion: The results suggest that patients with Parkinson's disease with diurnal sialorrhea and SLP/SA have an increased risk of respiratory infections, which is the main cause of death in PD patients. The data support a greater emphasis on preventive interventions for silent aspirations and silent penetration to improve survival in patients with Parkinson's disease.