Abstract
Dysphagia is common in Parkinson's disease (PD) and is assumed to complicate medication intake. This study comprehensively investigates dysphagia for medication and its association with motor complications in PD. Based on a retrospective analysis, a two-dimensional and graduated classification of dysphagia for medication was introduced differentiating swallowing efficiency and swallowing safety. In a subsequent prospective study, sixty-six PD patients underwent flexible endoscopic evaluation of swallowing, which included the swallowing of 2 tablets and capsules of different sizes. Dysphagia for medication was present in nearly 70% of PD patients and predicted motor complications according to the MDS-UPDRS-part-IV in a linear regression model. Capsules tended to be swallowed more efficiently compared to tablets, irrespective of size. A score of ≥1 on the swallow-related-MDS-UPDRS-items can be considered an optimal cut-off to predict dysphagia for medication. Swallowing impairment for oral medication may predispose to motor complications.