Motor subtypes and other risk factors associated with drooling in Parkinson's disease patients
Of these symptoms, drooling is a common and disturbing symptom, with frequencies ranging from 10% to 80% in controlled studies.5 Drooling can cause a series of physical and psychosocial complications, including perioral skin damage, increased aspiration‐related lung infections, and increased risk of death in patients with PD and may be socially disabling.6
Drooling is defined as excessive pooling of saliva in the oral cavity due to overproduction of saliva or impaired salivary clearance, caused by swallowing difficulties or inability to maintain saliva within the oral cavity.6 In patients with PD, there is no increase of serous saliva production, but a significant saliva retention which could produce discomfort in swallowing, suggesting that drooling in patients with PD is probably caused by impaired and infrequent swallowing.7
Studies showed that male sex, age, dysarthria, PD family history, and some motor and non‐motor symptoms were related to drooling in patients with PD.8 A more significant association between drooling and the bradykinesia questions of the motor part of UPDRS III was found.9 There is lack of investigations on the relationship between drooling and motor subtypes. The aim of the study is to explore the relationship between motor subtypes and drooling, and other motor and non‐motor risk factors related to drooling in a large cohort of 586 Chinese patients with PD.