Self-Perception of Drooling Impact in People with Parkinson's Disease: A Case-Control and Cross-Sectional Study

Drooling, defined as the involuntary loss of saliva from the anterior oral cavity, is potentially problematic for people with Parkinson's disease (PwP). However, there is little research on how PwP perceive the impact of drooling and what factors contribute to it.

The objective was to evaluate the self-perceived impact of drooling in people with and without Parkinson's disease and the contributing clinical factors in PwP.

We conducted a cross-sectional and case-control study. Participants were clinically examined, and the primary outcome was the Sialorrhea Clinical Scale for Parkinson's disease. Clinical variables were compared between PwP and control subjects using the Mann-Whitney test, correlations between drooling impact and clinical factors in PwP were analyzed using Spearman's test, and predictors were identified using linear regression.

The study included 101 PwP and 101 sex- and age-matched controls. PwP experienced significantly more severe impact of drooling compared to controls across all domains: diurnal and nocturnal drooling, drooling severity and frequency, social discomfort, speech, and eating impairments. The greater impact of drooling in PwP was significantly associated with drooling severity, disease duration, levodopa equivalent daily dose, clinical global impression of saliva accumulation (CGI-S), chewing, swallowing, speech, oromotor, motor and non-motor impairments. Significant predictors of greater impact of drooling in PwP include drooling severity, higher CGI-S, facial expression, and swallowing impairments.

PwP have a significantly greater impact of drooling compared to controls, affecting several domains. Drooling impact and its contributing clinical factors should be investigated in a Parkinson's consultation.