OBJECTIVE: The aims of this study were to assess the incidence rate and risk factors for sialorrhea in the long-term follow-up in a cohort of 170 patients with advanced Parkinson's disease [84 with deep brain stimulation (DBS) and 86 on medical treatment].

Design, setting, and participants: This study was a multi-center prospective non-randomized concurrent clinical trial. A total of198 persons with Parkinson disease were referred for DBS between June 2019 and July 2021 and analyzed between June 2023 and July 2023.The primary outcome follow-up visit was conducted 36 months after DBS.

IMPORTANCE: Sialorrhea is a frequent and disabling symptom in patients with PD. No prospective study has been specifically designed to test the effects of DBS on sialorrhea development.

OBJECTIVE: The aims of this study were to assess the incidence rate and risk factors for sialorrhea in the long-term follow-up in a cohort of 170 patients with advanced Parkinson's disease [84 with deep brain stimulation (DBS) and 86 on medical treatment].

Design, setting, and participants: This study was a multi-center prospective non-randomized concurrent clinical trial. A total of198 persons with Parkinson disease were referred for DBS between June 2019 and July 2021 and analyzed between June 2023 and July 2023.The primary outcome follow-up visit was conducted 36 months after DBS.

INTERVENTIONS: Bilateral subthalamic nucleus DBS was performed in one study arm and not performed in the other. Both arms of the study completed the drooling rating scale (DRS), the drooling severity and frequency scale (DSFS) and examination of salivary secretion rate.

MAIN OUTCOMES AND MEASURES: The primary outcome was the DRS scores of the patients with PD, with or without STN-DBS 36 months postoperatively. The secondary outcomes included the DSFS scores, saliva secreting rate, ratio of botox injection in different group.

Inclusion Criteria:

• Clinical diagnosis of Alzheimer's Disease
• Age between 20 and 80 years
• without drooling
• swallowing function <5 on the Drooling Rate Scale (DRS).
• Medications affecting drooling had to have stopped medications at least 4 weeks before study entry.

Exclusion Criteria:

• Not he typical PD
• Subjects on warfarin,
• with significant medical illnesses or neuromuscular transmission disorders
• past use of BoNT
• -cognitive impairment (<23/30 on Mini Mental Status Exam) were excluded.

individual participant data (IPD) could be available to other researchers on request without business benefits.

Investigator was blinded to the status of DBS or non-DBS during the scoring of DRS, DSFS and drooling rate examination.