Incobotulinum Toxin A (Xeomin®) for Troublesome Sialorrhea in Parkinson's Disease (PD)/Parkinsonism

Participants will be recruited if they have Parkinson's disease, Parkinsonism. Inclusion and exclusion criteria are summarized below. Participants will be screened at the first visit to make sure they are eligible for the trial. They will then undergo baseline testing including neurologic evaluation, questions to assess their memory and cognitive status and evaluation of their disease status using parts of the Unified Parkinsons's Disease Ratings Scale (UPDRS) that are routinely used to follow disease progression. They will be given a questionnaire to evaluate the severity of their drooling. Their saliva production will be measured by having them spit into a cup for 5 minutes, twice.

At the first visit, after making sure they are eligible for the study and performing the baseline testing and procedures, they will be given either Xeomin or placebo (saline injections without medication) injections in the 4 glands that produce saliva. They will not know which injection they received. This visit will take about 2 hours. They will be followed up every month and asked about side effects, have neurologic evaluation and UPDRS testing and fill-in the questionnaire for drooling severity. Saliva volume will be measured as done at the first visit. At either Month 4 or 5, participants will receive the second injection. This will be a "cross-over" injection, i.e., if they received Xeomin at the first injection they will receive saline at the second and vice versa. Thus, all participants will receive the study medication Xeomin, either as the first injection or the second injection at 4 months or 5 months. The follow up after the second injection will be one monthly visit for 3 months, with similar evaluations as described above. The follow-up visit will take about 1 hour each.

Inclusion criteria

• For PD/ Parkinsonism: 1. PD, Multiple Systems Atrophy (MSA), or Progressive Supranuclear Palsy (PSP) diagnosed by clinical criteria, ages 20-80 with troublesome sialorrhea as defined below**.

• Sialorrhea that patients or their families or treating physicians think is troublesome

• Swallowing function: Functional Oral Intake Scale (FOIS)* of 5 or greater
• If patients have been treated with other medications for sialorrhea earlier, they should be off the medications at least 4 weeks prior to the baseline evaluation.
• If they are on other medications for sialorrhea at the time of the baseline evaluation, the doses will be held stable throughout the period of the study.
• Women of child bearing age will need to be on a reliable method of birth control for the duration of the study.

Exclusion criteria

• For PD:

• Current use of Coumadin
• Concurrent significant medical illness
• History of myasthenia gravis or Lambert-Eaton Syndrome
• Ongoing substance abuse
• History of unreliable follow-up
• Past use of Xeomin® or other botulinum toxin preparations
• Cognitive impairment, defined as a score ≤ 23/30 on the Mini Mental Status Exam