Sialorrhea, or excessive saliva beyond the margin of the lip, is a common problem in many neurological diseases. Previously, sialorrhea has been underrecognized in Parkinson's disease (PD) patients. Despite this, many patients rank sialorrhea as one of the most debilitating complaints of Parkinson's disease. Previous treatment for sialorrhea has been suboptimal and has been plagued by significant side effects that are bothersome and can be dangerous in patients with a concurrent neurodegenerative disease. This review sought to review the anatomy, function, and etiology of sialorrhea in PD. It then sought to examine the evidence for the different treatments of sialorrhea in PD, and further examined newer evidence for safety and efficacy in minimally invasive treatment such as botulinum toxin.
Keywords: Abobotulinumtoxin A; Incobotulinumtoxin A; Onabotulinumtoxin A; Parkinson’s disease; Rimabotulinumtoxin B; botulinum toxin; drooling; sialorrhea.