Sialorrhea in Parkinson's disease: a review.

A significant number of patients with Parkinson's disease (PD) experience sialorrhea. This problem can cause social embarrassment, and because saliva pools in the mouth, may lead to aspiration pneumonia. Sialorrhea in PD is thought to be caused by impaired or infrequent swallowing, rather than hypersecretion. Oral medications, botulinum toxin injections, surgical interventions, radiotherapy, speech therapy, and trials of devices may be used to treat sialorrhea in PD, but few controlled trials have been published. This article reviews current knowledge regarding the frequency, etiology, assessment, and treatment of sialorrhea in PD.