Does botulinum toxin injection in parotid glands interfere with the swallowing dynamics of Parkinson's disease patients?

Abstract Background During recent years, sialorrhea in Parkinson's disease (PD) has been treated with botulinum toxin type A (BT-A); however, there are no data describing its effects on swallowing dynamics in this group of patients. Objective To investigate whether injection of BT-A into the parotid glands interferes with the oropharyngeal swallowing dynamics of patients with Parkinson's disease. Methods Sixteen patients with diurnal sialorrhea were selected and evaluated during the “on” period by a standardized questionnaire and swallowing videofluoroscopy before and 30 days after ultrasound-guided BT-A injection into the parotid glands. Results A decrease in sialorrhea was observed in all studied patients. Silent laryngeal penetration was observed in three patients, and silent aspiration was observed in two of them. There were no changes in swallowing dynamics when comparing patients before and after BT-A parotid injection ( p  = 1), suggesting similar levels of dysphagia in the two measurements. Conclusion BT-A injection into parotid glands does not interfere with the oropharyngeal swallowing dynamics of PD patients.