An Interesting Case of Oropharyngeal Dysphagia after a Botox injection for Sialorrhea

Abstract

Purpose: Sialorrhea is caused by excessive salivation that is commonly seen in patients with neurodegenerative diseases. Botox injection to the parotid gland and submandibular gland offer an effective and localized method to decreased saliva secretion. Although botox injection is relatively safe and effective, serious complication such as hypoglossal nerve paralysis, diffuse oropharyngeal muscle paralysis, or death can occur. We present an interesting case of oropharyngeal dysphagia from diffuse muscular paralysis of oropharyngeal muscles and hypoglossal nerve paralysis after a Botox injection for idiopathic sialorrhea. This patient had hypersalivation for over 1 year and was seen by ENT for Botox injections. She received her first Botox injection (25 units of Botox to each parotid gland) 2 months prior with symptomatic improvement. Shortly after the first botox injection, her hypersalivation returned back to baseline. She was seen by a neurologist for evaluation. Patient had a normal EMG and MRI brain. She then returned to ENT for her second botox injection (total of 70 units of botox was injected to bilateral parotid glands and left submandibular gland). Two days after her second Botox injection, the patient developed dysarthria and dysphagia to both solid and liquids. Due to severe dehydration, patient was admitted for intravenous hydration. ENT evaluation showed symmetric and mobile vocal cords with good abduction and closure, intact gag reflex, and laryngeal sensation. CT neck and chest showed a collapsed esophagus. Esophagram was limited with tertiary contractions seen throughout the esophagus. Upper endoscopy was unremarkable and did not reveal any mass or stricture. Video fluoroscopy swallow showed a significant reduced lingual anterior to posterior propulsion, and poor pharyngeal transit resulting in moderate pharyngeal retention. Given the clinical presentation and repeat EMG study, neurology concluded that it is unlikely ALS or myasthenia gravis. In exclusion, patient was thought to have lingular dyscoordination and dysarthria consistent with bilateral cranial nerve XII palsy or diffuse muscular paralysis of oropharyngeal muscles. Due to severe dehydration, patient had a PEG tube placement for nutrition until her symptoms improved. Patient continued to require PEG tube for nutrition 1 year after the initial event because of persistent oropharyngeal dysphagia. An ultrasound-guided Botox injection will offer a safer approach by delivering Botox to the proper location and minimizing complications. Also, decreasing the dose or frequency of botox injections should be considered to avoid serious complications.