Bilateral Recurrent Laryngeal Nerve Injury Following Botulinum Toxin Injection at the Cricopharyngeus Muscle:...

Bilateral vocal cord paralysis poses life-threatening risks to patients who do not undergo prompt diagnostic intervention and airway management. Although developing bilateral vocal cord paralysis is extremely rare, if injury does occur, it is more frequently due to surgical resection sequelae in the neck. This case is particularly unique as we present a patient with a history of stage III laryngeal carcinoma status post chemotherapy in remission, who developed respiratory distress three days following an upper endoscopy procedure for an esophageal stricture at the level of the cricopharyngeus muscle, where he received a botulinum injection. This manuscript discusses the anatomy, clinical practices of botulinum toxin, nerve innervation, and mechanisms of injury for patients who develop bilateral recurrent laryngeal nerve injury. In addition, this manuscript details vocal cord positioning and how the positioning of the cords during laryngoscopy investigation can lead to diagnostic confirmation. With few reported cases of bilateral recurrent laryngeal nerve injury secondary to botulinum toxin particularly at the cricopharyngeus level, this report should serve as a guide for future clinicians regarding the risks of using this toxin, the risks of local spread, and management.