Ultrasonography-guided botulinum toxin injection to the cricopharyngeus muscle: a case report and technical notes.

Dysphagia associated with the cricopharyngeus muscle (CPm) dysfunction negatively influences the quality of life. This high-pressure region must relax and the lumen must open for smooth food passage. The CP muscle is therefore a common target of chemodenervation with botulinum toxin (BTX). Here we presented a patient with severe left lateral medullary syndrome and non-relaxation of the CPm. We described how to localize the CPm in the transverse and longitudinal views under ultrasonography and offered a video demonstrating ultrasonography-guided BTX injection. Ultrasonography-guided CPm injection with BTX may serve as a reliable, rapid, and effective choice for treatment of cricopharyngeal dysphagia.