Botulinum Toxin Injection Into the Cricopharyngeal Muscle for Syringobulbia-induced Dysphagia: A Case Report

We report a patient treated with botulinum toxin (BTX) for syringo-bulbia-induced cricopharyngeal dysphagia. A 54 year-old man with prior history of posttraumatic syringomyelia developed dysphagia suddenly. Bulbar function revealed palatal paresis and complete aglutition without lingual paresis. A videofluoroscopic swallow-ing study disclosed non-relaxation of the cricopharyngeal muscles (CPM). Follow-up magnetic resonance imaging displayed progres-sion of syringobulbia and ascending syringomyelia. Symmetric slit-like medullary cavities could cause CPM dysfunction. A thoracic syringoperitoneal shunt had no therapeutic effects on dysphagia. He refused to undergo a syringocisternal shunt or cricopharyngeal myotomy. BTX (20 units) was injected into the left CPM under electromyographic guidance. Five days later, he was able to eat and drink gradually. Clinicoradiological profile of our patient indicated that the interruption of bilateral inhibitory projections from the soli-tary nuclei to the ambiguus nuclei could elicit uncontrollable CPM. BTX is beneficial and hopeful treatment for cricopharyngeal dys-phasia due to progressive syringobulbia