Treatment of Dysfunction of the Cricopharyngeal Muscle with Botulinum a Toxin: Introduction of a New, Noninvasive Method

Abstract

Botulinum toxin is known as a relatively safe and efficacious agent for the treatment of various neurologic and ophthalmologic disorders. Since dysphagia and deglutition problems combined with aspiration are often caused by spasticity, hypertonus, or delayed relaxation of the upper esophageal sphincter (UES), conventional treatment including lateral cricopharyngotomy was replaced by localized injections of botulinum toxin into the cricopharyngeal muscle (CM) in a series of 7 patients. The study comprised patients with slight dysphagia caused by isolated hypertonus of the UES, as well as patients with severe deglutition disorders, complete inability to swallow, and aspiration problems. Preoperative diagnostic evaluation included careful history-taking, physical examination, cineradiography, and esophageal manometry to exclude other causes of dysphagia. For precise localization, injections were performed under general anesthesia after location of the CM by direct esophagoscopy and electromyographic guidance. Injections were administered into the dorsomedial part and on both sides into the ventrolateral parts of the muscle. Depending on the severity of symptoms and the intraluminal pressure of the UES, the dose varied between 80 and 120 units (botulinum toxin A from Dysport). The treatment outcome was evaluated by a disability rating score: patients' complaints were scored by subjective and objective parameters before and after injection. All but 2 patients experienced complete relief or marked improvement of their complaints. There were no severe side effects or postoperative complications. Local botulinum toxin injection proved to be an effective alternative treatment to invasive procedures for patients with isolated dysfunction of the UES, and also for patients with more complex deglutition problems combined with aspiration.