ABSTRACT
Objective@#Botulinum toxin was used to treat patients with difficulty in relaxation of the upper esophageal sphincter (UES), but the treatment did not always yield good results. We, therefore, attempted to investigate if there was any other factor affecting the outcome and hypothesized that this could be caused due to pharyngeal constriction. @*Methods@#We conducted a retrospective study on a botulinum toxin injection treatment given to eleven patients with nasal backflow and pharyngeal stasis in the course of a videofluoroscopic swallowing study from August 2006 to December 2012. After the injection, the cases showing an esophageal passage of diluted barium regardless of aspiration were defined as “good”, and the cases showing no passage were defined as “bad”. Pharyngeal strength was measured using the pharyngeal constriction ratio (PCR), which was compared between the two groups using the Mann-Whitney U test for proving the hypothesis. @*Results@#Five of the eleven patients showed esophageal passage after the injection treatment and were assigned to the “good” group. The remaining 6 were assigned to the “bad” group. When comparing the average PCR of each group, the ‘good’ group’s ratio was at 0.09±0.03 and the ‘bad’ group was at 0.29±0.16, showing a statistically significant difference (P＜0.05). @*Conclusion@#The strength of pharyngeal constriction could be considered to be an important factor influencing the outcome after botulinum toxin treatment for the difficulty in relaxation of the UES.