Laterality of pharyngeal bolus passage in Wallenberg's syndrome patients with dysphagia

In this study, bolus passage through the pharynx and the mechanism that causes laterality of bolus passage were examined in 29 dysphagic patients with Wallenberg's syndrome (63±10 years). Video-fluorography was taken to visualize the bolus passage. For the purposes of analysis, the pharynx was divided into the thyropharyngeal portion and the cricopharyngeal portion. The period after disease onset of the cases with bolus passage dominantly on the affected side in the thyropharyngeal portion was significantly shorter than that of cases with bolus passage on both sides. The period was not different among the passage sides in the cricopharyngeal portion significantly. The bolus passages in the cricopharyngeal portion were significantly associated with the passages in the thyropharyngeal portion. Passage of the bolus dominantly on the affected side in the thyropharyngeal portion may be attributed to the asymmetric contraction of the pharynx caused by the paralysis of the pharyngeal constrictor. Together, the bolus passage in the thyropharyngeal portion and the open status of the cricopharyngeal portion presumably determine the path that the bolus takes in the cricopharyngeal portion.