The Effect of Stroke on Pharyngeal Laterality During Swallowing

To investigate whether patterns of dysphagia and swallowing laterality differ according to the location of brain lesions in patients with stroke.

Patients with stroke >20 years of age were enrolled in this study. A videofluoroscopic swallowing study (VFSS) including the anterior-posterior view was used to assess swallowing. Patterns of swallowing were classified into three types according to the width of barium sulfate flow while passing the pharyngoesophageal segment: right-side-dominant flow, left-side-dominant flow, and no laterality in flow. Laterality was defined when the width of one side was twice or more the width of the other side.

A total of 92 patients who underwent swallowing function evaluations by VFSS were enrolled from Sep-tember 2012 to May 2013. Of these, 72 patients had supratentorial lesions (group I) and 20 patients had infratento-rial lesions (group II). Only 10 patients (13.9%) in group I and three patients (15.0%) in group II showed laterality. Of these 13 patients, laterality occurred on the left side regardless of the side of the brain lesion. No relationships were found between swallowing laterality and location of stroke or motor weakness.

The results suggest that swallowing laterality was not prevalent among patients with stroke and that lesion side, location of the brain lesion, or motor weakness did not influence swallowing laterality. Although stroke can cause symptoms of dysphagia, it is difficult to conclude that stroke has a crucial impact on swallowing laterality.