Which Factors Affect the Severity of Dysphagia in Lateral Medullary Infarction?

The purpose of this study was to identify factors associated with the severity of dysphagia after lateral medullary infarction (LMI). Patients with dysphagia after lateral medullary infarction who were admitted to a rehabilitation unit were included and divided into two groups (non-severe vs. severe). Severe dysphagia was defined as the condition showing decreased bilateral pharyngeal constriction without esophageal passage in a videofluoroscopic swallowing study that initially required enteral tube feeding. Their clinical data (age, sex, lesion side, duration of the illness, penetration-aspiration scale, functional oral intake scale, Modified Barthel index, National Institutes of Health Stroke Scale, and anatomical lesion on diffusion-weighted MRI) were compared to find differences between the two groups. Twelve patients had absence of esophageal passage among a total of 30 patients with dysphagia after LMI. Only anatomical lesion location and extent were significantly different between the two groups. The severe group showed posterolateral involvement in the upper and lower parts of the medulla. Otherwise, there were no significant differences between the two groups. The location and extent of involvement in the medulla were the most important factors associated with the severity of dysphagia after LMI.