Dysphagia can be caused by various mechanisms such as impaired tongue movement, delayed swallowing reflex, decreased pharyngeal peristalsis, incomplete closure of epi-glottis and cricopharyngeal dysfunction. Cricopharyngeal muscle, forming the upper esophageal sphincter, acts as a muscular sling between the pharynx and the esophagus. Normally, it closes constantly at rest and opens during laryngeal elevation through active relaxation on the one hand and passive traction by the antero-cephalad laryngeal movement on the other. If its incoordination or hypertonicity happens, dysphagia can develop. Cricopharyngeal muscle dysfunction is caused by various situations such as neuro-muscular diseases, postoperative changes and stroke, parti-cularly after brainstem stroke. We report a case of isolated dysphagia caused by failure of active relaxation of crico-pharyngeal muscle without aspiration after left lateral me-dullary lacunar infarction. (J Korean Acad Rehab Med 2009; 33: 252-254)
