Cricopharyngeal achalasia.
D000367:Age Factors; D000368:Aged; D004106:Dilatation; D004931:Esophageal Achalasia / Q000209:etiology / Q000601:surgery / Q000628:therapy; D004947:Esophagus / Q000033:anatomy & histology / Q000502:physiology; D005260:Female; D006801:Humans; D007817:Laryngeal Cartilages / Q000033:anatomy & histology / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000033:anatomy & histology / Q000502:physiology; D012737:Sex Factors