gastrointestinal disorders
Achalasia
Introduction
Achalasia is a neurogenic esophageal motility disorder characterized by impaired esophageal peristalsis and a lack of lower esophageal sphincter relaxation during swallowing. Symptoms are slowly progressive Dysphagia , usually to both liquids and solids, and regurgitation of undigested food. Evaluation typically includes manometry, barium swallow, and endoscopy. Treatments include dilation, botulinum toxin injection, surgical myotomy, and peroral endoscopic myotomy. (See also Overview of Esophageal and Swallowing Disorders .) Achalasia is thought to be caused by a loss of ganglion cells in the myenteric plexus of the esophagus, resulting in denervation of esophageal muscle. Etiology of the denervation is unknown, but viral and autoimmune causes are suspected, and certain tumors may cause achalasia either by direct obstruction or as a paraneoplastic process. Chagas Disease , which causes destruction of autonomic ganglia, may result in achalasia. Increased pressure at the lower esophageal sphincter (LES) causes obstruction with secondary dilation of the esophagus. Esophageal retention of undigested food and liquid is common. 