Pathology - Achalasia

Pathology - Achalasia 
Achalasia is a medical condition characterized by the inability of the muscles in the esophagus to properly relax, leading to difficulty in swallowing.

The incidence steadily increases with age.

Pathological: Enlargement of the esophagus occurring above the Lower Esophageal Sphincter (LES) 
The esophagus wall lacks ganglionic cells of the myenteric plexus at a microscopic level.
Pathophysiology refers to the study of the functional changes that occur in the body as a result of a disease or injury. The absence of the myenteric plexus leads to the absence of peristalsis in the smooth muscle of the lower two-thirds of the esophagus, as well as a hindered ability of the lower esophageal sphincter to relax. 
The individual experiences a gradual and progressive difficulty in swallowing both solid and liquid substances. They also regurgitate undigested food and feel pain and fullness below the sternum after eating.
Complications including a heightened susceptibility to squamous cell carcinoma of the esophagus.
Imaging: A barium esophageal swallow reveals an enlarged esophagus with a narrowed lower esophageal sphincter, resembling a "bird-beak" or rat-tailed appearance.

Treatment options for this condition include the administration of botulinum toxin injections to alleviate pain, the use of nifedipine or nitrates before meals to induce dilatation of the lower esophageal sphincter (LES), pneumatic dilation of the LES, and surgical myotomy.
Esophageal dysfunction is observed in Chagas disease, esophageal tumors, systemic sclerosis, and esophageal spasm.