Pathogenesis (development of disease)
Primary achalasia is caused by degeneration of inhibitory neurons (nerve cells) of the myenteric plexus, also called Auerbach’s plexus. The Auerbach’s plexus is located within the muscular layer of the esophagus (food pipe). There is no relaxation of the esophageal sphincter (esophageal sphincter), which is physiologically triggered by the swallowing reflex. In addition, the resting pressure of the lower esophageal sphincter is increased. Both result in the esophageal sphincter being permanently contracted (contracted). As a result, emptying of the esophageal contents into the stomach is incomplete or fails to occur.
The cause of primary achalasia is as yet unknown. Possibly, the disease is triggered by autoimmunological processes (autoimmune disease). Furthermore, a genetic disposition is discussed (HLA association).
Etiology (Causes)
Biographic Causes-Primary Achalasia.
- Genetic burden from parents, grandparents – possible association with HLA-DQw1 (antigen).
- Genetic diseases
- Hereditary (inherited) forms of achalasia are usually associated with a classic clinical syndrome (e.g. Allgrove syndrome [triple A syndrome]: rare autosomal recessive disorder characterized by achalasia, alacrimia (congenital condition in which lacrimal fluid is not produced), and adrenocorticotropic hormone (ACTH)-resistant – usually adrenocortical insufficiency (adrenocortical weakness), as well as neurologic abnormalities)
- Genetic diseases
Disease-related causes – Secondary achalasia.
- Bronchial carcinoma (lung cancer)
- Chagas disease (American trypanosomiasis) – infectious disease (mainly) in South America caused by Trypanosoma cruzi and transmitted by predatory bugs.
- Gastric carcinoma (stomach cancer)
- Esophageal carcinoma (cancer of the esophagus)
