No abstract

Swallowing is a complex mechanism that is based on the coordinated interplay of tongue, pharynx, and esophagus. Disturbances of this interplay or disorders of one or several of these components lead to dysphagia, non-cardiac chest pain, or regurgitation. The major esophageal motility disorders include achalasia, diffuse esophageal spasm, hypercontractile esophagus ("nutcracker esophagus"), and hypocontractile esophagus ("scleroderma esophagus"). Other esophageal diseases such as hypopharyngeal (Zenker's) diverticula or gastroesophageal reflux disease also may be sequelae of primary esophageal motility disorder. Finally, a substantial group of patients referred for evaluation of possible esophageal motor disorders have milder degrees of dysmotility--referred to as nonspecific esophageal motor disorder--that are of unclear clinical significance. Medical treatment of esophageal motility disorders involves the uses of agents that either reduce (anti-cholinergic agents, nitrates, calcium antagonists) or enhance (prokinetic agents) esophageal contractility. Despite the beneficial effect of the various drugs on esophageal motility parameters, the clinical benefit of medical treatment is often disappointing. From clinical and epidemiological studies there is some evidence for a "psychological" component in the pathogenesis or perception of esophageal symptoms. Further understanding of esophageal pathophysiology, as well as development of new receptor selective drugs, might increase our chances of successful treatment of esophageal motility disorders.