The clinical relevance of esophageal motility abnormalities such as diffuse esophageal spasm (DES) and nutcracker esophagus is best understood when working from a classification system for these abnormalities.
An esophageal motility disorder is defined as motility that differs significantly from accepted normal variations. Classifications of esophageal motility abnormalities are based upon motility findings that exceed two standard deviations from those found in a large group of normal subjects .
There is considerable controversy concerning the clinical significance of abnormal esophageal motility patterns. The most important questions are whether they represent actual disorders or are only manometric abnormalities and whether they cause or explain the patient's symptoms. With the exceptions of achalasia and scleroderma, no specific pathology or pathophysiology has been described for any of these dysmotility patterns, including the more generally accepted "disorder" of DES.
This topic review will attempt to characterize the relevant information on these motility abnormalities without the implication that they are actual disease entities, excluding the one true motility disorder, achalasia. Achalasia and chest pain of esophageal origin are discussed separately. (See "Clinical manifestations and diagnosis of achalasia" and "Pathophysiology and etiology of achalasia" and "Overview of the treatment of achalasia" and "Chest pain of esophageal origin".)
CLASSIFICATION OF ESOPHAGEAL MOTILITY ABNORMALITIES
Esophageal motility abnormalities are generally classified into those that are an isolated phenomenon (primary) (table 1) and those associated with generalized disease (secondary) (table 2). Within each of these major categories, the motility abnormalities can usually be subcategorized into hypercontracting, hypocontracting, and discoordinated motility.