Non-achalasic motor disorders of the oesophagus.

Motor abnormalities of the oesophagus are characterised by a chronic impairment of the neuromuscular structures that co-ordinate oesophageal function. The best-defined entity is achalasia, which is discussed in a separate chapter. Other motor disorders with clinical relevance include diffuse oesophageal spasm, oesophageal dysmotility associated with scleroderma, and ineffective oesophageal motility. These non-achalasic motor disorders have variable prevalence but they could be associated with invalidating symptoms such as dysphagia, chest pain and gastro-oesophageal reflux disease. New oesophageal diagnostic techniques, including high-resolution manometry, high-frequency intraluminal ultrasound and intraluminal impedance, allow (1) better definition of peristalsis and sphincter function, (2) assessment of changes in oesophageal wall thickness, and (3) evaluation of pressure gradients within the oesophagus and across the sphincters that can produce normal or abnormal patterns of bolus transport. This chapter discusses recent advances in physiology, pathophysiology, diagnosis and treatment of non-achalasic oesophageal motor disorders.