Achalasia: symptoms and radiology.

THE essential disturbance in achalasia is a failure of the cardiac sphincter to relax adequately when the patient swallows. This causes the oesophageal tube to be closed to both liquids and solids by an elastic process that can be forced open a varying amount by building up pressure in the oesophagus, in addition there is damage to some of the postganglionic neurones in the wall of the oesophagus so that not all the impulses sequentially emitted from the medulla get through to the oesophageal muscle and the peristaltic wave is partially or wholly disorganized. Spasm is a word to be avoided because it has no useful meaning; diffuse spasm is a form of achalasia, and corkscrew oesophagus is either a form of achalasia or an achalasia-like picture probably caused by senile changes in the postganglionic neurones of the oesophageal wall. Achalasia does not always cause significant dysphagia, and it does not always produce an enormously dilated oesophagus. It is rarely a progressive disorder; the damage to the postganglionic neurones seems to happen over a short period of time and changes in the size of the oesophagus and the symptoms seem to depend on the severity and persistence of the obstruction. If the obstruction is relieved early enough the oesophagus may return a long way but never the whole way towards a normal shape and activity.