Achalasia of the esophagus sphi due to System may be degenerative change of vagus nerve nuclei in the brain g4 Achalasia of the esophagus • A motility disorder charaterised by failure to dilate the lower esophagus sphincter due to absence or reduction of the ganglion cells of Auerbach’s plexus. • There may be degenerative change of vagus nerve nuclei in the brain system. 10’