Primary esophageal causes of dysmotility include Achalasia Diffuse esophageal spasm Eosinophilic esophagitis Systemic disorders causing esophageal dysmotility include Systemic sclerosis Chagas disease Many generalized disorders of neuromuscular function (eg, myasthenia gravis, amyotrophic lateral sclerosis, stroke, Parkinson disease) can affect swallowing but are not typically classified as esophageal motility disorders because they largely cause oropharyngeal dysphagia and not esophageal dysphagia.