You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Motility in the upper third of the esophagus is decreased in all except: and explain in detail?
Classification of Esophageal Motility Disorders Disorders of the Pharyngo-esophageal junction Neurological: Stroke, motor neurone disease, multiple sclerosis, Parkinson&;s disease Myogenic: Myasthenia, muscular dystrophy Pharyngo-esophageal (Zenker&;s diveiculum) Disorders of the body of the esophagus Diffuse esophageal spasm Nutcracker esophagus Autoimmune disorders- Systemic Sclerosis (CREST) Reflux associated idiopathic Allergic Eosinophilic esophagitis Non-specific esophageal dysmotility Disorders of the lower esophageal sphincter Achalasia Incompetent lower sphincter (i.e., GERD) Ref: Bailey and Love 27th edition Pgno: 1096