Botulinum Toxin Injection in Hypercontractile Esophagus

Inclusion Criteria: * Patient with non-cardiac chest pain and/or dysphagia with global Eckardt score strictly above 3 points or equal to 3 only for " chest pain " or " dysphagia " - Hypercontractile esophagus with normal esogastric junction relaxation based on the Chicago classification in high resolution manometry * Man or woman 18-year old or older * Normal upper gastrointestinal endoscopy within one year before inclusion * Barium swallow without argument for external compression * Effective form of birth control (if applicable) * Signed written informed consent form voluntarily * Patient with health insurance Exclusion Criteria: * Man or woman under 18-year old * Past history of eso-gastric surgery * Evolutive cancer or coagulation disorders * Absence of effective form of birth control (if applicable) * Pregnant woman or woman who plans to become pregnant during the expected length of the study * Breastfeeding woman * Allergy to botulinum toxin or excipients * Myasthenia * Aminoglycoside treatment * Endoscopic contraindication prior to the study * Endoscopic contraindication during the study * Psychiatric or addictive disease which could affect compliance to the constraints of the study * Patient refusing to participate to the study * Language barrier limiting the understanding of the study * Incapability to give consent * Concomitant participation to another research study * No written consent form