Description of the trial In the first step of this study patients will be selected for inclusion in the trial according to the following criteria : 1: men or women aged between 18 and 75 years ; 2: genetic confirmation and characterisation of OPMD 3: SSO dysfunction confirmed by the stasis of saliva or food above the sphincter visualised by fibroscopy and a defect in the opening of the SSO also confirmed by videofluoroscopy of swallowing; the SSO defect may be associated with a reduction in pharyngeal propulsion as revealed by fibroscopy and videofluoroscopy of swallowing 4: official signed consent of the patients to participate in this clinical trial.