The aim of this study is to demonstrate that sensitive electrical stimulation could improve oropharyngeal dysphagia in hemispheric stroke patients. 118 patients should be included in seven centers. Sensitive electrical stimulation will be applied either as active stimulation, either as a placebo. Active electrical stimulation will be realised at 80 hz during 30 minutes, under motor threshold and above sensitive threshold. It will be administrated via surface electrodes over the hyoid bone. Patients will be separated by randomisation.