The effect of 5Hz high-frequency rTMS over contralesional pharyngeal motor cortex in post-stroke oropharyngeal dysphagia: a randomized controlled study

Background We sought to find the therapeutic effect of 5Hz high-frequency repetitive transcranial magnetic stimulation (rTMS) over the unaffected pharyngeal motor cortex in post-stroke dysphagic patients. Methods Eighteen patients with unilateral hemispheric stroke oropharyngeal dysphagia that lasted more than 1month were randomly divided into two groups. They all performed videofluoroscopic swallowing study (VFSS) before rTMS intervention. The experimental group (EG) received 5Hz rTMS over contra-lesional pharyngeal motor cortex for 10min per day for 2weeks. The control group (CG) received sham stimulation under the same condition. Videofluoroscopic swallowing study were performed again just after treatment cessation and 2 weeks afterward. The evaluation was performed using videofluoroscopic dysphagia scale (VDS) and penetration-aspiration scale (PAS). Key Results Mean baseline VDS and PAS of EG was 33.6 +/- 12.1 and 3.41 +/- 2.32 respectively and the scores were reduced to 25.3 +/- 9.8 and 1.93 +/- 1.52 just after 2weeks intervention (P<0.05). This effect lasted for up to 2 weeks after treatment. However, there was no change in the CG. Baseline prevalence of aspiration, pharyngeal residue, delayed triggering of pharyngeal swallowing and abnormal pharyngeal transit time (PTT) in EG was 66.7%, 66.7%, 33.3%, and 44.4%, respectively. After rTMS, the prevalence of aspiration and pharyngeal residue was reduced to 33.3% and 33.3%, respectively. However, the prevalence of delayed triggering and abnormal PTT was not changed. Conclusions & Inferences A 5Hz high-frequency rTMS on contra-lesional pharyngeal motor cortex might be beneficial for post-stroke dysphagic patients. This intervention can be used as a new treatment method in post-stroke patients with dysphagia.