Effects of 5Hz repetitive Transcranial Magnetic Stimulation (rTMS) on swallowing functions of dysphagic individuals

Abstract

INTRODUCTION: Repetitive transcranial magnetic stimulation (rTMS) modulates brain activities using electromagnetic induction. Recent studies have shown that rTMS can improve limb motor functions and swallowing functions after stroke. The current study investigates the effects of 5Hz rTMS applied over the tongue area of the motor cortex on swallowing functions of individuals with chronic post-stroke dysphagia. MATERIALS AND METHODS: 15 participants (mean age = 64.6 years old) with chronic post-stroke dysphagia were randomly assigned into experimental (N=11) and sham (N=4) group. The experimental group received 3000 pulses of 5Hz rTMS everyday for 10 days. The sham group was given sham stimulation using the same stimulation protocol. The stimulation target was the tongue area of the motor cortex. All participants were assessed one week before, two months after and six months after stimulation. The outcome measurements include videofluoroscopic swallow study (VFSS), swallowing-related quality-of-life questionnaire and tongue strength. RESULTS: Greater reduction in pharyngeal residue across food consistencies (thin, honey-thick and paste) was observed in the experimental group than in the sham group at both post-stimulation follow up assessments. Improvement in swallowing-related quality-of-life after stimulation was shown in the experimental group but not in the sham group. Tongue strength remained relatively unchanged after stimulation in both groups. CONCLUSIONS: Preliminary results showed that 5Hz rTMS applied over the tongue area of the motor cortex potentially improves swallowing functions and swallowing-related quality-of-life of individuals with chronic post-stroke dysphagia. ACKNOWLEDGEMENT: This project was funded by Early Career Scheme, University Grants Council, Hong Kong