Rapid improvement in brain and swallowing behaviour induced by cerebellar repetitive transcranial magnetic stimulation in post-stroke dysphagia: a single patient case controlled study

INTRODUCTION: The cerebellum has been showed by numerous studies to be active during the process of swallowing. Cortically targeted repetitive transcranial magnetic stimulation (rTMS) is a technique which has been shown to result in beneficial electrophysiological and behavioral changes in healthy participants and patients with post stroke dysphagia. Cerebellar rTMS is a relatively unstudied area of this emerging field. Here we apply cerebellar targeted rTMS to a patient with post stroke dysphagia in an attempt to improve their swallowing.

METHODS: A 67-year-old woman with post stroke dysphagia was recruited to undergo a crossover active rTMS vs sham rTMS study. Outcome measures were pharyngeal motor evoked potential (PMEP) amplitude and cumulative penetration-aspiration score (cPAS). The patient attended the laboratory on two occasions. During each attendance, baseline PMEP and cPAS measurements were acquired followed by either active or sham rTMS. Following this, PMEP and cPAS measurements were repeated at 30 minutes.

RESULTS: Active cerebellar rTMS was able to increase both PMEP amplitude (55% over baseline) and improve swallowing safety (17% below baseline). Sham rTMS did not result in any beneficial PMEP or cPAS changes.

CONCLUSION: Our results suggest that cerebellar rTMS has plausible therapeutic potential for post stroke dysphagia.