Aftereffects of PES Preconditioned with RTMS on the Human Pharyngeal Motor Cortex

The goal of this interventional study is to optimize the excitatory brain effects of combined neuromodulatory therapies on swallowing areas of the brain. The main question it aims to answer is:

Does preconditioning with 1 Hertz (Hz) repetitive transcranial magnetic stimulation (rTMS) delivered over hemispheric pharyngeal areas enhance the activating effects of pharyngeal electrical stimulation (PES) on cortical excitability?

Participants will:

* Visit the department three times, with at least a one-week gap between visits. * Undergo baseline measurements for Pharyngeal motor evoked potential (PMEP) and Thenar motor evoked potential (TMEP), involving an electromyography (EMG) pharyngeal catheter inserted into the pharynx and gel electrodes to detect muscle activity. * Be randomly allocated to one of the three preconditioning-conditioning procedures during each visit : 1Hz rTMS followed by 5Hz PES, sham 1Hz rTMS followed by 5Hz PES, and 1Hz rTMS followed by sham 5Hz PES

1. Real rTMS will involve a figure-of-eight coil flat against the head delivering 1Hz stimulation at 90% of the thenar resting motor threshold. 2. Sham rTMS will involve holding the coil perpendicular to the scalp to prevent brain stimulation. 3. PES will involve a catheter delivering 0.2-ms pulses at 5Hz and 75% of the maximal tolerated intensity for 10 minutes. Sham PES will involve deactivating the current generator. * Complete PMEP and TMEP measurements at baseline before intervention and every 15 minutes from 0 - 60 minutes after the rTMS-PES procedure. * Complete a survey regarding tolerability and safety at the end of each visit.