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

Summary

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.

Conditions

• Healthy Subjects (HS)

Interventions

DEVICE

repetitive transcranial magnetic stimulation (Magstim Super Rapid stimulator, The Magstim Company Ltd, Whitland, UK)

The paradigm will be applied over the dominant cerebral hemisphere for 10 minutes (600 pulses) over the dominant pharyngeal motor cortex capped at 120% of pharyngeal resting motor threshold.

DEVICE

pharyngeal electrical stimulation (Digitimer model DS7; Welwyn-Garden City, Herts, UK)

The PES (0.2-ms pulses, 280 V) was delivered at a set frequency (5 Hz), intensity (75% of maximal tolerated), and duration (10 minutes), which have been reported as the most effective parameters for PES.

DEVICE

sham repetitive transcranial magnetic stimulation(Magstim Super Rapid stimulator, The Magstim Company Ltd, Whitland, UK)

Sham rTMS is delivered with the coil tilted to its side at 90 degrees and with the identical stimulation conditions as active 1 Hz rTMS.

DEVICE

sham pharyngeal electrical stimulation (Digitimer model DS7; Welwyn-Garden City, Herts, UK)

For sham pharyngeal stimulation, the same method including the insertion of the catherter will be employed without actual electrical stimulation.

Sponsors & Collaborators

• University of Manchester

  lead OTHER

Principal Investigators

• Shaheen Hamdy, PhD · The University of Manchester

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

FACTORIAL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-09-14

Primary Completion

2025-08-31

Completion

2025-08-31

Countries

• United Kingdom

Study Locations