Effects of Respiratory Muscle Training on Tongue Corticomotor Excitability

NCT07737015 | Completed

• 1 other identifier: TMS-RMT
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

The tongue plays a central role in essential oral functions, including swallowing, speech, and upper airway control. Its coordinated interaction with the respiratory system is particularly relevant in clinical conditions such as obstructive sleep apnea and dysphagia. While respiratory muscle training is increasingly used in these contexts, its effects on the neural control of tongue function remain poorly understood. This randomized cross-over pilot study aimed to investigate the acute effects of inspiratory (IMT) and expiratory (EMT) muscle training on tongue corticomotor excitability using transcranial magnetic stimulation. These results will provide novel insight into the neurophysiological mechanisms linking respiratory interventions and oral motor control.

Conditions

Healthy Adult Participants

Keywords

Transcranial magnetic stimulation; tongue; motor-evoked potentials; respiratory muscle training; corticomotor excitability

Outcome Measures

Primary Outcomes (1)

• Motor-evoked potentials

  The amplitude of tongue-related motor-evoked potentials are assessed using transcranial magnetic stimulation over the tongue motor cortex.

  Measured two times: immediately before the training session (baseline) and immediately after completion of the training session (approximately 45 minutes after baseline)

Secondary Outcomes (2)

• Maximum Inspiratory and Expiratory Pressure

  Measured two times: immediately before the training session (baseline) and immediately after completion of the training session (approximately 45 minutes after baseline)

• Tongue elevation peak pressure

  Measured two times: immediately before the training session (baseline) and immediately after completion of the training session (approximately 45 minutes after baseline)

Study Arms (2)

Inspiratory Muscle Training

EXPERIMENTAL

Participants will perform a short term session of inspiratory muscle training, using an adjustable external load.

Device: IMT

Expiratory muscle training

EXPERIMENTAL

Participants will perform a short term session of expiratory muscle training, using an adjustable external load

Device: EMT

Interventions

IMT DEVICE

An inspiratory threshold loading device set at 50% of the baseline maximal inspiratory pressure (PImax) was used. The training session consisted of five cycles of 20 breaths performed against the device, with a 2-minute rest period between cycles. Each breath consisted of quiet exhalation through the device, followed by a deep and forceful inspiration against the prescribed load.

Inspiratory Muscle Training

EMT DEVICE

An expiratory threshold loading device set at 50% of the baseline maximal expiratory pressure (PEmax) was used. The training session consisted of five cycles of 20 breaths performed against the device, with a 2-minute rest period between cycles. Each breath consisted of quiet inhalation through the device, followed by a deep and forceful expiration against the set load.

Expiratory muscle training

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• years of age or older
• good general health
• ability to read and understand the project information

You may not qualify if:

• medical, physical or psychological disorder
• metal implants in the head
• medications affecting the nervous system
• craniofacial abnormalities
• neuromuscular or inflammatory diseases
• history of epilepsy
• presence of pacemaker or implanted medical devices
• pregnancy

Sponsors & Collaborators

• Université Catholique de Louvain: lead

Study Sites (1)

Aarhus University

Aarhus, 8000, Denmark

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator, Professor

Study Record Dates

• First Submitted: July 25, 2026
• First Posted: July 30, 2026
• Study Start: October 1, 2024
• Primary Completion: December 6, 2024
• Study Completion: December 6, 2024
• Last Updated: July 30, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

DK (1)