Subthreshold Vestibular Stimulation as a Strategy for Rehabilitation

NCT ID: NCT06732440

Last Updated: 2025-11-12

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 48 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-01-01
• Study Completion Date: 2026-12-31

Brief Summary

The nervous system responds to changes in external or internal conditions by altering the behavior of neurons through multiple forms of neural plasticity. A specific form of plasticity, "homeostatic plasticity", stabilizes neural activity by driving the excitability of neurons toward a "set-point" level of activity. Over the last six years, new data have come to light showing that the vestibular system also possess a robust capacity to modulate sensitivity to self-motion cues in response to prolonged periods of motion. Collectively, these studies have demonstrated a capacity to use motion perturbations (i.e., low, or high levels of vestibular stimulation) to dynamically adjust the sensitivity of the vestibular system on both the single neuron and behavioral levels. The ability to use subthreshold motion stimuli to drive plasticity in the vestibular system motivates this study. The investigators aim to determine the impact of subthreshold motion on (a) balance performance and (b) balance training in individuals with peripheral vestibular hypofunction.

Detailed Description

The investigators aim to test (1) if sub threshold motion improves motion perception, (2) if sub threshold motion improves balance performance, and (3) if sub threshold motion prior to balance training leads to improved balance performance. Twenty-four subjects with peripheral vestibular hypofunction (12 with bilateral and 12 with unilateral hypofunction) and twenty-four healthy control participants will complete the study. Each participant will complete four visits to the laboratory. Day 1 will measure the capacity to modify balance and self-motion perception after a single block of subthreshold motion, including any retention effects after a washout period. Days 2-4 will be performed in random order and will test changes in balance and self-motion perception after (a) repeated balance training, (b) repeated subthreshold motion, and (c) balance training combined with sub threshold motion.

Conditions

Vestibular Hypofunction; Bilateral Vestibular Hypofunction; Presbyvestibulopathy; Healthy Controls

Keywords

Bilateral Vestibular Hypofunction; Vestibular Rehabilitation

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Balance training performed with and without added subthreshold conditioning.

Each participant in this single group design will complete the same three conditions of the experiment in a randomized order.

Group Type: EXPERIMENTAL

Subthreshold Vestibular Conditioning

Intervention Type: BEHAVIORAL

Subthreshold vestibular conditioning will be performed while seated on a motion platform and blindfolded. The stimulus will consist of a pseudorandom sum-of-sinusoids roll tilt motion (\~0.08 to 1 Hz) delivered at a peak velocity equal to 57.4% of the measured baseline roll tilt perceptual threshold (e.g., 0.574°/s for a 1 °/s threshold). The participant will be informed that while the chair may vibrate or move slightly, the motion will not occur in any particular direction.

Balance Training

Intervention Type: BEHAVIORAL

Balance training will consist of progressive exposure to continuous one-dimensional roll pseudorandom platform perturbations delivered using a 6DoF motion platform. Participants will stand on a MOOG hexapod motion platform and will be secured using a safety harness tethered to the ceiling and a full enclosure of safety rails. Roll tilt perturbations will be progressed by gradually increasing the displacement/velocity/acceleration of the platform motion.

Balance Training Plus Subthreshold Conditioning

Intervention Type: OTHER

Subthreshold vestibular conditioning will be performed while seated on a motion platform and blindfolded prior to each bout of balance training. Subthreshold conditioning will consist of a pseudorandom sum-of-sinusoids roll tilt motion (\~0.08 to 1 Hz) delivered at a peak velocity equal to 57.4% of the measured baseline roll tilt perceptual threshold (e.g., 0.574°/s for a 1 °/s threshold). The participant will be informed that while the chair may vibrate or move slightly, the motion will not occur in any particular direction. Balance training will consist of progressive exposure to continuous two-dimensional (2D) pseudorandom platform perturbations delivered using a 6DoF motion platform. 2D perturbations (roll and pitch tilt) will be progressed by gradually increasing the displacement/velocity/acceleration of the motion stimulus.

Interventions

Subthreshold Vestibular Conditioning

Subthreshold vestibular conditioning will be performed while seated on a motion platform and blindfolded. The stimulus will consist of a pseudorandom sum-of-sinusoids roll tilt motion (\~0.08 to 1 Hz) delivered at a peak velocity equal to 57.4% of the measured baseline roll tilt perceptual threshold (e.g., 0.574°/s for a 1 °/s threshold). The participant will be informed that while the chair may vibrate or move slightly, the motion will not occur in any particular direction.

Intervention Type: BEHAVIORAL

Balance Training

Balance training will consist of progressive exposure to continuous one-dimensional roll pseudorandom platform perturbations delivered using a 6DoF motion platform. Participants will stand on a MOOG hexapod motion platform and will be secured using a safety harness tethered to the ceiling and a full enclosure of safety rails. Roll tilt perturbations will be progressed by gradually increasing the displacement/velocity/acceleration of the platform motion.

Intervention Type: BEHAVIORAL

Balance Training Plus Subthreshold Conditioning

Subthreshold vestibular conditioning will be performed while seated on a motion platform and blindfolded prior to each bout of balance training. Subthreshold conditioning will consist of a pseudorandom sum-of-sinusoids roll tilt motion (\~0.08 to 1 Hz) delivered at a peak velocity equal to 57.4% of the measured baseline roll tilt perceptual threshold (e.g., 0.574°/s for a 1 °/s threshold). The participant will be informed that while the chair may vibrate or move slightly, the motion will not occur in any particular direction. Balance training will consist of progressive exposure to continuous two-dimensional (2D) pseudorandom platform perturbations delivered using a 6DoF motion platform. 2D perturbations (roll and pitch tilt) will be progressed by gradually increasing the displacement/velocity/acceleration of the motion stimulus.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

1. Bilateral lateral canal VOR gain of < 0.8 on video head impulse testing OR bilateral positive bedside head impulse test

1. Unilateral yaw aVOR gain of < 0.8 on video head impulse testing OR unilateral positive bedside head impulse test

1. Must be able to stand for 5 minutes unassisted

2. No leg or foot amputations

3. No lower limb braces

4. Not currently pregnant by self-report

5. Weight <= 300 pounds (due to limitations of testing equipment)

Exclusion Criteria

1. Severe head trauma or traumatic brain injury

2. History of seizures

3. Alternative neurologic illness or condition known to impact vestibular or balance function (e.g., stroke, neurodegenerative disorders, demyelinating illness)

4. Major psychiatric (e.g., panic disorder, psychosis, etc.) disorder

5. Any of the following eye diseases or conditions: amblyopia (or "lazy eye") or history of amblyopia, diagnosis of age- related macular degeneration, retina dystrophy, glaucoma, cataracts,

6. Recent (<6 months) orthopedic injury that may affect test performance

7. Recent surgery (< 6 months) that may impact test performance.

8. Other severe health problems (heart disease, pulmonary disease, cancer, etc.) that may affect test performance

9. Due to potentially nauseogenic nature of some motions and to protect fetus and mother, pregnant women will also be excluded from this study

• Minimum Eligible Age: 19 Years
• Maximum Eligible Age: 89 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

National Institute on Deafness and Other Communication Disorders (NIDCD)

NIH

Sponsor Role: collaborator

Creighton University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Creighton University

Omaha, Nebraska, United States

Countries

United States

Central Contacts

Andrew R Wagner, PhD

Role: CONTACT

Phone: 402.280.5188

Email: andrewwagner@creighton.edu

Facility Contacts

Andrew R Wagner, PhD

Role: primary

References

Wagner AR, Kobel MJ, Tajino J, Merfeld DM. Improving self-motion perception and balance through roll tilt perceptual training. J Neurophysiol. 2022 Sep 1;128(3):619-633. doi: 10.1152/jn.00092.2022. Epub 2022 Jul 27.

Reference Type: BACKGROUND

PMID: 35894439 (View on PubMed)

Dietrich H, Straka H. Prolonged vestibular stimulation induces homeostatic plasticity of the vestibulo-ocular reflex in larval Xenopus laevis. Eur J Neurosci. 2016 Jul;44(1):1787-96. doi: 10.1111/ejn.13269. Epub 2016 Jun 1.

Reference Type: BACKGROUND

PMID: 27152983 (View on PubMed)

Kobel MJ, Wagner AR, Merfeld DM, Mattingly JK. Vestibular Thresholds: A Review of Advances and Challenges in Clinical Applications. Front Neurol. 2021 Feb 19;12:643634. doi: 10.3389/fneur.2021.643634. eCollection 2021.

Reference Type: BACKGROUND

PMID: 33679594 (View on PubMed)

Other Identifiers

4R00DC020759-02

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2004550

Identifier Type: -

Identifier Source: org_study_id