Subthreshold Vestibular Stimulation as a Strategy for Rehabilitation

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.

Conditions

• Vestibular Hypofunction
• Bilateral Vestibular Hypofunction
• Presbyvestibulopathy
• Healthy Controls

Interventions

BEHAVIORAL

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.

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.

OTHER

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.

Sponsors & Collaborators

• National Institute on Deafness and Other Communication Disorders (NIDCD)

  collaborator NIH

• Creighton University

  lead OTHER

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

19 Years

Max Age

89 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-02-09

Primary Completion

2026-12-31

Completion

2026-12-31

Countries

• United States

Study Locations