Vestibular Rehabilitation and Otolith Dysfunction

Recent studies suggest that otolith dysfunction is a common finding in individuals with a history of head trauma/blast exposure and/or noise-induced hearing loss. Therefore, otolith dysfunction may be a significant health concern for the Veteran population, and determining optimal intervention strategies for otolith dysfunction is important for VA healthcare. The purpose of this project is to identify optimum stimulus parameters of a novel treatment, off-axis rotation (centrifugation) for otolith dysfunction, in healthy participants.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Dizziness Neurologic Manifestations Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms

Age range

18 year–69 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Mountain Home VA Medical Center James H. Quillen VA Medical Center, Mountain Home, TN

Mountain Home, Tennessee, 37684, United States

About this study

The primary function of the vestibular (inner ear balance) system is to maintain gaze and postural stability. The vestibular system is comprised of two types of sensory organs (semicircular canals and otolith organs) each with unique contributions to balance.

Vestibular Rehabilitation (VR) is the treatment of choice for patients experiencing dizziness, imbalance, and mobility impairments related to vestibular dysfunction. VR typically includes gaze stability exercises, gait and balance training, and general conditioning. Gaze stability exercises were developed based on the concepts of adaptation and substitution with the goal of improving gaze stability by facilitating vestibular compensation of the semicircular canal-mediated vestibulo-ocular reflex (VOR).

Many factors that might influence recovery, such as the involvement of different vestibular sensory organs (semicircular canals versus otolith organs) have not been examined to determine their impact on recovery. Most studies examining the effectiveness of VR have used only tests of VOR function (caloric and rotational tests) that measure horizontal semicircular canal to determine vestibular loss. Thus, little is known about interventions to facilitate vestibular compensation of the otolith organs.

Recent studies have demonstrated adaptation following otolith organ stimulation using centrifugation (or linear acceleration), but there is no data regarding optimum stimulus parameters. The concept of using centrifugation for otolith adaptation may be similar to using gaze stability exercises for VOR adaptation. Healthy control subjects (n = 5 per experiment) will participate in three separate experiments to determine: (1) the optimum off-axis distance of the rotary chair, (2) the optimum duration of off-axis rotation (OAR), and (3) the optimum OAR stimulation/training schedule.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

At least 18 years of age
Documented balance or mobility problems, or healthy control without imbalance
Otolith dysfunction or healthy control without vestibular dysfunction

Exclusion criteria

Progressive neurological disorders and central vestibular abnormalities
Benign paroxysmal positional vertigo
Superior semicircular canal dehiscence
Middle-ear pathology with conductive hearing loss
Lower extremity joint replacement
Cognitive impairment (Mini Mental Status Exam < 24/30)
Severe depression (geriatric depression scale 10)
Severe anxiety (geriatric anxiety inventory 11/30)
Best-corrected visual acuity worse than 20/40 in the better eye

Treatment and study plan

Centrifugation Distance

Behavioral

To determine optimal distance off-axis, participants were rotated in a darkened rotary chair booth with 1 ear positioned 3.5 cm off-axis and the other ear positioned on-axis for 1 minute. Participants received 5 sessions in a 1-week period. Following a 2-week washout period, participants were rotated in a darkened rotary chair booth with 1 ear positioned 7.0 cm off-axis and the other ear positioned on-axis for 1 minute. Participants received 5 sessions in a 1-week period.

Centrifugation Duration

Behavioral

To determine optimal duration, after a two week washout period, participants were rotated off-axis at 3.5 cm (determined to be optimal in Exp 1) for 3 minutes. Participants received 5 sessions in a 1-week period.

Centrifugation Schedule

Behavioral

To determine optimal schedule, after a two week washout period, participants were rotated off-axis at 3.5 cm (determined to be optimal in Exp 1) for 3 minutes (determined to be optimal in Exp 2). Participants received biweekly sessions for a total of 5 sessions.

Primary outcomes

Change in Static Subjective Visual Vertical (SVV)

Time frame: baseline, immediately after 5 sessions of OAR training (1 week)

Static subjective visual vertical (SVV) assesses spatial perception and is influenced by otolith function. Perception of vertical is measured in a darkened room with subject seated upright. The test assesses an individual's ability to adjust a laser line to be parallel with true vertical in the absence of any other visual cues. The start position of line for SVV testing is randomized and participants are instructed to use the track ball to position the line in a vertical position. Five trials are completed, and the software calculates the distance (in degrees) from vertical. The average of the trials is calculated and used for data analysis.

Sponsors and collaborators

Lead sponsor

VA Office of Research and Development

Fed

Registry information

Important dates

Study start: 2016
Primary completion: 2020
Study completion: 2020
First posted: Jan 11, 2016
Registry last updated: Nov 4, 2021

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

Completed