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Vestibular Precision: Physiology & Pathophysiology

Primary Purpose

Vestibular Schwannoma, Inner Ear Disease, Dizziness

Status
Enrolling by invitation
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
VOR precision training
Sponsored by
Massachusetts Eye and Ear Infirmary
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Vestibular Schwannoma focused on measuring VOR variability, Vestibular Precision, Neural Noise, Motion Perception, Perceptual Precision, Vestibular Ocular Reflex

Eligibility Criteria

8 Years - 80 Years (Child, Adult, Older Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

Normal subjects:

  • normal vestibular-oculomotor exams
  • normal low-frequency standard rotational testing
  • normal hearing

Vestibular Schwannoma:

  • existence of unilateral vestibular schwannoma (pre & post surgical resection)
  • must have sub-occipital surgical approach with complete sectioning of the vestibular nerve
  • rotational testing to assess pre-surgical vestibular function
  • audiogram
  • brain MRI consistent with vestibular schwannoma
  • audiography in each ear

Exclusion Criteria:

Normal subjects

  • history of otologic or neurologic disease
  • on vestibular suppressant medication (benzodiazepine, antihistamine, anticholinergic)

Vestibular Schwannoma

  • other otologic disease (other than presbycusis) or any neurologic disease (other than migraine)
  • on vestibular suppressant medication (benzodiazepine, antihistamine, anticholinergic)

Sites / Locations

  • Massachusetts Eye and Ear Infirmary

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Experimental

Arm Label

Normal Controls

Peripheral Vestibular Dysfunction

Arm Description

normal control participants - no history of neurologic or inner ear disease

Patients with unilateral vestibular damage due to monophasic illness such as vestibular neuritis or vestibular schwannoma (VS). For VS patients, the investigators will test them in three states: pre-op, sub-acute post-op (6 weeks), and chronic post-op (6 months).

Outcomes

Primary Outcome Measures

Change in perceptual thresholds
Measurements of motion perception thresholds (yaw for rotational tasks, roll tilt for tilt task) before and after training.
Change in rapid measure of gait
This measure is scored before and after VOR precision training in UVD (unilateral vestibular dysfunction) patients. Gait is scored by performance on a task derived from the FGA (walking 40 feet while turning the head from side to side). It is scored on a 0 to 10 visual scale and provides a rapid assessment of vestibular function pre and post adaptation.
Change in measure of inducible dizziness
Looking at the change between before and after VOR precision training in UVD (unilateral vestibular dysfunction) patients. Inducible dizziness is the symptom severity provoked by a task derived from the FGA (walking 40 feet while turning the head from side to side). It is scored on a 0 to 10 visual scale and provides a rapid assessment of vestibular function pre and post adaptation.

Secondary Outcome Measures

Full Information

First Posted
May 12, 2021
Last Updated
March 14, 2023
Sponsor
Massachusetts Eye and Ear Infirmary
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1. Study Identification

Unique Protocol Identification Number
NCT04890132
Brief Title
Vestibular Precision: Physiology & Pathophysiology
Official Title
Vestibular Precision: Physiology & Pathophysiology
Study Type
Interventional

2. Study Status

Record Verification Date
March 2023
Overall Recruitment Status
Enrolling by invitation
Study Start Date
July 1, 2020 (Actual)
Primary Completion Date
June 30, 2025 (Anticipated)
Study Completion Date
June 30, 2025 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Massachusetts Eye and Ear Infirmary

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No

5. Study Description

Brief Summary
This project will investigate the role of noise in the vestibular system, and in particular its effects on the variability (precision) of vestibular-mediated behaviors. The investigators will study vestibular precision in normal subjects and patients with peripheral vestibular damage, and will investigate its potential plasticity. The goals are to develop a better understanding of the role noise plays in the vestibular system in normal and pathologic populations, and to determine if the brain can learn to improve signal recognition within its inherently noisy neural environment, which would result in improved behavioral precision.
Detailed Description
The goal of this study is to investigate vestibular precision by quantifying the variability in behavioral responses that result from the neural noise inherent to the peripheral and central vestibular systems. Because neural noise contaminates the signals that are transduced by the ear and processed by the brain, vestibular-mediated behavioral responses vary even when identical stimuli are provided. In this study, the investigators focus on vestibular precision in human subjects and investigate its sources, its effects on behavior, and its degradation when the periphery is damaged and its potential plasticity. Specifically, the investigators will investigate: (1) Vestibular precision in normal subjects - physiology: A) The investigators will measure the angular and linear vestibulo-ocular reflex (VOR) using novel motion combinations that reinforce or cancel eye movement responses, which will allow us to determine the distribution and magnitude of noise produced in the sensory (canal, otolith) pathways and in the oculomotor pathway. The investigators hypothesize that normal subjects will demonstrate a bimodal distribution of noise with either sensory or motor predominance, and that subjects with more sensory noise will demonstrate other behavioral characteristics that reflect this characteristic (e.g., higher perceptual thresholds); and B) The investigators will assay vestibular noise from trial-trial variations in the VOR and will compare VOR dynamics with those predicted by a Bayesian model using the assayed noise. The investigators predict variations in VOR dynamics across subjects, age and stimulus amplitudes will be consistent with Bayesian processing of noise. Potential confounding factors will be carefully controlled, including attention, fatigue, and non-vestibular cues. (2) Vestibular precision after peripheral damage - pathophysiology: A) The investigators will examine the changes in vestibular precision that occur when one vestibular nerve is damaged (by a vestibular schwannoma, VS) and after the damaged nerve is surgically sectioned, and will investigate if precision measurements can provide evidence of pathologic noise produced by the damaged nerve and therefore help predict clinical outcome when the nerve is sectioned. The investigators hypothesize that changes in signal reliability due to the VS will be traceable to both the reduced redundancy caused by loss of afferent fibers and to aberrant noise generated by the damaged vestibular nerve and that changes in precision after neurectomy will correlate the outcome measures that characterize patient disability; and B) The investigators will examine the plasticity of vestibular precision in the oculomotor and perceptual realms with the goal of determining if precision can be improved. Using novel training approaches that provide challenging signal extraction tasks, the investigators hypothesize that participants will improve their vestibular precision on the trained task. As secondary outcome measures, the investigators will determine if training one behavior generalizes to the non-trained behavior and if patient's symptoms are affected by improved precision.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Vestibular Schwannoma, Inner Ear Disease, Dizziness, Neurofibromatosis 2, Vestibular Disorder
Keywords
VOR variability, Vestibular Precision, Neural Noise, Motion Perception, Perceptual Precision, Vestibular Ocular Reflex

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
Participant
Allocation
Non-Randomized
Enrollment
90 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Normal Controls
Arm Type
Experimental
Arm Description
normal control participants - no history of neurologic or inner ear disease
Arm Title
Peripheral Vestibular Dysfunction
Arm Type
Experimental
Arm Description
Patients with unilateral vestibular damage due to monophasic illness such as vestibular neuritis or vestibular schwannoma (VS). For VS patients, the investigators will test them in three states: pre-op, sub-acute post-op (6 weeks), and chronic post-op (6 months).
Intervention Type
Behavioral
Intervention Name(s)
VOR precision training
Intervention Description
Subjects are rotated in yaw using a pseudo-random sum of sines motion (0.5 - 2.0 Hz), view a monitor 1 m away, and are instructed to move their avatar through a maze using a joystick. The size of the maze becomes smaller in real-time when they are successful so that the patient is at the limit of their acuity. This task requires patients to optimize dynamic visual acuity to threshold-level images while rotating. We predict that VOR precision will gradually improve during training and that after training VOR precision will be better than the pre-training data. The sham task is as above but the acuity required to see the maze will set at a much larger level so baseline visual precision will be adequate to perform the task easily.
Primary Outcome Measure Information:
Title
Change in perceptual thresholds
Description
Measurements of motion perception thresholds (yaw for rotational tasks, roll tilt for tilt task) before and after training.
Time Frame
baseline and post-training (1 hour)
Title
Change in rapid measure of gait
Description
This measure is scored before and after VOR precision training in UVD (unilateral vestibular dysfunction) patients. Gait is scored by performance on a task derived from the FGA (walking 40 feet while turning the head from side to side). It is scored on a 0 to 10 visual scale and provides a rapid assessment of vestibular function pre and post adaptation.
Time Frame
baseline and post-training (1 hour)
Title
Change in measure of inducible dizziness
Description
Looking at the change between before and after VOR precision training in UVD (unilateral vestibular dysfunction) patients. Inducible dizziness is the symptom severity provoked by a task derived from the FGA (walking 40 feet while turning the head from side to side). It is scored on a 0 to 10 visual scale and provides a rapid assessment of vestibular function pre and post adaptation.
Time Frame
baseline and post-training (1 hour)

10. Eligibility

Sex
All
Minimum Age & Unit of Time
8 Years
Maximum Age & Unit of Time
80 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: Normal subjects: normal vestibular-oculomotor exams normal low-frequency standard rotational testing normal hearing Vestibular Schwannoma: existence of unilateral vestibular schwannoma (pre & post surgical resection) must have sub-occipital surgical approach with complete sectioning of the vestibular nerve rotational testing to assess pre-surgical vestibular function audiogram brain MRI consistent with vestibular schwannoma audiography in each ear Exclusion Criteria: Normal subjects history of otologic or neurologic disease on vestibular suppressant medication (benzodiazepine, antihistamine, anticholinergic) Vestibular Schwannoma other otologic disease (other than presbycusis) or any neurologic disease (other than migraine) on vestibular suppressant medication (benzodiazepine, antihistamine, anticholinergic)
Facility Information:
Facility Name
Massachusetts Eye and Ear Infirmary
City
Boston
State/Province
Massachusetts
ZIP/Postal Code
02114
Country
United States

12. IPD Sharing Statement

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Vestibular Precision: Physiology & Pathophysiology

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