Optimising Balance Function In Vestibular Schwannoma
Funder
National Health and Medical Research Council
Funding Amount
$271,817.00
Summary
This project examines human balance function in subjects with vestibular Schwannoma, a slow growing tumor that presents with hearing loss and imbalance. We will measure inner ear balance function using 2 new non invasive tests called the video head impulse and the vestibular evoked myogenic potential. We will seek test parameters that predict tumor growth, explore reasons for post surgical imbalance, develop and validate home-based rehabilitation methods to optimise balance after surgery.
Testing Of Vestibular Function By Active Head Movements.
Funder
National Health and Medical Research Council
Funding Amount
$180,509.00
Summary
The vestibular system of the inner ear is responsible for our sense of balance and for maintaining clear vision and stable posture during head movements. This complex interdependent sensory system is comprised of three paired semicircular canals for sensing head rotations and two paired otolith organs for sensing head position and linear movements of the head. A major goal of our research programs is to develop simple tests which can be used in the clinic or at the bedside to diagnose specific d ....The vestibular system of the inner ear is responsible for our sense of balance and for maintaining clear vision and stable posture during head movements. This complex interdependent sensory system is comprised of three paired semicircular canals for sensing head rotations and two paired otolith organs for sensing head position and linear movements of the head. A major goal of our research programs is to develop simple tests which can be used in the clinic or at the bedside to diagnose specific deficits of each vestibular sensory region. Most present clinical tests only test the part of the system concerned with horizontal head rotations but there are many other sensory regions in the inner ear whose functional status needs to be evaluated, especially those regions concerned with signalling linear head movements and head position - the otolith sensory regions. The usual principle in vestibular testing is to move the person's head and measure the eye movement which occurs in response to that passive movement. One of our recent observations suggest that it may be possible to measure vestibular functioning during active head movements. Active testing does not require expensive, invasive testing systems and could be carried out in the clinic. This project will compare the eye movement response to active and passive head movements in the same patients. We will test both the angular and linear sensing systems by asking patients to rotate their head or slide it laterally, recording the head movement stimulus and eye movement response. Two groups of patients will be studied; those who have recovered well and those who are poorly recovered after unilateral vestibular loss. The outcome will, we hope, be safe simple low cost tests which will evaluate the functional status of all the inner ear sensory regions and yet be clinically practical. They may provide the answer as to why some patients do not recover well after unilateral loss whereas others do.Read moreRead less
Comprehensive Clinical Tests Of Vestibular Function To Track Vestibular Compensation And Meniere’s Disease
Funder
National Health and Medical Research Council
Funding Amount
$390,625.00
Summary
This Project will apply new, fast, safe, comprehensive, balance tests we have developed to measure the function of the balance receptors of the inner ear. We will track changes in balance function during disease and recovery in the many, and increasing, number of Australian patients with balance disorders. These tests will give us insight into changes in the inner ear associated with severe attacks of vertigo and why some patients recover so poorly after damage to inner ear balance receptors.
Vestibulo-ocular Responses To Bone Conducted Vibration
Funder
National Health and Medical Research Council
Funding Amount
$282,772.00
Summary
This project is about an entirely new way of clinically evaluating balance function of the inner ear by using bone conducted vibration (BCV). We will make measures of the BCV stimulus in order to specify the stimulus at the receptors, and relate this stimulus to the eye-movement responses it causes. Measuring the exact stimulus and the response will give us a much better understanding of why this stimulus works, allowing us to optimize the clinical tests of balance function.
The Neural Basis Of Clinical Vestibular Testing By Bone Conducted Sound
Funder
National Health and Medical Research Council
Funding Amount
$260,986.00
Summary
Dysfunction of the balance system of the inner ear (the vestibular system) causes recurring dizzy attacks and persistent unsteadiness which can disrupt the most productive years of some people's lives. Balance-related falls account for more than half of accidental deaths in the elderly (Marchetti and Whitney 2005). Despite this, most doctors find dizziness difficult to diagnose and almost impossible to treat in part because of the subjective nature of the patients' reports. Fast, simple, safe, o ....Dysfunction of the balance system of the inner ear (the vestibular system) causes recurring dizzy attacks and persistent unsteadiness which can disrupt the most productive years of some people's lives. Balance-related falls account for more than half of accidental deaths in the elderly (Marchetti and Whitney 2005). Despite this, most doctors find dizziness difficult to diagnose and almost impossible to treat in part because of the subjective nature of the patients' reports. Fast, simple, safe, objective clinical tests are needed to diagnose these patients' problems and to identify which of the 10 vestibular sensory regions is affected. A new way of testing balance function is to use sound because sound can activate the vestibular system as well as the auditory system. We are using that fact to develop a whole new way of clinical testing of vestibular function and this largely Australian development has been very rapidly accepted by the international vestibular community. In a recent NHMRC project (253620) we discovered 1) that bone conducted vibration specifically activates some sensory nerves from one of the gravity sensing regions of the balance system (the otoliths) and 2) that air-conducted (AC) sound and bone-conducted vibration (BCV) appear to probe the function of different vestibular sensory regions 3) most importantly that BCV causes an eye movement response in alert guinea pigs (as it does in alert human subjects). This seems to be the objective response for testing otolith function which we are seeking. In this project we plan to extend these results by recording single vestibular nerve cells in guinea pigs, testing hypotheses about their responses to various types of sound and then injecting the neurons with stains which will allow us to confirm definitely the location of the receptors activated by the sound stimuli. The outcome will be the physiological basis of a new clinical test of balance using bone conducted vibration.Read moreRead less