Measurement of vestibular function and balance of patients with Vestibular Schwannoma. - A feasibility study -

Vestibular lesions lead to balance problems and vertigo. This has a major
influence on the patient*s daily functioning. It is estimated that 40% of
people older than 40 years have balance problems and vertigo of which 35-55%
have a peripheral vestibular lesion. Although vestibular rehabilitation is
recommended to facilitate recovery, the therapy effect shows large differences
between the patients with vestibular lesions. A possible reason for these
differences in therapy effect could be that current clinical vestibular
function and balance tests can not discriminate properly between patients that
recover full, less or not at all after receiving vestibular rehabilitation. A
solution might be to use more advanced techniques to measure vestibular
function and balance. Before this, we have to know whether it is feasible to
use these techniques on patients with vestibular lesions.

The objective of the study is to determine if a 3D motion platform (to measure
vestibular function) and accelerometry and a insole pressure system (to measure
balance) can be used in future research on patients with vestibular lesions.
For this, we evaluate the feasibility and discriminative value of these
measurement techniques.

Research questions:
1. Is it feasible to measure the vestibular function with a 3D motion platform,
and balance with accellerometry and an insole pressure system of patients with
a vestibular schwannoma?

2. Can a 3D motion platform, regarding vestibular function, and accellerometry
and an insole pressure system, regarding balance, discriminate better than
current clinical tests between a) healthy persons and patients with an
vestibular lesion and b) between different patients with an vestibular lesion?

It is a cross-sectional study design. Five patients with vestibular schwannoma
and balance problems receiving radiation therapy and 5 healthy controls are
selected to participate. Vestibular function is measured by a moving platform,
and balance is measured by accelerometry and an insole pressure device. The
feasibility to perform these measurements is evaluated by questionnaires for
the participants and the researchers. All measurements are performed once.

The vestibular and balance tests are not painful or harmfull.

For the vestibular test, contact lenses are placed on the eye with a drop of
mimins (oxybuprocaine). 25 years of experience exists with this procedure.
Vertigo elicit by the vestibular test with the movement platform dissapears
soon after this test.

During the balance measuremenets, patients are continuously watched by a
researcher or therapist. The risk of falling is, therefore, negligible.
Patients with severe balance problems do not perform balance tests with their
eyes closed.