The Use of Virtual Reality in Rehabilitation in Patients After Vestibular Schwannoma Surgery.

Resection of the vestibular schwannoma leads to acute peripheral or combined vestibular loss caused by a surgical lesion to the branches of the vestibular nerve and, less frequently also the lesion of the cerebellum. The lesion presents in patients with postural instability, vertigo, oscillopsia, and vegetative symptoms that may accompany it. The organism reacts to this state with the process of central compensation with the significant role of the cerebellum. The goal of the rehabilitation is to support this process and thus to make recovery faster and more efficient since not all patients are capable of complete restoration of the vestibular function. Up to date, rehabilitation includes, apart from the specific vestibular exercise, also the possibility of modern techniques using virtual reality space and prehabituation. Thanks to prehabituation, i.e., chemical labyrinthectomy with intratympanically installed gentamicin, the timing of the origin of the acute vestibular loss and the surgical procedure is separated. Therefore, there is a chance of achieving vestibular compensation before vestibular schwannoma removal. In the last decade, due to the advances in technology in the field of computer games and the applications for smartphones, the tools for virtual reality have become less expensive and more available in common praxis. Virtual reality is a technique for generating an environment that can strengthen three-dimensional optokinetic stimulation, subsequently the process of central compensation. Overall, it may shorten the time of recovery after the surgery and improve patients' quality of life.

This study was approved by institutional ethics committee of the University Hospital Motol and all patients provide inform consent prior to study commencement.

In this prospective randomized single-center study, we will enroll patients who undergo vestibular schwannoma resection in our department. All patients must be found to be indicated for the surgery. The size of the tumor will be classified according to the Koos classification. The patients with hearing loss will undergo prehabituation (group A). The rest of the patients will be randomly divided into either a virtual reality group (group B), or the control group (group C). Two days before the surgery (time 1) all of the patients will undergo a clinical oto-neurological examination as well as examination by objective methods - video-nystagmography (VNG), air calorics, video Head Impulse Test (vHIT), and cervical Vestibular Evoked Myogenic Potentials (cVEMP). They will also fill out a set of questionnaires - the Penn Acoustic Neuroma Quality-Of-Life scale (PANQOL), Dizziness Handicap Inventory (DHI), Generalized Anxiety Disorder 7 - item scale (GAD-7), and Self-rating Depression Scale (SDS). All of them were translated into the Czech language. In addition to it, we used the in-house questionnaire focused on vertigo symptoms.

On the second day after the surgery, all groups of patients begin to practice the vestibular training program adopted for patients with acute vestibular loss under the supervision of a physical therapist. The program includes gaze stability exercises, smooth pursuit, and saccadic eye movements, and postural exercises to improve balance control and gait stability. Each session will last around 30 minutes and will happen daily for the whole time of the hospitalization, thus seven days. Additionally, during that time, group B will obtain seven sessions of 30-minute-long optokinetic stimulation via virtual reality goggles. Subjective and objective assessments will be repeated at the hospital discharge which is on the 7-10th postoperative day (time 2) and 3 months after surgery (time 3).

Eligibility Criteria:
Inclusion Criteria:

* Vestibular Schwannoma appropriate to surgical resection

Exclusion Criteria:

* Eye disorder
* Oculomotor disorder in patient history
* Nerve palsy other than n. VIII, n. VII.