The Effect of Vestibulo-ocular Reflex Improving Exercise on Gait and Balance Among Post Stroke Sub Acute Patients

Background Stroke global incidence is rising, in Israel 40% of the stroke patients are in need for hospitalized rehabilitation. Improving mobility, and in particular walking after stroke, is utterly important to reduce the risk of falling and is strongly correlated to higher patient autonomy and improved quality of life. During walking balance maintenance, is a complex function relying upon three modalities of sensory information. The sensory weighting process is compromised in stroke patients, so they are excessively reliant on visual information to control their posture. applying vestibular inputs, such as vestibulo-ocular reflex (VOR) habituation exercise, as part of vestibular focused rehabilitation (VR) is one of the methods to trigger sensory reweighting processes in post stroke patients. The VOR role in balance is to assist stabilizing images on the retina during head movement. It may be possible to explain the phenomena of head stabilization during gait in post stroke patients, as an attempt to maintain gaze stability due to reduced dynamic visual acuity (DVA) arising from decreased VOR function.

Aims The aims of this study are firstly to investigate the effectiveness of VOR exercise on gait speed and balance in post stroke patients with no dizziness, and secondly, to test the correlation between the efficiency of the VOR, as reflected by DVA and gait velocity.

Methods A prospective experimental study, randomized controlled, double blinded (assessor and statistician). Sixty adults, 65 years and older, hospitalized in the geriatric rehabilitation departments at the Sheba Medical Center, Israel will be divided to control and intervention groups. The intervention will include physiotherapy sessions including 10 minutes dedicated to VOR habituation exercise, comparing to physiotherapy sessions with no VOR exercise.

Prior to the baseline testing (T1), the participants will perform the outcome measures tests twice (two consecutive days) to determine the smallest real difference. Following this, the outcome measures will be tested at three time-points: before the beginning of the vestibular training (T1); three weeks later, at the termination of the vestibular training (T2) and three weeks after the termination of the training period (T3), to measure retention. For assessing gait and balance, the Dynamic Gait Index (appendix 1), the 10 Meters Walking Test (appendix 2) and the Timed Up and Go test (appendix 3) will be utilized. For assessing balance confidence the Activities-specific Balance Confidence Scale (ABC) questionnaire will be applied. For assessing the DVA, the Dynamic visual acuity test will be applied.