Assessment of Vestibulo-ocular Reflex Gain and Catch-up Saccades During Vestibular Rehabilitation

Objective: To assess, in patients referred to vestibular rehabilitation (VR) for persistence of disability after acute unilateral vestibulopathy (AUV), whether the video head impulse test (vHIT) can be a useful technique to define the efficacy of the treatment. Study Design: Prospective clinical study. Setting: Tertiary academic referral hospitals. Patients: Thirty patients with residual symptoms after AUV were included. Intervention: Patients underwent a 10-week VR program. Main Outcome Measures: Evaluation of dizziness handicap inventory score, high-velocity vestibulo-ocular reflex gain, asymmetry index, and catch-up saccade parameters before and after VR. Results: All patients reported a clear clinical improvement after VR, also demonstrated by better dizziness handicap inventory scores (p < 0.001). A consistent increased gain and decreased asymmetry index were also observed (p < 0.001 for both). Patients did not show any change in covert catch-up saccades, while a statistically significant reduction of the number and amplitude of the overt catch-up saccades was interestingly detected (p = 0.009 and p = 0.030, respectively). Conclusion: VR is a valid approach for patients with residual disability after AUV. A reduction in number and amplitude of overt catch-up saccades seems useful to evaluate the efficacy of VR and to be related to clinical improvement.