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

Abstract

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.

Head impulse compensatory saccades: Visual dependence is most evident in bilateral vestibular loss

“…As reported by numerous previous investigators [5,7,22,23,25,[57][58][59][60][61], we found that as the VOR loss increased compensatory saccade characteristics generally followed a similar pattern: the amplitude, frequency, and clustering increased while the latency became earlier (Fig 8). The rate of these changes to the reduction in VOR gain depended on both the visual condition and saccade number.…”

The Relationship of Vestibulo-Ocular Reflex With Self-Reported Dizziness Handicap in Patients With Vestibular Deafferentation

“…Although this was not determined to be statistically significant, it has been objectively reflected in a previous study which showed that the ''PR'' index (representing the scattering pattern) reduced in patients with acute unilateral vestibulopathy after VR. 13 In the long-term results of the current study of patients with vestibular deafferentation, the percentages of the organized pattern were found to be very high.…”

“…Despite a lack of objective data, this can be considered to be related to the mobility or sedentary lifestyle of the patient, and the decrease in the number of overt saccades in patients undergoing VR supports this idea. 13 Based on this, a patient with scattered saccades and complaints of dizziness may be a true candidate for VR. Therefore, VHIT can be recommended as a valuable tool for postoperative follow-up of vestibular differentiation patients to be able to select suitable VR candidates.…”

“…22,25,26 The amplitude of saccades has also been found to increase with ageing, 6 while VR has been shown to decrease the amplitude of saccades. 13 As a secondary Figure 5. Saccadic pattern transformation in the VHIT tests of the patient who underwent VN procedure first followed by TL due to incomplete vertigo control (A) after VN procedure, (B) 1 month after TL procedure, and (C) 1 year after TL procedure.…”

“…12 It has also been shown that vestibular rehabilitation (VR) decreases the abnormality on VHIT and the dizziness perceived by patients. 13 Therefore, the aim of this study was to determine objective indicators for the level of dizziness handicap through the evaluation of saccadic features in the VHIT results of long-term follow-up of patients with vestibular deafferentation. To achieve this, VHIT was applied to patients to objectively detect VOR and the DHI was administered to patients to evaluate dizziness perception.…”