Commentary on: Convergence Vestibulo-ocular Reflex in Unilateral Vestibular Hypofunction: Behavioral Evidence in Support for a Novel Gaze Stability Exercise

2021 ◽  
Vol 45 (1) ◽  
pp. 12-13
Author(s):  
Anne K. Galgon ◽  
Janene M. Holmberg
2020 ◽  
Vol 29 (3) ◽  
pp. 310-314 ◽  
Author(s):  
Theresa L. Miyashita ◽  
Paul A. Ullucci

Context: Managing a concussion injury should involve the incorporation of a multifaceted approach, including a vision assessment. The frontoparietal circuits and subcortical nuclei are susceptible to trauma from a concussion injury, leading to dysfunction of the vestibulo-ocular system. Research investigating the effect of cumulative subconcussive impacts on neurological function is still in its infancy, but repetitive head impacts may result in vestibular system dysfunction. This dysfunction could create visual deficits, predisposing the individual to further head trauma. Objective: The purpose of this study was to investigate the cumulative effect of subconcussive impacts on minimum perception time, static visual acuity, gaze stability, and dynamic visual acuity scores. Design: Prospective cohort. Setting: Division I university. Patients: Thirty-three Division I men’s lacrosse players (age = 19.52 [1.20] y). Intervention: Competitive lacrosse season. Main Outcome Measures: At the beginning and end of the season, the players completed a vestibulo-ocular reflex assessment, using the InVision™ system by Neurocom® to assess perception, static acuity, gaze stability, and dynamic visual acuity. Score differentials were correlated with the head impact exposure data collected via instrumented helmets. Results: A significant correlation was found between change in perception scores and total number of head impacts (r = .54), and between changes in dynamic visual acuity loss scores on the rightside and maximum rotational acceleration (r = .36). No statistical differences were found between preseason and postseason vestibulo-ocular reflex variables. Conclusions: Cumulative subconcussive impacts may negatively affect vestibulo-ocular reflex scores, resulting in decreased visual performance. This decrease in vestibulo-ocular function may place the athlete at risk of sustaining additional head impacts or other injuries.


2021 ◽  
pp. 279-292

Background: Vestibular and vision functions are important contributors to posture control and fall avoidance. This review examines how the vestibulo-ocular reflex can be rehabilitated to help restore postural control. Methods: PubMed searches (7th April 2021) using the terms ‘vestibulo-ocular reflex’, ‘imbalance and vestibular dysfunction’, ‘vestibular dysfunction and dizziness’, ‘dynamic visual acuity’, ‘vestibular dysfunction rehabilitation’, and ‘gaze stabilization exercises’ yielded 4986, 495, 3576,1830, 3312, and 137 potentially useful publications respectively. Selections of those which were found to be the most relevant and representative of a balanced and current account of these topics, as well as selections from the most relevant reports referenced in those publications, were included in this review. Results: Just as there are age-related losses of static visual acuity even when there are no specific visual pathologies diagnosed, patients may also present with age-related loss of vestibular functions in the absence of specific vestibular pathologies. For example, cases of dizziness which are diagnosed as idiopathic might be usefully classified as age-related as the basis for the initiation of rehabilitation exercises. Conclusions: Apart from age-related loss of vestibular functions, cases diagnosed as having a particular form of vestibular pathology may have that condition exacerbated by age-related losses of vestibular functions. The effects of vestibular rehabilitation gaze stability exercises in patients with vestibular dysfunction are well established and include both improved dynamic acuity and postural stability. Improvements in posture control following rehabilitation of the vestibulo-ocular reflex are apparently due to improved peripheral and/or central vestibular balance control which has occurred in conjunction with enhanced gaze stability. The complex nature of increased fall risk suggests that an interdisciplinary approach to rehabilitation that includes vestibulo-ocular reflex rehabilitation appears likely to be associated with optimum outcomes for both pathological and age-related cases.


2004 ◽  
Vol 84 (2) ◽  
pp. 151-158 ◽  
Author(s):  
Michael C Schubert ◽  
Ronald J Tusa ◽  
Lawrence E Grine ◽  
Susan J Herdman

Abstract Background and Purpose. The head thrust test (HTT) is used to assess the vestibulo-ocular reflex. Sensitivity and specificity for diagnosing unilateral vestibular hypofunction (UVH) in patients following vestibular ablation is excellent (100%), although sensitivity is lower (35%–39%) for patients with nonsurgically induced UVH. The variability of the test results may be from moving the subject's head outside the plane of the lateral semicircular canals as well as using a head thrust of predictable timing and direction. The purpose of this study was to examine sensitivity and specificity of the horizontal HTT in identifying patients with UVH and bilateral vestibular hypofunction (BVH) when the head was flexed 30 degrees in attempt to induce acceleration primarily in the lateral semicircular canal and the head was moved unpredictably. Subjects. The medical records of 176 people with and without vestibular dysfunction (n=79 with UVH, n=32 with BVH, and n=65 with nonvestibular dizziness) were studied. Methods. Data were retrospectively tabulated from a de-identified database (ie, with health information stripped of all identifiers). Results. Sensitivity of the HTT for identifying vestibular hypofunction was 71% for UVH and 84% for BVH. Specificity was 82%. Discussion and Conclusion. Ensuring the head is pitched 30 degrees down and thrust with an unpredictable timing and direction appears to improve sensitivity of the HTT.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Carlo N. Rinaudo ◽  
Michael C. Schubert ◽  
Phillip D. Cremer ◽  
William V. C. Figtree ◽  
Christopher J. Todd ◽  
...  

2018 ◽  
Vol 33 (1) ◽  
pp. 24-33 ◽  
Author(s):  
Andrea Viziano ◽  
Alessandro Micarelli ◽  
Ivan Augimeri ◽  
Domenico Micarelli ◽  
Marco Alessandrini

Objective: To investigate the long-term effects of adding virtual reality–based home exercises to vestibular rehabilitation in people with unilateral vestibular hypofunction. Design: Follow-up otoneurological examination in two randomized groups following a previous one-month trial. Setting: Tertiary rehabilitation center. Subjects: A total of 47 patients with unilateral vestibular hypofunction, one group ( n = 24) undergoing conventional vestibular rehabilitation and the other one ( n = 23) implementing, in addition, head-mounted gaming home exercises, 20 minutes per day for one month. Interventions: One year after completing rehabilitation, patients underwent testing with static posturography, video head impulse test, self-report questionnaires, and a performance measure. Main measures: Vestibulo-ocular reflex gain, posturographic parameters such as length, surface, and fast Fourier transform power spectra, self-report, and gait performance measure scores. Results: Vestibulo-ocular reflex gain was significantly better with respect to pretreatment in both groups. The mixed-method group showed significantly higher gain scores: mean (standard deviation (SD)) at 12 months was 0.71 (0.04), versus 0.64 (0.03) for the vestibular rehabilitation–only group ( P < 0.001). Accordingly, some classical posturography scores such as surface with eyes open and length with eyes closed and low-frequency power spectra were significantly different between groups, with the virtual reality group showing improvement ( P < 0.001). Self-report measures were significantly better in both groups compared to pretreatment, with significant improvement in the mixed-method group as compared to conventional rehabilitation alone: Dizziness Handicap Inventory mean total score was 24.34 (2.8) versus 35.73 (5.88) with a P-value <0.001. Conclusion: Results suggest that head-mounted gaming home exercises are a viable, effective, additional measure to improve long-term vestibular rehabilitation outcomes.


2008 ◽  
Vol 18 (2-3) ◽  
pp. 147-157
Author(s):  
Matthew Scherer ◽  
Americo A. Migliaccio ◽  
Michael C. Schubert

While active dynamic visual acuity (DVA) has been shown to improve with gaze stabilization exercises, we sought to determine whether DVA during {passive} head impulses (pDVA) would also improve following a rehabilitation course of vestibular physical therapy (VPT) in patients with unilateral and bilateral vestibular hypofunction. VPT consisted of gaze and gait stabilization exercises done as a home exercise program. Scleral search coil was used to characterize the angular vestibulo-ocular reflex (aVOR) during pDVA before and after VPT. Mean duration of VPT was 66 ± 24 days, over a total of 5 ± 1.4 outpatient visits. Two of three subjects showed improvements in pDVA with a mean reduction of 43% (LogMAR 0.58 to 0.398 and 0.92 to 0.40). Our data suggest improvements in pDVA may be due in part to improvements in aVOR velocity and acceleration gains or reduced latency of the aVOR. Each subject demonstrated a reduction in the ratio of compensatory saccades to head impulses after VPT. Preliminary data suggest that active gaze stability exercises may contribute to improvements in pDVA in some individuals.


Author(s):  
Morteza Hamidi Nahrani ◽  
Mehdi Akbari ◽  
Mohammad Maarefvand

Background and Aim: Evaluating the effective­ness of vestibular rehabilitation (VR) in patients with vestibular lesions has always been a challe­nge. The questionnaires that are used for this pur­pose mostly show the degree of vestibular dis­ability rather than providing information about improvement of vestibular dysfunction. This study aimed to evaluate whether video head imp­ulse test (vHIT) that is used for the examination of vestibulo-ocular reflex (VOR), is a useful method for predicting the effectiveness of VR and has a correlation with dizziness handicap inventory (DHI) score. Methods: Participants were 42 patients with unilateral peripheral vestibular hypofunction (UPVH) undergoing VR. Patients were assessed before and after rehabilitation by the vHIT in all ipsilesional and contralesional semicircular can­als (SCCs) and the DHI. The changes in DHI score and VOR gain before and after rehabili­tation, were shown as ΔDHI and ΔVOR and their correlation was evaluated. Results: VOR gain from ipsilesional and contra­lesional SCCs was improved significantly after VR. There was a significant strong negative correlation between ΔVOR gain from ipsile­sional SCCs and ΔDHI score but no significant correlation was found between the ΔDHI score and ΔVOR gain from contralesional SCCs. Conclusion: vHIT test is a useful tool to evaluate the effectiveness of VR. VOR gain is correlated with the DHI score. Therefore, the improvement in vHIT results in all three SCCs after VR may be a good predictor of the degree of improvement in dizziness-related disability. Keywords: Vestibular rehabilitation; follow-up; unilateral vestibular hypofunction; video head impulse test; dizziness handicap inventory


Sign in / Sign up

Export Citation Format

Share Document