Colin R. Grove

Objectives: Peripheral vestibular hypofunction (PVH) affects a significant portion of the population and impairs visual acuity during head motion (dynamic visual acuity, DVA). This study compared the effectiveness of a novel gaze stability training called Incremental VOR Adaptation (IVA) versus traditional vestibular physical therapy (VPT) for improving DVA. Methods: The Incremental Velocity Error as a New Treatment in Vestibular Rehabilitation (INVENT) trial is a randomized, controlled, cross-over study involving 24 participants with chronic unilateral or bilateral PVH. Participants underwent either IVA or VPT for 3 weeks, followed by a washout period and then the alternate intervention (IVA-VPT or VPT-IVA). DVA was measured at baseline, after each intervention, at the completion of the washout period, and at 6-month follow-up. Results: There was a significant main effect of treatment Group, F (1,19) = 7.75, p = 0.012, with (IVA-VPT) consistently demonstrating lower DVA scores than VPT-IVA. A significant main effect of Side was also observed, F (1,19) = 13.35, p = 0.0017, indicating lower DVA scores for contralesional compared to ipsilesional head rotation. We found no effect of Time ( F (4,76) = 1.44, p = 0.23), suggesting that scores remained stable from baseline through the 6-months follow-up. There were no significant interactions, including Group × Side ( F (1,19) = 0.11, p = 0.74), Group × Time ( F (4,76) = 1.33, p = 0.27), or Group × Side × Time ( F (4,76) = 0.59, p = 0.67). Conclusion: DVA scores were consistently better at all time points after participants completed IVA. Using an intent to treat analysis, with no baseline demographic differences between groups, our data support that exposure to the first gaze stability training type exerts a stable influence on DVA that persisted to 6-month follow-up. Clinically, this implies that once DVA improvements are established through either IVA or VPT, they tend to remain stable over 6 months. Level of Evidence: Level 2.

People with multiple sclerosis (PwMS) who report dizziness often have gaze instability due to vestibulo-ocular reflex (VOR) deficiencies and compensatory saccade (CS) abnormalities. Herein, we aimed to describe and compare the gaze stabilization mechanisms for yaw and pitch head movements in PwMS. Thirty-seven PwMS (27 female, mean ± SD age = 53.4 ± 12.4 years old, median [IQR] Expanded Disability Status Scale Score = 3.5, [1.0]. We analyzed video head impulse test results for VOR gain, CS frequency, CS latency, gaze position error (GPE) at impulse end, and GPE at 400 ms after impulse start. Discrepancies were found for median [IQR] VOR gain in yaw (0.92 [0.14]) versus pitch-up (0.71 [0.44], p < 0.001) and pitch-down (0.81 [0.44], p = 0.014]), CS latency in yaw (258.13 [76.8]) ms versus pitch-up (208.78 [65.97]) ms, p = 0.001] and pitch-down (132.17 [97.56] ms, p = 0.006), GPE at impulse end in yaw (1.15 [1.85] degs versus pitch-up (2.71 [3.9] degs, p < 0.001), and GPE at 400 ms in yaw (-0.25 [0.98] degs) versus pitch-up (1.53 [1.07] degs, p < 0.001) and pitch-down (1.12 [1.82] degs, p = 0.001). Compared with yaw (0.91 [0.75]), CS frequency was similar for pitch-up (1.03 [0.93], p = 0.999) but lower for pitch-down (0.65 [0.64], p = 0.023). GPE at 400 ms was similar for yaw and pitch-down (1.88 [2.76] degs, p = 0.400). We postulate that MS may have preferentially damaged the vertical VOR and saccade pathways in this cohort.

Introduction: Spatial navigation, the ability to move through one’s environment, is a complex skill utilized in everyday life. The effects of specific vestibular end-organ deficits and hearing impairments on spatial navigation have received little to no attention. We hypothesized that hearing impairment adversely affects spatial navigation and that bimodal impairments (vestibular and hearing) further impair navigation ability. Methods: Data from 182 participants in the Baltimore Longitudinal Study of Aging who had interpretable results for the video head impulse test (vHIT), cervical vestibular evoked myogenic potentials (cVEMP) and ocular vestibular evoked myogenic potentials (oVEMP), audiometric testing, and the triangle completion test (TCT) were retrospectively analyzed. Multiple linear regression, controlling for age, sex, and cognition, was employed to identify predictors of TCT performance in terms of end-point error, angle deviation, and distance walked. Results: oVEMP abnormalities were associated with larger end-point error (p = 0.008) and larger angle deviation (p = 0.002) but were not associated with distance walked (p = 0.392). Abnormalities on cVEMP testing and vHIT were not associated with distance walked (p = 0.835, p = 0.300), end-point error (p = 0.256, p = 0.808), or angle deviation (p = 0.192, p = 0.966). Compared with normal-hearing adults, hearing-impaired adults walked a shorter distance during the TCT (p = 0.049) but had a similar end-point error (p = 0.302) and angle deviation (p = 0.466). There was no interaction between vestibular and hearing function for predicting spatial navigation ability. Conclusion: In this cohort analysis, utricular dysfunction and hearing impairment were associated with poorer spatial navigation performance. We postulate that hearing impairment negatively affects one’s ability to use real-time, intrinsic auditory cues and/or prior experience to guide navigation.

Globally, there are nearly three million people living with multiple sclerosis (PLW-MS). Many PLW-MS experience vertigo and have signs of vestibular dysfunction, e.g., low vestibulo–ocular reflex (VOR) gains or the presence of compensatory saccades (CSs), on video head impulse testing (vHIT). We examined whether the vestibular function and compensatory oculomotor behaviors in PLW-MS differed based on the level of MS-related disability. The VOR gain, CS frequency and latency, and gaze position error (GPE) were calculated from the individual traces obtained during six-canal vHIT for 37 PLW-MS (mean age 53.4 ± 12.4 years-old, 28 females) with vertigo and/or an imbalance. The subjects were grouped by their Expanded Disability Status Scale (EDSS) scores: PLW-min-MS (EDSS = 1.0–2.5, n = 8), PLW-mild-MS (EDSS = 3.0–4.5, n = 23), and PLW-moderate-MS (EDSS = 5.0–6.0, n = 6). The between-group differences were assessed with Kruskal–Wallis tests. The VOR gains for most of the canals were higher for PLW-min-MS compared to PLW-mild- and mod-MS, respectively. CS occurred less often in PLW-min-MS versus PLW-mild- and mod-MS, respectively. No clear trend in CS latency was found. The GPE was often lower for PLW-min-MS compared to PLW-mild- and mod-MS, respectively. Thus, our data demonstrate that worse VOR and compensatory oculomotor functions are associated with a greater MS-related disability. PLW-MS may benefit from personalized vestibular physical therapy.

Compensatory saccades (CSs) are recruited by individuals with unilateral vestibular deafferentation (UVD) to compensate for an impaired vestibulo-ocular reflex (VOR). The effectiveness of CS in multiple sclerosis (MS), a central vestibular impairment, is unknown. We show that in UVD and in MS, covert CSs compensate for reduced VOR gain and minimize gaze position error (GPE), yet in >50% of individuals with MS, overt CS worsened GPE, suggesting unique roles for peripheral and central vestibular inputs.

Introduction: Benign paroxysmal positional vertigo (BPPV) is the most frequently occurring peripheral vestibular disorder. Clinical practice guidelines (CPG) for BPPV exist; however, little is known about how affected patients perceive their condition is being managed. We aimed to leverage registry data to evaluate how adults who report BPPV are managed. Material and Methods: We retrospectively analyzed of data from 1,262 adults (58.4 ± 12.6 years old, 81.1% female, 91.1% White) who were enrolled in the Vestibular Disorders Association Registry from 2014 to 2020. The following patient-reported outcomes were analyzed by proportions for those who did and did not report BPPV: symptoms experienced, falls reported, diagnostics undertaken, interventions received (eg, canalith repositioning maneuvers [CRMs], medications), and responses to interventions. Results: Of the 1,262 adults included, 26% reported being diagnosed with BPPV. Many adults who reported BPPV (83%) also endorsed receiving additional vestibular diagnoses or may have had atypical BPPV. Those with BPPV underwent magnetic resonance imaging and were prescribed medications more frequently than those without BPPV (76% vs 57% [χ²=36.51, p< 0.001] and 85% vs 78% [χ²=5.60, p=0.018], respectively). Falls were experienced by similar proportions of adults with and without BPPV (55% vs 56% [χ²⁼=11.26, p=0.59]). Adults with BPPV received CRMs more often than those without BPPV (86% vs 48%, χ²=127.23, p< 0.001). More registrants with BPPV also endorsed benefit from CRMs compared to those without BPPV (51% vs 12% [χ²=105.30, p< 0.001]). Discussion: In this registry, BPPV was often reported with other vestibular disorders. Healthcare utilization was higher than would be expected with care based on the CPG. The rates of falls in those with and without BPPV are higher than previously reported. Adults with BPPV reported significant differences in how their care is managed and their overall outcomes compared to those without BPPV. Conclusion: Patient-reported outcomes provide useful information regarding the lived experience of adults with BPPV.

Vestibular disorders affect 5% to 10% of the general population^1,2 and cause functional impairments in vision,³ balance,⁴ and gait.⁵ Although the effects of peripheral vestibular loss on balance⁶ and gaze stability^7,8 are well documented, less attention has been devoted to its effect on gait.^9-11 Greater understanding of vestibulopathic gait is needed because regaining the ability to walk safely is a high priority for patients.¹²

This retrospective study was undertaken to assess balance recovery and dizziness handicap in 32 patients after a vestibular and balance rehabilitation program. Outcomes were compared between 12 patients with peripheral vestibular disorders and 20 patients with central or mixed balance disorders. The patients were tested with posturography (sensory organization test [SOT]) and the Dizziness Handicap Inventory (DHI) before and after their therapy program. The vestibular SOT, composite SOT, and functional DHI scores obtained before and after exercise were significantly improved in both the peripheral and central groups. The visual SOT mean scores obtained before and after therapy were significantly different only for the group with central or mixed vestibular disorders. Changes in SOT scores were not directly correlated with changes in DHI scores. Outcome measures of vestibular rehabilitation protocols confirmed objective and subjective improvement of balance and dizziness handicap in patients with peripheral and central vestibular disorders.