Journal of Vestibular Research - Volume 30, issue 4

Authors: Zamaro, Ewa | Saber Tehrani, Ali S. | Kattah, Jorge C. | Eibenberger, Karin | Guede, Cynthia I. | Armando, Lenz | Caversaccio, Marco D. | Newman-Toker, David E. | Mantokoudis, Georgios

Article Type: Research Article

Abstract: BACKGROUND: International consensus on best practices for calculating and reporting vestibular function is lacking. Quantitative vestibulo-ocular reflex (VOR) gain using a video head impulse test (HIT) device can be calculated by various methods. OBJECTIVE: To compare different gain calculation methods and to analyze interactions between artifacts and calculation methods. METHODS: We analyzed 1300 horizontal HIT traces from 26 patients with acute vestibular syndrome and calculated the ratio between eye and head velocity at specific time points (40 ms, 60 ms) after HIT onset (‘velocity gain’), ratio of velocity slopes (‘regression gain’), and ratio of area under the curves …after de-saccading (‘position gain’). RESULTS: There was no mean difference between gain at 60 ms and position gain, both showing a significant correlation (r2  = 0.77, p  < 0.001) for artifact-free recordings. All artifacts reduced high, normal-range gains modestly (range –0.06 to –0.11). The impact on abnormal, low gains was variable (depending on the artifact type) compared to artifact-free recordings. CONCLUSIONS: There is no clear superiority of a single gain calculation method for video HIT testing. Artifacts cause small but significant reductions of measured VOR gains in HITs with higher, normal-range gains, regardless of calculation method. Artifacts in abnormal HITs with low gain increased measurement noise. A larger number of HITs should be performed to confirm abnormal results, regardless of calculation method. Show more

Keywords: vHIT, video head impulse test, VOR, gain, artifacts, calculation methods, regression, area under the curve, HIT device, position gain, regression gain, video-oculography

DOI: 10.3233/VES-200708

Citation: Journal of Vestibular Research, vol. 30, no. 4, pp. 225-234, 2020

Authors: Luecke, Vivien Nancy | Buchwieser, Laura | zu Eulenburg, Peter | Marquardt, Torsten | Drexl, Markus

Article Type: Research Article

Abstract: BACKGROUND: Sound is not only detected by the cochlea, but also, at high intensities, by the vestibular system. Acoustic activation of the vestibular system can manifest itself in vestibular evoked myogenic potentials (VEMPs). In a clinical setting, VEMPs are usually evoked with rather high-frequency sound (500 Hz and higher), despite the fact that only a fraction of saccular and utricular hair cells in the striolar region is available for high-frequency stimulation. OBJECTIVE: As a growing proportion of the population complains about low-frequency environmental noise, including reports on vestibular symptoms, the activation of the vestibular system by low-frequency sound deserves …better understanding. METHODS: We recorded growth functions of oVEMPs and cVEMPs evoked with air-conducted sound at 120 Hz and below. We estimated VEMP thresholds and tested whether phase changes of the stimulus carrier result in changes of VEMP amplitude and latency. RESULTS: The VEMP response of the otholith organs to low-frequency sound is uniform and not tuned when corrected for middle ear attenuation by A-weighting the stimulus level. Different stimulus carrier phases result in phase-correlated changes of cVEMP latencies and amplitudes. CONCLUSIONS: VEMPs can be evoked with rather low-frequency sound, but high thresholds suggest that they are unlikely to be triggered by environmental sounds. Show more

Keywords: Vestibular evoked myogenic potentials, low-frequency sound, utricle, saccule, striola

DOI: 10.3233/VES-200712

Citation: Journal of Vestibular Research, vol. 30, no. 4, pp. 235-247, 2020

Authors: Quintana, C. | Heebner, N.R. | Olson, A.D. | Abt, J.P. | Hoch, M.C.

Article Type: Research Article

Abstract: BACKGROUND: The vestibular-ocular reflex (VOR) integrates the vestibular and ocular systems to maintain gaze during head motion. This reflex is often negatively affected following sport-related concussion. Objective measures of gaze stability, a function mediated by the VOR, such as the computerized dynamic visual acuity test (DVAT) and gaze stabilization test (GST), may have utility in concussion management. However, normative data specific to sport, sex, or concussion history have not been established in collegiate athletes. OBJECTIVE: The objective of this study was to establish normative values for the DVAT and GST in collegiate athletes and explore the effect of …sport, sex, and concussion history on VOR assessments. METHODS: The DVAT and GST were completed by 124 collegiate athletes (72 male, 52 female, mean±SD, age: 19.71±1.74 years, height: 173.99±13.97 cm, weight: 80.06±26.52 kg) recruited from Division-I athletic teams (football, soccer and cheerleading). The DVAT and GST were performed in the rightward and leftward directions during a single session in a standardized environment. Normative values for DVAT and GST measures were expressed as percentiles. Non-parametric statistics were used to compare differences between groups based on sex, sport, and concussion history. Alpha was set a-priori at 0.05. RESULTS: Overall, the median LogMAR unit for 124 athletes completing the DVAT was 0 (IQR = 0.17) for both leftward and rightward. The median velocities achieved on the GST were 145 °/sec and 150 °/sec (IQR = 45 and 40) for the leftward and rightward directions respectively. Significant differences were observed between sports (p  = 0.001–0.17) for the GST with cheerleading demonstrating higher velocities than the other sports. However, no significant differences were identified based on sex (p ≥0.09) or history of concussion (p ≥0.15). CONCLUSIONS: Normative estimates for the DVAT and GST may assist in the clinical interpretation of outcomes when used in post-concussion evaluation for collegiate athletes. Although sex and previous concussion history had no effect on the DVAT or GST, performance on these measures may be influenced by type of sport. Sport-related differences in the GST may reflect VOR adaptations based on individual sport-specific demands. Show more

DOI: 10.3233/VES-200710

Citation: Journal of Vestibular Research, vol. 30, no. 4, pp. 249-257, 2020

Authors: D’Silva, Linda J. | Siengsukon, Catherine F. | Devos, Hannes

Article Type: Research Article

Abstract: BACKGROUND: Disruption of visual-vestibular interaction after concussion can cause gaze instability with head movements. The long-term impact of concussion on gaze stability is unknown. OBJECTIVE: This cross-sectional comparative pilot study examined gaze stability in the chronic stage after concussion (greater than one year). A secondary objective was to examine the relationship between gaze stability and sleep. METHODS: Outcome measures included: 1. Gaze stability in logMAR (mean loss of dynamic visual acuity (DVA) in the yaw and pitch planes); 2. Pittsburgh Sleep Quality Index (PSQI); 3. Epworth Sleepiness Scale (ESS). Post-Concussion Symptom Scale (PCSS), time since injury, …and number of concussions were collected for the people with concussion. RESULTS: The study sample included thirty-four adults (mean age 23.35±1.3 years). Seventeen had a history of 1–9 concussions, with a mean duration of 4.4±1.9 years since last concussion; and 17 were age and sex-matched controls. Mean pitch plane DVA loss was greater in the concussion group compared to the control group (p  = 0.04). Participants with previous concussion had lower sleep quality based on the PSQI (p  = 0.01) and increased daytime sleepiness based on the ESS (p  = 0.01) compared to healthy controls. Mean DVA loss in the pitch plane was significantly correlated with the PSQI (r  = 0.43, p  = 0.01) and the ESS (r  = 0.41, p  = 0.02). CONCLUSION: Significant differences in dynamic visual acuity may be found in young adults long after a concussion, compared with those who have no concussion history. Furthermore, loss of dynamic visual acuity was associated with poorer sleep quality and higher daytime sleepiness. Show more

Keywords: Gaze stability, chronic concussion, sleep quality

DOI: 10.3233/VES-200706

Citation: Journal of Vestibular Research, vol. 30, no. 4, pp. 259-266, 2020

Authors: Lin, Sang-I | Tsai, Yi-Ju | Lee, Pei-Yun

Article Type: Research Article

Abstract: BACKGROUND: Patients with Benign Paroxysmal Positional Vertigo (BPPV) often report a sensation of disequilibrium before treatment with the canalith repositioning maneuvers. Apart from vestibular information, visual input also contributes to balance control. How visual stimuli influence balance control in BPPV patients is unclear. OBJECTIVE: To investigate the influence of visual stimuli on balance performance in BPPV patients. METHODS: Three groups of participants, patients with BPPV, and healthy young and older adults, were instructed to stand under three conditions: 1) eyes open (EO); 2) while watching a static picture via a video display; and 3) while watching …a rotating visual scene. Antero-posterior (AP), lateral (ML), and total sway path during standing were analyzed. RESULTS: In all conditions, patients with BPPV showed significantly larger AP, ML and total sway path than young, whereas older adults only showed significantly larger AP and total sway path than young adults. During the visual stimuli, all participants exhibited significantly increased AP and total sway while watching a static image and a moving scene as compared with the EO condition. CONCLUSIONS: Patients with BPPV have similar balance control to older adults, but poorer balance control than young adults. The reduced lack of standing balance control in the coronal plane of patients with BPPV, might affect balance strategy after external perturbations. Show more

Keywords: Benign paroxysmal positional vertigo (BPPV), visual stimuli, standing balance

DOI: 10.3233/VES-200709

Citation: Journal of Vestibular Research, vol. 30, no. 4, pp. 267-274, 2020

Authors: Baghdadi, Moetez | Caldani, Simona | Maudoux, Audrey | Audo, Isabelle | Bucci, Maria Pia | Wiener-Vacher, Sylvette R.

Article Type: Research Article

Abstract: Highlights • The estimation of verticality (assessed with Subjective visual vertical (SVV)) is more variable in patients with Usher (type I and II) compared to healthy participants. • Visual and vestibular information are essential for the visual vertical (VV) perception. • A reweighting of sensory information from the central nervous system seems to be able to compensate for the absence of vestibular function in patients with Usher type I.

Keywords: Subjective visual vertical, Usher syndrome, visuo-vestibular inputs, somes- thesia, perception of space, verticality

DOI: 10.3233/VES-200711

Citation: Journal of Vestibular Research, vol. 30, no. 4, pp. 275-282, 2020