Dissociation between caloric and head impulse testing in patients with congenital abnormalities of the semicircular canals

2018 ◽  
Vol 132 (10) ◽  
pp. 932-935 ◽  
Author(s):  
B Shaw ◽  
R S Raghavan

AbstractBackgroundDissociation between caloric and head impulse test results in patients with vestibular disorders has been well documented since the introduction of video head impulse testing. Prior to the introduction of video head impulse testing, vestibular diagnostic services relied mainly on caloric testing, and it is now known that the caloric testing shows more positive results than video head impulse testing. A dissipation model was proposed to explain this dissociation.Case reportsThis paper presents two cases in which caloric testing indicated an absent or significantly reduced response on the horizontal semicircular canal plane but video head impulse testing showed near-normal or normal vestibulo-ocular reflex gain on the same plane.ConclusionThis report supports the dissipation theory and questions the functional relevance of canal paresis values calculated from caloric test results.

Author(s):  
Homa Zarrinkoob ◽  
Hadi Behzad ◽  
Seyed Mehdi Tabatabaee

Background and Aim: One of the tools for ass­essing the vestibulo-ocular reflex (VOR) is using video head impulse test (vHIT). In this test by placing the head at different angles and shaking the head, three semicircular canals of the vestibular system in each ear can be exami­ned separately. The purpose of this study was to investigate the relationship between the low and high velocities of the vHIT test with VOR and its compensatory saccades. Methods: The vHIT test was performed by an examiner in 49 normal individuals aged 23–39 at low and high velocities. All participants had normal hearing, visual, and vestibular systems. Results: Mean gains in the horizontal, anterior and posterior semicircular canals in the right ear respectively were 0.92, 1 and 0.90 and in the left ear 0.93, 0.99 and 0.95 for low velocity and 0.78, 0.92 and 0.79 in the right ear and 0.80, 0.85 and 0.86 in the left ear for high velocity. Also, the number of compensatory saccade at high velocity was higher than those at the low velocity and the latency of compensatory sacc­ade was lower at the higher velocity. Conclusion: In the vHIT test, VOR gain decreases at high velocity that is statistically significant. Also, compensatory saccades are more likely to occur at high velocity with sma­ller delay. Therefore, high-velocity vHIT test is not recommended for the purpose of examining the VOR gain and compensatory saccade.


2018 ◽  
Vol 23 (5) ◽  
pp. 285-289 ◽  
Author(s):  
Patricia Castro ◽  
Sara Sena Esteves ◽  
Florencia Lerchundi ◽  
David Buckwell ◽  
Michael A. Gresty ◽  
...  

Gaze stabilization during head movements is provided by the vestibulo-ocular reflex (VOR). Clinical assessment of this reflex is performed using the video Head Impulse Test (vHIT). To date, the influence of different fixation distances on VOR gain using the vHIT has not been explored. We assessed the effect of target proximity on the horizontal VOR using the vHIT. Firstly, we assessed the VOR gain in 18 healthy subjects with 5 viewing target distances (150, 40, 30, 20, and 10 cm). The gain increased significantly as the viewing target distance decreased. A second experiment on 10 subjects was performed in darkness whilst the subjects were imagining targets at different distances. There were significant inverse relationships between gain and distance for both the real and the imaginary targets. There was a statistically significant difference between light and dark gains for the 20- and 40-cm distances, but not for the 150-cm distance. Theoretical VOR gains for different target distances were calculated and compared with those found in light and darkness. The increase in gain observed for near targets was lower than predicted by geometrical calculations, implying a physiological ceiling effect on the VOR. The VOR gain in the dark, as assessed with the vHIT, demonstrates an enhancement associated with a reduced target distance.


2015 ◽  
Vol 130 (2) ◽  
pp. 145-150 ◽  
Author(s):  
P Eza-Nuñez ◽  
C Fariñas-Alvarez ◽  
N Perez Fernandez

AbstractObjectives:This study aimed to evaluate the results of the video head impulse test and of the caloric and rotatory chair tests in patients with dizziness. Agreement between test results was assessed and the best protocol for detecting peripheral vestibulopathy was identified.Methods:Participants comprised 116 patients, 75 with a peripheral vestibulopathy and 41 with non-peripheral vestibulopathy. The main outcome measures were classified as normal or abnormal according to our laboratory data.Results:Agreement between tests was low. Vestibulopathy testing that required all three results to be abnormal had a sensitivity of 0.547, a specificity of 0.878, and positive and negative predictive values of 0.891 and 0.514, respectively. Vestibulopathy testing that required just one result to be abnormal had a sensitivity of 0.933, a specificity of 0.292, and positive and negative predictive values of 0.701 and 0.705, respectively.Conclusion:In peripheral vestibulopathy, there was weak concordance in the assessment of horizontal semicircular canal function among the different tests. However, the video head impulse test had sufficient statistical power to be recommended as the first-line test.


2021 ◽  
Vol 12 ◽  
Author(s):  
Dmitrii Starkov ◽  
Bernd Vermorken ◽  
T. S. Van Dooren ◽  
Lisa Van Stiphout ◽  
Miranda Janssen ◽  
...  

Objective: This study aimed to identify differences in vestibulo-ocular reflex gain (VOR gain) and saccadic response in the suppression head impulse paradigm (SHIMP) between predictable and less predictable head movements, in a group of healthy subjects. It was hypothesized that higher prediction could lead to a lower VOR gain, a shorter saccadic latency, and higher grouping of saccades.Methods: Sixty-two healthy subjects were tested using the video head impulse test and SHIMPs in four conditions: active and passive head movements for both inward and outward directions. VOR gain, latency of the first saccade, and the level of saccade grouping (PR-score) were compared among conditions. Inward and active head movements were considered to be more predictable than outward and passive head movements.Results: After validation, results of 57 tested subjects were analyzed. Mean VOR gain was significantly lower for inward passive compared with outward passive head impulses (p < 0.001), and it was higher for active compared with passive head impulses (both inward and outward) (p ≤ 0.024). Mean latency of the first saccade was significantly shorter for inward active compared with inward passive (p ≤ 0.001) and for inward passive compared with outward passive head impulses (p = 0.012). Mean PR-score was only significantly higher in active outward than in active inward head impulses (p = 0.004).Conclusion: For SHIMP, a higher predictability in head movements lowered gain only in passive impulses and shortened latencies of compensatory saccades overall. For active impulses, gain calculation was affected by short-latency compensatory saccades, hindering reliable comparison with gains of passive impulses. Predictability did not substantially influence grouping of compensatory saccades.


2019 ◽  
Vol 11 (6) ◽  
pp. 479-485 ◽  
Author(s):  
Abdulaziz A. Alkathiry ◽  
Anthony P. Kontos ◽  
Joseph M. Furman ◽  
Susan L. Whitney ◽  
Eric R. Anson ◽  
...  

Background: Oculomotor impairments, dizziness, and imbalance are common after sports-related concussion (SRC) in adolescents and suggest a relationship between SRC and vestibular system dysfunction. However, it is not clear whether the source of these problems is attributable to the peripheral or central vestibular system. Hypothesis: The video Head Impulse Test (vHIT), which assesses peripheral vestibular function, will show differences in gain between adolescents with and without SRC. Furthermore, there will be an association between vHIT and clinical balance and vestibular/oculomotor testing. Study Design: Cross-sectional study. Level of Evidence: Level 2. Methods: Twenty-five symptomatic adolescents aged between 12 and 19 years with a recent (within 10 days) SRC and 22 healthy controls aged 13 to 20 years were assessed using the vHIT, Balance Error Scoring System (BESS), and Vestibular Ocular Motor Screening (VOMS) tools. The vestibulo-ocular reflex (VOR) gain was calculated independently for right and left head impulses. Independent-samples t tests or Mann-Whitney U tests for nonnormal distributions were used to compare concussed patients and controls on the measures. Spearman rank-order correlations were used to assess the association of vHIT with BESS and VOMS. Results: VOR gain in all adolescents with SRC was greater than 0.8, which is considered within normal limits. VOR gain and BESS scores were not significantly different between groups. Adolescents with SRC had significantly worse VOMS item scores than adolescents without SRC ( P < 0.001). There were no significant correlations among vHIT gain and VOMS or BESS. Conclusion: There was no evidence for dysfunction in the peripheral horizontal semicircular canal function at high rotation speeds (ie, vHIT) after SRC, and vHIT was unrelated to balance and vestibular/oculomotor symptoms and dysfunction. However, adolescents with SRC scored worse on vestibular and oculomotor testing than those without SRC. Vestibular dysfunction and symptoms after SRC may be centrally derived. Clinical Relevance: We do not recommend the assessment of head impulse function in adolescents with SRC unless more definitive signs of peripheral vestibular injury are present. We recommend using the VOMS to assess symptoms of suspected SRC injury in adolescents.


2020 ◽  
Vol 31 (08) ◽  
pp. 613-619
Author(s):  
Başak Mutlu ◽  
Sıdıka Cesur ◽  
Merve Torun Topçu ◽  
Cennet Reyyan Geçici ◽  
Öyküm Esra Aşkın ◽  
...  

Abstract Objective The video head impulse test (vHIT) is a diagnostic tool to assess the function of the semicircular canals and branches of the vestibular nerve. The aim of this study was to analyze the interexaminer variability of vHIT results in healthy subjects. Materials and Methods A total of 21 healthy participants were included in the study. vHIT responses were collected by four clinicians. Variability of the vHIT results between examiners was analyzed statistically. Results The vestibulo-ocular reflex (VOR) velocity regression values were from 0.99 to 1.09 degrees per second for the lateral canals. For the vertical canals, VOR velocity regression values were from 0.87 to 1.21 degrees per second. According to repeated measures analysis of variance, the normality assumptions for the velocity regression of the left lateral canal (p = 0.002) and the right anterior canal (p < 0.01) were met and the differences were statistically significant. The normality assumptions were not met for 40, 60, and 80 ms median gain of the right lateral canal (p = 0.016, p = 0.038, and p = 0.001, respectively); 40 and 60 ms median gain of the left lateral canal (p < 0.001 and p = 0.008, respectively); and the velocity regression of the left posterior canal (p < 0.00). These differences were found to be statistically significant by using the Friedman test. Conclusion The interexaminer differences of the VOR gain values for the vHIT were statistically significant. Serial vHIT testing should be performed by the same examiner to reduce the effects of interexaminer variability.


2021 ◽  
pp. 1-13
Author(s):  
Tuğba Emekci ◽  
Hatice Seyra Erbek

BACKGROUND: fHIT is an easily applicable test battery that indirectly evaluates the vestibulo-ocular reflex (VOR) from a functional perspective. AIMS/OBJECTIVES: The aim of this study was to Individuals determine the correlation between age and the percentage of correct answers (% CA) obtained in the functional head impulse test (fHIT) in healthy individuals. MATERIAL AND METHODS: A total of 105 volunteers, 50 males and 55 females, between the ages of 18 and 70 years, participated in the study. A Beon Solution fHIT system (Zero Branco (TV), Italy) was used in the study. RESULTS: In our study, a decrease in the mean % CA was observed in all semicircular canals (SCCs) with increasing age. Between age and mean % CA, a significant negative moderate (–0.311) correlation was observed in lateral SCCs, and a significant negative low (–0.257) correlation was observed in posterior SCCs (p <  0.05). In anterior SCCs, there was no statistically significant relationship between age and mean % CA (p >  0.05). CONCLUSIONS: The present study performed in a healthy population will be helpful in terms of making comparisons in studies to be conducted in various vestibular diseases. It will also be a guide for identifying pathological consequences in vestibular diseases.


Revista CEFAC ◽  
2020 ◽  
Vol 22 (6) ◽  
Author(s):  
Patricia Oyarzún Díaz ◽  
Sebastián Rivera Retamal ◽  
Sergio Jiménez Cofré ◽  
Hugo Segura Pujol

ABSTRACT Purpose: to identify and analyze the available evidence on the reference values of the vestibulo-ocular reflex gain obtained with the video head impulse test. Methods: an integrative review based on the PRISMA protocol, searching the ProQuest, EBSCO, PubMed, ScienceDirect, Cochrane Library, LILACS, and SciELO databases with keywords. The studies included were original research articles, systematic reviews, and meta-analyses published since 2009, involving humans, written in English, Spanish and/or Portuguese. Results: 10,250 studies related to the keywords were found. Of these, 10 articles met the inclusion criteria and were analyzed following the CADE protocol. On the horizontal plane, the values ranged from 0.80 to 1.06, while on the right anterior/left posterior and on the left anterior/right posterior planes, the values ranged from 0.80 to 1.03. Other relevant data for obtaining the gain were analyzed, such as the number of impulses, the assessor’s experience, the patient-object distance, and the percentage of asymmetry. Conclusion: little research on the theme, recently developed and published, mostly in European countries, was found. This shows the need for a greater number of studies to strengthen the scientific evidence.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ming Li ◽  
Yangming Leng ◽  
Bo Liu

Background: By examining the clinical features and results of video head impulse test (vHIT) and caloric tests in patients with enlarged vestibular aqueduct (EVA) presenting with vertigo, we aimed to investigate the function of angular vestibulo-ocular reflex (VOR) and its clinical implications.Methods: Nine patients with EVA manifesting with vertigo were enrolled. The medical history, audiological examination, imaging, and the results of the caloric test and the vHIT were analyzed.Results: Of the nine patients with EVA (eight bilateral and one unilateral case), five were pediatric cases. All 17 ears exhibited sensorineural hearing loss (SNHL). Enlarged vestibular aqueduct patients can present with recurrent (seven cases) or single (two cases) vertigo attack, trauma-induced (two cases), or spontaneous (seven cases) vertigo. Diminished caloric responses were observed in 77.8% (7/9) of the patients (four cases unilaterally and three bilaterally), while unilateral abnormal vHIT results in 11.1% (1/9) patients. Abnormal caloric and normal horizontal vHIT responses were found in 66.7% (6/9) of EVA patients.Conclusions: Vestibular manifestations in EVA are diverse. Enlarged vestibular aqueduct patients with vertigo can present with a reduced caloric response and normal horizontal vHIT, and this pattern of angular VOR impairment was also found in other hydropic ear diseases.


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