What does the video head impulse test tell us about post-caloric vestibular recruitment?

Abstract Objective: The vestibular recruitment observed in caloric testing is a new tool in the study of the vestibulo-ocular reflex. This study aimed to determine the sensitivity and specificity of the video head impulse test to detect post-caloric vestibular recruitment. Method: In this cross-sectional study, all participants underwent the standard otoneurological assessment of the service, caloric test, and video head impulse test. A non-linear mixed model was used to test for associations. Results: The study group consisted of 250 (89 male and 161 female) patients, with a mean age of 54.84 years. The control group comprised 35 participants, 18 men and 17 women, with a mean age of 40.42 years. Sex and age had no effect on group responses. There was no difference between the study and control groups regarding the interaction between recruitment and gain (p = 0.7487); recruitment and overt (p = 0.7002) and covert saccades (p = 1.0000); and recruitment and anti-compensatory saccades in the contralateral ear (p = 0.3050). The video head impulse test had a sensitivity of 51% and a specificity of 50% as a predictor of post-caloric recruitment. Conclusion: The video head impulse test results showed no relevance in predicting post-caloric vestibular recruitment.

Dissociation between video head impulse test and caloric test: a marker of menière's disease? - A systematic review and meta-analysis

Abstract Objective To analyze, by means of a systematic review and meta-analysis, the proportion of patients with Meniere's disease who have altered caloric test and vHIT, as well as to determine the prevalence of altered caloric test and normal vHIT dissociation in the diagnosis of Meniere's disease. Methods The literature search had no restriction regarding the period of publication on the following indexed data platforms: PubMed, PubMed PMC, BVS-Bireme, Web of Science, Embase and Cochrane Library. Articles that evaluated patients with Meniere's disease who underwent caloric test and vHIT were included. Two researchers independently conducted the analysis of the articles, promoting the selection and capture of data, following the recommendations of the PRISMA method, and complying with the criteria for articles inclusion and exclusion defined in the research protocol. In case of disagreement during the selection process, a third researcher was included for analysis. Results From a total of 427 initial studies, the researchers selected 12 articles, published between 2014 and 2021, with a total of 708 patients evaluated, with a mean age of 52.72 years old. The prevalence of patients with Meniere's disease with altered caloric reflex test was 64% (95% CI 57%‒71%), while the prevalence of altered vHIT was only 28% (95% CI 16%-40%). The prevalence of the altered caloric test + normal vHIT dissociation was 47% (95% CI 37%-57%). Conclusion The video head impulse test and the caloric test are valuable tools for vestibular assessment. The dissociation of findings between these two tests in patients with Meniere's disease was more prevalent in this meta-analysis and may be a result of the tonotopy of specialized hair cells in the ampullary crest. The prevalence of altered caloric test was 64% and anormal vHIT was 28%. The dissociation caloric asymmetry and normal vHIT was observed in 47% of the patients. Level of evidence: 1.

Application of vestibular function examination in the analysis of damaged site in patients with acute vestibular neuritis / 临床耳鼻咽喉头颈外科杂志

Objective:To analyze the site of vestibular nerve damaged in patients with acute vestibular neuritis. Methods:Fifty-seven patients with acute vestibular neuritis were recruited, and each patient underwent caloric irrigation test, video head impulse test（vHIT） and vestibular evoked myogenic potentials（VEMPs）. The results were further analyzed. Results:Analysis of abnormal rates of different vestibular function tests: the abnormal rate of caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and posterior semicircular canal vHIT were 92.98%, 92.98%, 92.98%, and 52.63%, respectively. The abnormal rate of cervical vestibular evoked myogenic potentials（cVEMP） and ocular vestibular evoked myogenic potentials（oVEMP） were 52.63% and 89.47%. The abnormal rate of caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and oVEMP were significantly higher than posterior semicircular canal vHIT and cVEMP（P<0.01）. Combination analysis of different vestibular function tests: there are twenty-six patients（45.61%, superior and inferior vestibular nerve） with abnormal caloric irrigation test, video head impulse test, and VEMPs. There are twenty-five patients（43.86%, superior vestibular nerve） with abnormal caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and oVEMP. There are 4 patients（7.02%, inferior vestibular nerve） with abnormal posterior semicircular canal vHIT and cVEMP. There are two patients（3.51%, ampullary vestibular nerve） with abnormal caloric irrigation test, horizontal semicircular canal vHIT, and anterior semicircular canal vHIT. The rate of superior and inferior vestibular neuritis and superior vestibular neuritis were significantly higher than inferior vestibular neuritis and ampullary vestibular neuritis（P<0.01）. Conclusion:Acute vestibular neuritis subtypes can be divided into four categories: superior and inferior vestibular neuritis, superior vestibular neuritis, inferior vestibular neuritis, and ampullary vestibular neuritis. Video head impulse test can accurately assess the site of vestibular nerve damage in patients with acute vestibular neuritis. In addition, vHIT combined with VEMPs can provide objective evidence for the diagnosis of ampullary vestibular neuritis.

Emerging and distinct video head impulse test responses in elderly with vestibular symptoms / Respostas emergentes e distintas do teste do impulso cefálico por vídeo em idosos com sintomas vestibulares

Abstract Introduction Dizziness has been reported to be the most common symptom in elderly population. Video head impulse test, VHIT, allows clinicians to assess the vestibular function in elderly individuals, during their initial stages of vestibular symptoms. Inferences from VHIT responses were traditionally low vestibulo-ocular reflex gain or a normal vestibulo-ocular reflex gain. However, the possibility of a third and new variant of the vestibulo-ocular reflex gain has not been clinically explored yet. Objectives To determine and report distinct patterns of vestibulo-ocular reflex gain using VHIT in elderly individuals with vestibular symptoms. Methods Retrospective cross-sectional study was done on a group of elderly patients who were above 70 years of age. These individuals were subjected to VHIT during their symptomatic phase. A vestibulo-ocular reflex gain value between 0.80-01.20 (Horizontal plane) was considered normal. The gain above and below this cutoff range was considered abnormal. Results 39 elderly patients (15 males and 24 females) whose mean age range was 74.71 years were evaluated for the VHIT response. Vestibulo-ocular reflex gain obtained was categorized into three distinct patterns: (i) normal vestibulo-ocular reflex gain, (ii) reduced vestibulo- ocular reflex gain and (iii) increased vestibulo-ocular reflex gain. The mean vestibulo- ocular reflex gain for both left and right horizontal canals varied significantly between the three groups (p< 0.05). No significant effect of age and vestibulo-ocular reflex gain was noted, though vestibulo-ocular reflex gain was higher in 80 years and above age (p> 0.05). Conclusion Elderly individuals with dizziness may show varying responses with vestibulo-ocular reflex gain during the symptomatic period. The third type of hyperactive vestibule-ocular reflex responses that emerged from the current study were potential indicators of fluid dynamic changes in the inner ear. These responses need to be explored further as it relates to new clinical markers for both peripheral and central vestibular disorders.

Resumo Introdução Estima‐se que a tontura seja o sintoma mais comum na população idosa. O teste do impulso cefálico por vídeo, VHIT (do inglês Video Head Impulse Test), permite que os médicos avaliem a função vestibular em idosos, durante os estágios iniciais dos sintomas vestibulares. As inferências das respostas do VHIT tradicionalmente tem sido baixo ganho de reflexo vestíbulo‐ocular ou ganho normal do reflexo vestíbulo‐ocular. Entretanto, a possibilidade de uma terceira e nova variante de ganho do reflexo vestíbulo‐ocular ainda não foi explorada clinicamente. Objetivos Determinar e relatar padrões distintos de ganho do reflexo vestíbulo‐ocular com VHIT em idosos sintomáticos com sintomas vestibulares. Método Estudo transversal retrospectivo feito em um grupo de idosos com mais de 70 anos. Esses indivíduos foram submetidos ao VHIT durante a fase sintomática. Um valor de ganho do reflexo vestíbulo‐ocular entre 0,80 a 01,20 (plano horizontal) foi considerado normal. O ganho acima e abaixo dessa faixa de corte foi considerado anormal. Resultados Foram avaliados para a resposta do VHIT 39 idosos (15 homens e 24 mulheres) com média de 74,71 anos. O ganho do reflexo vestíbulo‐ocular obtido foi categorizado em três padrões: (i) ganho de reflexo vestíbulo‐ocular normal, (ii) ganho de reflexo vestíbulo‐ocular reduzido e (iii) ganho de reflexo vestíbulo‐ocular aumentado. O ganho médio do reflexo vestíbulo‐ocular para ambos os canais horizontais esquerdo e direito variou significativamente entre os três grupos (p < 0,05). Nenhum efeito significante da idade e ganho do reflexo vestíbulo‐ocular foi observado, embora o ganho do reflexo vestíbulo‐ocular fosse maior na idade de 80 anos e acima (p > 0,05). Conclusão Indivíduos idosos com tontura podem apresentar respostas variáveis com o ganho do reflexo vestíbulo‐ocular durante o período sintomático. O terceiro tipo de respostas hiperativas do reflexo vestíbulo‐ocular que emergiram do estudo atual foi indicador potencial de mudanças na dinâmica dos fluidos na orelha interna. Essas respostas precisam ser mais exploradas, pois podem estar relacionadas a novos marcadores clínicos para distúrbios vestibulares periféricos e centrais.

Does the video head impulse test replace caloric testing in the assessment of patients with chronic dizziness? A systematic review and meta-analysis / O video head impulse test substitui a prova calórica na avaliação de pacientes com tontura crônica? Uma revisão sistemática e metanálise

Abstract Introduction: Caloric testing is the most frequently used test to assess peripheral vestibular function since the beginning of the 20th century. However, the video head impulse test, vHIT, has gained prominence in the field of neurotology, as it is a faster examination, easier to perform and less uncomfortable for the patient. Objective: To compare, through systematic review and meta-analysis, the proportion of altered cases between vHIT tests and caloric testing in patients with chronic dizziness, in addition to assessing the sensitivity and specificity of vHIT, with caloric testing as the gold standard. Methods: The literature search was carried out in the PubMed, Scopus, BVS-Bireme, Web of Science, Embase, Cochrane and ProQuest indexed databases, with no restrictions regarding the publication period. All articles that contained the results of the two tests were included in the evaluation of patients with dizziness. Two researchers independently conducted data selection and extraction from the studies, strictly following the inclusion and exclusion criteria defined in the research protocol. In case of disagreement during the selection, a discussion was carried out with a third evaluator. Results: Eleven of the 1293 initial articles met the eligibility criteria and were analyzed. 2670 patients were evaluated, of which 1112 (41.6%) were males and 1558 (58.4%) females, with a mean age of 51.6 years. The proportion of altered results in the vHIT was 21% (95%CI 9% --33%), and 55% in the caloric testing (95%CI 43% --67%). Conclusion: The vHIT does not substitute for caloric testing. The tests are complementary in assessing the patient with dizziness, as they describe the tonotopy of the ampullary crest at different frequency ranges of stimulation. In chronic cases, the vHIT has a low sensitivity and high diagnostic specificity in comparison to caloric testing.

Resumo Introdução: A prova calórica é o exame mais usado para avaliação da função vestibular periférica desde os primórdios do século XX. Porém, o vídeo teste de impulso cefálico, vHIT, tem ganhado destaque no campo da otoneurologia por ser um exame mais rápido, de fácil execução e menos desconfortável para o paciente. Objetivo: Comparar, através de revisão sistemática e metanálise, a proporção de casos alterados entre os exames vHIT e prova calórica nos pacientes com tontura crônica, além de avaliar a sensibilidade e especificidade do vHIT, tendo a prova calórica como padrão-ouro. Método: A busca na literatura foi feita nas bases de dados indexadas PubMed, Scopus, BVS-Bireme, Web of Science, Embase, Cochrane e ProQuest, sem restrições quanto ao período da publicação. Foram incluídos todos os artigos que tivessem os resultados dos dois exames na avaliação de pacientes com tontura. Dois pesquisadores conduziram de forma independente a seleção e extração de dados dos estudos, obedeceram rigorosamente os critérios de inclusão e exclusão definidos no protocolo de pesquisa. Em caso de discordância na seleção, fez-se discussão com um terceiro avaliador. Resultados: Onze dos 1.293 artigos iniciais preencheram os critérios de elegibilidade e foram analisados. Foram avaliados 2.670 pacientes, 1.112 (41,6%) do sexo masculino e 1.558 (58,4%) do feminino, com média de 51,6 anos. A proporção de exames alterados no vHIT foi de 21% (95% IC 9%-33%) e na prova calórica foi de 55% (95% IC 43%-67%). Conclusão: O vHIT não substitui a prova calórica. Ambos os testes são complementares na avaliação do paciente com tontura, pois descrevem a tonotopia da crista ampular em diferentes faixas de frequência de estimulação. Nos quadros crônicos, o vHIT tem baixa sensibilidade e alta especificidade diagnóstica em relação à prova calórica.

Vestibular status in partial deafness / Condição vestibular na surdez parcial

Abstract Introduction The hair cells of the cochlea and the vestibulum are closely connected and may be susceptible to the same noxious factors. The relationship between their function has been a continuing field of investigation. The indications for cochlear implantation have been broadened and now include the patients with partial deafness. This raises the question of their vestibular status. Objective The aim of the study was to investigate whether there is any difference between the vestibular function of patients with low frequency residual hearing and those with totally deaf ears. Methods A total of 360 ears with profound sensorineural hearing loss were analysed before cochlear implantation. The patients were divided into four groups, according to their low frequency residual hearing (Group 1 ‒ normal or slightly elevated low frequency residual hearing; Group 2 ‒ elevated threshold but still usable hearing at low frequencies; Group 3 - non-functional residual hearing; Group 4 ‒ no detectable hearing threshold within the limits of the audiometer). The patients underwent vestibular tests: cervical vestibular evoked myogenic potential, ocular vestibular evoked myogenic potential, caloric test and video-head impulse test. Results The rates of elicited responses in cervical vestibular evoked myogenic potential were as follows: in Group 1 (59.3 %); Group 2 (57.5 %); Group 3 (35.2 %); Group 4 (7.7 %). For ocular vestibular evoked myogenic potential the percentage of correct outcomes was: Group 1 (70.8 %); Group 2 (56.0 %); Group 3 (40.0 %); Group 4 (14.3 %). For the caloric test we counted normal responses in 88.9 % of Group 1; 81.6 % of Group 2; 57.9 % of Group 3; 53.3 % of Group 4. For video-head impulse test we also found markedly better results in Group1, followed by Group 2, and much worse in Group 3 and 4. Conclusion Patients with partial deafness not only have a better cochlea but also better vestibular function, which needs to be protected. In summary, the better the low frequency residual hearing, the better the vestibular status.

Resumo Introdução As células ciliadas da cóclea e do vestíbulo estão intimamente ligadas e podem ser suscetíveis aos mesmos fatores nocivos. A relação entre suas funções tem sido um campo de investigação há muito tempo. As indicações para implante coclear foram ampliadas e agora incluem os pacientes com surdez parcial. Isso levanta a questão de sua condição vestibular. Objetivo Investigar se existe alguma diferença entre a função vestibular de pacientes com audição residual de baixa frequência e aqueles com surdez total. Método Foram analisadas antes do implante coclear 360 orelhas com perda auditiva neurossensorial profunda. Os pacientes foram divididos em quatro grupos, de acordo com a audição residual de baixa frequência (Grupo 1 - audição residual de baixa frequência normal ou levemente elevada; Grupo 2 - limiar auditivo elevado, mas ainda usável em baixas frequências; Grupo 3 - audição residual não funcional; Grupo 4 - sem limiar auditivo detectável dentro dos limites do audiômetro). Os pacientes foram submetidos a testes vestibulares: potencial evocado miogênico vestibular cervical, potencial evocado miogênico vestibular ocular, prova calórica e teste do impulso cefálico com vídeo. Resultados As taxas de respostas obtidas no potencial evocado miogênico vestibular cervical foram as seguintes: no Grupo 1 (59,3%); Grupo 2 (57,5%); Grupo 3 (35,2%); Grupo 4 (7,7%). Para o potencial evocado miogênico vestibular ocular, o percentual de resultados corretos foi: Grupo 1 (70,8%); Grupo 2 (56,0%); Grupo 3 (40,0%); Grupo 4 (14,3%). Para a prova calórica, contamos respostas normais em 88,9% do Grupo 1; 81,6% do grupo 2; 57,9% do Grupo 3; 53,3% do Grupo 4. Para o teste do impulso cefálico com vídeo, também encontramos resultados significativamente melhores no Grupo 1, seguidos pelo Grupo 2, e muito piores nos Grupos 3 e 4. Conclusão Pacientes com surdez parcial não só apresentam uma função coclear melhor, mas também melhor função vestibular, que precisa ser protegida. Em resumo, quanto melhor for a audição residual de baixa frequência, melhor a condição vestibular.

Caloric test and video head impulse test sensitivity as vestibular impairment predictors before cochlear implant surgery

OBJECTIVES: Currently, cochlear implant procedures are becoming increasingly broad and have greatly expanded. Bilateral cochlear implants and cochlear implants are more frequently applied in children. Our hypothesis is that the video head impulse test may be more sensitive than the caloric test in detecting abnormal vestibular function before cochlear implant surgery. The objective of this study was to compare the video head impulse test and caloric test results of patients selected for cochlear implant procedures before surgery. METHODS: The patients selected for cochlear implant surgery were submitted to a bithermal caloric test and video head impulse test. RESULTS: By comparing angular slow phase velocity values below 5° in the bithermal caloric test (hypofunction) and video head impulse test with a gain lower than 0.8, we identified 37 (64.9%) patients with vestibular hypofunction or canal paresis and 21 (36.8%) patients with abnormal video head impulse test gain before the cochlear implant procedure. Of the 37 patients with caloric test vestibular hypofunction, 20 (54%) patients exhibited an abnormal gain in the video head impulse test. CONCLUSION: The caloric test is more sensitive than the video head impulse test (Fisher's exact test, p=0.0002) in detecting the impaired ear before cochlear implant delivery. The proportion of caloric test/video head impulse test positive identification of abnormal vestibular function or caloric test/video head impulse test sensitivity was 1.8:1.

Long-Term Changes in Video Head Impulse and Caloric Tests in Patients with Unilateral Vestibular Neuritis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Video head impulse tests (vHITs) and caloric tests are widely used to assess the loss of vestibular function in acute vestibular neuritis. Although previous studies have reported on the results of each test, longitudinal comparison of these tests is rare. In the present study, vHITs and caloric tests were performed in patients with unilateral vestibular neuritis during the acute phase and after a long follow-up period (>6 months). The goal of this study was to evaluate the changes in vHIT and caloric test results and to analyze the relationships between them. SUBJECTS AND METHOD: Between September 2013 and December 2015, charts from 13 patients with unilateral vestibular neuritis were retrospectively reviewed. Among the 13 patients, caloric tests and vHITs were performed in 9 and 10 patients, respectively. Results of the vHITs and caloric tests were analyzed and the changes were compared. RESULTS: During the acute phase of vestibular neuritis, the results of the caloric test showed an increase in canal paresis (CP), and the results of the vHIT showed a decrease in horizontal gain. Although subjective symptoms improved in all patients after a long follow-up period (mean: 13.9 months), the occurrence of CP determined from the caloric test was not significantly changed (p=0.889). On the other hand, the mean horizontal gain of the vHIT had improved significantly (p < 0.05). CONCLUSION: While CP determined from the caloric test did not change after a long follow-up period, the decreased horizontal gain in the vHIT was significantly recovered in patients with unilateral vestibular neuritis.

Analysis of Age-Dependent Normative Values of Suppression Video-Head-Impulse Test in Healthy Korean Subjects / 대한평형의학회지

OBJECTIVES: Suppression head impulse paradigm (SHIMP) in video head impulse test is now newly used to test vestibular function. The aim of this study was to analyze normative values of SHIMP for healthy Korean subjects in each decade of life. METHODS: SHIMP and HIMP responses were measured with the video head impulse test in 70 healthy subjects. Vestibulo-ocular reflex gain and anticompensatory saccade were analyzed and compared at each decade of life. RESULTS: All subjects produced anticompensatory saccades in SHIMP. Gain values did not vary significantly with age. Gain values in SHIMP were lower than gain values in HIMP. The gain values of rightward impulse were higher than the gain values of leftward impulse. CONCLUSIONS: Gain values and anticompensatory saccades in SHIMP were consistently equal in each decade of life. Normative values of SHIMP seems largely unaffected by aging.

Confiabilidad interevaluador de la prueba video head impulse test en estudiantes de primer año de la generación 2016 de la Escuela de Fonoaudiología de la Universidad de Valparaíso Casa Central / Inter-rater reliability of the video head impulse test in students from the School of Speech and Language therapist of the University of Valparaiso main campus class 2016

RESUMEN Introducción: El video head impulse test es un método rápido, no invasivo y cómodo para evaluar el reflejo vestíbulo ocular, el cual está siendo utilizado con mayor frecuencia en la evaluación de pacientes con alteraciones del equilibrio. Sin embargo, en Chile se evidencia una falta de estudios relacionados a la confiabilidad interevaluador de dicha prueba. Objetivo: Determinar el nivel de concordancia de los resultados de la eficiencia del reflejo vestíbulo ocular de los canales semicirculares horizontales, obtenidos mediante la aplicación de la prueba video head impulse test, por parte de 3 evaluadores. Material y método: Estudio cuantitativo, correlacional, no experimental transversal descriptivo, con muestreo no probabilístico, de participación voluntaria. La prueba video head impulse test fue aplicada por 3 examinadores a 30 estudiantes que cumplieron con los criterios de inclusión. Resultados: El método de Bland y Altman mostró gran concordancia en las mediciones realizadas entre los 3 examinadores. La correlación intraclase para la ganancia del canal semicircular horizontal derecho e izquierdo fue de 0,85 y 0,91 respectivamente y de 0,75 para el valor de asimetría. Conclusión: El estudio mostró una confiabilidad interevaluador adecuada de la prueba video head impulse test para la evaluación de los canales semicirculares horizontales.

ABSTRACT Introduction: The video head impulse test is a rapid, non-invasive and comfortable method for the evaluation of the vestibulo-ocular reflex that is being used more often in the evaluation of patients with balance disorders. In Chile there is a lack of studies related to the inter-rater reliability for this test. Aim: To determine the level of agreement on the results for the vestibulo-ocular reflex of the horizontal semicircular canals obtained by the execution of the video head impulse test by 3 raters. Material and method: Quantitative, correlational, non-experimental, cross-sectional descriptive study with a type of non-probability sampling with voluntary participation. The video head impulse test was applied by 3 raters to 30 students who fulfilled the inclusion criteria. Results: The Bland-Altman method demonstrated good agreement in the measurements made between the 3 raters. The inter-rater reliability for the gain of the left and right horizontal semicircular canals was 0.85 and 0.91 respectively and 0.75 for the asymmetry value. Conclusion: The study showed an adequate inter-rater reliability for the video head impulse test in the evaluation of the horizontal semicircular canals.

Clinical Usefulness of Video Head Impulse Test-Comparison of Bithermal Caloric Test and Bedside Head Impulse Test / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Video head impulse test system (vHIT) is an easy-to-use test and there are numerous studies showing its efficacy. The aim of the study was to evaluate the clinical usefulness of vHIT as an initial test in determining vestibular hypofunction in patients with dizziness. SUBJECTS AND METHOD: The study recruited 103 outpatients who visited our ear clinic with dizziness. We performed both bedside head impulse test (bHIT), vHIT and bithermal caloric tests for 103 patients. Both bHIT and vHIT were consecutively performed in each subject on the same day by the same examiner. RESULTS: The sensitivity of bHIT and vHIT was determined based on the bithermal caloric test results, which showed that vHIT was more sensitive than bHIT. There was a significant negative correlation between vHIT gain and canal paresis (p < 0.05). Results of some patients indicated dissociation between vHIT and caloric test. CONCLUSION: T here is a significant correlation between the results of vHIT and caloric test. Although vHIT does not replace the caloric test, it would be useful to evaluate the initial vestibular loss in patients with dizziness.

Application of video head impulse test in detecting damage and recovery features of semicircular canal of patients with acute vestibular neuritis / 第二军医大学学报

Objective To investigate the application of video head impulse test in detecting the impairment of semicircular canal of patients with acute vestibular neuritis and the recovery features of the damaged semicircular canal. Methods The clinical data of 28 patients with acute vestibular neuritis, who were diagnosed in the Department of Neurology, Changzheng Hospital, Second Military Medical University from Mar. 2015 to Mar. 2016, were analyzed and regularly followed up. The damage and recovery of each semicircular canal function were evaluated by video head impulse test. Results During the onset period, the horizontal semicircular canal function was abnormal in 28 patients (100.00%), the anterior semicircular canal function was abnormal in 24 cases (85.71%), and the posterior semicircular canal function was abnormal in 4 cases (14.29%). After 2 months of follow-up, the gain of the patients with severe damage of horizontal semicircular canal (gain0.5) at onset did not return to normal, while that of 80.00% (12/15) of the patients with less damage of horizontal semicircular canal (gain ranged from 0.5 to 0.8) recovered; 82.35% (14/17) of the patients with severe damage of anterior semicircular canal (gain0.5) at onset did not recover, while that of the patients with less damage of anterior semicircular canal (gain ranged from 0.5 to 0.7) returned to normal. Conclusion In patients with vestibular neuritis, the damage of semicircular canal dominated by superior vestibular nerve is more severe than that dominated by inferior vestibular nerve. Video head impulse test is suitable for the detection and follow-up of the function of impaired semicircular canal. The recovery of impaired semicircular canal is related to its severity at onset.

Clinical Application and Update of Video Head Impulse Test / 대한평형의학회지

Recently with the introduction of video head impulse test (vHIT), it can be easily performed quantitative and objective measurement of vestibulo-ocular reflex (VOR). vHIT has been used as a clinical vestibular function test that can individually evaluate the function of each semicircular canal. Loss of VOR gain and corrective catch-up saccades that occur during the vHIT usually indicate peripheral vestibular hypofunction, whereas in acute vestibular syndrome, normal vHIT should prompt a search for a central lesion. In this study, we will examine the principle of vHIT and its interpretation, and explain its clinical application in peripheral and central vestibulopathy. In addition, we will compare the caloric test and the differences, and review the most recently introduced suppression head impulse paradigm test.

Sensitivity of caloric test and video head impulse as screening test for chronic vestibular complaints

OBJECTIVE: This study compared the results of the caloric test with those of the video head impulse test obtained during the same session and evaluated whether the former can be used to screen for non-acute vestibular dysfunction. METHODS: A total of 157 participants complaining of dizziness with vestibular characteristics of varying durations and clinical courses completed the caloric test and video head impulse test. RESULTS: Significantly more caloric test results than video head impulse test results were abnormal. CONCLUSIONS: The results of the caloric test and video head impulse test are distinct but complement each other. Within our sample, the caloric test was more sensitive for vestibular dysfunction. Therefore, the video head impulse test is not a suitable screening tool of the vestibular system in patients with chronic complaints.

Influence of Diazepam on Video Head Impulse Test in Patients with Acute Vestibular Neuritis: Preliminary Study / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Although video head impulse test (V-HIT) has emerged as a popular test for vestibular function, there have been no reports about the influence of benzodiazepine on the test. The aim of this study is to investigate the influence of diazepam on the V-HIT in patients with acute vestibular neuritis. SUBJECTS AND METHOD: We retrospectively analyzed charts and medical records of 10 patients diagnosed with acute vestibular neuritis. The patients repeated V-HIT before and after intravenous (IV) injection of diazepam. Gain and presence of catch-up saccade (CUS) were compared. RESULTS: Gain in the affected ear was decreased compared to that in the unaffected ear. After the injection of IV diazepam, the presence of CUS was not changed significantly. Gain of CUS in V-HIT was also unchanged both in the affected and unaffected ear after the injection of IV diazepam. CONCLUSION: The influence of IV diazepam on the gain and presence of CUS in V-HIT were insignificant, indicating that it could be considered as a useful test to evaluate vestibular function in patients treated with diazepam.

Eficiencia del reflejo vestíbulo ocular mediante la aplicación de la prueba Video Head Impulse Test, en estudiantes de primer año de las escuelas de Fonoaudiología y de Tecnología Médica de la universidad de Valparaíso / Efficiency of the vestibular ocular reflex using video Head Impulse Test in students from the schools of fonoaudiología and Tecnología Médica of the university of Valparaíso

Introducción: Video Head Impulse Test es una nueva tecnología dirigida a la evaluación de los canales semicirculares, específicamente a la eficiencia del reflejo vestíbulo ocular. Es un procedimiento rápido, no invasivo y bien tolerado por el paciente. En Chile se evidencia una falta de estudios relacionados a esta prueba. Objetivo: Analizar los resultados de la eficiencia del reflejo vestíbulo ocular de los canales semicirculares horizontales, obtenidos mediante la aplicación de la prueba Video Head Impulse Test en estudiantes de las Escuelas de Fonoaudiología y de Tecnología Médica de la Universidad de Valparaíso. Material y método: Estudio cuantitativo, descriptivo, no experimental, transversal descriptivo con un tipo de muestreo no probabilístico de participante voluntario. A los 80 estudiantes que cumplieron con los criterios de inclusión se les aplicó la prueba Video Head Impulse Test. Resultados: El promedio de la ganancia del canal semicircular horizontal derecho fue de 0,92 ± 0,07 y el de izquierdo fue de 0,85 ± 0,07. Además el promedio de porcentaje de asimetría fue de 10% ± 7,45. Conclusión: La investigación entrega datos referenciales en relación a los valores de normalidad para la eficiencia del reflejo vestíbulo ocular en una muestra específica, los que servirán como base para la ejecución de estudios posteriores.

Introduction: Video Head Impulse Test is a new technology directed to the evaluation of the semicircular canals, specifically the vestibular ocular reflex efficiency. It is a rapid, noninvasive and well tolerated procedure. In Chile there is a lack of studies related to this evaluation. Aim: Analyze the results of the efficiency of the vestibular ocular reflex of the horizontal semicircular canals, using Video Head Impulse Test in students from the schools of Fonoaudiología and Tecnología Médica of the University of Valparaíso. Material and method: A quantitative, descriptive, non-experimental descriptive study with a type of non-probability sampling with voluntary participant. The 80 students who fulfill the inclusion criteria were evaluated with Video Head Impulse Test. Results: The mean gain of the right horizontal semicircular canal was 0.92 ± 0.07 and for the left was 0.85 ± 0.07. In addition the mean percentage of asymmetry was 10% ± 7.45. Conclusions: The investigation delivery referential data regarding normal values for the efficiency of the vestibular ocular reflex in a specific sample, which serve as the basis for the implementation of future studies.

Changes of the Video Head Impulse Test Gains by the Directions of Head Rotation at Different Target Distances and Rotation Speeds / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The conventional instrument for video head impulse test (vHIT) records the movement of the right eye only. The aim of this study was to evaluate the changes in the gain of vHIT results qdue to different directions of head rotation directons at different target distances and rotation speeds. SUBJECTS AND METHOD: Horizontal head impulse was recorded by vHIT in 20 normal subjects. vestibulo-ocular reflex (VOR) gains to the right and left directions were compared at different test conditions. Two different impulses with low (50-150 deg/sec) and high (200-300 deg/sec) peak-head-velocities were tested and the subjects were also instructed to fixate a laser dot on a screen at different distances of 60, 100, and 200 cm. Eye movements were recorded on the right eye. RESULTS: Regardless of the target distances and peak-head-velocities, the VOR gains to the rightward head rotation were significantly greater than those to the leftward head rotation. In more than 85% of normal subjects, vHIT gain to the rightward head rotation was greater than that to the leftward head rotation. Mean gain asymmetries were 2.16-3.33% and the mean interaural vHIT gain differences were 0.04-0.07. CONCLUSION: Regardless of the target distances and peak-head-velocities, the VOR gains to the rightward head rotation were significantly greater than those to the leftward head rotation. Directional asymmetry of VOR gain should be considered when interpreting vHIT results in patients with vestibular disorders.