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.

Further exploration of the classification and clinical value of head-shaking nystagmus / 临床耳鼻咽喉头颈外科杂志

Objective:To investigate the classification of head shaking nystagmus（HSN） and its clinical value in vestibular peripheral diseases. Methods:Clinical data of 198 patients with peripheral vestibular disorders presenting with HSN were retrospectively analyzed. Video Nystagmograph（VNG） was applied to detect spontaneous nystagmus（SN）, HSN, and Caloric Test（CT）. The intensity and direction of SN and HSN as well as the unilateral weakness（UW） and direction preponderance（DP） values in caloric test was analyzed in patients. Results:Among the 198 patients with vestibular peripheral disease, there were 105 males and 93 females, with an average age of（49.1±14.4） years （range: 14-87 years）. One hundred and thirty seven patients were diagnosed as Vestibular Neuritis（VN）, 12 as Meniere's Disease（MD）, 41 as sudden deafness（SD） and 8 as Hunt's syndrome accompanied by vertigo. Among them, there were 116 patients in the acute phase, including 68 cases（58.6%） with decreased HSN, 4 cases（3.4%） with increased HSN, 5 cases（4.3%） with biphasic HSN, 38 cases（32.8%） with unchanged HSN, and 1 case（0.9%） with perverted HSN. There were 82 cases in the non-acute phase, 51 cases（62.2%） with decreased HSN, 3 cases（3.6%） with increased HSN, 9 cases（11.0%） with biphasic HSN, and 19 cases（23.2%） with unchanged HSN. In biphasic HSN, the intensity of phase I nystagmus was usually greater than that of phase II, and the difference was statistically significant（P<0.01）. There was no correlation between HSN type and course of disease or DP value. The intensity of HSN was negatively correlated with the course of disease（r=-0.320, P<0.001） and positively correlated with DP value（r=0.364, P<0.001）, respectively. The intensity of unchanged nystagmus and spontaneous nystagmus were（8.0±5.7） °/s and（8.5±6.4）°/s, respectively. There was no statistically significant difference in the intensity of nystagmus before and after shaking the head. Conclusion:HSN can be classified into five types and could be regarded as a potential SN within a specific frequency range （mid-frequency）. Similarly, SN could also be considered as a common sign of unilateral vestibular impairment at different frequencies. HSN intensity can reflect the dynamic process of vestibular compensation, and is valuable for assessing the frequency of damage in peripheral vestibular diseases and monitoring the progress of vestibular rehabilitation.

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.

Achados neurológicos e vestibulares em três casos de Esclerose Múltipla / Neurological and vestibular findings in three cases of Multiple Sclerosis

RESUMO A Esclerose Múltipla (EM) é uma doença autoimune crônica e inflamatória que afeta o sistema nervoso central (SNC). A disfunção do equilíbrio corporal também é um sintoma comum e pode estar relacionada às lesões neurológicas decorrentes desta doença. O objetivo deste estudo foi caracterizar os achados neurológicos e vestibulares de três casos clínicos com diagnóstico de EM. Dados sobre a avaliação neurológica e do exame de ressonância magnética de crânio foram coletados dos prontuários. Os pacientes responderam a uma entrevista inicial e foram submetidos à avaliação clínica do equilíbrio corporal e ao Video Head Impulse Test (vHIT). Observou-se presença de sintomas vestibulares e alterações em pelo menos uma das provas clínicas do equilíbrio corporal e função cerebelar. No vHIT, obteve-se alterações em testes oculomotores, como presença de nistagmo semi-espontâneo e em parâmetros do teste sacádico, e ganho reduzido em um ou mais canais verticais. Foram verificadas lesões, na ressonância magnética de crânio, em áreas centrais que processam as informações vestibulares, como cerebelo e tronco encefálico. A associação destes achados sugere a presença de disfunção vestibular central, compatível com as lesões detectadas nos exames de imagem.

ABSTRACT Multiple sclerosis (MS) is a chronic and inflammatory autoimmune disease that affects the central nervous system (CNS). Dysfunction of body balance is also a common symptom and may be related to neurological injuries resulting from this disease. The aim of this study was to characterize the neurological and vestibular findings of three clinical cases diagnosed with MS. Data on the neurological evaluation and the magnetic resonance imaging of the skull were collected from the medical records. The patients responded to an initial interview and underwent clinical assessment of body balance and Video Head Impulse Test (vHIT). Vestibular symptoms and alterations were observed in at least one of the clinical tests of body balance and cerebellar function. In vHIT, changes were obtained in oculomotor tests, such as the presence of semi-spontaneous nystagmus and in parameters of the saccade test, and reduced gain in one or more vertical channels. Lesions were found on MRI of the skull in central areas that process vestibular information, such as the cerebellum and brainstem. The association of these findings suggests the presence of central vestibular dysfunction, compatible with the lesions detected in imaging exams.

Evaluation of the vestibulo-ocular reflex in patients with chronic otitis media / Avaliação do reflexo vestíbulo-ocular em pacientes com otite média crônica

Abstract Introduction In recent years, scientific evidence has shown that chronic otitis media may cause balance and vestibular dysfunction. Objective To compare the results of the video head impulse test (gain and symmetry of the vestibulo-ocular reflex and presence of covert and overt saccades) in patients with chronic otitis media and controls. Methods Cross-sectional study of patients with chronic otitis media (study group), aged between 18 and 60 years. The patients in the study group were further divided according to the chronic otitis media type as (1) non-suppurative, (2) suppurative, and (3) cholesteatomatous. For the comparative analysis, we selected volunteers with no history of ear and vestibular diseases (control group), who met the same inclusion and exclusion criteria as the study group. Patients in both groups underwent a video head impulse test. Results The study group consisted of 96 volunteers, and the control group of 61 individuals. The prevalence of vestibular symptoms was 66% in the study group and 3.2% in the control group (p< 0.001). The results show a higher prevalence of changes in the vestibulo-ocular reflex gain (22.9%) and corrective saccades (12.6%) in the chronic otitis media group compared to the control group (p< 0.001). Despite the higher prevalence of changes in gain, the average vestibulo-ocular reflex gains in the chronic otitis media groups were within the pre-defined values ​​of normality; however, the mean vestibulo-ocular reflex gain in the anterior semicircular canal was statistically worse in the cholesteatomatous chronic otitis media group compared to controls (p< 0.001). Regarding the corrective saccades, the prevalence of saccades was statistically higher in the suppurative and cholesteatomatous chronic otitis media subgroups compared to the non-suppurative and control groups (p= 0.004). Conclusion The present study demonstrated that chronic otitis media is associated with a higher prevalence of vestibular symptoms and also a higher prevalence of changes in gain and corrective saccades when compared to controls.

Resumo Introdução Nos últimos anos, evidências científicas demonstraram que a otite média crônica se associa a alterações de equilíbrio e disfunção vestibular. Objetivo Comparar os resultados do teste do impulso cefálico por vídeo (ganho e simetria do reflexo vestíbulo-ocular e presença de sacadas cobertas e descobertas) em pacientes com otite média crônica e controles. Método Estudo transversal que envolveu pacientes com otite média crônica (grupo de estudo), entre 18 a 60 anos. Os pacientes no grupo estudo ainda foram divididos de acordo com o tipo de otite média crônica em (1) não supurativa, (2) supurativa e (3) colesteatomatosa. Para análise comparativa, selecionamos voluntários sem história de doenças otológicas e vestibulares (grupo controle), que obedeceram aos mesmos critérios de inclusão e exclusão do grupo de estudo. Os pacientes de ambos grupos foram submetidos ao teste de impulso cefálico por vídeo. Resultados O grupo estudo foi composto por 96 voluntários e o grupo controle por 61 indivíduos. A prevalência de sintomas vestibulares foi de 66% no grupo de estudo e 3,2% no grupo controle (p < 0,001). Os resultados mostram maior prevalência de alterações do ganho do reflexo vestíbulo-ocular (22,9%) e de sacadas corretivas (12,6%) no grupo otite média crônica em comparação ao grupo controle (p < 0,001). Apesar da maior prevalência de alterações de ganho, a média dos ganhos do reflexo vestíbulo-ocular dos grupos de otite média crônica estava dentro dos valores pré-definidos de normalidade; porém, a média do ganho do reflexo vestíbulo-ocular no canal semicircular anterior foi estatisticamente pior no grupo otite média crônica colesteatomatosa em comparação aos controles (p< 0,001). Em relação às sacadas corretivas, a prevalência de sacadas foi estatisticamente maior nos subgrupos otite média crônica supurativa e colesteatomatosa em comparação aos grupos não supurativa e controle (p = 0,004). Conclusão A otite média crônica se associa à maior prevalência de sintomas vestibulares e também maior prevalência de alterações no ganho e de sacadas corretivas em comparação a controles.

Video head impulse test in bilateral vestibulopathy / Teste do impulso efálico com vídeo (vHIT) na vestibulopatia bilateral

Abstract Introduction: Bilateral vestibulopathy is a rare chronic condition with multiple etiologies. Bilateral vestibulopathy is characterized mainly by unsteadiness when walking or standing, which worsens in darkness, as well as oscillopsia. The degree of handicap caused by bilateral vestibulopathy is variable and remains controversial. Objectives: To determine the value of the video Head Impulse Test in quantifying vestibular deficit and to establish its impact on the quality of life. Methods: Twenty patients (mean age, 41.9 years; range 14-80 years) fulfilling the recent Barany criteria of bilateral vestibulopathy, responded to the Situational Vertigo Questionnaire and underwent vestibular examination including fixation, positional tests, oculomotor test battery and video head impulse test. Results: The relation between each of the video head impulse test parameters and the scores from the questionnaire were statistically analyzed. We observed that patients with covert saccades on the video head impulse test were more likely to have a better quality of life than those with both covert and overt saccades, regardless of the vestibulo-ocular reflex gain in each semicircular canal. The presence of covert saccades was found to be associated with an improved quality of life regardless of the severity of vestibule ocular reflex-deficit. Our conclusion was that vestibule ocular reflex gain, measured by video head impulse test, does not quantify the severity of affection of quality of life in patients with bilateral vestibulopathy. Conclusion: Covert saccades are strategies aiming at minimizing the blurring of vision during head movement, that is an adaptive mechanism that improves quality of life. Therefore, we recommend that video head impulse test should be a part of the routine diagnostic workup of bilateral vestibulopathy.

Resumo Introdução: A vestibulopatia bilateral é uma condição crônica rara, com múltiplas etiologias. É caracterizada principalmente por instabilidade ao caminhar ou ficar de pé, que piora na escuridão, e oscilopsia. O grau de deficiência causado pela vestibulopatia bilateral é variável e permanece controverso. Objetivos: Determinar o valor do teste do impulso cefálico na quantificação do déficit vestibular e estabelecer seu impacto na qualidade de vida. Método: Vinte pacientes (média de 41,9 anos; variação de 14 a 80) que atendiam aos critérios recentes da Bárány Society de vestibulopatia bilateral responderam ao Situational Vertigo Questionnaire e foram submetidos a exame vestibular, inclusive fixação, testes posicionais, bateria de testes oculomotores e teste do impulso cefálico com vídeo. Resultados: A relação entre cada um dos parâmetros do teste do impulso cefálico com vídeo e os escores do questionário foram analisados estatisticamente. Observamos que pacientes com sacadas corretivas cobertas do tipo covert no teste de impulso cefálico com vídeo tinham maior probabilidade de ter melhor qualidade de vida do que aqueles com ambas sacadas corretivas cobertas e sacadas corretivas abertas do tipo overt, independentemente do ganho no reflexo vestíbulo-ocular em cada canal semicircular. Verificou-se que a presença de sacadas corretivas do tipo covert está associada a uma melhor qualidade de vida, independentemente da gravidade do déficit no reflexo vestibulo-ocular. Concluímos que o ganho no reflexo vestíbulo-ocular, medido pelo teste do impulso cefálico com vídeo, não quantifica a gravidade do comprometimento da qualidade de vida em pacientes com vestibulopatia bilateral. Conclusão: As sacadas corretivas do tipo covert são estratégias que visam minimizar o embaçamento da visão durante o movimento da cabeça, ou seja, um mecanismo adaptativo que melhora a qualidade de vida. Portanto, recomendamos que o teste do impulso cefálico com vídeo faça parte da rotina de diagnóstico da vestibulopatia bilateral.

Vestibular dysfunction in Wernicke encephalopathy / 中华神经科杂志

Objective:To analyze the abnormal vestibular function of Wernicke encephalopathy (WE) and to explore its diagnostic value.Methods:WE patients who visited the Vertigo Center of the Second Affiliated Hospital of Zhengzhou University from January 2018 to January 2021 were retrospectively collected. All patients were evaluated by clinical neurology. Before treatment, all patients completed video head impulse test (vHIT) and video nystagmusgraphy (VNG) in addition to cranial magnetic resonance and serum thiamine level examination.Results:All 12 patients had a history of eating defects, including 8 cases of alcoholism. All 12 patients had walking instability, 7 cases had dizziness and 8 cases had oscillopsia. Six cases had ophthalmoplegia. All 12 cases showed positive gaze nystagmus. The pathological saccades of bilateral horizontal semicircular canals were found in 12 patients by vHIT before treatment, but there was only 1 patient showing abnormality in vertical semicircular canals, the difference being statistically significant ( P<0.05). All patients could detect bilateral, horizontal, gaze-evoked nystagmus, including 3 cases with vertical nystagmus, 1 case with abnormal saccade test, 3 cases with abnormal smooth tracking test and 1 case with abnormal optokinetic test. There were abnormalities in the caloric test, including 6 cases of bilateral dysfunction and 2 cases of unilateral dysfunction. Conclusions:WE patients may have abnormal vHIT and bilateral, horizontal, gaze-evoked nystagmus, which is similar to the special abnormal signs of simultaneous damage of both peripheral and central vestibular dysfunction.Vestibular function test is valuable for diagnosis of WE, and it is suitable for patients with a history of nutritional disorders who have dizziness or walking instability and suspected WE.

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome with replication factor C subunit 1 gene mutation: a case report and literature review / 中华神经科杂志

Objective:To investigate the clinical and genetic characteristics of cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) with replication factor C subunit 1 (RFC1) gene mutation to improve the understanding of this disease.Methods:A case of CANVAS diagnosed in the Peking University Third Hospital in January 2021 was reported. Detailed genetic analyses of ataxia were performed with DNA extracted from the peripheral blood of the patient. Studies including pathogenic variants of RFC1 gene causing CANVAS were reviewed and the clinical and genetic characteristics of the disease were summarized.Results:The patient was a 51-year-old female with the prominent manifestation of progressive walking instability. And the clinical data met the diagnostic criteria of CANVAS. The genetic tests excluded other hereditary ataxia mutations and identified the biallelic expansion of the pathogenic variant structure (AAGGG)exp repeat amplification in RFC1 gene. A total of 14 studies on CANVAS with RFC1 gene mutation were reviewed. The overall mutation rate of RFC1 gene in CANVAS was 68%-100%, and it varied in sporadic and familial CANVAS. And the mutation had ethnic differences.Conclusions:Among adult patients with late-onset ataxia, the combination of brain magnetic resonance imaging, electrophysiology tests and vestibular function examination is beneficial to the identification of CANVAS. And the genetic test of RFC1 gene has significant value in the diagnosis of this disease. This patient with CANVAS expands the disease spectrum of ataxia in China, and confirms that RFC1 gene mutation is of great significance in the screening of ataxia disorders in the Chinese population.

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.

Video Head Impulse Test e doenças do sistema nervoso central: uma revisão integrativa / Video Head Impulse Test and central nervous system diseases: a integrative review

RESUMO Objetivos verificar a aplicabilidade do Video Head Impulse Test (vHIT) em doenças do sistema nervoso central (SNC), bem como os resultados encontrados e as doenças descritas. Estratégia de pesquisa revisão integrativa da literatura, em que foi realizada a busca em nove bases eletrônicas de dados, a partir da palavra-chave "video head impulse test". Critérios de seleção foram incluídos estudos que utilizaram o vHIT no diagnóstico de doenças do SNC e excluídos os estudos publicados antes de 2009 e estudos que realizaram outros procedimentos de investigação clínica, ou que aplicaram o teste no diagnóstico de doenças vestibulares periféricas. Resultados a amostra final foi composta por 18 estudos. Os resultados verificados mostraram que o reflexo vestíbulo-ocular (RVO) tem apresentado alterações na população investigada. Foram observados achados sugestivos de acometimento central, tais como ganho ou média de ganho do RVO nos canais semicirculares verticais, inferior aos laterais, ganho aumentado, correlação negativa do ganho com a gravidade da doença na ataxia espinocerebelar tipo 3, ponto de corte de 0,70 e assimetria de ganho menor de 20% para diferenciar neurite vestibular de derrame no ramo medial da artéria cerebelar posteroinferior, ganho normal com provas oculomotoras alteradas, presença de nistagmo espontâneo vertical, além de alterações no RVO com e sem otimização visual, na perseguição sacádica e no teste de desvio de inclinação. Conclusão verificou-se que o vHIT é aplicável quanto a avaliação do RVO de alta frequência em indivíduos com doenças do SNC, uma vez que trouxe evidências clínicas sobre alterações da função vestibular periférica e central nos diferentes quadros neurológicos.

ABSTRACT Purpose To verify the applicability of the Video Head Impulse Test (vHIT) in central nervous system (CNS) diseases, as well as the results found and the diseases described. Research strategy Integrative literature review, in which nine electronic databases were searched using the keyword "video head impulse test". Selection criteria Studies that used the vHIT in the diagnosis of CNS diseases were included, and studies published before 2009, studies that performed other clinical investigation procedures or that concerned the diagnosis of peripheral vestibular diseases were excluded. Results The final sample consisted of 18 studies. The verified results show that the vestibulo-ocular reflex (VOR) has shown alteration in this population. Suggestive findings of central involvement were observed, such as lower gain or average VOR in the vertical semicircular canals than in the lateral ones, increased gain, the negative correlation of gain with disease severity in Spinocerebellar Ataxia Type 3, cutoff point of 0.70, and gain asymmetry of less than 20% to differentiate vestibular neuritis from a stroke in the medial branch of the posteroinferior cerebellar artery, normal gain with altered oculomotor tests, presence of spontaneous vertical nystagmus, as well as alterations in the VOR with and without visual enhancement, in saccadic pursuit, and the tilt deviation test. Conclusion We found that the vHIT applies to the assessment of high-frequency VOR in individuals with CNS diseases since it provided clinical evidence of changes in peripheral and central vestibular function in different neurological conditions

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.

A supressão do (La supresión del) reflexo vestíbulo-ocular humano / The human supression vestibulo-ocular reflex

O objetivo do presente estudo foi revisar os conceitos relativos ao funcionamento e alterações da supressão do reflexo vestíbulo-ocular (SRVO) e as principais formas de avaliação atualmente. Trata-se de uma pesquisa descritivo-exploratória, baseada em uma revisão da (El trabajo es una investigación descriptiva-exploratoria, basada en una revisión de la) literatura, realizada no (en el) Portal de Periódicos da Capes, no período de abril de 2020. Os (Los) operadores booleanos utilizados foram vestibulo-ocular reflex (OR), semicircular canal (OR), vestibular (AND) suppression. Como estratégia de pesquisa, na (en la) etapa de triagem (selección) foram utilizados os filtros: descritores no (en) título, publicações dos (de los) últimos dez anos, tipo de material, idioma e artigos revisados por pares. Dos 30 artigos triados (seleccionados), 20 apresentaram resumo de acordo com o tema e 13 estudos atenderam aos critérios de incluso (presentaron resúmenes relacionados al tema y 13 estudios cumplieron los criterios de inclusión). Scopus, Medline/PubMed e Science Citation Index Expanded foram as bases mais abrangentes (fueron las bases más abarcativas). A maioria dos (La mayoría de los) estudos, sobretudo os mais recentes, utilizaram os testes de impulso cefálico com o paradigma ´suppression head impulse test´ (SHIMP) comparando-o ao ´head impulse test´ (HIMP). A cadeira rotatória (La silla rotatoria) com eletronistagmografia foi o segundo teste mais utilizado. Apenas um estudo utilizou a Scleral Search Coil. A partir dessa revisão constata-se que a SRVO é influenciada pela idade, pode ser alterada por disfunções vestibulares periféricas unilaterais ou bilaterais, mas também por alterações neurológicas, como as cerebelares (las cerebelosas). Além da via visual, a SRVO pode ser desencadeada por fontes auditivas, somestésicas e até mesmo imagéticas (e incluso imaginativas, fantasiosas)

The present study aimed to review the concepts related to the functioning and changes in vestibular-ocular reflex suppression (VORS) and the most used assessments today. This is descriptive-exploratory research, based on a literature review, carried out on the Capes Journals Portal, in April 2020. The Boolean operators used were Vestibulo-ocular reflex (OR) Semicircular canal (OR) Vestibular (AND) Suppression. As a research strategy, in the screening stage, with the filters: descriptors in the title, last ten years, type of material, language, and peer-reviewed articles. Thirty articles were screened, 20 presented a summary according to the theme and 13 studies met the inclusion criteria. Scopus, Medline/PubMed, and Science Citation Index Expanded were the most comprehensive databases. Most studies, especially the most recent ones, used cephalic impulse tests with the SHIMP paradigm (suppression head impulse test) comparing it to the HIMP (head impulse test, HIMP). The rotary chair with electronystagmography was the second most used test. Only one study used the Scleral Search Coil. From this review, it appears that the SRVO is influenced by age; it can be altered by unilateral or bilateral peripheral vestibular disorders, but also by neurological changes, such as the cerebellar ones. In addition to the visual pathway, other sources can trigger SVOR, such as auditory, somesthetic and even imagery sources

Importance of Vestibulo-ocular Reflex Gain and Refixation Saccade Analysis in Individuals with Auditory Neuropathy Spectrum Disorder

Abstract Introduction Auditory neuropathy spectrum disorder (ANSD) features the presence of otoacoustic emissions, poor speech identification score and absent auditory brainstem response. Objective The present study was designed to evaluate the functioning of all six semicircular canals in individuals with ANSD and to compare it with those of normalhearing individuals. Methods A total of 50 individuals participated in the present study, in which Group I comprised25normal-hearingindividuals, and GroupII comprised25individualswithANSD. All of the participants underwent case history, pure tone audiometry, immittance, otoacoustic emissions, auditory evoked response and video head impulse test (vHIT). Results The independent sample t-test revealed significantly lower vestibulo-ocular reflex gain values in individuals with ANSD. A presence of 100% corrective refixation saccades was observed in the same group. The Pearson correlation test revealed no significant correlation between vestibulo-ocular reflex (VOR) gain with duration of hearing loss and pure tone thresholds for any of the three orthogonal planes. The chisquared test revealed no association between the VOR gain values and the presence or absence of saccades in any of the semicircular canals (p>0.05). Conclusion Huge percentages of individuals with ANSD have been found to have associated vestibular dysfunction as well. Therefore, the vHIT can be used as one of the important tests of the vestibular test battery to evaluate all six semicircular canals in individuals with ANSD.

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.

Normal Vestibulo Ocular Reflex (VOR) gain Measured Using the Video Head Impulse Test (vHIT) in Healthy Young Adults

@#Introduction: Many new objective tests to assess the function of specific structures of the vestibular organ are currently adopted in vestibular clinics. One of the objective assessments include the video head impulse test (vHIT) where gain & velocity responses of eye relative to the head movements are recorded using an infrared camera. Methods: Thirty normal hearing subjects age between 18 to 25 years old participated in this study. At least ten Lateral, Left Anterior Right Posterior (LARP), and Right Anterior Left Posterior (RALP) responses were recorded for each participant by making small and rapid unpredictable head movements. Results: The average velocity gain for Lateral responses at 40 ms, 60 ms and 80 ms were 1.05 ± 0.003, 1.03 ± 0.002 and 1.01 ± 0.003 respectively. The LARP average velocity regression were 1.01 ± 0.24 for Left Anterior and 1.05 ± 0.25 for Right Posterior, with an average gain asymmetry of 5.13%. The RALP average velocity regression were 1.08 ± 0.31 for Right Anterior and 1.12 ± 0.30 for Left Posterior, with an average gain asymmetry of 5.87%. One sample T-test were conducted to compare Lateral responses to a previous study by Mossman et al. (2015) where significant differences in velocity gain at 60 ms and 80 ms between studies were found where, t (59) = 5.56, p <0.01 and t (59) = 2.86, p < 0.01 respectively. Conclusion: This indicates the importance of establishing on-site norms for every clinical settings as techniques used and equipment differences could affect the results.

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.

Exploración de los conductos semicirculares verticales con estimulación rotatoria inducida / Exploration of vertical semicircular ducts with induced rotatory stimulation

Las pruebas rotatorias han sido utilizadas durante más de un siglo para el estudio de la función vestibular por ser un estímulo fisiológico controlado muy efectivo sobre el laberinto posterior, habitualmente son los conductos semicirculares horizontales los que se exploran, pues se afectan con más frecuencia y son más fáciles de estudiar, sin embargo en ocasiones son los verticales los lesionados y por tanto deben emplearse otras alternativas para llegar a un diagnóstico certero. Se presenta un caso donde se evalúa la función fisiológica de los conductos semicirculares verticales a través de la electronistagmografía con estimulación rotatoria, empleando la técnica de estimulación tiempo-velocidad, con fases sucesivas de aceleración, velocidad constante, desaceleración y parada brusca, con una silla rotatoria computarizada, acoplada a un electronistagmógrafo. Se obtuvo arreflexia del canal vertical anterior derecho. A velocidades inferiores a 1 Hz es posible evaluar el reflejo vestíbulo ocular en los conductos semicirculares verticales, a pesar de que la frecuencia del estímulo está por debajo del nivel en que este reflejo funciona en las actividades diarias(AU)

Rotatory tests have been used for over a century for the study of vestibular function because it is a very effective physiological controlled stimulus on the posterior labyrinth, usually the horizontal semicircular ducts that are explored, since they are affected more frequently and are more easy to study, however sometimes the injured are vertical and therefore other alternatives must be used to arrive at a correct diagnosis. The aim of this study is to evaluate the range of physiological function of vertical semicircular ducts using electronystagmography and rotary stimulation. The method used was the technique of time - speed stimulation, with successive phases of acceleration, constant speed, deceleration and abrupt stop, with a computerized rotating chair. Vestibulo-ocular arreflexia of the right anterior vertical channel. It was shown that at speeds lower than 1 Hz it is possible to evaluate the Ocular Lobe Reflex in the vertical semicircular ducts, although the frequency of the stimulus is below the level at which this reflex works in daily activities(AU)

Suppression head impulse paradigm in healthy adult population: the values and features of the parameters / 中华耳鼻咽喉头颈外科杂志

Objective@#To observe the parameters of the results of suppression head impulse paradigm (SHIMP) in healthy adults, and to provide reference for evaluating vestibular oculomotor reflex function in patients with peripheral vertigo.@*Methods@#Fifty healthy adults, 22 males and 28 females, aged from 23-65 years, with an average age of (38.5±11.6) years, were recruited from January to March 2018. Parameters provided by the video head pulse software included the gains, the latency and the peak velocity of saccades, and comparison was made with head impulse paradigm (HIMP).@*Results@#All subjects were elicited anti-compensatory saccades in SHIMP. The normal values of left and right gains were 1.02 and 1.10 in HIMP, and 0.93 and 1.01 in SHIMP respectively. The left and right saccades latency were (201.1± 50.8)ms and (187.0± 42.9)ms, and the peak saccadic velocity were (302.7±58.5)°/s and (291.5±46.5)°/s in SHIMP; there were small but significant difference between two sides about gains in HIMP and SHIMP, as well as latency in SHIMP(P<0.05); there were small but significant difference between HIMP and SHIMP about gains in ipsilateral(P<0.01); there were no significant difference between two sides about peak saccadic velocity in SHIMP(P>0.05).@*Conclusions@#SHIMP can be used for the examination of vestibular oculomotor reflex function in adult population. It is easy to be operated and is convenient for clinical application. Combined with head pulse test, the function of the semicircular canal can be evaluated together.

The characteristics and clinical significance of vestibular autorotation test in patients with vestibular migraine / 中华耳鼻咽喉头颈外科杂志

Objective@#To investigate the characteristics and clinical utility of vestibular autorotation test (VAT) in patients with vestibular migraine(VM).@*Methods@#This study included two groups, a VM group (441 patients from Tianjin First Center Hospital between January 2015 and May 2016) and a control group (65 healthy subjects). Both groups undertook VAT; the parameters evaluated were horizontal gain/phase, vertical gain/phase and asymmetry. The differences in VAT results between the two groups were investigated.@*Results@#There were statistically significant differences in VAT results between the VM and the control group, namely elevated horizontal gain at frequency 2, 3, 4 and 5 Hz, delay horizontal phase at frequency 2, 4, 5 and 6 Hz, elevated vertical gain at frequency 2-6 Hz and delay vertical phase at frequency 4-6 Hz. There was no significant difference in asymmetric values between the VM group and the control group.@*Conclusions@#The results of this study indicate that VM patients have elevated horizontal gain and vertical gain, and delay horizontal phase and vertical phase. It is suggested that VAT represents a useful diagnostic tool which may provide objective evidence for the diagnosis and differential diagnosis of VM.

Clinical significance of bedside dynamic visual acuity test / 中华耳鼻咽喉头颈外科杂志

Objective@#Dynamic visual acuity (DVA) is defined as the visual acuity when there are relative movements between subjects and visual targets. The purpose of this study was to discuss the correlation between bedside DVA test and other examinations of vestibular function, and to assess the value of DVA test for clinical diagnosis.@*Methods@#Retrospective analysis of 323 cases with peripheral vestibular disorder, and analyzing the correlation between bedside DVA results and caloric test were performed.@*Results@#Out of these 323 cases, 113 cases showed positive results of DVA.Among these 113 cases with positive DVA test, 109 cases were bilateral or unilateral vestibular function loss according to the results of caloric test or VEMP. The disease with the highest positive rate of DVA was bilateral vestibulopathy(BVP), followed by vestibular neuritis (VN) and profound sudden sensorineural hearing loss (pSSNHL).@*Conclusions@#Bedside DVA is effective to determine the cases with BVP and severe unilateral vestibular function loss.