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.

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.

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.

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.

Medición del ángulo vestíbulo-lingual en conductos mesiales de primeros molares inferiores utilizando tomografía de haz cónico / Measuring the vestibular-lingual angle in lower molar first mesial ducts using cone beam tomography

El objetivo del presente estudio fue medir la curvatura vestíbulo-lingual de los conductos de las raíces mesiales de primeros molares inferiores en personas adultas del estado de Chihuahua, por medio de la técnica de tomografía computarizada de haz cónico (CBCT, por sus siglas en inglés) y usando el software de análisis 3D EndoTM (Dentsply/Sirona USA). Se llevó a cabo la medición por dos observadoras, empleando dos métodos diferentes, Schneider y 3D EndoTM (Dentsply/Sirona USA). Los resultados obtenidos tuvieron valores mayores a los 100 grados con la técnica 3D EndoTM y a los 20 grados con la técnica de Schneider. No se detectó una diferencia estadística significativa al comparar los diferentes conductos entre sí (AU)

The objective of the present study was to measure the vestibule-lingual curvature of the ducts of the mesial roots of lower first molars, of adults from the state of Chihuahua. Using the cone beam computed tomography (CBCT) technique and using the 3D analysis software EndoTM (Dentsply/Sirona USA). The measurement was carried out by two observers using two different methods, Schneider and 3D EndoTM (Dentsply/Sirona USA). The results obtained had values greater than 100 degrees with the 3D EndoTM technique and at 20 degrees with the Schneider technique. No statistically significant difference was detected when comparing the different ducts with each other (AU)

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.

Análise das respostas do VEMP cervical e ocular em indivíduos hígidos / Analysis of cervical and ocular VEMP responses in healthy individuals / Análisis de las respuestas VEMP cervicales y oculares en individuos sanos

Introdução: os potenciais evocados miogênicos vestibulares (VEMP) são respostas eletrofisiológicas que conseguem fornecer informações dos órgãos otolíticos sáculo, utrículo e do nervo vestibular. O VEMP é um exame complementar à avaliação vestibular, consistindo num exame rápido, de fácil aplicação e objetivo. Objetivo: analisar os parâmetros de latência, amplitude, limiar e índice de assimetria das respostas do VEMP cervical (cVEMP) e ocular (oVEMP) de indivíduos sem queixas vestibulares. Métodos: estudo transversal realizado com 53 indivíduos de ambos os sexos, sem queixas auditivas e vestibulares. Resultados: encontrou-se simetria de respostas nas latências, amplitudes e limiares de respostas do exame cVEMP. Entretanto, verificou-se diferença entre orelhas da latência P15 do exame oVEMP, sendo maior à direita no sexo feminino. Conclusão: Encontrou-se simetria nas respostas de todos os parâmetros avaliados do cVEMP. Houve assimetria apenas na latência de P15 do oVEMP no sexo feminino. Os limiares de resposta encontrados nos exames cVEMP e oVEMP foram iguais ou maiores que 75 dBNA.

Introduction: Vestibular evoked myogenic potentials (VEMP) are electrophysiological responses that can provide information on the otolithic organs saccule, utricle and of the vestibular nerve. VEMP is a complementary exam to the vestibular assessment; it is a quick exam, easy to apply and objective. Purpose: to analyze the parameters of latency, amplitude, threshold and asymmetry index of the cervical (cVEMP) and ocular VEMP (oVEMP) responses of individuals without vestibular complaints. Methods: cross-sectional study carried out with 53 individuals of both genders without hearing and vestibular complaints. Results: response symmetry was found in the latencies, amplitudes and thresholds of cVEMP test responses. However, there was a difference between the ears of the P15 latency of the oVEMP exam, and this was greater on the right ear in females. Conclusion: symmetry was found in the responses of all cVEMP evaluated parameters. There was asymmetry in oVEMP P15 latency only in female patients. The response thresholds found in the cVEMP and oVEMP tests were equal or greater than 75 dBHL.

Introducción: los potenciales miogénicos evocados vestibulares (VEMP) son respuestas electrofisiológicas que pueden proporcionar información sobre los órganos otolíticos el sáculo, el utrículo y el nervio vestibular. El VEMP es un examen complementario a la evaluación vestibular; es un examen rápido, fácil de aplicar y objetivo. Objetivo: analizar los parámetros de latencia, amplitud, umbral e índice de asimetría de las respuestas VEMP cervical (cVEMP) y ocular (oVEMP) de individuos sin quejas vestibulares. Métodos: estudio transversal realizado con 53 individuos de ambos sexos, sin quejas auditivas y vestibulares. Resultados: Se encontró simetría de respuestas en las latencias, amplitudes y umbrales de respuestas en el examen cVEMP. Sin embargo, hubo una diferencia entre los oídos de la latencia P15 del examen oVEMP, siendo mayor a la derecha en el sexo femenino . Conclusión: se encontró simetría en las respuestas de todos los parámetros evaluados de cVEMP. Hubo asimetría solo en la latencia P15 de oVEMP en el sexo femenino. Los umbrales de respuesta encontrados en las pruebas cVEMP y oVEMP fueron iguales o superiores a 75 dBHL.

Bilateral Narrow Internal Auditory Canal With Duplication: High Resolution CT And MRI Findings

Inner ear malformations account for only 20 % of cases of congenital sensorineural hearing loss.A narrow internal auditory canal (IAC) with duplication is a very rare congenital anomaly that can be associated with other malformative ear abnormalities. Identification and characterization of these abnormalities will be crucial for the proper management of patients.We report two cases of bilateral duplicated internal auditory canal with other associated inner ear anomalies.

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.

Patología infecciosa del vestíbulo nasal / Infectious diseases of the nasal vestibule

El vestíbulo nasal corresponde a la primera porción de la fosa nasal, éste se encuentra delimitado lateralmente por los cartílagos alares y medialmente por el borde caudal del septum nasal y la columela. Las enfermedades infecciosas del vestíbulo nasal son patologías frecuentes en la práctica clínica; su diagnóstico se realiza en base a sospecha clínica y examen físico, requiriendo habitualmente solo manejo médico ambulatorio. Desde el punto de vista etiológico pueden ser virales, bacterianas y fúngicas. Las principales especies bacterianas involucradas corresponden a Staphylococcus coagulasa negativa, S. epidermidis, S. hominis y S. haemolyticus, difteroides spp y S. aureus. Su manejo es esencialmente médico con casos excepcionales requiriendo manejo quirúrgico. En la actualidad existe escasa información epidemiológica al respecto, lo que dificultad la clasificación de los dichos cuadros clínicos. Se realizó una revisión de la literatura sobre cuadros infecciosos que afectan el vestíbulo nasal para lograr sistematizar y clarificar las distintas patologías y sus tratamientos.

The nasal vestibule corresponds to the first portion of the nasal passage, limited laterally by the lateral crus and medially by the caudal edge of the nasal septum and columella. Infectious diseases of the nasal vestibule are frequent in clinical practice, diagnosis is made based on clinical suspicion and physical examination, usually requiring only ambulatory medical management. In terms of etiology, they can be viral, bacterial and fungal. The main bacterial species involved correspond: Coagulase-negative Staphylococcus, S. epidermidis, S. hominis and S. haemolyticus, difteroides spp and S. aureus. Management is essentially medical and only exceptionally requires surgery. Currently, there is a lack of epidemiological information in this regard, which makes it difficult to classify these clinical conditions. A review of the literature on infectious conditions that affect the nasal vestibule was performed, to systematize and clarify the different pathologies and their management.

Mecanismos neurofisiológicos de la rehabilitación vestibular / Neurophysiological mechanisms of vestibular rehabilitation

RESUMEN La rehabilitación vestibular es un concepto terapéutico utilizado en pacientes que presentan síntomas como vértigos y/o mareos, asociados a una afectación vestibular, además de otras manifestaciones clínicas. Este artículo busca entregar un análisis amplio de los elementos que interactúan para definir una patología, como a su vez intervenir en su compensación. Serán presentados elementos neuroanatómicos, fisiológicos y conceptuales de la rehabilitación para este tipo de pacientes con un enfoque clínico basados en la evidencia.

ABSTRACT Vestibular rehabilitation is a therapeutic concept used in patients suffering from dizziness and/or dizziness, in addition to other clinical manifestations. This article gives a broad analysis of the elements that interact to define a pathology, as well as to intervene in their compensation. Neuro anatomical, physiological and conceptual elements of rehabilitation for this type of patients will be presented with a clinical approach based on evidence.

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.

Postural responses of galvanic vestibular stimulation: comparison between groups of older adults and young people / Respostas posturais frente à estimulação vestibular galvânica: comparação entre grupo de pessoas idosas e jovens

Abstract Objective: To evaluate the effect of vestibular manipulation on the postural sway and muscle activation of younger and older adults. Methods: The study analyzed the effects of three intensity levels of galvanic vestibular stimulation (GVS) (0.3; 0.6 and 1m) on the pattern of muscle activity and center of pressure (CP) displacements of 12 older adults (EG) and 12 young adults (CG) while maintaining their balance on a stable surface, with no vision. Results: The EG showed a positive correlation between CP displacement and muscle activity and GVS intensity. On the other hand, the magnitude of postural response in the EG was not modulated in accordance with GVS intensities. Additionally, during the highest GVS intensity level (1 mA) greater muscle activity was used to increase stiffness, decrease the amplitude of oscillation and ensure stability. This unusual response characterizes a pattern of co-activation and is perhaps a safety mechanism to ensure stability. Conclusion: The EG individuals were not able to select the appropriate motor strategy to efficiently compensate the effects of GVS. This unusual strategy reflects deficits in the vestibular system of older adults, a fact which negatively interferes with their ability to reevaluate sensory information.

Resumo Objetivo: Avaliar a interferência da manipulação das informações vestibulares na oscilação postural e atividade muscular de jovens e idosos. Métodos: Foi analisado o efeito de três intensidades (0,3; 0,6 e 1mA) de estimulação vestibular galvânica (GVS) no padrão de ativação muscular e deslocamento do centro de pressão (CP) de 12 idosos (GI) e 12 adultos jovens (GC), durante a manutenção do equilíbrio em uma superfície estável sem visão. Resultados: O GC mostrou correlação positiva entre o deslocamento de CP e a ativação muscular com a intensidade da GVS. Por outro lado, o GI não foi capaz de modular a magnitude da resposta postural com a intensidade da GVS. Durante o maior valor de GVS (1mA), houve um aumento da ativação muscular de agonista e antagonista caracterizando um padrão de coativação que aumentou a rigidez e diminuiu a amplitude de oscilação. Conclusão: Os indivíduos do GI selecionaram uma estratégia motora atípica para compensar os efeitos da GVS. Essa estratégia incomum refletiu deficit no sistema vestibular dos idosos e pode interferir negativamente na capacidade de reorganização das informações sensoriais.