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

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

Efeito da idade no equilíbrio corporal e nos resultados do vídeo teste do impulso cefálico em pacientes com insuficiência cardíaca / Effect of age on body balance and on the results of the video head impulse test in patients with heart failure

RESUMO Objetivo verificar se existe associação entre a avaliação clínica do equilíbrio e o ganho do reflexo vestíbulo-ocular com o avanço da idade em pacientes com insuficiência cardíaca. Métodos estudo transversal analítico-descritivo, de caráter observacional, que incluiu pacientes com diagnóstico de insuficiência cardíaca, divididos em dois grupos, por idade (G1, menos de 60 anos e G2, 60 anos ou mais). Os pacientes foram avaliados por meio de anamnese, avaliação cardiológica, avaliação clínica do equilíbrio corporal (triagem da função cerebelar e avaliação do equilíbrio estático e dinâmico) e instrumental da função vestibular (Video Head Impulse Test-vHIT). Os achados obtidos foram descritos e comparados por meio de análise estatística inferencial. Resultados foram avaliados 34 pacientes com média de idade de 55 anos e 9 meses, a maioria homens (71,49%). Não houve associação do ganho do reflexo vestíbulo-ocular, simetria dos canais semicirculares e avaliações do equilíbrio corporal com o avanço da idade. Observaram-se associações entre os resultados da prova de Unterberger-Fukuda com o ganho do reflexo vestíbulo-ocular do canal semicircular lateral direito e posterior esquerdo e com os percentuais de simetria dos canais semicirculares anteriores para os pacientes do Grupo 2. Para os indivíduos do Grupo 1, foi observada associação entre os resultados da prova de Unterberger-Fukuda com os valores de simetria dos canais semicirculares anteriores e do ganho de reflexo vestíbulo-ocular dos canais semicirculares anterior esquerdo e posterior direito. Conclusão não houve associação entre os resultados da avaliação clínica do equilíbrio corporal e dos achados do vHIT com o avanço da idade, em pacientes com insuficiência cardíaca. Entretanto, observou-se diferença entre o ganho do reflexo vestíbulo-ocular específico para alguns canais semicirculares, com maiores índices de alteração na prova de equilíbrio dinâmico, em ambos os grupos. Os resultados dos testes aplicados permitiram caracterizar o predomínio da hipofunção vestibular crônica de origem periférica nos pacientes com insuficiência cardíaca, independentemente da faixa etária.

ABSTRACT Purpose to verify whether there is an association between the clinical assessment of balance and the gain in the vestibulo-ocular reflex with advancing age in patients with heart failure. Methods analytical-descriptive, observational cross-sectional study, which included patients diagnosed with heart failure, divided into two groups by age (G1, under 60 years old and G2, 60 years old or older). The patients were evaluated through anamnesis, cardiac assessment, clinical assessment of body balance (cerebellar function screening and assessment of static and dynamic balance) and instrumental assessment of vestibular function (Video Head Impulse Test-vHIT). The findings were described and compared through inferential statistical analysis. Results 34 patients with a mean age of 55 years and 9 months, mostly men (71.49%). There was no association between vestibulo-ocular reflex gain, symmetry of the semicircular canals and body balance with advancing age. Associations were observed between the results of the Unterberger-Fukuda test with the gain in the vestibulo-ocular reflex of the right lateral and left posterior semicircular canals and with the percentages of symmetry of the anterior semicircular canals for patients in Group 2. In Group 1, an association was observed between the results of the Unterberger-Fukuda test and the symmetry values of the anterior semicircular canals and the gain in the vestibulo-ocular reflex of the left anterior and right posterior semicircular canals. Conclusion there was no association between the results of the clinical assessment of body balance and the vHIT findings with advancing age in patients with heart failure. However, there was a difference between the gain of the specific vestibulo-ocular reflex for some semicircular canals, with higher rates of alteration in the dynamic balance test, in both groups. The results of the applied tests allowed characterize the predominance of chronic vestibular hypofunction of peripheral origin in patients with heart failure, regardless of age group.

Relação entre a idade, o risco de queda e o nível de confiança no equilíbrio corporal com a função dos canais semicirculares / Relationship between age, the risk of falling and level of confidence in body balance with semicircular canal function

RESUMO Objetivo verificar a relação entre o risco de queda, o nível de confiança nas atividades que envolvem equilíbrio e a idade com os valores de ganho e simetria dos canais semicirculares (CSCs), por meio do Vídeo Teste do Impulso Cefálico (vHIT), em pacientes com disfunção vestibular periférica. Método estudo transversal, composto por 12 indivíduos submetidos à avaliação funcional por meio da Activities-specific Balance Confidance Scale (ABC Scale) e do Dynamic Gait Index (DGI) e avaliação vestibular com o vHIT. Os resultados foram comparados por meio do Coeficiente de Correlação de Spearman. Resultados observou-se predomínio do gênero feminino (75%), com média de idade de 59 anos e 8 meses. A média de escore no DGI foi de 19,70 pontos e 43,65% na ABC Scale, característico de baixo nível de confiança. Observou-se correlação de grau moderado entre os parâmetros idade com o DGI, DGI e ABC Scale com os valores de ganho e simetria dos CSCs do vHIT. Conclusão Observaram-se relações entre o maior risco de queda em pacientes com hipofunção vestibular e idade avançada e entre o baixo nível de confiança para realizar atividades diárias diante da assimetria de ganho dos CSCs.

ABSTRACT Purpose to verify the relationship between the risk of falling, the level of confidence in activities involving balance, and age with the values of gain and symmetry of the semicircular canals (SSCs), using the Head Video Impulse Test (vHIT) in patients with peripheral vestibular dysfunction. Methods Cross-sectional study in 12 individuals submitted to functional evaluation using the Activities-specific Balance Confidence Scale (ABC Scale) and the Dynamic Gait Index (DGI), and vestibular evaluation with vHIT. The results were compared using Spearman's Correlation Coefficient. Results There was a predominance of females (75%), with a mean age of 59 years and 8 months. The mean score in DGI was 19.70 points and on the ABC Scale, 43.65%, which is characteristic of a low confidence level. A moderate correlation was observed between age and DGI and between DGI and ABC Scale and SCC gain and symmetry values with vHIT. Conclusion A relationship was observed between a higher risk of falling in patients with vestibular hypofunction and advanced age and between a low level of confidence to perform daily activities due to asymmetrical SCC gain.

Interface entre as medidas de benefício após a reabilitação vestibular - relato de casos / Interface between measures of benefit after vestibular rehabilitation - case report

RESUMO Esta pesquisa teve como objetivo caracterizar o efeito da reabilitação vestibular (RV) sobre o ganho do reflexo vestíbulo-ocular (RVO), a ocorrência das sacadas compensatórias, bem como sobre o equilíbrio corporal e a qualidade de vida, em três pacientes com hipofunção vestibular periférica. Trata-se de um estudo descritivo. Participaram da pesquisa três pacientes do gênero feminino, duas com 55 anos e uma com 67 anos, com diagnóstico médico de disfunção vestibular periférica. As participantes foram submetidas à anamnese, questionário Dizziness Handicap Inventory (DHI), avaliação clínica do equilíbrio corporal e ao Vídeo Teste do Impulso Cefálico (vHIT), pré e após RV. A RV foi aplicada de forma personalizada, baseada no protocolo de Cawthorne e Cooksey, associada a estímulos de realidade virtual. Após a RV, observou-se a redução da média do escore total do DHI, sugestivo da diminuição na restrição de participação. Na avaliação clínica do equilíbrio obtiveram-se resultados dentro da normalidade para as provas alteradas, pré RV. Quanto ao vHIT, constatou-se aumento do ganho do RVO para os canais semicirculares anteriormente afetados, condizente com padrões de normalidade, e extinção ou diminuição de ocorrência das sacadas compensatórias, nos três casos avaliados. O aumento do ganho do RVO e a extinção ou redução das sacadas compensatórias, após a RV, evidenciam sinais sugestivos de compensação vestibular. Esses resultados mostraram-se compatíveis com o aumento da estabilidade postural e menor restrição da qualidade de vida. Os achados, em conjunto, demonstram o benefício proporcionado pela RV nos três casos avaliados.

ABSTRACT The purpose of this research is to characterize the vestibular rehabilitation (VR), vestibulo-ocular reflex (VOR) gain, the occurrence of compensatory saccades, the static and dynamic balance, and the impact on quality of life in three patients with peripheral vestibular hypofunction. This is a descriptive study, approved by the ethics in research committee, under number 4,462.519. Three female patients participated in the study, two aged 55 and one aged 67, with a medical diagnosis of peripheral vestibular dysfunction. The participants underwent anamnesis, Dizziness Handicap Inventory (DHI) questionnaire, clinical assessment of postural balance and Video Head Impulse Test (vHIT), pre and post VR. The VR was applied in a personalized manner, based on the Cawthorne and Cooksey protocol, associated with virtual reality stimuli. After VR, a reduction in the total score average of DHI was observed, suggesting a decrease in participation restriction. The clinical balance assessment results were within the normal range for the altered tests, pre VR. In the three evaluated cases, vHIT showed increased RVO gain for the previously affected semicircular ducts (SCDs), compatible with normality standards, and reduction or extinction in the occurrence of compensatory saccades. The increase in VOR gain and the reduction or suppression of compensatory saccades after VR are suggestive signs of vestibular compensation. These results were compatible with increased postural stability and less restricted quality of life. These findings demonstrate the benefit provided by VR in the three evaluated cases.

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

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

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

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

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

Evaluación del Video Head Impulse Test (V-Hit) en el diagnóstico del neurinoma del acústico / Evaluation of video Head Impulse Test (v-HIT) in the diagnosis of acoustic neuroma

Introducción: La gran mayoría de lesiones que comprometen el conducto auditivo interno corresponden a schwannomas vestibulares (90%). Dentro de las nuevas pruebas diagnósticas del sistema vestibular aparece la prueba de impulso cefálico y su registro con el video Head Impulse Test (v-HIT) que permite el estudio de todos los canales semicirculares. Objetivo: Comparar el v-HIT para canales semicirculares laterales con las pruebas calóricas clásicas registradas mediante videonistagmografía en el comportamiento de los neurinomas intracanaliculares y evaluar su utilidad como test diagnóstico. Material y método: Dieciocho pacientes fueron reclutados con diagnóstico de neurinomas, confirmado mediante resonancia magnética y estudios con pruebas calóricas clásicas y v-HIT para canal horizontal. Resultados: Los resultados anormales de asimetría de ganancia y de sacadas correctivas fue de 13 pacientes (72%) y con hipoexcitabilidad en la prueba calórica fue de 9 pacientes (50%), con una sensibilidad de la prueba de 72% para vHIT y de 50% para la prueba calórica al compararlo con la resonancia magnética. Conclusión: El v-HIT es una herramienta complementaria a las pruebas calóricas y debe ser incluida como test diagnóstico dentro de la batería de exámenes para evaluar el sistema vestibular en forma completa mediante un vestibulograma.

Introduction: The majority of injuries involving the internal auditory canal correspond to vestibular schwannomas (90%). Within the new diagnostic tests for the vestibular system appears the Head Impulse test and the video head impulse test (v-HIT) which allows the studying of all the semicircular canals. Aim: Compare the v-HIT lateral semicircular canals with classical caloric tests recorded by videonistagmography (VNG) in the behavior of intracanalicular neuroma and evaluate its usefulness as a diagnostic test. Material and method: Eigtheen patients were enrolled with a diagnosis of schwannomas, confirmed by MRI and studied classical caloric tests and v-HIT for horizontal channel. Results: Abnormal results of asymmetry gain and corrective saccades was 13 patients (72%) and hypoexcitability in the caloric test was 9 patients (50%), with a test sensitivity of 72% for vHIT and 50% for caloric test compared with MRI. Conclusions: The v-HIT is a complementary tool to caloric tests and should be included as a diagnostic test within the battery of tests to evaluate the vestibular system in complete form by vestibulogram.

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

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

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

Experiencia en el uso video-Impulso Cefálico (vHIT) en la evaluación del reflejo vestíbulo-ocular para el canal semicircular horizontal / Assesing vestibulo-ocular reflex of the horizontal semicircular canal with video Head Impulse Testing (vHIT)

Introducción: La prueba de impulso cefálico consiste en una herramienta sencilla y rápida para evaluar la función del reflejo vestíbulo ocular. La implementación de un acelerómetro y una cámara de alta velocidad, permiten registrar alteraciones sutiles de este fenómeno, optimizando esta prueba. Objetivo: Describir la experiencia inicial y relevancia clínica de la prueba de impulso cefálico asistida por video y acelerómetro (vHIT). Material y método: Se realizó prueba vHIT a pacientes con indicación de estudio funcional de VIII par. Resultados: Utilizando prueba calórica como patrón de oro se evaluaron 60 pacientes. vHIT presentó una especificidad de 93% y una sensibilidad de 74%. En un paciente con colesteatoma bilateral con vértigo agudo, el examen contribuyó en la identificación del lado complicado, además de registrar fenómenos de compensación vestibular. Discusión y conclusión: vHIT demostró ser altamente específico. Los supuestos falsos positivos presentaban sintomatología vestibular, por lo que consideramos que podrían representar casos donde vHIT es más sensible que la prueba calórica. vHIT presenta además una buena sensibilidad. Los casos de falsos negativos podrían explicarse en relación a la diferencia de velocidad angular usada en la estimulación entre vHIT y la prueba calórica. vHIT podría representar un importante complemento al estudio del paciente con patología vestibular.

Introduction: The head impulse test is a simple and quick tool for assessing the vestibulo-ocular reflex. The implementation of an accelerometer and a high-speed camera, allows the recording of subtle, priorly unaccessible alterations, thus optimazing the test. Aim: To describe an initial experience and clinical relevance of a video and accelerometer assisted head impulse test (vHIT). Material and method: We performed vHITon patients with indication of vestibular testing due to vertigo or balance related symptoms. Results: Regarding caloric testing as gold standard, 60 patients were evaluated. vHIT had a specificity of 93% and a sensitivity of 74%. In a patient with bilateral cholesteatoma with acute vertigo, vHIT examination contributed in identifying the complicated side, in addition to recording previously undetectable vestibular compensation phenomena. Discussion and conclusion: vHIT proved to be highly specific. Every supposed false positive cases had vestibular symptoms, so we consider these cases to represent a scenario where vHIT is actually more sensitive than caloric testing. vHIT showed also good sensitivity. False negative cases could be explained in relation to the test's angular velocity stimuli difference existing between VHIT and caloric test. VHIT could represent an important contribution to patients with vestibular disorders.

Prueba de impulso cefálico: bases fisiológicas y métodos de registro del reflejo vestíbulo oculomotor / Head impulse test: physiological basis and registration methods of the vestibulo-ocular reflex

En la historia de la evaluación clínica vestibular, siempre se ha buscado la manera de medir en forma individual los seis canales semicirculares y los cuatro órganos otolíticos. Basados en el conocimiento de la fisiología vestibular, en 1988 Halmagyi y Curthoys describieron la Prueba de Impulso Cefálico o Head Impulse Test (HIT) como un método diagnóstico para evaluar la efectividad del reflejo vestíbulo oculomotor en pacientes con sintomatología vestibular. Esta revisión pretende dar a conocer las bases fisiológicas del HIT y su evolución hasta el video HIT (vHIT) actual.

In the history of vestibular clinical evaluation, it has always been sought the way to measure individually each of the six semicircular canals and the four otolith organs. Based on vestibular physiology, in 1988 Halmagyi and Curthoys described the Head impulse test (HIT) as a diagnostic method to evaluate the effectiveness of the vestibulo-oculomotor reflex in patients with vestibular symptoms. This review shows the physiological basis for HIT and its evolution towards nowdays video HIT (vHIT).

Evaluación de la función vestibular angular: prueba de impulso cefálico multiaxial a ojo desnudo / Angular vestibular function assessment: Multiaxial Head Impulse Test

Introducción: La prueba de impulso cefálico consiste en un examen rápido, sencillo para evaluar la función vestibular angular. Clásicamente se utiliza para el canal horizontal, pero puede implementarse para evaluar los canales semicirculares anteriores y posteriores. Objetivo: Explorar la sensibilidad y especificidad de esta prueba para los canales verticales a ojo desnudo en nuestro medio, en relación a la prueba calórica. Material y método: Estudio prospectivo de evaluación de test diagnóstico. Se realizó prueba de impulso cefálico para todos los canales semicirculares a pacientes con indicación de evaluación funcional de VIII par. Resultados: Se evaluaron 118 pacientes, donde 49,2% presentó una prueba calórica clásica alterada. La sensibilidad del impulso cefálico para el canal posterior fue 13,1(0)% (y 3,2%% para el canal anterior) con una especificidad de 100%% para ambos. Para el canal horizontal la sensibilidad fue de 63,9%% y la especificidad de 100%%. Discusión: La prueba de impulso cefálico para los canales anteriores y posteriores a ojo desnudo es altamente específico, pero muy poco sensible, teniendo una utilidad relativa dentro de la clínica, a diferencia de la misma prueba para el canal horizontal que con la misma especificidad pero con una sensibilidad aceptable representa un examen rápido y de simple ejecución.

Introduction: The Head Impulse Head test represents a quick and simple technique for perioheral vestibular function assessment, by means of exploring the vestíbulo-ocular reflex. It is usually períormed on the horizontal semicircular canals planes, but it can also explore the anterior and posterior canals. Aim: To assess the head impulse test's sensitivity and specificity for the anterior and posterior canals on a bedside scenario, taking the classic caloric test as gold standard. Material and method: Prospective test-assessment study. A head impulse test for every semicircular canal was períormed on patients with indication of vestibular study with caloric test. Results: 118 patients were evaluated, where 49,2%% presente an abnormal caloric test. The head impulse test's sensitivity for the posterior canal canal was 13,1%% (3,2%% for the anterior canal). The test's specificity was 100%% for both vertical canals. On the horizontal plane, sensitivity reached 63,9%%, while specificity was 100%% Discussion: The head impulse test for vertical (anterior and posterior) canal on a bedside scenario is highly specific but poorly sensitive, thus having a relatively low clinical utility. On the contrary the test for the horizontal canal remains a quick and simple tool, with acceptable sensitivy and great sensitivity for assessing vestibular function loss.