Recent progress in vestibular prosthesis / 临床耳鼻咽喉头颈外科杂志

Bilateral vestibulopathy（BVP） is one of the common diseases in the vestibular nervous system, with an incidence rate of about 4%-7% in the population, which can lead to a variety of body dysfunctions. At present, there are two main treatment methods for BVP. One is vestibular rehabilitation. However, only part of BVP patients can finally benefit from vestibular rehabilitation, and most patients will remain with permanent vestibular dysfunction. Benefiting from the maturity of cochlear implant technology, European and American countries took the lead in the development of vestibular prosthesis（VP） technology to restore the vestibular function in patients with BVP. This review will focus on the development history, principles, future applications and the related research progress of VP in China.

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.

Síndrome de Miller Fisher: relato de caso / Miller Fisher syndrome: case report

A síndrome de Miller Fisher é uma desmielinização dos nervos cranianos e periféricos, gerando graves consequências para o paciente, como, por exemplo, redução ou ausência dos reflexos, paralisia do III, IV e VI nervos cranianos e ataxia. Este relato descreveu o caso de uma mulher de 51 anos, natural e procedente de Penápolis (SP), admitida em um hospital de Araçatuba (SP) com quadro de arreflexia, ataxia e oftalmoplegia. No contexto clínico, foi suspeitada a hipótese de síndrome de Miller Fisher e, assim, começou o processo de investigação, com base nos critérios diagnósticos. O caso foi diagnosticado como síndrome de Miller Fisher, e o tratamento teve início.

Miller Fisher Syndrome is a demyelinating disease affecting cranial and peripheral nerves, leading to severe problems to the patient, such as reduced or absent reflexes, III, IV and VI cranial nerves palsy, and ataxia. This report describes the case of a 51-year-old woman from the city of Penápolis, in the state of São Paulo, who was admitted to the hospital in the city of Araçatuba, in the same state, with ataxia, areflexia and ophthalmoplegia. In the clinical context, the suspicion of Miller Fisher Syndrome was raised, and then investigation ensued for the disease, based on the diagnostic criteria. After evaluation, Miller Fisher Syndrome was confirmed and treatment was started.

Terapia vestibular en vestibulopatía bilateral por gentamicina: reporte de un caso y revisión de la literatura / Vestibular therapy in a case of gentamicin-induced vestibulopathy: case report and literature revision

La vestibulopatía bilateral es poco frecuente, se caracteriza principalmente por inestabilidad al caminar o al estar de pie, visión borrosa inducida por el movimiento u oscilopsia al caminar o al realizar movimientos rápidos de la cabeza o del cuerpo, empeoramiento de la estabilidad en la oscuridad o terrenos irregulares, reducción de los síntomas al estar en condiciones estáticas, ganancia del reflejo vestíbulo-ocular angular reducida de forma bilateral, entre otros. Existen múltiples causas. Dentro de las causas identificables, se describen principalmente medicamentos ototóxicos, meningitis y enfermedad de Ménière. Se presenta el caso de una paciente de 64 años diagnosticada con vestibulopatía bilateral posterior a tratamiento intramuscular con gentamicina por sobreinfección bacteriana cutánea de las manos. La evaluación vestibular complementada con videonistagmografía y prueba de impulso cefálico asistida por video confirman el diagnóstico y se inicia tratamiento con rehabilitación vestibular enfocada en promover la compensación central a través de estrategias de sustitución principalmente; además de habituación y adaptación vestibular, favoreciendo la estabilización de la mirada, mantención del equilibrio, control postural, marcha y reducción de los síntomas.

Bilateral vestibulopathy is infrequent, and it is characterized mostly by unstable walking or when standing, blurred vision induced by movement, or oscillopsia when walking or performing fast movements; worsening of the stability in darkness or uneven ground, but with lack of symptoms in static conditions. Other symptoms may include bilateral reduction of the oculo-vestibular reflex. Among the identifiable causes, there is the use of ototoxic medication, meningitis, Ménière's disease, although it can be idiopathic or have a neurological cause. We hereby describe the case of a 64-year-old woman, diagnosed with bilateral vestibulopathy secondary to intramuscular treatment with gentamicin due to a bacterial hand infection. Vestibular assessment was complemented with video-nystagmography and video head impulse test which confirmed the diagnosis, and therapy was started with vestibular rehabilitation focused on promoting central compensation mainly, through substitution strategies. Also, habituation exercise and vestibular adaptation strategies were used, thus promoting sight stabilization, balance maintenance, postural control, walking, and reduction of the symptoms.

Asociaciones entre función vestibular y habilidades cognitivas: un enfoque básico-clínico / Associations between vestibular function and cognitive abilities: from basic to clinical approach

RESUMEN El sistema vestibular tiene un rol fundamental en funciones sensorio-motoras, control del equilibrio y estabilidad de la mirada. En las últimas décadas un amplio número de trabajos ha descrito la importancia de las aferencias vestibulares en el funcionamiento de diversas áreas del cerebro relacionadas con funciones cognitivas tales como la atención, memoria, navegación y otras habilidades visuo-espaciales. Estudios en pacientes con vestibulopatía han demostrado que estos individuos presentan disminución de su rendimiento en algunas pruebas neuropsicológicas; y, a su vez, que personas con patología cognitiva como deterioro cognitivo leve y demencia por enfermedad de Alzheimer tienen mayor probabilidad de presentar pruebas vestibulares alteradas. Esta revisión se enfoca en el papel que cumple el sistema vestibular y su asociación con habilidades cognitivas; basándose en estudios básicos y clínicos que describen una red vestibular cerebral y que han llevado a proponer modelos teóricos que relacionan la función vestibular con la cognición.

ABSTRACT The vestibular system is widely known for its role in sensory-motor functions, balance control and gaze stability. In recent decades, several research articles have described the importance of vestibular afferents in the functioning of brain areas related to cognitive skills such as attention, spatial memory, spatial navigation and other visuospatial abilities. Studies involving subjects with vestibulopathy reveal that these individuals show decreased performance on neuropsychological tests; and that patients with neurocognitive pathologies, such as mild cognitive impairment and dementia due to Alzheimer's disease, have a greater probability of producing diminished or absent responses in clinical vestibular electrophysiological tests. This literature review focuses on the role played by the vestibular system and its association with cognitive abilities. The review incorporates a description of basic and clinical research that describe the cortical vestibular network and emerging theoretical models linking vestibular function to cognition.

Recovery Phase Spontaneous Nystagmus, Its Existence and Clinical Implication

BACKGROUND AND OBJECTIVES: Determination of the lesion side based on the direction of the nystagmus could result in confusions to the clinicians due to mismatch between the vestibular function tests and also between vestibular and audiologic features. To minimize these mistakes, we elucidated the clinical manifestation and vestibular function test results in cases with recovery spontaneous nystagmus (rSN). SUBJECTS AND METHODS: Patients who visited ENT clinic of tertiary referral hospital for acute onset continuous vertigo from January 2008 to December 2011 were enrolled. In these patients, we assessed onset time of vertigo, time point of paralytic spontaneous nystagmus (SN) and time point of rSN. At each time point of SN, vestibular function tests and hearing function tests were performed. RESULTS: We confirmed the rSN among patients with unilateral vestibulopathy and demonstrated that high gain of the rotatory chair test (slow harmonic acceleration) and/or mismatch of the SN direction and contralateral caloric weakness could indicate the recovery state of patients and nystagmus observed in this stage is recovery phase nystagmus. CONCLUSIONS: In acute vestibulopathy patients, recovery phase nystagmus was observed and on this stage of disease vestibular function tests shows several features that could predict recovery state.

Customized Vestibular Rehabilitation in the Patients with Bilateral Vestibulopathy: A Pilot Study in One Referred Center / 대한평형의학회지

OBJECTIVES: Bilateral vestibulopathy is characterized with unsteadiness and oscillopsia when walking or standing, worsening in darkness and/or on uneven ground. To establish the effect of customized vestibular rehabilitation in bilateral vestibulopathy, we analyzed the questionnaires and functional status before and after treatment. METHODS: Among 53 patients with customized vestibular rehabilitation from January 1st to November 30th in 2018, 6 patients (3 males; median age, 71 years; range, 54–75 years) who regularly exercised with good compliance were retrospectively enrolled. They were educated and trained the customized vestibular rehabilitation once a month or two by a supervisor during 40 minutes, and then exercised at home for 30 minutes over 5 days in a week. Dizziness handicap inventory (DHI), Korean vestibular disorders activities of daily living scale (vADL), Beck's depression index (BDI), test for dynamic visual acuity (DVA), and Timed Up and Go test (TUG) were performed before and after the customized vestibular rehabilitation. RESULTS: The patients exercised for median 5.5 months (range, 2–10 months) with the customized methods of vestibular rehabilitation, which included gaze and posture stabilization and gait control exercises. DHI score and TUG was improved after rehabilitation (DHI before vs. after rehabilitation=33 vs. 16, p=0.027, TUG before vs. after rehabilitation=12 vs. 10, p=0.026). BDI, DVA, and vADL scores did not differ between before and after treatment. CONCLUSIONS: Customized vestibular rehabilitation can improve dizziness and balance state in bilateral vestibulopathy. The steady exercises adapted individual peculiarities is the most important for vestibular rehabilitation.

Characteristic of Sudden Sensorineural Hearing Loss with Objective Vestibular Involvement / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: To analyze the difference in audiologic-vestibular and clinical characteristics between acute cochlea-vestibulopathy (ACV) and idiopathic sudden sensorineural hearing loss (ISSNHL). SUBJECTS AND METHOD: We retrospectively analyzed the clinical characteristics of 91 patients diagnosed as sudden hearing loss (ACV; n=20, ISSNHL; n=71). Patients with vestibular hypofunction were categorized as ACV and all others as ISSNHL. Demographics and clinical findings were compared. Audiologic features such as degree of hearing loss, type of audiometric configuration and hearing improvements were analyzed. In addition, vestibular function test results and hearing recovery were further analyzed among ACV group. RESULTS: Demographics and other clinical findings were not much different between groups. There was a significant difference with respect to audiologic features between the ACV group and ISSNHL group: the initial hearing threshold of the ACV group was higher than that of the ISSNHL group, and their treatment onset was also shorter. There was also a significant difference in the hearing outcome showing very low rate of complete recovery in ACV group. The final hearing threshold of the ACV group was higher than that of the ISSNHL group. Dizziness was the only significant variable in the multiple regression analysis. In the ACV group, the cervical vestibular evoked myogenic potential inter-aural amplitude difference (cVEMP IAD) ratio showed a correlation to the hearing recovery in some frequencies; patients with no cVEMP response showed poor outcome compared to those with cVEMP waveform. CONCLUSION: The ACV group shows a poor prognosis just as in the case of sudden hearing loss defined in the traditional sense of vertigo. The IAD value of the vestibular evoked myogenic potentials test will be helpful in assessing hearing improvement, especially when a high IAD value at the middle frequency is associated with a poor prognosis.

Isolated hemorrhage in the cerebellar vermis with vertigo and body lateropulsion to the contralesional side / 영남의대학술지

There have been several reports of patients with isolated lesions of the cerebellar vermis presenting with clinical features similar to those of peripheral vestibulopathy. We report a case of small, isolated hematoma in the cerebellar vermis in a patient who presented with vertigo, ipsilesional nystagmus, and body lateropulsion to the contralesional side without the usual signs or symptoms of cerebellar dysfunction. Although they present with symptoms that mimic those of peripheral vestibulopathy, and brain computed tomography shows no abnormality, as there may be a small, isolated hematoma or infarction in the cerebellar vermis. Thus, brain magnetic resonance imaging should be performed in elderly patients with vascular risk factors.

The Clinical Efficacy of Vestibular Function Tests in Patients with Acute Unilateral Vestibulopathy / 대한평형의학회지

OBJECTIVES: Aim of this study is to investigate the clinical efficacy of the vestibular function tests (VFTs) and the predictability of lesion side of vestibular asymmetry parameters in acute unilateral peripheral vestibulopathy. METHODS: Medical records and results of VFTs (caloric, rotatory chair, and head impulse tests) of 57 patients with acute unilateral vestibulopathy were reviewed retrospectively. The VFTs were examined within 7 days after the clinical onset. RESULTS: For the caloric test, 74% showed significant canal paresis and the predictability of lesion side was 88%. For the sinusoidal harmonic acceleration test, 91% had low gain in at least 1 Hz, phase lead showed 70%, 89% showed phase asymmetry and the predictability of lesion side was 90%. For velocity step test, 67% had abnormal Tc asymmetry and the predictability of lesion side was 95%. In bedside head impulse test (HIT), abnormal catch up saccades were observed in 89% and the predictability of lesion side was 100%. For the video HIT, cover or overt catch-up saccades were observed in 95% and the predictability of lesion side was 100%. One hundred percent (100%) had low gain on the video HIT, but the lesion sides were uncertain because of bilateral involvements or artifacts. CONCLUSIONS: The most important things in the diagnosis of acute unilateral vestibulopathy are typical clinical symptoms and spontaneous nystagmus. A combination of rotatory, caloric, and HITs will result in a more complete examination of the vestibular system. Among them, HIT is recommended as the best tool in acute unilateral vestibulopathy.