A comparative study of detection methods for assessing superior and inferior vestibular nerve damages in patients with vestibular neuritis / 临床耳鼻咽喉头颈外科杂志

Objective:This study aims to compare the examination results of the vestibular evoked myogenic potential（VEMP） and video head impulse testing（vHIT） in patients with vestibular neuritis（VN）, thus exploring the methods to distinguish superior and inferior vestibular nerve damages in VN patients, and their feasibility. Methods:A total of 25 patients with unilateral VN treated in the Otology Department of the First Hospital of Qinhuangdao from May 2018 to July 2021 were recruited. They were respectively tested for ocular VEMP（oVEMP）, cervical VEMP（cVEMP） and vHIT, and the examination results were analyzed. Results:Examination results of oVEMP showed that 96%（24/25） patients had one-ear abnormalities with the amplitude decline or no waveform introduced, and 4%（1/25） patient had no waveform introduced of both ears. The overall abnormal rate examined by oVEMP was 100%（26/26）. Examination results of cVEMP showed that 36%（9/25） patients had one-ear abnormalities with the amplitude decline or no waveform introduced, and 4%（1/25） patients had no waveform introduced of both ears. The overall abnormal rate examined by cVEMP was 40%（10/25）, and 60%（15/25） patients had normal waveforms of both ears. Examination results of vHIT showed that 100%（25/25） patients had semicircular canal gain decline of one side, 92%（23/25） had anterior Semicircular canal decline of one side, and 36%（9/25） had posterior semicircular canal decline of one side. VEMP and vHIT results were compared. Examination results of VEMP showed that 60%（15/25） VN patients had superior vestibular nerve damage, and 40%（10/25） had both superior and inferior vestibular nerve damages. Examination results of vHIT showed that 64%（16/25） VN patients had superior vestibular nerve damage, and 36%（9/25） had both superior and inferior vestibular nerve damages. There was no significant difference in the ratio of VN patients with superior and inferior vestibular nerve damages examined by VEMP or vHIT（χ²=0.085, P>0.05）. The matching ratio of VEMP and vHIT results was 80%（20/25）, and the non-matching ratio was 20%（5/25）. Conclusion:Consistent results obtained from both VEMP and vHIT can preliminarily identify the type of vestibular nerve damage. If their results are not consistent, it is recommended not to identify the scope of the vestibular nerve damage.

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.

Aplicações dos potenciais evocados miogênicos vestibulares: revisão sistemática de literatura / Applications of vestibular-evoked myogenic potentials: a systematic literature review

RESUMO Objetivos Revisar a literatura científica sobre as principais técnicas usadas para gerar o potencial evocado miogênico vestibular (VEMP) e suas aplicações clínicas. Estratégia de pesquisa Os artigos que descrevem os métodos de registro e as aplicações do VEMP foram localizados nas bases de dados PubMed, Web of Science, MEDLINE, Scopus, LILACS e SciELO. O levantamento realizado limitou-se aos artigos publicados nos idiomas Inglês, Português e Espanhol, entre janeiro de 2012 e maio de 2018. Critérios de seleção Artigos sobre os aspectos técnicos para a realização do VEMP ocular, cervical ou do músculo sóleo, com estimulação auditiva ou galvânica e artigos sobre as aplicações clínicas do VEMP foram incluídos; artigos repetidos nas bases de dados, artigos de revisão de literatura, relato de casos, cartas e editoriais foram excluídos. Resultados A estratégia de busca resultou na seleção de 28 artigos. Os estudos evidenciaram três métodos de registro do VEMP: cervical, ocular e no músculo sóleo. As aplicações clínicas do VEMP incluíram doença de Ménière, neurite vestibular, síndrome da deiscência do canal semicircular superior, doença de Parkinson, lesões centrais isquêmicas e mielopatias motoras. Conclusão Independentemente da técnica de registro, o VEMP mostrou-se útil como ferramenta complementar para o diagnóstico de doenças vestibulares periféricas e centrais.

ABSTRACT Purpose To review the scientific literature on the main techniques used to generate vestibular-evoked myogenic potential (VEMP) and its clinical applications. Research strategy A search for articles describing VEMP recording methods and applications was conducted in the PubMed, Web of Science, MEDLINE, Scopus, LILACS and SciELO databases. The search was limited to articles published in English, Portuguese, and Spanish between January 2012 and May 2018. Selection criteria Articles addressing the technical aspects for performing ocular, cervical or soleus VEMP with auditory or galvanic stimulation and articles on the clinical applications of VEMP were included in this review, whereas articles repeated in the databases, literature reviews, case reports, letters, and editorials were excluded. Results The search strategy resulted in the selection of 28 articles. The studies evidenced three methods of VEMP recording: responses from the cervical, ocular and soleus muscle. Clinical applications of VEMP included Meniere's disease, vestibular neuritis, superior semicircular canal dehiscence syndrome, Parkinson's disease, central ischemic lesions, and motor myelopathies. Conclusion Regardless of the recording technique, VEMP has proved to be useful as a complementary tool for the diagnosis of peripheral and central vestibular diseases.

Schwannoma gigante del ángulo pontocerebeloso / Giant Schwannoma of the cerebellopontine angle

Los Schwannomas del acústico son tumores benignos de crecimiento lento de la división superior del nervio vestibular, con una incidencia de 1,9 por cada 100.000 habitantes. En la actualidad, la tecnología de la neuroimagen en conjunto con la exploración audiológica clínica e instrumentada permiten el diagnóstico en estadios tempranos e incluso como hallazgo clínico, por tal motivo solo el 6 % a nivel mundial se cataloga como tumor grande al momento del diagnóstico. Se presenta el caso de una mujer de 16 años con cefalea, mareo, vómito, hipoacusia, parálisis facial y diadococinesia, por lo que se realizaron estudios de neuroimagen en los que se evidenció masa ocupativa a nivel ángulo pontocerebeloso; por las dimensiones se cataloga según la clasificación de Koss como estadio IV. Se confirmó diagnóstico mediante estudio histopatológico.

Acoustic schwannomas are benign tumors of slow growth in the top division of the vestibular nerve, with an incidence of 1.9 per 100,000 inhabitants. Currently, imaging technology together with the clinical examination audiological and implemented allow diagnosis at an early stage and even as a clinical finding, on that ground only 6 % worldwide are categorized as large tumor at diagnosis. For a woman of 16 with headache, dizziness , vomiting , hearing loss, facial paralysis and diadochokinesia occurs, so neuroimaging studies in which a space- occupying mass level cerebellopontine angle were made evident ; by the dimensions it is classified as classified as stage IV Koss . Diagnosis was confirmed by histopathology.

Paroxismia vestibular: reporte de un caso / Vestibular paroxysmia: case report

Presentamos el caso de un paciente joven quien presenta 4 a 5 crisis diarias de vértigo espontáneo de segundos de duración, todos o casi todos los días desde hace 9 meses. Estas crisis no tienen gatillo posicional, y hay completa ausencia de sintomatologia entre crisis. Como discutimos en el artículo, este cuadro coíncide con los recientemente publicados criterios para una paroxismia vestibular, entidad supuestamente secundaria a la compresión neurovascular del nervio vestibular. El paciente respondió de forma inmediata y completa a carbamazepina a dosis bajas, el tratamiento de elección en la paroxismia vestibular.

We present the case of a young patient, with a 9-month long history of 4 to 5 daily spells of spontaneous vertigo, each lasting only seconds. There is no positional trigger, and there is a complete lack of symptoms between attacks. As is discussed in the article, this matches the recently published criteria for Vestibular Paroxysmia, an entity allegedly secondary to neurovascular compression of the vestibular nerve. The patient responded immediately and completely to carbamazepine at low dosage, the preferred treatment for vestibular paroxysmia.

Cardiovascular Risk Factors in Total or Divisional Vestibular Neuritis / 대한평형의학회지

OBJECTIVES: In vestibular neuritis (VN), the lesion preferentially affects the superior vestibular nerve because of the anatomic arrangement. It is well known that VN patients have a higher score of metabolic syndrome or a higher incidence of vertebral artery hypoplasia than controls. However, it is unclear whether the frequency of cardiovascular risk factors can affect the selective involvement of the branch of the vestibular nerve. Thus, we investigated the influence of cardiovascular risk factors on the development of total- or divisional VN. METHODS: 61 patients with VN were enrolled. Video head impulse tests and caloric tests were performed to determine which vestibular divisionswere affected. The patients were divided into divisional-VN (superior or inferior) and total-VN groups. Statistical analysis of the frequency of cardiovascular risk factors was performed only in superior and total VN groups because the number of inferior VN patients was too small to be statistically analyzed. RESULTS: Nineteen (31.1%) patients were classified as the total-VN group. In the divisional-VN group (42 patients, 65.6%), 40 were superior VN. The frequency of cardiovascular risk factors are not significantly different in superior VN and total-VN groups (All patients 50/61 [82.0%], superior-VN 36/40 [90.0%], total-VN 13/19 [68.4%]). The frequency of having more than one cardiovascular risk factor was slightly higher in the superior VN group, (13 [68.4%] vs. 36 [90.0%], p=0.062) but did not show any significant difference. CONCLUSIONS: The number of cardiovascular risk factors did not differ in superior VN patients compared to total VN patients.

A Patient with Sudden Hearing Loss with Vertigo Showing Exclusive Posterior Semicircular Canal Abnormality / 대한평형의학회지

It is known that about 30% of patients with sudden hearing loss present with vertigo or dizziness. In clinical practice, this is called sudden hearing loss with vertigo (SHLV) although definite diagnostic criteria have not been established. Dizziness in SHLV is known to be caused by the dysfunction of the vestibular end-organs as well as the superior vestibular nerve or both vestibular nerve divisions. Lesions of the inferior vestibular nerve or a single semicircular canal have also been reported in these patients. Herein we report a 71-year-old male patient with SHLV who demonstrated vestibular dysfunction involving only the posterior semicircular canal. The patient showed normal results in the bithermal caloric test and the cervical vestibular evoked myogenic potentials test as well as positional test. Video head impulse test showed decreased gain only in the posterior semicircular canal. This case is significant in showing that dizziness in SHLV patients can occur by an abnormality involving only a single semicircular canal.

Video head impulse test for evaluation of vestibular function in patients with vestibular neuritis and benign paroxysmal positional vertigo / 浙江大学学报·医学版

To assess the clinical application of video head impulse test (vHIT) for vestibular function in vestibular neuritis (VN) and benign paroxysmal positional vertigo (BPPV) patients.Thirty-three patients with VN and 43 patients with BPPV were enrolled from Sir Run Run Shaw Hospital and Ningbo Second Hospital from March 15 to September 10, 2015; and 50 healthy controls were also enrolled in the study. vHIT was used to quantitatively test the vestibulo-ocular reflex (VOR) gains of a pair of horizontal semicircular canals. VOR gains two pairs of vertical semicircular canals, and the corresponding asymmetrical value of three VOR gains. The saccades information was also recorded.Compared with the healthy control group and BPPV patients, the affected horizontal and vertical VOR gains were declined and the corresponding asymmetries were increased in VN patients (all<0.01). BPPV group also showed higher vertical VOR gain asymmetries compared with the healthy control group (all<0.01), but no significant difference was observed in VOR gains and horizontal VOR gain asymmetry (all>0.05). The sensibility of vHIT in diagnosis of VN was 87.9%. Among 33 VN patients, 22 were diagnosed with superior vestibular nerve dysfunction, 7 were found with inferior vestibular nerve dysfunction and 3 were with both dysfunction; and 1 case was not distinguished.Video head impulse test can quantitatively evaluate the vestibular dysfunction of VN and can help early diagnosis of VN, which may be widely used in clinic.

Anatomía, fisiología y rol clínico de la corteza vestibular / Anatomy, physiology and clinical role of the vestibular cortex

El sistema vestibular, mediante sus órganos periféricos, nos permite procesar correctamente los cambios de aceleración angular de la cabeza y lineal del cuerpo y así permitirnos una correcta orientación en el espacio. Esta información sensorial es dirigida hacia los núcleos vestibulares y desde aquí se comunica con los núcleos óculo-motores y estructuras del tálamo a través de tractos ascendentes del tronco encefálico. Posteriormente la información se dirige hacia centros subcorticales y corticales de naturaleza eminentemente multisensorial. La naturaleza y función de estas estructuras es controversial. En esta revisión se abordan los principales conceptos y descubrimientos a nivel de investigación básica y clínica del procesamiento cortical generado por estimulación de tipo vestibular.

The vestibular system, thanks to its peripheral organs, allows us to properly process the angular head movements and linear acceleration in order to give us a proper orientation in space. The information from these sensory inputs is routed to the vestibular nuclei and thence ascending tracts of the brainstem, which communicate with the oculomotor nuclei of the thalamus and structures. Then the information goes to subcortical and cortical centers, which are eminently multisensory nature. The nature and function of these structures are controversial. In this review the main concepts and discoveries at the level of basic and clinical research generated cortical processing of vestibular stimulation are addressed.

Comparison of Video Head Impulse Test with Posterior Semicircular Canal Plane and Cervical Vestibular Evoked Myogenic Potential / 대한평형의학회지

OBJECTIVE: Cervical vestibular evoked myogenic potential (cVEMP) is thought to be assessing the function of the saccule and inferior vestibular nerve. Therefore, cVEMP indirectly reflects the function of the posterior semicircular canal. Recently, the video head impulse test (vHIT) is considered as useful clinical tool to detect each semicircular canal dysfunction. Goal of this study was to evaluate and compare the results of cVEMP with posterior canal plane of vHIT (p-vHIT). METHODS: Retrospectively, we compared the results of cVEMP with p-vHIT in 43 patients who visited with dizziness. We analyzed the inter-test agreement of cVEMP with p-vHIT. RESULTS: Positive asymmetry of cVEMP was present in 37.2% (16/43), and no responses of both ears were identified in 16.3% (7/43). In p-vHIT analysis, unilateral positive was 27.9% (12/43), bilateral positive was 11.6% (5/43) and negative in both sides was 60.5% (26/43). The inter-test agreement between cVEMP and p-vHIT was 75.8% (25/33) as we considered even in lesion side. And, Fleiss's kappa value showed a fair to good agreement (kappa value=0.559). In bilateral no response group (7 patients) in cVEMP, variable additional information could be obtained using p-vHIT. CONCLUSION: cVEMP and p-vHIT showed relatively lower inter-test agreement than expected. But, p-vHIT could be easily performed, and give additional information for differential diagnosis.

Significance of Vestibular Testing on Distinguishing the Nerve of Origin for Vestibular Schwannoma and Predicting the Preservation of Hearing / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Determining the nerve of origin for vestibular schwannoma (VS), as a method for predicting hearing prognosis, has not been systematically considered. The vestibular test can be used to investigate the function of the superior vestibular nerve (SVN) and the inferior vestibular nerve (IVN). This study aimed to preoperatively distinguish the nerve of origin for VS patients using the vestibular test, and determine if this correlated with hearing preservation.</p><p><b>METHODS</b>A total of 106 patients with unilateral VS were enrolled in this study prospectively. Each patient received a caloric test, vestibular-evoked myogenic potential (VEMP) test, and cochlear nerve function test (hearing) before the operation and 1 week, 3, and 6 months, postoperatively. All patients underwent surgical removal of the VS using the suboccipital approach. During the operation, the nerve of tumor origin (SVN or IVN) was identified by the surgeon. Tumor size was measured by preoperative magnetic resonance imaging.</p><p><b>RESULTS</b>The nerve of tumor origin could not be unequivocally identified in 38 patients (38/106, 35.80%). These patients were not subsequently evaluated. In 26 patients (nine females, seventeen males), tumors arose from the SVN and in 42 patients (18 females, 24 males), tumors arose from the IVN. Comparing with the nerve of origins (SVN and IVN) of tumors, the results of the caloric tests and VEMP tests were significantly different in tumors originating from the SVN and the IVN in our study. Hearing was preserved in 16 of 26 patients (61.54%) with SVN-originating tumors, whereas hearing was preserved in only seven of 42 patients (16.67%) with IVN-originating tumors.</p><p><b>CONCLUSIONS</b>Our data suggest that caloric and VEMP tests might help to identify whether VS tumors originate from the SVN or IVN. These tests could also be used to evaluate the residual function of the nerves after surgery. Using this information, we might better predict the preservation of hearing for patients.</p>

Potencial evocado miogênico vestibular ocular: revisão de literatura / Ocular vestibular evoked myogenic potential: literature review

RESUMO Objetivo Identificar e sistematizar os principais estudos sobre o potencial evocado miogênico vestibular ocular e suas aplicações no diagnóstico das diversas doenças vestibulares. Estratégia de pesquisa Foram localizados artigos que descrevem a utilização do potencial evocado miogênico vestibular ocular na avaliação de doenças vestibulares nas bases PubMed, Web of Science, MEDLINE, Scopus, LILACS e SciELO. Critérios de seleção Foram incluídos estudos originais, com resumo disponível, publicados no período de janeiro de 2010 a março de 2016. Análise dos dados Foi realizada a descrição do delineamento do estudo e elencados os achados para a avaliação de potencial evocado miogênico vestibular ocular. Resultados Foram encontrados 265 estudos, dos quais 14 contemplaram os critérios de seleção propostos. Em relação à população/amostra de pacientes com alterações vestibulares incluída nos estudos, observou-se que as doenças mais investigadas foram a neurite vestibular, a vertigem posicional paroxística benigna, o Schwanoma vestibular e a doença de Ménière. Conclusão A maior parte das pesquisas realizadas nos últimos anos e publicadas nas bases de dados PubMed, Web of Science, MEDLINE e Scopus revelou que o potencial evocado miogênico vestibular ocular representa um método eficaz para avaliar a função utricular nas mais diversas doenças vestibulares.

ABSTRACT Purpose To identify and systematize the main studies on the ocular vestibular evoked myogenic potentials and their applications in the diagnosis of various vestibular diseases. Research strategy Articles that describe the use of ocular vestibular evoked myogenic potentials the evaluation of vestibular diseases were located in PubMed, Web of Science, MEDLINE, Scopus, LILACS e SciELO. Selection criteria Original studies, with available abstract, published in the period 2010 to March 2016 were included. Data analysis The study design was described, and the characteristics for the evaluation of ocular vestibular evoked myogenic potentials were listed. Results 265 studies were found, but just 14 contemplated the proposed selection criteria. In relation to the population / sample of patients with vestibular disorders included in the study, it was observed that the most researched diseases were the vestibular neuritis, benign paroxysmal positional vertigo, vestibular Schwanoma and Meniere's disease. Conclusion The most of the research realized in recent years and published in the databases PubMed, Web of Science, MEDLINE and Scopus revealed that the ocular vestibular evoked myogenic potentials is an effective method to evaluate the utricular function in various vestibular disorders.

Macroscopic description of the external and middle ear of paca (Cuniculus paca Linnaeus, 1766) / Descrição macroscópica da orelha externa e media da paca (Cuniculus paca Linnaeus, 1766)

Paca (Cuniculus paca), one of the largest rodents of the Brazilian fauna, has inherent characteristics of its species which can conribute as a new option for animal experimantation. As there is a growing demand for suitable experimental models in audiologic and otologic surgical research, the gross anatomy and ultrastructural ear of this rodent have been analyzed and described in detail. Fifteen adult pacas from the Wild Animals Sector herd of Faculdade de Ciências Agrárias e Veterinárias, Unesp-Jaboticabal, were used in this study. After anesthesia and euthanasia, we evaluated the entire composition of the external ear, registering and ddescribing the details; the temporal region was often dissected for a better view and detailing of the tympanic bulla which was removed and opened to expose the ear structures analyzed mascroscopically and ultrastructurally. The ear pinna has a triangular and concave shape with irregular ridges and sharp apex. The external auditory canal is winding in its path to the tympanic mebrane. The tympanic bulla is is on the back-bottom of the skull. The middle ear is formed by a cavity region filled with bone and membranous structures bounded by the tympanic membrane and the oval and round windows. The tympanic membrane is flat and seals the ear canal. The anatomy of the paca ear is similar to the guinea pig and from the viewpoint of experimental model has major advantages compared with the mouse ear.

A paca (Cuniculus paca), um dos maiores roedores da fauna brasileira, possui características inerentes à sua espécie que podem contribuir como uma nova opção de animal experimental; assim, considerando-se que há crescente busca por modelos experimentais apropriados para pesquisas audiológicas e otológica cirúrgicas foram analisados e descritos em detalhes a anatomia macroscópica e ultraestrutural da orelha desse roedor. Para o estudo, utilizaram-se 15 animais adultos provenientes do plantel do Setor de Animais Silvestres da Faculdade de Ciências Agrárias e Veterinárias, Unesp-Jaboticabal, Jaboticabal/SP. Após anestesia e eutanásia, avaliou-se toda a composição da orelha externa, registrando-se e descrevendo-se os detalhes, também se dissecou a região temporal para melhor visibilização e detalhamento da bula timpânica e estas foram removidas e abertas a fim de expor as estruturas da orelha, as quais foram analisadas, macroscopicamente e ultraestruturalmente. O pavilhão auricular apresenta forma triangular e côncava com cristas irregulares e ápice pontiagudo; o conduto auditivo externo é sinuoso em seu trajeto até a membrana timpânica; a bula timpânica encontra-se na parte posterior-inferior do crânio; a orelha média é formada por uma região cavitária preenchida por estruturas ósseas e membranosas. É delimitada pela membrana timpânica e as janelas redonda e oval, sendo a membrana timpânica de forma plana e que veda todo o conduto auditivo. A anatomia da orelha da paca é semelhante à da cobaia e do ponto de vista de modelo experimental apresenta grandes vantagens em comparação com a orelha do rato.

Conditions of Cervical Vestibular Evoked Myogenic Potentials Test to Minimize Interaural Variation / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Cervical vestibular evoked myogenic potentials (cVEMP) test has been widely used to assess the function of the saccule and inferior vestibular nerve. Electrode location and stimulating sound are important factors which might affect the test results. Today those parameters are usually selected to maximize the waveform response. In this study, we tried to find the optimal condition to minimize the range of normal value of cVEMP. SUBJECTS AND METHOD: Thirteen normal subjects (26 ears) were included. We placed electrodes at five different locations over the sternocleidomastoid muscle (SCM) and used four different stimulation sounds. Variances of parameters, including interpeak amplitude, interaural difference (IAD) and normal value were analyzed and compared. RESULTS: When using the classical condition (mid point of SCM and 500 Hz) without rectification, IAD ratio was 20.8+/-14.2% and the range of normal value was 39%. When we used 2000 Hz tone burst sound at the classical electrodes site, IAD ratio and normal value were minimized, resulting in 18.7+/-14.3% and 31% respectively. After the rectification, when using the classical condition, IAD ratio was 26.4+/-22.3% and the range of normal value was 49%. The minimum IAD ratio was measured as 17.4+/-13.7% when we used click sound at SCM at the level of mandibular angle. And the minimum normal value of 32% was measured when we used 1000 Hz tone burst sound at SCM at the level of mandibular angle. CONCLUSION: Although the condition was not optimal for maximizing the interpeak amplitude, we could alternatively use the condition to minimize the normal value.

Clinical Applications of Vestibular Evoked Myogenic Potentials in Vestibular Disorders / 대한평형의학회지

Cervical and ocular vestibular evoked myogenic potential (VEMP) may be one of the important clinical tools for evaluation of vestibular function. Cervical VEMP evaluates saccule and reflects the functional status of inferior vestibular nerve combining with vertical head impulse test. Ocular VEMP assesses utricle function and provides superior vestibular nerve function in addition to horizontal head impulse test and caloric test. Currently, the clinical implications of VEMP have been expanded to estimate disease severity and location, differentiate diverse vestibular disorders, and predict the prognosis. In present review, we discuss the findings of VEMP according to the lesion location from peripheral vestibular dysfunction to central vestibulopathy and disease characteristics from monophasic transient disorders to chronic progressive disorders.

The Principle and Methodology of Vestibular Evoked Myogenic Potential / 대한평형의학회지

Vestibular evoked myogenic potential (VEMP) has developed as a broadly applied vestibular function test in clinics from its introduction in 1992. In the past, there was only one well known VEMP protocol, which is cervical VEMP, however recently ocular VEMP is also popular. Therefore, clarifying the VEMP recording protocol (cervical VEMP or ocular VEMP) before discussing the VEMP result has become essential. There is considerable difference regarding this VEMP test from other vestibular function tests. VEMP is thought to be assessing the functions of the otolith organs (utricle and saccule) which are evoked by acoustic stimulus. Cervical VEMP is valuable since this is the only available test method which could speculate the function of the saccule and inferior vestibular nerve. Still, there's less clearly understood part regarding the central pathway of VEMP. However, many clinicians and researchers participating in vestibular research speculate that this functional test will have a more dominant role in the near future. Here we describe the basic principles and methodological considerations regarding VEMP recording.

Evaluation of the injured range of vestibular superior and inferior nerves in sudden deafness patients with vertigo using video head impulse test / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To discuss the video head impulse tests (vHIT) application values in assessment of the vestibular nerves, function in sudden deafness patients with vertigo.</p><p><b>METHODS</b>There were 60 cases (120 ears) of healthy volunteers as control group, and 182 cases (182 ears) of sudden deafness with vertigo patients as study group. The study group received vHIT and caloric test, and the control group received vHIT. Functions of vestibular superior and inferior nerves were analyzed by the gains of vHIT and the nystagmus, s unilateral weakness of caloric test, with SPSS17.0 software.</p><p><b>RESULTS</b>The values of vHIT-G of the six semicircular canals in the control group were normal distribution and no statistical significance among them (F = 0.005, P = 1.000). The vHIT-G averages of both sides of anterior, horizontal and posterior semicircular canals were (15.20 ± 11.00) %, (15.30 ± 13.30) %, and (15.15 ± 14.72) % respectively. In the study group, the vHIT-G of the affected side were (21.73 ± 14.84) %, (21.20 ± 28.24) %, and (19.22 ± 23.50) %, with normal distribution, and in which statistical significance was detected comparing with those in the control group (P < 0.05). The positive rates were 26.9% (49/182) in vHIT, 70.3% (128/182) in caloric test. Significant difference (P < 0.05) was observed between vHIT and caloric test examined by chi-square test. According to the results of vHIT, there were 15 cases (8.2%) damaged vestibular superior and inferior nerves areas, 19 cases (10.4%) damaged the superior vestibular nerve area, and 15 cases (8.2%) damaged the inferior vestibular nerve area. In combination with caloric test results, it was shown that there were 29 cases (15.9%) damaged vestibular superior and inferior nerves areas, 101 cases (55.5%) damaged the superior vestibular nerve area, and 1 case (0.5%) damaged the inferior vestibular nerve area.</p><p><b>CONCLUSIONS</b>vHIT can assess the function of six semicircular canals and illustrate high frequency of vestibular nerves. Caloric test combined with vHIT have more advantages to comprehensive assess vestibular damage of sudden deafness patients with vertigo.</p>

Unidentified Bright Objects on Brain Magnetic Resonance Imaging Affect Vestibular Neuritis

OBJECTIVES: The aim of this study was to investigate the differences in clinical manifestations of in two groups of vestibular neuritis (VN) patients with or without unidentified bright objects (UBOs). METHODS: A prospective, observational study with 46 patients diagnosed with VN between May 2013 and November 2013 was executed. A caloric test, a cervical vestibular-evoked myogenic potentials (cVEMPs) test, brain magnetic resonance imaging (MRI), spontaneous nystagmus test, head impulse test, and head-shaking nystagmus test were performed. RESULTS: Of the patients, 56.5% (n=26) were classified as UBO-positive by MRI. These showed lower caloric weakness and more prominent cVEMP asymmetry compared with the UBO-negative group (P0.05). CONCLUSION: UBOs on T2-weighted or fluid attenuated inversion recovery MRI may affect the patterns of the vestibular nerve in patients with VN.

Ruptured Total Intrameatal Anterior Inferior Cerebellar Artery Aneurysm

Among the distal anterior inferior cerebellar artery (AICA) aneurysms, a unique aneurysm at the meatal loop inside the internal auditory meatus is extremely rare. The authors report a case of surgically treated total intrameatal AICA aneurysm. A 62-year-old female patient presenting with sudden bursting headache and neck pain was transferred to our department. Computed tomography and digital subtraction angiography showed subarachnoid hemorrhage at the basal, prepontine cistern and an aneurysm of the distal anterior inferior cerebellar artery inside the internal auditory meatus. Surgery was performed by retrosigmoid craniotomy with unroofing of the internal auditory meatus. The aneurysm was identified between the seventh and eighth cranial nerve in the meatus and was removed from the canal and clipped with a small straight Sugita clip. After operation the patient experienced transient facial paresis and tinnitus but improved during follow up.

Air-conducted ocular vestibular-evoked myogenic potential in patients with sudden sensorineural hearing loss / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the characteristics of air-conducted ocular vestibular-evoked myogenic potential(oVEMP) in patients with sudden sensorineural hearing loss (SSHL). So as to understanding the range and the degree of the vestibular system damage in patients with SSHL.@*METHOD@#Thirty-five cases of unilateral SSHL were enrolled as the observing group from December in 2013 to December in 2014. 500 Hz air-conducted tone burst was employed as stimulation. Fifity-five healthy young subjects were recruited as the control group. The results were compared between the affected ears, the contralateral ears and the normal controls.@*RESULT@#Thirty-five patients with SSHL, 31 of them in both ears lead to oVEMP Waveform, 4 sick ears did not elicit oVEMP waveform, extraction rate of 88%. 95 dBHL air-conducted get the latencies of P1 and N1, P1-N1 interval, peak-to-peak P1-N1 amplitude in healthy ear were (11.92 ± 0.85)ms; (17.07 ± 1.04)ms, (5.15 ± 0.69)ms, (5.44 ± 2.53) µv. 95 dBHL air-conducted get the latencies of P1 and N1, P1-N1 interval, peak-to-peak P1-N1 amplitude in sick ear were (12.16 ± 0.76) ms; (16.94 ± 2.57)ms, (5.16 ± 0.73)ms, (2.89 ± 1.66) v. The 55 cases (110 ears) were elicited P1-N1 complex typical, extraction rate was 100%. The threshold of oVEMP examination was (82.23 ± 2.92) dBHL, 95 dBHL air-conducted get the latencies of P1 and N1, P1-N1 interval, peak-to-peak P1-N1 amplitude in these healthy young people were (11.53 ± 0.80)ms, (16.61 ± 0.87) ms, (5.18 ± 1.04) ms, (5.96 ± 2.59) µv, there were no significant differences between the affected ears, the contralateral ears and the normal controls in the latencies P1 and N1, P1-N1 interval. The wave amplitude in SSHL were lower than the healthy ear and the healthy control group.@*CONCLUSION@#Through the detection of oVEMP in patients with SSHL,we observed that P1-N1 wave amplitude decreased, and it may be related to the damage of the utricle and vestibular nerve.