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.

Hallazgos vestibulares y oculomotores en migraña vestibular: una revisión actualizada

La migraña vestibular es una de las etiologías más frecuentes del síndrome vestibular episódico a nivel mundial. Presenta varias hipótesis de patofisiología, principalmente a nivel de sistema vestibular central y genético. Su diagnóstico es fundamentalmente clínico, pero se han observado alteraciones a nivel de la función vestibular y de las pruebas oculomotoras. Los hallazgos clínicos no solo están presentes en el momento de la crisis, sino también se han observado en intervalos asintomáticos. La paresia unilateral en la prueba calórica suele ser más frecuente que una ganancia baja del reflejo vestíbulo-ocular del canal lateral en la videonistagmografía, sin embargo, existe una tasa elevada de discordancia entre ambas pruebas. Respecto a la prueba de estudio del movimiento ocular, se han observado alteraciones en el seguimiento pendular, movimiento sacádico, nistagmo optocinético, nistagmo evocado por la mirada, nistagmo espontáneo y nistagmo posicional. Es frecuente observar que el nistagmo provocado por cambios posicionales presenta características centrales durante la crisis de migraña vestibular, pero también se pueden presentar en periodos libres de síntomas en este grupo de pacientes.

Vestibular migraine is one of the most frequent etiologies of episodic vestibular syndrome worldwide. It presents several pathophysiology hypotheses, mainly at the central vestibular system and genetic level. Its diagnosis is fundamentally clinical, but changes in vestibular function and oculomotor tests have been observed. Clinical findings are present not only during the crisis, but also have been seen in the symptom-free interval. Unilateral paresis on caloric testing is usually more common than low gain of the vestibulo-ocular reflex in the lateral canal on videonystagmography, however, there is a high rate of discrepancy between these tests. Regarding the eye movement study test, alterations have been seen in pendulum tracking, saccadic movement, optokinetic nystagmus, gaze-evoked nystagmus, spontaneous nystagmus and positional nystagmus. It is common to observe that nystagmus caused by positional changes has central features during vestibular migraine attacks, but it can also be seen in the symptom-free interval in this group of patients.

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.

Vestibular recruitment: new application for an old concept / Recrutamento vestibular: nova aplicação para um conceito antigo

Abstract Introduction Vestibular recruitment is a sign of hyperexcitability of central vestibular neurons and may be characteristic of peripheral vestibular damage. Objective To define the post-caloric recruitment index and its ability to predict the stage of vestibular compensation and peripheral lesion. Methods First of all, we demonstrated that larger values in the cold post-caloric stimulation compared to warm stimulation were equivalent to vestibular recruitment observed during the sinusoidal harmonic acceleration test. In the next step, patients with vestibular complaints and asymptomatic controls were submitted to the caloric test. We calculated post-caloric recruitment index for the control group. Among the study group, we analyzed the relation between post-caloric recruitment and unilateral weakness as well as the types of vestibular diagnoses. Results Mean post-caloric recruitment was 17.06% and 33.37% among the control and study group, respectively. The ratio between post-caloric recruitment and unilateral weakness was 1.3 in the study group. Among recruiting subjects, no significant difference of unilateral weakness from the lesioned or healthy side was observed. We found no differences in vestibular diagnoses between recruiting and non-recruiting subjects. Conclusion Post-caloric recruitment index identified asymmetric vestibular tonus and central compensation. The normal value was established at 17.06%.

Resumo Introdução O recrutamento vestibular é um sinal de hiperexcitabilidade dos neurônios vestibulares centrais e pode ser característico de lesão vestibular periférica. Objetivo Definir o índice de recrutamento pós‐calórico e sua capacidade de predizer o estágio de compensação vestibular e lesão periférica. Método Em primeiro lugar, demonstramos que valores maiores na estimulação pós‐calórica fria em relação à estimulação quente foram equivalentes ao recrutamento vestibular observado durante o teste de aceleração harmônica sinusoidal. Na etapa seguinte, os pacientes com queixas vestibulares e controles assintomáticos foram submetidos à prova calórica. Calculamos o índice de recrutamento pós calórico para o grupo controle. No grupo de estudo, analisamos a relação entre o recrutamento pós‐calórico e predomínio labiríntico, bem como os tipos de diagnósticos vestibulares. Resultados O recrutamento pós‐calórico médio foi de 17,06% e 33,37% nos grupos controle e estudo, respectivamente. A razão entre o recrutamento pós‐calórico e o predominício labiríntico foi de 1,3 no grupo de estudo. Nos sujeitos com recrutamento, não foi observada diferença significativa de predominício labiríntico do lado lesionado ou saudável. Não encontramos diferenças de diagnóstico vestibular entre sujeitos com recrutamento e sem recrutamento. Conclusão O índice de recrutamento pós‐calórico identificou tônus vestibular assimétrico e compensação central. O valor normal foi estabelecido em 17,06%.

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.

Long-Term Changes in Video Head Impulse and Caloric Tests in Patients with Unilateral Vestibular Neuritis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Video head impulse tests (vHITs) and caloric tests are widely used to assess the loss of vestibular function in acute vestibular neuritis. Although previous studies have reported on the results of each test, longitudinal comparison of these tests is rare. In the present study, vHITs and caloric tests were performed in patients with unilateral vestibular neuritis during the acute phase and after a long follow-up period (>6 months). The goal of this study was to evaluate the changes in vHIT and caloric test results and to analyze the relationships between them. SUBJECTS AND METHOD: Between September 2013 and December 2015, charts from 13 patients with unilateral vestibular neuritis were retrospectively reviewed. Among the 13 patients, caloric tests and vHITs were performed in 9 and 10 patients, respectively. Results of the vHITs and caloric tests were analyzed and the changes were compared. RESULTS: During the acute phase of vestibular neuritis, the results of the caloric test showed an increase in canal paresis (CP), and the results of the vHIT showed a decrease in horizontal gain. Although subjective symptoms improved in all patients after a long follow-up period (mean: 13.9 months), the occurrence of CP determined from the caloric test was not significantly changed (p=0.889). On the other hand, the mean horizontal gain of the vHIT had improved significantly (p < 0.05). CONCLUSION: While CP determined from the caloric test did not change after a long follow-up period, the decreased horizontal gain in the vHIT was significantly recovered in patients with unilateral vestibular neuritis.

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.

Effects of cavity reconstruction on morbidity and quality of life after canal wall down tympanomastoidectomy / Efeitos da reconstrução da cavidade da timpanomastoidectomia com técnica aberta na morbidade e qualidade de vida

Abstract Introduction: Canal wall down tympanomastoidectomy is commonly used to treat advanced chronic otitis media or cholesteatoma. The advantages of canal wall down mastoidectomy are excellent exposure for disease eradication and postoperative control of residual disease; its disadvantages include the accumulation of debris requiring life-long otological maintenance and cleaning, continuous ear drainage, fungal cavity infections, and the occurrence of dizziness and vertigo by changing temperature or pressure. Objective: To evaluate whether cavity-induced problems can be eliminated and patient comfort can be increased with mastoid cavity reconstruction. Methods: In total, 11 patients who underwent mastoid cavity reconstruction between March 2013 and June 2013 comprised the study group, and 11 patients who had dry, epithelialized CWD cavities were recruited as the control group. The study examined three parameters: epithelial migration, air caloric testing, and the Glasgow Benefit Inventory. Epithelial migration, air caloric testing, and the Glasgow Benefit Inventory were evaluated in the study and control groups. Results: The epithelial migration rate was significantly faster in study group (1.63 ± 0.5 mm/week) than control group (0.94 ± 0.37 mm/week) (p = 0.003, p < 0.05). The mean slow component velocity of nystagmus of the study group (13.33 ± 5.36°/s) was significantly lower when compared to control group (32.11 ± 9.12°/s) (p = 0.018). The overall the Glasgow Benefit Inventory score was −7.21, and the general subscale, physical and social health scores were −9.71, −21.09, and +20.35, respectively in the control group. These were +33.93, +35.59, +33.31, and +29.61, respectively in the study group. All but the social health score improved significantly (0.007, 0.008, 0.018, and 0.181, respectively). Conclusions: Cavity reconstruction improves epithelial migration, normalizes caloric responses and increases the quality of life. Thus, cavity rehabilitation eliminates open-cavity-induced problems by restoring the functional anatomy of the ear.

Resumo Introdução: A timpanomastoidectomia com a técnica Canal Wall Down, ou técnica aberta, é comumente utilizada para tratar otite média crônica avançada ou colesteatoma. As vantagens da mastoidectomia pela técnica aberta são uma excelente exposição para a erradicação da doença e controle pós-operatório da doença residual; suas desvantagens incluem o acúmulo de detritos que requerem manutenção e limpeza otológica ao longo da vida, drenagem contínua da orelha, infecções fúngicas na cavidade e a ocorrência de tonturas e vertigem com alterações de temperatura ou pressão. Objetivo: Avaliar se os problemas induzidos pela cavidade podem ser eliminados e o conforto do paciente aumentado com a reconstrução da cavidade mastoide. Método: No total, 11 pacientes submetidos à reconstrução da cavidade mastoide entre março de 2013 e junho de 2013 constituíram o grupo de estudo, e 11 pacientes com cavidades secas e epitelizadas, operadas pela técnica aberta, foram recrutados como grupo controle. O estudo analisou três parâmetros: migração epitelial, prova calórica com estimulação a ar e o questionário Glasgow Benefit Inventory. A migração epitelial, a prova calórica e o Glasgow Benefit Inventory foram avaliados nos grupos de estudo e controle. Resultados: A taxa de migração epitelial foi significativamente mais rápida no grupo de estudo (1,63 ± 0,5 mm/semana) do que no grupo controle (0,94 ± 0,37 mm/semana) (p = 0,003, p < 0,05). A velocidade média do componente lento do nistagmo no grupo de estudo (13,33 ± 5,36°/s) foi significativamente menor se comparada ao grupo controle (32,11 ± 9,12°/s) (p = 0,018). O escore global do Glasgow Benefit Inventory foi de -7,21 e os escores da subescala geral, saúde física e social foram -9,71, -21,09 e +20,35, respectivamente, no grupo controle. Esses escores foram +33,93, +35,59, +33,31 e +29,61, respectivamente, no grupo de estudo. Todos, exceto o escore de saúde social, melhoraram significativamente (0,007, 0,008, 0,018 e 0,181, respectivamente). Conclusões: A reconstrução da cavidade melhora a migração epitelial, normaliza as respostas da prova calórica e aumenta a qualidade de vida. Assim, a reabilitação da cavidade elimina os problemas induzidos por cavidades abertas ao restaurar a anatomia funcional da orelha.

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.

Clinical Implication and Proposed Mechanism of Direction Changing Vibration Induced Nystagmus in Unilateral Vestibular Hypofunction / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: We evaluated the clinical characteristics and vestibular function of patients with direction changing vibration induced nystagmus (DC VIN) and unilateral vestibular hypofunction and suggest clinical implication and a proposed mechanism of DC VIN. SUBJECTS AND METHOD: The records of 315 patients who underwent the VIN test were reviewed retrospectively. Among these, 18 patients (5.7%) showed DC VIN, and out of whom, 15 patients (4.8%) were diagnosed as unilateral vestibular hypofunction by caloric, rotation chair (RCT), and video head impulse test (vHIT). We analyzed the relationship between DC VIN and the dizziness characteristics, duration of disease, and the outcome of the vestibular function test. RESULTS: The mean age of 15 patients was 67.4±10.7 years and the mean duration of dizziness was 13.6±29.7 months. The caloric test revealed 25% of the patients to have significant canal paresis [Caloric vestibular neuritis (VN)], while 75% showed normal caloric response. However, unilateral vestibular hypofunction was observed by abnormal results in RCT or vHIT (Non-caloric VN). Seven patients showed ipsilateral DC VIN (nystagmus to vibrated side) and eight patients contralateral DC VIN (nystagmus to opposite side of vibration). Patients with ipsilateral DC VIN were shown to have a significant longer duration of dizziness than those with contralateral DC VIN. CONCLUSION: Although rare, DC VIN can also be found in patients with unilateral vestibular hypofunction. Patients with DC VIN had a mild vestibular asymmetry with Non-caloric VN or Caloric VN in the process of compensation. The mechanism of ipsilateral DC VIN seems to be due to the small amount of vestibular asymmetry, which is smaller than the interaural attenuation of vibration.

Caloric Test as a Possible Prognostic Indicator in Sudden Deafness / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Dizziness has been known as a prognostic factor in sudden sensorineural hearing loss (SSHL), but it is difficult to describe and quantify its subjective symptoms. Also, dizziness itself cannot imply vestibular dysfunction in SSHL. Comprehensive evaluation of vestibular function may help us understand the extent of lesions in sudden deafness. The purpose of this study is to determine whether an impaired caloric response is associated with disease severity and hearing outcome. SUBJECTS AND METHOD: A retrospective chart review was conducted of 488 patients diagnosed as unilateral SSHL. The patients were divided into two, an abnormal caloric group (canal paresis >20%) and normal caloric group (canal paresis ≤20%). Initial demographic and audiologic findings and final hearing outcomes were compared between the two groups. RESULTS: The initial pure tone averages of SSHL patients of abnormal caloric group and normal caloric group were 75.4±28.4 dB HL and 68.2±25.4 dB HL (p=0.004), respectively. Patients of abnormal caloric test group showed worse hearing outcome across all frequencies compared to those of the normal caloric group. Also, a significant correlation was noted between the magnitude of hearing recovery and canal paresis (r=-0.223, p < 0.001). CONCLUSION: SSHL patients of abnormal caloric test showed worse initial hearing level and poorer hearing outcome. Evaluation of vestibular function in SSHL patients is important because subjective symptoms alone cannot account for vestibular hypofunction patients, and the caloric test can help in the counseling of patients and prediction of hearing outcome in SSHL patients.

Clinical Usefulness of Video Head Impulse Test-Comparison of Bithermal Caloric Test and Bedside Head Impulse Test / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Video head impulse test system (vHIT) is an easy-to-use test and there are numerous studies showing its efficacy. The aim of the study was to evaluate the clinical usefulness of vHIT as an initial test in determining vestibular hypofunction in patients with dizziness. SUBJECTS AND METHOD: The study recruited 103 outpatients who visited our ear clinic with dizziness. We performed both bedside head impulse test (bHIT), vHIT and bithermal caloric tests for 103 patients. Both bHIT and vHIT were consecutively performed in each subject on the same day by the same examiner. RESULTS: The sensitivity of bHIT and vHIT was determined based on the bithermal caloric test results, which showed that vHIT was more sensitive than bHIT. There was a significant negative correlation between vHIT gain and canal paresis (p < 0.05). Results of some patients indicated dissociation between vHIT and caloric test. CONCLUSION: T here is a significant correlation between the results of vHIT and caloric test. Although vHIT does not replace the caloric test, it would be useful to evaluate the initial vestibular loss in patients with dizziness.

Application of video head impulse test in detecting damage and recovery features of semicircular canal of patients with acute vestibular neuritis / 第二军医大学学报

Objective To investigate the application of video head impulse test in detecting the impairment of semicircular canal of patients with acute vestibular neuritis and the recovery features of the damaged semicircular canal. Methods The clinical data of 28 patients with acute vestibular neuritis, who were diagnosed in the Department of Neurology, Changzheng Hospital, Second Military Medical University from Mar. 2015 to Mar. 2016, were analyzed and regularly followed up. The damage and recovery of each semicircular canal function were evaluated by video head impulse test. Results During the onset period, the horizontal semicircular canal function was abnormal in 28 patients (100.00%), the anterior semicircular canal function was abnormal in 24 cases (85.71%), and the posterior semicircular canal function was abnormal in 4 cases (14.29%). After 2 months of follow-up, the gain of the patients with severe damage of horizontal semicircular canal (gain0.5) at onset did not return to normal, while that of 80.00% (12/15) of the patients with less damage of horizontal semicircular canal (gain ranged from 0.5 to 0.8) recovered; 82.35% (14/17) of the patients with severe damage of anterior semicircular canal (gain0.5) at onset did not recover, while that of the patients with less damage of anterior semicircular canal (gain ranged from 0.5 to 0.7) returned to normal. Conclusion In patients with vestibular neuritis, the damage of semicircular canal dominated by superior vestibular nerve is more severe than that dominated by inferior vestibular nerve. Video head impulse test is suitable for the detection and follow-up of the function of impaired semicircular canal. The recovery of impaired semicircular canal is related to its severity at onset.

Assessment of the horizontal semicircular canal function after cochlear implantation by video head impulse test and caloric test / 临床耳鼻咽喉头颈外科杂志

To analyze the functional change of horizontal semicircular canals after cochlear implantation.Eighteen patients were enrolled in this study.Their vestibular function was evaluated by using the caloric test and video head impulse test before and one week,one month after CI surgery,respectively.The unilateral weakness(UW),slow phase velocity(SPV)in caloric test and gain in video head impulse test(vHIT-G)were observed.Caloric test was abnormal when UW>25% or SPV mean<6°/s,while vHIT was abnormal when vHIT-G<0.8.The SPV of the implanted ear were[(10.36±8.01)°/s;(14.77±14.24)°/s]pre-operatively,[(6.45±7.52)°/s;(5.14±4.67)°/s]1 week post-operatively and[(6.05±3.86)°/s;(6.27±4.17)°/s]1 month post-operatively.Statistically significant difference(<0.05)was found between pre-and post-operative period.The vHIT-G of the implanted ear were(0.73±0.33)pre-operatively,(0.65±0.32)1 week post-operatively and(0.71±0.36)1 month post-operatively.There was no statistically significant difference of vHIT-G between preand post-operative period((pre-operative/1 week post-operative)=0.084,(pre-operative/1 month post-operative)=0.679).Four patients presented with vertigo and one of them manifested slight unsteadiness post-operatively.All symptoms resolved within 7 days.These symptoms had no correlate with age,gender,implantedear and results of vestibular test.Cochlear implantation can affect the horizontal semicircular canal function,and the video head impulse test and caloric test should be used in a complementary fashion.

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.

Application of Ocular Vestibular Evoked Myogenic Potential and Caloric Test to Different Stages of Meniere Disease / 听力学及言语疾病杂志

Objective To investigate the characteristics and clinical significance of ocular vestibular evoked myogenic potential (oVEMP) and caloric test in Meniere disease (MD) at different hearing stages.Methods Fifty-five patients(52.8±15.8 years old) with MD were divided into stage 1(9 cases,48.8±13.8 years old), stage 2(9 cases,46.0±16.3 years old), stage 3(23 cases,50.3±13.5 years old) and stage 4(cases 14, 53.5±16.2 years) respectively according to the pure tone audiometry.They were evaluated by oVEMP and caloric test.Results The abnormal rates of oVEMP were 55.6%, 66.7%, 78.3%, 78.6%,and caloric tests were 22.2%, 33.3%, 78.3%,and 85.7% respectively in stage 1, 2, 3, and 4 MD patients.The amplitudes of oVEMP in stage of 1, 2, 3, and 4 MD patients were 4.3±4.0 μV,3.5±2.3 μV,2.5±2.4 μV,and 1.3±0.5 μV,respectively.Conclusion The abnormal rates of oVEMP and caloric tests in MD patients increased with the degree of hearing impairment and the amplitudes of oVEMP were decreased, suggesting that utricle and horizontal semicircular canal injuries were aggravated.

The minimal caloric test asymmetric response in vertigo-free migraine patients / A resposta assimétrica ao teste calórico mínimo nos pacientes com enxaqueca sem vertigem

ABSTRACT Vertigo symptoms and subclinical vestibular dysfunctions may occur in migraine. The Minimal Caloric Test (MCT), an easy-to-perform, convenient and yet informative procedure was used to test the vestibular function in 30 vertigo-free migraine patients outside attacks and 30 paired controls. Although not statistically significant, a right-to-left nystagmus duration asymmetry greater than 25% was present in both groups. This difference was greater in the patients group, suggesting the presence of subclinical vestibular imbalance in migraine.

RESUMO Vertigem e alterações vestibulares subclínicas têm sido identificadas na enxaqueca. O teste calórico mínimo é simples de realizar, informativo e conveniente. Ele foi realizado em 30 pacientes com enxaqueca sem queixa de vertigem e 30 controles pareados. Embora não estatisticamente significativo, ocorreu assimetria direita-esquerda superior a 25% na duração do nistagmo em ambos os grupos, maior nos pacientes, o que sugere a presença de desequilíbrio vestibular subclínico na enxaqueca.

The clinical value of vestibular autorotation test in the diagnosis of otogenic vertigo / 临床耳鼻咽喉头颈外科杂志

Objective:To explore the clinical value of vestibular autorotation test (VAT) in the treatment for otogenic vertigo patients. Method:One hundred and twenty-nine definite otogenic vertigo patients were included. All patients underwent the VAT and caloric test (CT). The results were analyzed statistically. Result:In VAT examination, 89 (69.0%) cases were abnormal. In CT examination, 56 (43.4%) cases were abnormal. In the contrast test of VAT and CT, VAT results were abnormal in 47 (36.4%) patients and CT results were abnormal in 14 (10.9%) patients. The number of patients whose both VAT and CT results were abnormal was 42 (32.6%). The total number of patients with various abnormal results was 103 (79.8%). According to statistical analysis, the abnormal result rate of VAT was higher than that of CT. The abnormal result rate of both VAT and CT was higher than that of each single test. There was statistic significance in the difference (χ²=1.670, P<0.05). Conclusion:For otogenic vertigo patients, their abnormal result rate of VAT is higher than that of CT. VAT and CT can be mutually complementary. The combination of VAT and CT can help to understand the function of semicircular canal in the general and provide reference for the treatment of otogenic vertigo diseases.

A clinical study into the vestibular function and therapy of patients with chronic positional symptoms after acute vestibular syndrome / 临床耳鼻咽喉头颈外科杂志

Objective:To investigate the status of the vestibular function of the patients with chronic positional symptoms after peripheral acute vestibular syndrome (AVS) and the curative effect of the vestibular rehabilitation therapy (VRT). Method:Using caloric test (CT), head shaking nystagmus test (HST), cervical vestibular evoked myogenic potentials as well as ocular vestibular evoked myogenic potentials to estimate the function of semicircular canal and otolith organs. The patients with normal VEMPs are divided as Group A. Otherwise are as Group B. Both groups are treated with VRT. The curative effect is estimated by vestibular symptom index (VSI) and Berg balance scale (BBS). Result:Thirty-three of 37 patients (86.5%) had an abnormal result of CT and HST, with 23 of these patients (65.7%) had an abnormal of both test. Twenty-two patients (59.5%) were in Group A and 15 (40.5%) in Group B. Before the therapy, Group B had a higher score of the balance and dizziness symptoms of VSI (P<0.05), and Group A had a higher score of the BBS (P<0.05). After the therapy, the VSI scores of both groups dropped and scores of the BBS raised. Conclusion:Patients with chronic positional symptoms after peripheral AVS have dynamic vestibular lesions to different extents. Those with otolith organs lesions tend to have a worse function of balance. Nevertheless, patients have a better off after VRT.

Normal Caloric Responses during Acute Phase of Vestibular Neuritis

BACKGROUND AND PURPOSE: We report a novel finding of caloric conversion from normal responses into unilateral paresis during the acute phase of vestibular neuritis (VN). METHODS: We recruited 893 patients with a diagnosis of VN at Dizziness Clinic of Seoul National University Bundang Hospital from 2003 to 2014 after excluding 28 patients with isolated inferior divisional VN (n=14) and those without follow-up tests despite normal caloric responses initially (n=14). We retrospectively analyzed the neurotological findings in four (0.5%) of the patients who showed a conversion from initially normal caloric responses into unilateral paresis during the acute phase. RESULTS: In those four patients, the initial caloric tests were performed within 2 days of symptom onset, and conversion into unilateral caloric paresis was documented 1-4 days later. The clinical and laboratory findings during the initial evaluation were consistent with VN in all four patients except for normal findings in bedside head impulse tests in one of them. CONCLUSIONS: Normal findings in caloric tests should be interpreted with caution during the acute phase of suspected VN. Follow-up evaluation should be considered when the findings of the initial caloric test are normal, but VN remains the most plausible diagnosis.