Diagnostic evolution of vestibular neuritis after long-term monitoring / Evolução diagnóstica da neurite vestibular após monitoração de longo prazo

Abstract Introduction The diagnosis of vestibular neuritis is based on clinical and laboratory findings after exclusion of other disease. There are occasional discrepancies between clinical impressions and laboratory results. It could be the first vertigo episode caused by other recurrent vestibular disease, other than vestibular neuritis. Objective This study aimed to analyze the clinical features and identify the diagnostic evolution of patients with clinically suspected vestibular neuritis. Methods A total of 201 patients clinically diagnosed with vestibular neuritis were included in this study. Clinical data on the symptoms and signs of vertigo along with the results of vestibular function test were analyzed retrospectively. Patients were categorized in terms of the results of caloric testing (CP - canal paresis) group; canal paresis ≥25%; (MCP -minimal canal paresis) group; canal paresis <25%). Clinical features were compared between the two groups and the final diagnosis was reviewed after long-term follow up of both groups. Results Out of 201 patients, 57 showed minimal canal paresis (CP < 25%) and 144 showed definite canal paresis (CP ≥ 25%). A total of 48 patients (23.8%) experienced another vertigo episode and were re-diagnosed. Recurring vestibular symptoms were seen more frequently in patients with minimal canal paresis (p = 0.027). Repeated symptoms were observed on the same affected side more frequently in the CP group. The proportion of final diagnosis were not different between two groups. Conclusions Patients with minimal CP are more likely to have recurrent vertigo than patients with definite CP. There was no significant difference in the distribution of the final diagnoses between two groups when the vertigo recurs.

Resumo Introdução O diagnóstico de neurite vestibular é baseado em achados clínicos e laboratoriais após exclusão de outra doença. Existem discrepâncias ocasionais entre a impressão clínica e os resultados laboratoriais. Pode ser o primeiro episódio de vertigem causado por outra doença vestibular recorrente, além da neurite vestibular. Objetivo Analisar as características clínicas e identificar a evolução diagnóstica de pacientes com suspeita clínica de neurite vestibular. Método Foram incluídos neste estudo 201 pacientes com diagnóstico clínico de neurite vestibular. Os dados clínicos sobre os sintomas e sinais de vertigem e os resultados dos testes de função vestibular foram analisados retrospectivamente. Os pacientes foram categorizados de acordo com os resultados das provas calóricos (Grupo PC: paresia do canal ≥ 25%; Grupo PMC: paresia mínima do canal < 25%). As características clínicas foram comparadas entre os dois grupos e o diagnóstico final foi revisado após o acompanhamento de longo prazo de ambos os grupos. Resultados De 201 pacientes, 57 apresentaram paresia mínima do canal (PC < 25%) e 144 apresentaram paresia definitiva do canal (PC ≥ 25%). Quarenta e oito pacientes (23,8%) apresentaram outro tipo de vertigem e foram diagnosticados novamente. Sintomas vestibulares recorrentes foram observados com mais frequência nos pacientes com paresia mínima do canal (p = 0,027). Sintomas recorrentes no mesmo lado afetado foram observados com mais frequência no Grupo PC. A proporção de diagnóstico final não foi diferente entre os dois grupos. Conclusão Os pacientes com paresia mínima do canal foram mais propensos a apresentar vertigem recorrente que os pacientes com paresia do canal definitiva. Não houve diferença significante na distribuição dos diagnósticos finais entre os dois grupos quando houve recorrência da vertigem.

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.

Vestibular Neuritis With Minimal Canal Paresis: Characteristics and Clinical Implication

OBJECTIVES: To analyze the clinical characteristics of vestibular neuritis patients with minimal canal paresis (canal paresis <25%). METHODS: Patients clinically diagnosed with vestibular neuritis and treated at our institute (n=201) underwent otoneurological examination and vestibular function tests. Patients were categorized in terms of the results of caloric testing (canal paresis<25%, n=58; canal paresis≥25%, n=143). Clinical characteristics and laboratory outcomes were compared between two groups. RESULTS: Existence of underlying diseases, preceding symptoms, and direction of spontaneous nystagmus were not different between the groups. The mean duration of spontaneous nystagmus was shortest in the minimal canal paresis group (P<0.001) and the direction of spontaneous nystagmus changed more frequently in this group (P<0.001) during recovery. Among the subgroup with minimal canal paresis, only 29.5% had an abnormal finding on the rotatory chair test, as compared to 81.5% of the canal paresis group. The minimal canal paresis group showed higher sensory organization test scores in computerized dynamic posturography. CONCLUSION: Patients with minimal canal paresis (canal paresis <25%) show similar clinical manifestations as conventional vestibular neuritis patients, but have faster recovery of symptoms and a higher incidence of recovery nystagmus. This finding support that the minimal canal paresis could be considered as a milder type of vestibular neuritis.

Resolution of Canal Paresis after Treatment in Benign Paroxysmal Positional Vertigo of the Horizontal Canal

Canal paresis in patients with benign paroxysmal positional vertigo (BPPV) has been variously reported from 26 to 50%. In such cases, BPPVs are developed secondary to accompanying vestibulopathy or other underlying inner ear diseases. Also the side of canal paresis is regarded as involved ear in the lateralization of horizontal canal BPPV (HC-BPPV), in which lateralization is sometimes ambiguous just by Eward's second law. In this case, authors report a woman who had HC-BPPV and pathologic canal paresis which resolved after canalith repositioning. This case may imply that dislodged particles block the endolymphatic flow resulting canal paresis.

The Simultaneous Binaural Bithermal Caloric Test / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The simultaneous binaural bithermal caloric test is performed by stimulating both ear canals with the water of same temperature at the same time. There are some reports that the simultaneous binaural bithermal caloric test appears to be more sensitive than the alternative bithermal caloric test in detecting caloric vestibular abnormalities. However, it is not well known yet what effect simultaneous binaural bithermal caloric test has on the vestibulo-ocular reflex. We attempted to verify the clinical usefulness of the simultaneous binaural bithermal caloric test. MATERIALS AND METHODS: Otoneurologically normal subjects (n=20) and patients who have complaints of dizziness (n=141) were tested. The regular bithermal caloric test was performed, using Life-Tech water irrigator and the water of temperatures 30degreesC and 44degreesC. The simultaneous binaural bithermal test was performed using Brooker-Grams closed loop irrigator with 27degreesC and 44degreesC water. The irrigation time was 40 seconds and nystagmus was detected for more than 120 seconds by electronystagmography. We divided the test response into six types with the reference value of canal paresis (CP) of the regular bithermal caloric test. RESULTS: The distribution of nystagmus type did not show regular pattern in the normal controls. The distribution of type I and II was 77.4% when CP was more than 25% in patients, 50.6% when CP was less than 25% in patients, and 42.5% in the normal group. The maximal velocity of slow component increased in the unilateral canal paresis patients (CP>25%), compared with the normal controls and no unilateral canal paresis patients (Cp<0.05). CONCLUSION: We observed that the simultaneous binaural bithermal caloric test has advantages of being less time-consuming and more comfortable. When the maximal velocity of slow component is more than 22.6 deg/sec with type I or II response, we could predict canal paresis; however, further studies should be made for abnormal response of simultaneous caloric response on the central nervous ststem.