Stapedial reflex and recruitment: what is the relationship with tinnitus?

Tinnitus is characterized by an auditory perception of sound, with no stimuli from the external environment. Tinnitus is an increasingly significant complaint, affecting 10-17% of the world population. As a symptom, it should always be considered with pathology in the auditory system. Our study aims to assess the relationship of this symptom with the presence of a stapedial reflex and the phenomenon of recruitment. Medical records of patients complaining of subjective tinnitus during their first consultation in the Outpatient Clinic of the Unicamp Teaching Hospital, in Brazil, between 2011 and 2012 were analyzed. We carried out a study with 65 non-randomized tinnitus individuals using questionnaires, clinical and audiological evaluations. The visual analogue scale was used to characterize the degree of disturbance caused by tinnitus. Statistical tests were performed using the IBM SPSS Statistics 19. No association was found between tinnitus and the presence of acoustic reflex or phenomenon of recruitment. We concluded that there is no relationship between tinnitus, the phenomenon of recruitment or the presence of an acoustic reflex.

Dissociation between video head impulse test and caloric test: a marker of menière's disease? - A systematic review and meta-analysis.

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.

Validation and reliability analysis of the Questionnaire on the Emotional Impact of Vertigo-CIEV version translated to the Brazilian Portuguese language. / Análise de validação e confiabilidade do Questionário Emocional da Vertigem-CIEV em versão traduzida para o Português-Brasileiro.

PURPOSE: To determine the internal consistency and reliability of the "Questionário de Impacto Emocional da Vertigem (CIEV)" and to validate the instrument with respect to the Dizziness Handicap Inventory (DHI) in a sample of individuals with balance disorders. METHODS: 38 subjects participated in the study, males and females, aged from 23 to 85 years, who presented dizziness, vertigo, and/or falls complaints and attended to the Vestibular Disorders clinic at the University Hospital. Individuals with hearing complaints and/or tinnitus unrelated to dizziness, previous psychiatric comorbidities, and/or cognitive impairments were excluded. We performed an anamnesis and collected complementary data from the medical records. After that, the self-perception questionnaires, DHI, and CIEV, were applied. Statistical analysis was performed in which the Cronbach's alpha verified the internal consistency of the CIEV. Reliability and validity of the CIEV related to the DHI were calculated using Intraclass Correlation Index (ICC) and Pearson's correlation test, respectively. RESULTS: There was a statistically significant correlation between the scores obtained, for both reliability and validation analysis (p<0.001). The mean ICC showed a moderate correlation between the total scores (0.695) and a strong correlation with the physical, emotional, and functional DHI domains (0.706 to 0.869), being the emotional aspect the highest degree (0.869). Pearson's correlation showed strong correlation between the total scores (r=0.820) and varied from moderate to strong, with strongest correlations to the DHI emotional domain (r=0.788). CONCLUSION: The outcomes illustrate important contribution to validation parameters to consider clinical use of the CIEV in the Brazilian population, aiming to identify emotional aspects in patients with balance disorders.

OBJETIVO: Determinar a consistência interna e confiabilidade do "Questionário de Impacto Emocional da Vertigem-CIEV" e validar o instrumento em relação ao Dizziness Handicap Inventory (DHI), em uma amostra de pacientes com distúrbio do equilíbrio corporal. MÉTODO: Participaram 38 sujeitos, idades entre 23 e 85 anos, ambos os sexos, com queixas relacionadas à tontura, desequilíbrios e/ou quedas, atendidos em um ambulatório de Otoneurologia do Hospital Universitário. Foram excluídos sujeitos com queixas auditivas e/ou zumbido sem tontura associada, comorbidades psiquiátricas prévias e/ou comprometimento cognitivo que impedisse a compreensão dos questionários. Foi realizada anamnese, levantamento de prontuário para caracterização da amostra e aplicados os questionários de autopercepção, DHI e CIEV. O alfa de Cronbach verificou a consistência interna do CIEV e a confiabilidade e validade do CIEV em relação ao DHI foram calculadas pelo Índice de Correlação intraclasse (ICC) e teste de Correlação de Pearson, respectivamente. RESULTADOS: Houve correlação estatisticamente significante entre os escores obtidos, tanto à análise de confiabilidade quanto de validação (p<0,001). O ICC médio demonstrou moderada correlação para o escore total (0,695) e forte correlação com os domínios físico, emocional e funcional do DHI (0,706 a 0,869) sendo o maior grau para o domínio emocional (0,869). A Correlação de Pearson demonstrou grau forte para o escore total (r=0,820) e variação de moderado a forte para os domínios, com melhor resultado também para o domínio emocional do DHI (r=0,788). CONCLUSÃO: Os achados representam parâmetros importantes de contribuição para a validação do CIEV para uso clínico na população brasileira, direcionado para a identificação de aspectos emocionais em pacientes com distúrbios do equilíbrio corporal.

Evaluation of factors related to the tinnitus disturbance.

INTRODUCTION: The perception of tinnitus varies among individuals. The limitations caused by tinnitus are related to psychological factors, mood changes and psychiatric conditions, while other factors related to discomfort caused by tinnitus are being studied. Hearing loss is an important factor for the onset of tinnitus. OBJECTIVES: To evaluate the correlation between the degree of discomfort caused by tinnitus and the hearing loss level. MATERIALS AND METHODS: A retrospective study of the patients treated at the Otolaryngology Service of the State University from Campinas for 15 months, using the Visual-Analogue Scale to classify the degree of discomfort by tinnitus. RESULTS: 107 patients were studied and there was no correlation between the degree of annoyance of tinnitus with hearing loss, age, gender, presence of dizziness, of neck pain, headache, changes of the temporomandibular joint, the use of caffeine or excessive intake of carbohydrates. The discomfort was slightly higher in patients without hearing loss and in women. CONCLUSION: Dizziness, neck pain, headache and caffeine abuse are prevalent complaints in patients with tinnitus.

Vestibular recruitment: new application for an old concept.

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%.

Benign paroxysmal positional vertigo: diagnosis and treatment.

Benign paroxysmal positional vertigo is a common disorder in Neurotology. This vestibular syndrome is characterized by transient attacks of vertigo, caused by change in head position, and associated with paroxysmal characteristic nystagmus. The symptoms result from movement of the free floating otoconia particles in the endolymph or their attachment to the cupulae of the semicircular canal. The diagnosis is essentially clinical and should be confirmed by performing diagnostic maneuvers. Treatment is based on the identification of the affected semicircular canal and performance of liberatory maneuvers or repositioning of free floating particles of otoliths. The effectiveness varies from 70 to 100%.

Does the video head impulse test replace caloric testing in the assessment of patients with chronic dizziness? A systematic review and meta-analysis.

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.

Proposal of standardization of Horus® computerized posturography in adults.

PURPOSE: To propose a normalization model of a posturography platform in adults without changes in body balance, through descriptive analysis by age group and sex. METHODS: Cross-sectional observational study. Adults, with no changes in body balance and no vestibular complaints were submitted to 6 sensory conditions on the Horus® posturography platform. The following variables were analyzed: stability limit area and confidence ellipse area, trajectory length and average velocity for each condition tested. The variables were analyzed by age group and sex. The equilibrium score, the sensory integration test and the equilibrium index were calculated on the conditions. RESULTS: Sixty-one subjects (38.3%) and 23 (37.7%) were male, 40 (65.57%) between the ages of 20 and 40 and 21 (34.43). %) between 41 and 59 years. The area of the stability limit and pressure center variables for 6 sensory conditions tested - confidence ellipse area, trajectory length, total mean velocity and confidence ellipse ratio by the area of the stability limit were described. There was a statistically significant difference in the comparison between the area of the stability limit between sexes and between age groups, being a higher value in males and in younger patients. Regarding the analysis of the variables by each condition, there was no difference of results between the sexes and age groups. CONCLUSION: Subjects of different sexes and age groups should be considered separately only in the analysis of the stability limit.

Predictors of falls in women with and without osteoporosis.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To evaluate the relationship between the occurrence of falls and muscle strength, flexibility, and balance in postmenopausal women with and without osteoporosis. BACKGROUND: Osteoporosis and falls are common problems encountered in the elderly. METHODS: A total of 133 women with and 133 without osteoporosis, aged 60 years or greater, were included in the study. Women were interviewed about clinical and social demographic characteristics and the occurrence of falls in the previous 12 months. The variables evaluated were presence of osteoporosis, muscle strength, flexibility, and balance. RESULTS: A significantly higher percentage of women with osteoporosis (51%) compared to those without osteoporosis (29%) had a history of at least 1 fall within the previous 12 months. There was a significant and inverse association between trunk extension strength and trunk flexion range of motion with falls. Logistic regression analyses showed that the variables associated with falls were trunk extension strength and presence of osteoporosis. Greater trunk extension strength was associated with a lower risk for falls (odds ratio, 0.97), while the presence of osteoporosis increased fall risk by a factor of 2.17. CONCLUSIONS: A greater percentage of women with postmenopausal osteoporosis had a history of 1 or more falls within the previous year and a higher risk of recurrent falls than women without osteoporosis. Muscle strength of the lumbar spine and the presence of osteoporosis are intrinsic factors associated with the risk of falls.

Neurotology: definitions and evidence-based therapies - Results of the I Brazilian Forum of Neurotology.

INTRODUCTION: Neurotology is a rapidly expanding field of knowledge. The study of the vestibular system has advanced so much that even basic definitions, such as the meaning of vestibular symptoms, have only recently been standardized. OBJECTIVE: To present a review of the main subjects of neurotology, including concepts, diagnosis and treatment of Neurotology, defining current scientific evidence to facilitate decision-making and to point out the most evidence-lacking areas to stimulate further new research. METHODS: This text is the result of the I Brazilian Forum of Neurotology, which brought together the foremost Brazilian researchers in this area for a literature review. In all, there will be three review papers to be published. This first review will address definitions and therapies, the second one will address diagnostic tools, and the third will define the main diseases diagnoses. Each author performed a bibliographic search in the LILACS, SciELO, PubMed and MEDLINE databases on a given subject. The text was then submitted to the other Forum participants for a period of 30 days for analysis. A special chapter, on the definition of vestibular symptoms, was translated by an official translation service, and equally submitted to the other stages of the process. There was then a in-person meeting in which all the texts were orally presented, and there was a discussion among the participants to define a consensual text for each chapter. The consensual texts were then submitted to a final review by four professors of neurotology disciplines from three Brazilian universities and finally concluded. Based on the full text, available on the website of the Brazilian Association of Otorhinolaryngology and Cervical-Facial Surgery, this summary version was written as a review article. RESULT: The text presents the official translation into Portuguese of the definition of vestibular symptoms proposed by the Bárány Society and brings together the main scientific evidence for each of the main existing therapies for neurotological diseases. CONCLUSION: This text rationally grouped the main topics of knowledge regarding the definitions and therapies of Neurotology, allowing the reader a broad view of the approach of neurotological patients based on scientific evidence and national experience, which should assist them in clinical decision-making, and show the most evidence-lacking topics to stimulate further study.

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.

Video head impulse test relevance in the early postoperative period after cochlear implantation.

BACKGROUND: Cochlear implantation (CI) is the gold standard therapy for profound or severe sensorineural hearing loss. It is a safe surgical procedure but, because of the proximity of the cochlea and vestibule, postoperative vestibular disorder may occur. Our hypothesis is that the video head impulse test (vHIT) may be a good tool to achieve a topographic diagnosis of dizziness in the early postoperative period after CI. AIMS/OBJECTIVES: To evaluate patients with instability, imbalance and vertigo between 7 and 14 days after CI procedure. MATERIAL AND METHODS: A total of 31patients scheduled for unilateral CI were included in this study. vHIT for horizontal semicircular canal was performed before CI and between days 7 to 14 after the surgery. RESULTS: Six subjects had dizziness complaints after CI: instability (N = 2), imbalance (N = 2) and vertigo (N = 2). The postoperative vHIT test turned abnormal only in subjects with vertigo as compared to the preoperative vHIT test results. CONCLUSION AND SIGNIFICANCE: vHIT is a good vestibular function test during the first 2 weeks after CI surgery when vertigo is the main complaint.

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.

Análise de validação e confiabilidade do Questionário Emocional da Vertigem-CIEV em versão traduzida para o Português-Brasileiro / Validation and reliability analysis of the Questionnaire on the Emotional Impact of Vertigo-CIEV version translated to the Brazilian Portuguese language

RESUMO Objetivo Determinar a consistência interna e confiabilidade do "Questionário de Impacto Emocional da Vertigem-CIEV" e validar o instrumento em relação ao Dizziness Handicap Inventory (DHI), em uma amostra de pacientes com distúrbio do equilíbrio corporal. Método Participaram 38 sujeitos, idades entre 23 e 85 anos, ambos os sexos, com queixas relacionadas à tontura, desequilíbrios e/ou quedas, atendidos em um ambulatório de Otoneurologia do Hospital Universitário. Foram excluídos sujeitos com queixas auditivas e/ou zumbido sem tontura associada, comorbidades psiquiátricas prévias e/ou comprometimento cognitivo que impedisse a compreensão dos questionários. Foi realizada anamnese, levantamento de prontuário para caracterização da amostra e aplicados os questionários de autopercepção, DHI e CIEV. O alfa de Cronbach verificou a consistência interna do CIEV e a confiabilidade e validade do CIEV em relação ao DHI foram calculadas pelo Índice de Correlação intraclasse (ICC) e teste de Correlação de Pearson, respectivamente. Resultados Houve correlação estatisticamente significante entre os escores obtidos, tanto à análise de confiabilidade quanto de validação (p<0,001). O ICC médio demonstrou moderada correlação para o escore total (0,695) e forte correlação com os domínios físico, emocional e funcional do DHI (0,706 a 0,869) sendo o maior grau para o domínio emocional (0,869). A Correlação de Pearson demonstrou grau forte para o escore total (r=0,820) e variação de moderado a forte para os domínios, com melhor resultado também para o domínio emocional do DHI (r=0,788). Conclusão Os achados representam parâmetros importantes de contribuição para a validação do CIEV para uso clínico na população brasileira, direcionado para a identificação de aspectos emocionais em pacientes com distúrbios do equilíbrio corporal.

ABSTRACT Purpose To determine the internal consistency and reliability of the "Questionário de Impacto Emocional da Vertigem (CIEV)" and to validate the instrument with respect to the Dizziness Handicap Inventory (DHI) in a sample of individuals with balance disorders. Methods 38 subjects participated in the study, males and females, aged from 23 to 85 years, who presented dizziness, vertigo, and/or falls complaints and attended to the Vestibular Disorders clinic at the University Hospital. Individuals with hearing complaints and/or tinnitus unrelated to dizziness, previous psychiatric comorbidities, and/or cognitive impairments were excluded. We performed an anamnesis and collected complementary data from the medical records. After that, the self-perception questionnaires, DHI, and CIEV, were applied. Statistical analysis was performed in which the Cronbach's alpha verified the internal consistency of the CIEV. Reliability and validity of the CIEV related to the DHI were calculated using Intraclass Correlation Index (ICC) and Pearson's correlation test, respectively. Results There was a statistically significant correlation between the scores obtained, for both reliability and validation analysis (p<0.001). The mean ICC showed a moderate correlation between the total scores (0.695) and a strong correlation with the physical, emotional, and functional DHI domains (0.706 to 0.869), being the emotional aspect the highest degree (0.869). Pearson's correlation showed strong correlation between the total scores (r=0.820) and varied from moderate to strong, with strongest correlations to the DHI emotional domain (r=0.788). Conclusion The outcomes illustrate important contribution to validation parameters to consider clinical use of the CIEV in the Brazilian population, aiming to identify emotional aspects in patients with balance disorders.

Can oculomotricity be altered in patients with tinnitus only? A preliminary study.

The study of oculomotricity is performed by evaluating three systems: saccadic ocular movements (SOMs), optokinetic nystagmus (OKN), and smooth pursuit eye movements (SPEMs). Our aim was to study oculomotricity in patients with a complaint of only tinnitus and to compare it with the value of our control group. We studied the SOMs, OKN, and SPEMs in 25 patients complaining only about tinnitus and in 35 normal adults and compared the results. The data analysis showed a significant difference in the value of the SOMs and SPEMs between the two groups. Sensorineural tinnitus can originate in the organ of Corti, in the cochlear nerve, or in the auditory pathways of the central nervous system. The auditory cortex connects with visual areas and with the superior colliculus. The latter structure is involved in the origin of SOMs and OKN. In our study, we found an increased delay in saccadic tests. In the SPEMs, we observed an increase in the degree of distortion, and a reduction in the gain. This outcome is in accordance with the literature. However, we detected a few alterations in the OKN, and this finding is in partial agreement with the studies analyzed. Alterations in oculomotricity can indicate involvement of the central nervous system in patients with a complaint of only tinnitus.

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.

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%.