Mariana Lopes Fávero

Estudo dos limiares eletrofisiológicos das vias aérea e óssea em crianças com até 2 meses de idade

O diagnostico diferencial de perdas auditivas com potencial evocado auditivo de tronco encefalico por via aerea e por via ossea em criancas pequenas tem sido pouco estudado no Brasil. OBJETIVO: Comparar as respostas do potencial evocado auditivo de tronco encefalico por vias aerea e ossea em criancas de ate 2 meses de idade sem perdas auditivas. FORMA DE ESTUDO: Clinico prospectivo com coorte transversal. MATERIAL E METODO: Foram avaliadas 12 criancas que passaram na triagem auditiva, por meio do potencial evocado auditivo de tronco encefalico por via aerea e via ossea. A via ossea foi realizada sem mascaramento contralateral. As respostas foram comparadas e analisadas por meio do teste de McNemar e pela analise de variância com medidas repetidas. RESULTADOS: Nao houve diferenca estatistica no limiar eletrofisiologico por via aerea e via ossea (p>0,05). O tempo de latencia por via ossea foi estatisticamente maior do que o tempo de latencia por via aerea (p=0,000). CONCLUSAO: Houve concordância no registro do Potencial Evocado Auditivo de Tronco Encefalico captado por vias aerea e ossea nas intensidades proximas ao limiar auditivo; a latencia da onda V registrada por via ossea foi estatisticamente maior que a registrada por via aerea.

Supressão contralateral das emissões otoacústicas nos indivíduos com zumbido

INTRODUCAO: A funcao do trato olivococlear medial e estudada pela supressao das emissoes otoacusticas com o uso de uma estimulacao contralateral e sofre influencia da lateralidade do sistema nervoso central, nao apresentando respostas iguais entre as orelhas. Uma disfuncao neste trato pode implicar na geracao do zumbido, porem isto ainda nao foi confirmado. OBJETIVO: Estudar a supressao das emissoes otoacusticas por produto de distorcao em individuos com zumbido. MATERIAL E METODO: Estudo caso-controle com 44 pessoas com zumbido, matriculadas no Ambulatorio de Zumbido da Divisao de Clinica Otorrinolaringologica do Hospital das Clinicas da Universidade de Sao Paulo e 44 voluntarios submetidos a emissao otoacustica por produto de distorcao com e sem estimulacao contralateral. Comparou-se os resultados das orelhas direita dos dois grupos. RESULTADOS: Houve associacao entre zumbido e ausencia de supressao em todas as frequencias estudadas (OR>2,1). CONCLUSOES: Houve uma correlacao entre menor efetividade do trato olivococlear medial e a presenca de zumbido.

Contralateral suppression of otoacoustic emission in patients with tinnitus

INTRODUCTION The medial olivocochlear bundle effect is studied through the suppression of otoacoustic emissions and seems to be influenced by the laterality of the central nervous system, presenting no symmetry between right and left ear. A dysfunction of this bundle may be involved in the generation of tinnitus, although this fact was not confirmed. OBJECTIVES Study the suppression of distortion product otoacoustic emissions in tinnitus patients. MATERIAL AND METHOD A case-controlled study involving 44 tinnitus patients from the Tinnitus Group of the ENT Department of the University of São Paulo Medical School and 44 controls who underwent distortion product otoacoustic emissions testing with and without contralateral noise. Only the results from the right ears from both groups were compared. RESULTS There was a relationship between the presence of tinnitus and the absence of suppression at all frequencies studied (OR>2.1). CONCLUSION There was a correlation between diminished effectiveness of the medial olivocochlear bundle and the presence of tinnitus.

Chloral Hydrate to Study Auditory Brainstem Response

UNLABELLED Chloral Hydrate (CH) is a sedative and hypnotic drug used in pediatric procedures owing to the low depressive effect it has on the respiratory and cardiac systems. AIM To assess the efficacy of the drug in performing ABR and to systematize its use. MATERIALS AND METHODS A prospective cross-sectional study with 41 children without history of heart or lung disease. The initial dose of CH at 10% was 50 mg/Kg, with a boost dose of 6 mg/Kg administered 30 minutes later in cases in which there was no sedation. Drug effectiveness was established by sleep induction by 1 hour after the administration of the initial dose. Sleep occurrence was correlated with doses (50 mg or 56 mg/Kg), age, weight and gender. RESULTS All the 41 children who participated in the study took 50 mg/kg of the agent and 23 of them slept within 30 minutes, 2 had respiratory complications, 16 had the 6 mg/Kg boost dose and 13 fell asleep after 30 minutes. The 56 mg/kg dose presented a statistically significant effect on sleep induction (p<0.05) when compared to the 50mg/kg dose. CONCLUSION CH produced a satisfactory effect with 50 mg/Kg dose plus 6 mg/kg up to one hour after administration. Complications can occur regardless of the dose used.

Electrophysiologic threshold study in air and bone conduction in children with 2 months or less age

UNLABELLED The differential diagnosis of hearing loss with air and bone Auditory Brainstem Response in small children has not been enough studied in Brazil. AIM To compare air and bone Auditory Brainstem Response results in children under 2 months of age with normal hearing. STUDY DESIGN clinical with transversal cohort. MATERIALS AND METHODS 12 children who passed the hearing screening were evaluated using air and bone Auditory Brainstem Response. No contralateral masking was used in the bone conduction test. The responses were compared and analyzed by the McNemar test and repetitive measurements of the variance test. RESULTS There were no statistic differences between air and bone conduction Auditory Brainstem Response thresholds (p>0.05). The bone conduction latency for wave V was statistically higher than air conduction latency (p=0.000). CONCLUSION There was agreement on the results recorded for air and bone conduction Auditory Brainstem Response for threshold intensities; latency for bone conduction wave V was statistically higher than the air conduction latency.

Mudanças nos parâmetros do clique durante a captação do BERA

Manipulation of auditory stimuli affect the ABR evoked potentials and aid the diagnosis, particularly in auditory neuropathy patients. Some patients with auditory neuropathy lose evoked otoacoustic emissions over time; in these cases, comparing responses to rarefaction and condensation clicks, and decreasing the stimulus rate can show an extended cochlear microphonism or yield an improved electric potential record. AIM: To analyze the effect of these click manipulations on the records of potentials of patients with hearing loss as a form of improving the diagnosis. STUDY DESIGN: A clinical prospective study. PATIENTS AND METHOD: 59 patients with hearing loss underwent ABR recording using rarefaction and condensation clicks at a stimulus rate of 27.7/sec, and rarefaction clicks at a stimulus rate of 3.3/sec. The records were compared to the otoacoustic evoked emission. RESULTS: Eight (13.53%) patients showed changes in the recorded ABR potentials as a result of manipulating the characteristics of clicks, such as extended cochlear microphonism or an improved record of electric potentials. Five patients had no otoacoustic evoked emissions. CONCLUSION: Manipulation of click stimuli can improve the topographic diagnosis of hearing loss, particularly in the group of auditory neuropathy patients with no otoacoustic evoked emissions, where usually, the diagnosis is only possible through the method described above.

Contralateral suppression of otoacoustic emission in subject with tinnitus

Abstract Objectives: The medial olivocochlear bundle effect is studied through the suppression of otoacoustic emissions and seems to be influenced by the laterality of the central nervous system, although this fact was not considered in many previous studies. Once dysfunctions of such regulating system may be involved in the generation of tinnitus, the objective of this study is to analyze this suppression in tinnitus patients and the influence of functional laterality upon this test. Methods: Forty-four patients with tinnitus and 44 without tinnitus underwent suppression of distortion product otoacoustic emissions. The suppression effect was calculated by subtracting the value of otoacoustic emissions obtained at the 1000 to 6000 Hz frequency range without contralateral noise from that obtained with contralateral noise. Only the results of the right ears were considered for analysis in each group. Afterwards, comparison between the results of right and left ears of the control group was performed to evaluate the influence of functional laterality over the suppression. Results: The results observed among subject with and without tinnitus showed an association between absence of contralateral suppression and presence of tinnitus at all frequencies studied (OR >2.1). The results obtained from the right and the left ears of subject without tinnitus showed higher right-side suppression at 1000 Hz, 2000 Hz, 3000 Hz, 4000 Hz. Conclusion: There was a clear correlation between diminished effectiveness of the medial olivocochlear bundle and the presence of tinnitus. The central nervous system laterality should be a controlled variable in the study of the functions of such pathways.

Pediatric phoniatry outpatient ward: clinical and epidemiological characteristics.

UNLABELLED Children with language or learning impairment and normal hearing need phoniatric assessment to analyse various communication and development aspects targeting the differential diagnosis and therapeutic indications. OBJECTIVE Characterize clinical and epidemiological features of a pediatric population treated in a phoniatric outpatient clinic. METHOD A cross-sectional historical cohort study (retrospective study) was performed involving 68 patients undergoing phoniatric consultation. Outcome measures were age, gender, source of referral for phoniatric consultation, phoniatric diagnosis, mean age at diagnosis, neonatal risks, family history of communication disorders and referrals. RESULTS 70.58% were male and 29.42% female, mean age 6.85 ± 2.49 years. 63.23% from external services and 45.59% had no hearing diagnosis. 14 different diagnoses were performed: 50% had Cerebral Palsy, Specific Language Impairment and Pervasive Developmental Disorder. The difference between the average ages was statistically significant (F = 4.369 p = 0.00). 50% had a family history of communication disorders and 51.47% history of neonatal risk. 51.47% were referred for neurological consultation and 79.41% for therapies. CONCLUSION The population seen was predominantly male, with more complex language development deviations probably due to multiple etiologies. Many of them had no hearing diagnosis.

Changes in click characteristics during ABR recording

UNLABELLED Manipulation of auditory stimuli affect the ABR evoked potentials and aid the diagnosis, particularly in auditory neuropathy patients. Some patients with auditory neuropathy lose evoked otoacoustic emissions over time; in these cases, comparing responses to rarefaction and condensation clicks, and decreasing the stimulus rate can show an extended cochlear microphonism or yield an improved electric potential record. AIM To analyze the effect of these click manipulations on the records of potentials of patients with hearing loss as a form of improving the diagnosis. STUDY DESIGN A clinical prospective study. PATIENTS AND METHOD 59 patients with hearing loss underwent ABR recording using rarefaction and condensation clicks at a stimulus rate of 27.7/sec, and rarefaction clicks at a stimulus rate of 3.3/sec. The records were compared to the otoacoustic evoked emission. RESULTS Eight (13.53%) patients showed changes in the recorded ABR potentials as a result of manipulating the characteristics of clicks, such as extended cochlear microphonism or an improved record of electric potentials. Five patients had no otoacoustic evoked emissions. CONCLUSION Manipulation of click stimuli can improve the topographic diagnosis of hearing loss, particularly in the group of auditory neuropathy patients with no otoacoustic evoked emissions, where usually, the diagnosis is only possible through the method described above.

The Relationship between the Etiology of Profound Prelingual Sensorineural Hearing Loss and the Results of Vestibular-Evoked Myogenic Potentials

Introduction  Cervical vestibular-evoked myogenic potentials (cVEMPs) are biphasic, short latency potentials, which represent the inhibition of the contraction of the sternocleidomastoid muscle (SCM) mediated by the saccule, the inferior vestibular nerve, the vestibular nuclei and the medial vestibular spinal tract. Objective  To evaluate the response of cVEMPs in individuals with profound prelingual bilateral cochlear hearing loss. Methods  A prospective case-control study. A total of 64 volunteers, divided into a study group (31 patients with profound prelingual sensorineural hearing loss) and a control group (33 subjects matched for age and gender with psychoacoustic thresholds of ≤ 25 dB HL between 500 and 8,000 Hz) were submitted to the cVEMP exam. The causes of hearing loss were grouped by etiology and the involved period. Results  The subjects of the study group are more likely to present changes in cVEMPs compared to the control group (35.5% versus 6.1% respectively; p  = 0.003), with an odds ratio (OR) of 8.52 ( p  = 0.009). It means that they had 8.52-fold higher propensity of presenting altered cVEMP results. There were no statistically significant differences between the latencies, the interamplitude and the asymmetry index. Regarding the etiology, there was a statistically significant difference when the cause was infectious, with an OR of 15.50 ( p  = 0.005), and when the impairment occurred in the prenatal period, with an OR of 9.86 ( p  = 0.009). Conclusion  The present study showed abnormalities in the sacculocolic pathway in a considerable portion of individuals with profound prelingual sensorineural hearing loss due to infectious and congenital causes, as revealed by the cVEMP results.