Abstract Introduction Otosclerosis is a primary osteodystrophy of the otic capsule, frequently responsible for acquired hearing loss in adults. Although the diagnostic value of imaging investigations in otosclerosis is debatable, they might still be employed with different goals within the context of the disease. Objectives The present paper aims to review the most recent literature on the use of imaging studies in otosclerosis for the most varied purposes, from routine application and differential diagnosis to prognostic prediction and investigation of surgical failure. Data Synthesis The diagnosis of otosclerosis is usually clinical, but computed tomography (CT) is paramount in particular cases for the differential diagnosis. The routine use, however, is not supported by strong evidence. Even so, there is growing evidence of the role of this method in surgical planning and prediction of postoperative prognosis. In specific scenarios, for example when superior semicircular canal dehiscence (SSCD) syndrome is suspected or in surgical failure, CT is crucial indeed. Magnetic resonance imaging (MRI), however, has limited - although important - indications in the management of individuals with otosclerosis, especially in the evaluation of postoperative complications and in the follow-up of medical treatment in active ostosclerosis. Conclusion Imaging studies have a broad range of well-established indications in otosclerosis. Besides, although the routine use of CT remains controversial, the most recent papers have shed light into new potential benefits of imaging prior to surgery.

INTRODUÇÃO: A Síndrome de Dandy Walker consiste em uma anormalidade congênita do sistema nervoso central, caracterizada por deficiência do desenvolvimento das estruturas médias cerebelares, dilatação cística de fossa posterior comunicando- se com o quarto ventrículo e deslocamento ascendente dos seios transversais, tentório e tórcula. Entre os sinais clínicos estão protuberância occipital, aumento progressivo do crânio, arqueamento das fontanelas anteriores, papiledema, ataxia, distúrbios da marcha, nistagmo e comprometimento intelectual. OBJETIVOS: Descrever um caso de paciente feminino, 13 anos com diagnóstico desta síndrome e perda auditiva bilateral submetida à cirurgia de implante coclear sob anestesia local e sedação. RELATO DE CASO: CGS, 13 anos, sexo feminino, foi referida ao Serviço de Otorrinolaringologia do Instituto paranaense de Otorrinolaringologia com diagnóstico de "síndrome de Dandy-Walker" para avaliação otorrinolaringológica por perda auditiva bilateral sem resposta ao uso de aparelhos de amplificação sonora. COMENTÁRIOS FINAIS: O campo da cirurgia de implante coclear está crescendo rapidamente. Acreditamos que a presença da síndrome de Dandy-Walker não pode ser considerada uma contra indicação para a realização da cirurgia de implante coclear, sendo que não houve intercorrências cirúrgicas devido às alterações neurológicas com resultados muito favoráveis para a paciente que apresenta excelente discriminação. Apresenta menor necessidade de leitura labial com melhora na qualidade da fala.

INTRODUCTION: Dandy Walker Syndrome is a congenital abnormality in the central nervous system, characterized by a deficiency in the development of middle cerebelar structures, cystic dilatation of the posterior pit communicating with the fourth ventricle and upward shift of the transverse sinuses, tentorium and dyes. Among the clinical signs are occipital protuberances, a progressive increase of the skull, bowing before the fontanels, papilledema, ataxia, gait disturbances, nystagmus, and intellectual impairment. OBJECTIVES: To describe a case of female patient, 13 years old with a diagnosis of this syndrome and bilateral hearing loss underwent cochlear implant surgery under local anesthesia and sedation. CASE REPORT: CGS, 13 years old female was referred to the Otolaryngological Department of Otolaryngology Institute of Parana with a diagnosis of "Dandy-Walker syndrome" for Otolaryngological evaluation for bilateral hearing loss with no response to the use of hearing aids. FINAL COMMENTS: The field of cochlear implants is growing rapidly. We believe that the presence of Dandy-Walker syndrome cannot be considered a contraindication to the performance of cochlear implant surgery, and there were no surgical complications due to neurological disorders with very favorable results for the patient who exhibits excellent discrimination. It has less need for lip reading with improvement in speech quality.

Existem duas técnicas para inserção dos eletrodos do implante coclear (IC): Via cocleostomia ou via janela redonda (JR). OBJETIVO: Comparar a telemetria de resposta neural (NRT) no pós-operatório imediato, verificando se há diferenças na estimulação do nervo auditivo entre estas duas técnicas. MÉTODOS: Prospectivo e transversal. Foram avaliados 23 pacientes. Seis submetidos à cirurgia via cocleostomia e 17 via JR. RESULTADOS: Comparação das unidades de corrente médias (UCM) para sons agudos: via JR com média de 190,4 (± 29,2) e via cocleostomia 187,8 (± 32,7), p = 0,71. Comparação das UCM para sons intermediários: via JR, média de 192,5 (± 22) e via cocleostomia 178,5 (± 18.5), p = 0,23. Comparação das UCM para sons graves: via JR, média de 183,3 (± 25) e via cocleostomia 163,8 (± 19,3), p = 0,19. CONCLUSÃO: Este estudo não mostrou diferença na captação do potencial de ação da porção distal do nervo auditivo em pacientes usuários do implante coclear multicanal submetidos à cirurgia via cocleostomia ou via JR, utilizando o próprio implante para eliciar o estímulo e gravar as respostas. Portanto, ambas as técnicas estimulam de maneira igual o nervo coclear, e baseado nisto conclui-se, também, que realizar o implante coclear via cocleostomia ou RW é uma escolha que depende da experiência cirúrgica e opção do cirurgião.

There are two techniques for cochlear implant (CI) electrode placement: cochleostomy and the round window (RW) approach. OBJECTIVE: This study aims to compare neural response telemetry (NRT) results immediately after surgery to check for possible differences on auditory nerve stimulation between these two techniques. MATERIALS AND METHODS: This is a prospective cross-sectional study. Twenty-three patients were enrolled. Six patients underwent surgery by cochleostomy and 17 had it through the RW approach. RESULTS: Mean charge units (MCU) for high frequency sounds: patients submitted to the RW approach had a mean value of 190.4 (± 29.2) while cochleostomy patients averaged 187.8 (± 32.7); p = 0.71. MCU for mid frequency sounds: patients submitted to the RW approach had a mean value of 192.5 (± 22) while cochleostomy patients averaged 178.5 (± 18.5); p = 0.23. MCU for low frequency sounds: patients submitted to the RW approach had a mean value of 183.3 (± 25) while cochleostomy patients averaged 163.8 (± 19.3); p = 0.19. CONCLUSION: This study showed no differences in the action potential of the distal portion of the auditory nerve in patients with multichannel cochlear implants submitted to surgery by cochleostomy or through the RW approach, using the implant itself to generate stimuli and record responses. Both techniques equally stimulate the cochlear nerve. Therefore, the choice of approach can be made based on the surgeon's own preference and experience.