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.
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.
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.
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.
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.
A otoneurologia é uma área de conhecimento que tem se expandido muito rapidamente. O estudo do sistema vestibular tem avançado tanto que mesmo definições básicas, como o significado dos sintomas vestibulares, foram apenas recentemente padronizadas.
Apresentar uma revisão dos principais assuntos da otoneurologia, inclusive conceitos, diagnóstico e tratamento da otoneurologia, definir a evidência científica atual para facilitar a tomada de decisões e demonstrar as áreas mais carentes de evidência para estimular novas pesquisas.
Este texto é fruto do I Fórum Brasileiro de Otoneurologia, que reuniu os principais pesquisadores brasileiros dessa área para uma revisão da literatura. Serão feitos três trabalhos de revisão a serem publicados. Este primeiro abordou as definições e as terapias, o segundo abordará as ferramentas diagnósticas e o terceiro definirá os principais diagnósticos. Cada autor fez um levantamento bibliográfico na base de dados da Lilacs, SciELO, Pubmed e Medline de um determinado assunto. O seu texto foi então submetido aos demais participantes do Fórum por 30 dias para análise. Um capítulo especial, da definição dos sintomas vestibulares, foi traduzido por serviço de tradução oficial e igualmente submetido às demais etapas do processo. Houve então uma reunião presencial em que todos os textos foram apresentados oralmente e houve uma discussão entre os participantes para a definição de um texto consensual para cada capítulo. Os textos consensuais foram então submetidos a uma revisão final por quatro professores de otoneurologia de três universidades brasileiras e, por fim, finalizado. A partir do texto completo, publicado no site da Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial, foi escrita esta versão-resumo como artigo de revisão.
O texto apresenta a tradução oficial para o português da definição dos sintomas vestibulares propostos pela Barany Society e agrupa as principais evidências científicas para cada um das principais terapias existentes para as doenças otoneurológicas.
Este texto agrupou de forma racional os principais tópicos de conhecimento a respeito das definições e terapias da otoneurologia, permite ao leitor uma visão ampla da abordagem dos pacientes otoneurológicos baseada em evidências científicas e experiência nacional, que deverá auxiliá-lo na tomada de decisões clínicas, e mostra os assuntos mais carentes de evidência para estimular novos estudos.
Triangular corridors have been used as reliable surgical entry points for open transcranial approaches to the petrous apex (PA) and petroclival region (PCR). The endoscopic endonasal approaches have ...grown rapidly in the last decade, and the indications have advanced. The knowledge of accurate and reliable anatomic landmarks through endoscopic endonasal route is essential and remain to be established. The purpose of this study was to describe the feasibility and surgical exposure of the anteromedial petrous (Gardner's) triangle as a novel corridor to the PA and PCR.
Five anatomic specimens were dissected. The PA and PCR were accessed through endoscopic endonasal approaches and contralateral transmaxillary approach. The limits of the anteromedial petrous (Gardner's) triangle were identified and dissected and associated measurements performed.
The dissection was divided into 6 steps. The limits of the anteromedial petrous (Gardner's) triangle were identified and defined by the paraclival internal carotid artery anterolaterally, the abducens nerve posteromedially, and the petroclival synchondrosis inferiorly. Three lines were established following the limits of the triangle. The mean distance of the anterolateral limit was 10.03 mm (SD = 0.94), of the posteromedial limit was 20.06 mm (SD = 2.90), and of the inferior limit was 17.99 mm (SD = 2.99). The mean area was 87.56 mm 2 (SD = 20.06). The 3 anatomic landmarks with a critical role to safely define the triangle were the pterygosphenoidal fissure, the petrosal process of the sphenoid bone, and the petroclival synchondrosis.
The anteromedial (Gardner's) triangle is a well-defined bone corridor which provides access to the entire petrous bone and petroclival junction through endoscopic endonasal route. Regardless of the anatomic variations or tumor location, the landmarks of the abducens nerve, paraclival internal carotid artery, and petroclival synchondrosis are key for understanding lateral access to tumors extending from the clivus.
The traditional access route for cochlear implantation was initially proposed by William House in 1961. Alternatives to this surgical approach have been suggested by many authors. The combined ...approach technique (CAT) is a variation of the traditional mastoidectomy-posterior tympanotomy method, which uses a transcanal approach to cochleostomy combined with a small mastoidectomy and an equally small posterior tympanotomy for the insertion of electrodes. This paper presents a detailed description of this alternative procedure, reporting our experience with 50 cases, and adds our contribution regarding possible advantages and implications of using a transcanal cochleostomy. The subjects had profound and severe bilateral hearing loss and had not benefited from external hearing aids. They underwent cochlear implantation at Hospital de Clinicas de Porto Alegre from May 2003. The median follow-up was 29 months. All cases were successfully implanted using CAT. No major complications, such as facial paralysis or paresis, meningitis, cholesteatoma, or cerebrospinal fluid leaks, were observed in any patient. The CAT is a safe and efficient variation of cochlear implantation surgery, which is especially appropriate if cochlear calcification or malformations are present, or whenever cochleostomy has to be performed anteriorly, and when the position of the facial nerve prevents an adequate posterior tympanotomy.
The combined approach technique (CAT) is a variation of the classical the mastoidectomy-posterior tympanotomy technique (MPTA) that combines a transcanal approach to cochleostomy with a reduced ...posterior tympanotomy for insertion of electrodes.
To compare and evaluate long-term safety and effectiveness outcomes obtained with the CAT and with MPTA approach in patients submitted to cochlear implant (CI) surgery. Design: series study.
Patients who underwent CI using CAT or MPTA at a Brazilian center were followed in a cohort study. Main outcomes were complications, audiometric performance and radiological evaluation of electrode position.
Fourty-four patients were implanted using CAT and 31 MPTA. There were no cases of facial nerve paralysis, mastoiditis, cholesteatoma or cerebrospinal fluid leaks after 3.4±1.0 years. Radiological evaluation of electrode position revealed that the median number of electrodes outside the cochlea was 0 in CAT and 3 in MPTA groups (p < 0.001). There were no differences between both surgical approaches in terms of mean pure-tone thresholds with CI at all frequencies.
Long-term follow-up data showed that the transcanal route to cochleostomy, combined with a reduced posterior tympanotomy, is a safe alternative approach in cochlear implant surgery, with no related major complications and fewer cases of electrode migration when compared with the MPTA. These findings encourage the use of the transcanal route to cochleostomy as an alternative approach option.
In the United States, roughly 10% of the population is exposed daily to hazardous levels of noise in the workplace. Twin studies estimate heritability for noise-induced hearing loss (NIHL) of ...approximately 36%, and strain specific variation in sensitivity has been demonstrated in mice. Based upon the difficulties inherent to the study of NIHL in humans, we have turned to the study of this complex trait in mice. We exposed 5 week-old mice from the Hybrid Mouse Diversity Panel (HMDP) to a 10 kHz octave band noise at 108 dB for 2 hours and assessed the permanent threshold shift 2 weeks post exposure using frequency specific stimuli. These data were then used in a genome-wide association study (GWAS) using the Efficient Mixed Model Analysis (EMMA) to control for population structure. In this manuscript we describe our GWAS, with an emphasis on a significant peak for susceptibility to NIHL on chromosome 17 within a haplotype block containing NADPH oxidase-3 (Nox3). Our peak was detected after an 8 kHz tone burst stimulus. Nox3 mutants and heterozygotes were then tested to validate our GWAS. The mutants and heterozygotes demonstrated a greater susceptibility to NIHL specifically at 8 kHz both on measures of distortion product otoacoustic emissions (DPOAE) and on auditory brainstem response (ABR). We demonstrate that this sensitivity resides within the synaptic ribbons of the cochlea in the mutant animals specifically at 8 kHz. Our work is the first GWAS for NIHL in mice and elucidates the power of our approach to identify tonotopic genetic susceptibility to NIHL.
Evaluate the hypopharyngeal packing effectiveness on prevention of postoperative nausea and vomiting (PONV) in nasal surgery.
A randomized clinical trial was conducted from July 2004 to October 2005. ...The intervention group was submitted to hypopharyngeal packing after orotracheal tube placement. The control group had no hypopharyngeal packing. Occurrence of nausea, vomiting, use of antiemetic drugs, and throat pain were checked blindly on recovery period.
One hundred forty-four patients were included in the study. There was no difference related to postoperative nausea (RR 1.34; CI 0.72-2.48), vomiting (RR 0.52; CI 0.19-1.47), use of antiemetic drugs (RR 1.54; CI 0.80-2.95), and throat pain (RR 0.91; 0.62-1.34) between both groups. A beta error could not be excluded.
Results suggest there is no benefit in hypopharyngeal packing on PONV prevention in nasal surgery. New studies with a greater number of patients should be carried out in order to confirm these results.
Genome-wide association studies (GWAS) have been successfully applied in humans for the study of many complex phenotypes. However, identification of the genetic determinants of hearing in adults has ...been hampered, in part, by the relative inability to control for environmental factors that might affect hearing throughout the lifetime, as well as a large degree of phenotypic heterogeneity. These and other factors have limited the number of large-scale studies performed in humans that have identified candidate genes that contribute to the etiology of this complex trait. To address these limitations, we performed a GWAS analysis using a set of inbred mouse strains from the Hybrid Mouse Diversity Panel. Among 99 strains characterized, we observed approximately two-fold to five-fold variation in hearing at six different frequencies, which are differentiated biologically from each other by the location in the cochlea where each frequency is registered. Among all frequencies tested, we identified a total of nine significant loci, several of which contained promising candidate genes for follow-up study. Taken together, our results indicate the existence of both genes that affect global cochlear function, as well as anatomical- and frequency-specific genes, and further demonstrate the complex nature of mammalian hearing variation.
This study aimed to investigate the genetic causes of vestibular dysfunction. We used vestibular sensory-evoked potentials (VsEPs) to characterize the vestibular function of 35 inbred mouse strains ...selected from the Hybrid Mouse Diversity Panel and demonstrated strain-dependent phenotypic variation in vestibular function. Using these phenotypic data, we performed the first genome-wide association study controlling for population structure that has revealed two highly suggestive loci, one of which lies within a haplotype block containing five genes (
Stard6
,
4930503L19Rik
,
Poli
,
Mbd2
,
Dcc
) on Chr. 18 (peak SNP rs29632020), one gene, deleted in colorectal carcinoma (
Dcc
) has a well-established role in nervous system development. An in-depth analysis of
Dcc
-deficient mice demonstrated elevation in mean VsEP threshold for
Dcc
+/−
mice (−11.86 dB) compared to wild-type (−9.68 dB) littermates. Synaptic ribbon studies revealed
Dcc
−/−
(P0) and
Dcc
+/−
(6-week-old) mice showed lower density of the presynaptic marker (CtBP2) as compared to wild-type controls. Vestibular ganglion cell counts of
Dcc
−/−
(P0) was lower than controls. Whole-mount preparations showed abnormal innervation of the utricle, saccule, and crista ampullaris at E14.5, E16.5, and E18.5. Postnatal studies were limited by the perinatal lethality in
Dcc
−/−
mice. Expression analyses using in situ hybridization and immunohistochemistry showed Dcc expression in the mouse vestibular ganglion (E15.5), and utricle and crista ampullaris (6-week-old), respectively. In summary, we report the first GWAS for vestibular functional variation in inbred mice and provide evidence for the role of
Dcc
in the normal innervation of the peripheral vestibular system.
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