Internal auditory canal hypoplasia associated with bilateral vestibulocochlear nerve aplasia and deviant facial nerve course: A case report and MRI findings.

The evaluation of internal auditory canals and cochlea has gained significant importance due to the increasing number of cochlear implantations worldwide. This region's anatomical study is essential for cochlear implant surgery using magnetic resonance imaging as the method of choice. We report a case of a 6-year-old male patient diagnosed with a rare bilateral malformation of the internal auditory canals associated with an aberrant course of the facial nerve and vestibulocochlear nerve aplasia. This report raises the importance of identifying this rare malformation for appropriate management and reinforces awareness of possible complications.

Cervical and ocular vestibular evoked myogenic potentials in determining nerve division involvement in patients with a tumor located in the internal auditory canal.

OBJECTIVES: The study aimed at the analysis of the parameters of acoustic cervical and ocular vestibular evoked myogenic potentials (AC-cVEMP and AC-oVEMP) response in patients with a confirmed tumor located in the internal auditory canal. It also aimed to assess to what degree a combination of these tests may be of benefit in the preoperative indication of the affected nerve division via preoperative determination whether the tumor originated from the superior or inferior division of the vestibular nerve, both divisions, or if it originated from a different nerve in the internal auditory canal. METHODS: The study group included 50 patients. Preoperative MRI scans were used to measure tumor diameter. AC-cVEMP and AC-oVEMP testing were performed before tumor resection. The surgeon was asked for a detailed description of the tumor origin. RESULTS: The corrected amplitude of cVEMP was significantly lower on the tumor side than on the non-affected side and in the control group. The corrected Asymmetry Ratio (AR) of cVEMPs in patients with the tumor was significantly elevated above the reference values with the mean being 58.29% and the mean AR of oVEMPs in patients the tumor was 71.78% which made both results significantly higher than in the control group. Neither cVEMP nor oVEMP latency was significantly correlated with tumor size. Data obtained from cVEMP and oVEMP tests was an effective indicator of tumor origin in 74% of patients showing which division (or both divisions) of the VIIIth nerve was affected in comparison with information obtained from the surgeon. CONCLUSIONS: The combined use of AC-cVEMP and AC-oVEMP tests may be useful in surgical planning in patients the tumor located in the internal auditory canal, providing a highly probable determination of the division of the affected nerve. Such information is valuable for the surgeon as it offers additional knowledge about the tumor before the procedure. cVEMP and oVEMP results may not be used as the basis for the calculation of tumor size in patients.

The Evidence for Selective Loss of Otolithic Function.

Recent advances in vestibular testing now permit functional testing of all peripheral vestibular sense organs (all three semicircular canals, utricle, and saccule). This makes it possible to identify patients with isolated dysfunction of the utricle or saccule, even though parallel pathways for vestibular information are ultimately integrated centrally. Selective, isolated unilateral loss of utricular function as measured by ocular vestibular-evoked myogenic potentials (VEMPs) has been observed in patients with normal semicircular canal function as measured by the video head impulse test of all six semicircular canals, and normal bilateral saccular function as determined by symmetrical cervical VEMPs. How these patients present clinically and how they recover is discussed and contrasted with acute vestibular neuritis. In some patients, the unilateral loss of otolith organ (utricle or saccule) function persists and yet the patient recovers functionally to their usual lifestyle. Until the testing of all peripheral vestibular sense organs is routine, the frequency of isolated loss of otolith function cannot be gauged.

Meningitis and Ramsay-Hunt syndrome in a 17-year old girl.

INTRODUCTION: Ramsay Hunt syndrome (RHS) is a rare manifestation of varicella-zoster virus (VZV) reactivation in geniculate ganglion. It usually manifests with a characteristic triad of symptoms including ipsilateral ear pain, vesicles in the external auditory canal, and facial nerve palsy. CASE: We present a case report showing RHS additionally manifested by meningitis and involvement of VIII cranial nerve. Clinical course was complicated by acute kidney injury induced by acyclovir therapy. RESULTS: Despite the involvement of the geniculate ganglion and vestibulocochlear nerve in the course of herpes zoster, and the occurrence of acute kidney injury, the patient fully recovered. CONCLUSIONS: A complete recovery of cranial nerves VII and VIII in the course of RHS can be achieved.

VACTERL Association with Situs Inversus Totalis: A Unique Combination.

BACKGROUND: VACTERL association is a sporadic, nonrandom series of congenital malformations diagnosed by the presence of three or more of the following: vertebral malformations, anal atresia, cardiac defects, tracheoesophageal fistula, renal malformations, and limb malformations. Situs inversus totalis (SIT) and esophageal malformations are rarely associated. This is the first reported case in North America of VACTERL association with SIT. IMPLICATIONS FOR PRACTICE: Respiratory distress in the term infant requires full exploration of all possible causes because the etiology may be far more complex than routinely diagnosed respiratory distress syndrome. This particular case demonstrates physical exam findings and supportive imaging that would be observed in infants with VACTERL association and with SIT, highlighting considerations when, rarely, both occur simultaneously.

MRI findings in vestibular paroxysmia - An observational study.

BACKGROUND/OBJECTIVES: Vestibular paroxysmia (VP) presents as episodic vertigo believed to be caused by neurovascular cross-compression (NVCC) of the vestibulocochlear nerve. We investigated whether NVCC occurred at a higher rate in VP, compared with controls and whether angulation of the nerve, the vessel involved and location of the point of contact were significant features. METHODS: Retrospective analysis was conducted of MR imaging performed in patients with VP and also patients with unilateral tinnitus (in whom the asymptomatic side was used as a control). Two independent, blinded reviewers assessed each case. RESULTS: Nine patients with VP and 20 patients with unilateral tinnitus were included. NVCC was demonstrated in all 9 VP patients (100%), compared with 9 of the controls (45%), p = 0.0049. NVCC was mostly caused by a branch of the anterior inferior cerebellar artery (AICA). Nerve angulation at the point of contact occurred in 5 of the cases (44%), but in none of the controls (specificity = 100%), p = 0.0053. There was no correlation between site of contact and VP. CONCLUSION: Our study supports the concept of NVCC in VP and additionally suggests that nerve angulation may be a specific feature. Neurovascular contact remains a common phenomenon in asymptomatic patients and therefore correlation with neuro-otology assessment remains essential.

Influence of socioeconomic factors on the perception of cochlear-vestibular symptoms and adherence to the treatment of congenital hypothyroidism / Influência dos fatores socioeconômicos na percepção de sintomas cócleo-vestibulares e na adesão ao tratamento do hipotireoidismo congênito

Abstract Objectives: to verify if there is an association between socioeconomic factors and adherence to treatment in congenital hypothyroidism and to verify if there is an association between socioeconomic factors and vestibulocochlear symptoms noticed by parents/caregivers of children diagnosed with congenital hypothyroidism. Methods: a cross-sectional, exploratory and descriptive study, with a convenience sample. The sample consisted of 108 children with clinical and laboratory diagnosis of congenital hypothyroidism, of both sexes, aged ≥ 5 years. The researchers applied a structured questionnaire to parents/caregivers, consisting of closed and objective questions about the presence or absence of tinnitus, hearing loss and dizziness/vertigo in children with congenital hypothyroidism. Results: There was no association between socioeconomic factors and adherence to treatment or perception of cochlear-vestibular symptoms. Conclusions: socioeconomic factors did not influence treatment adherence or perceived cochlear-vestibular symptoms by caregivers of children with congenital hypothyroidism.

Resumo Objetivos: verificar se existe associação entre fatores socioeconômicos e adesão ao tratamento no hipotireoidismo congênito e verificar se existe associação entre fatores socioeconômicos e sintomas vestibulococleares percebidos pelos pais / cuidadores de crianças diagnosticadas com hipotireoidismo congênito. Métodos: estudo transversal, exploratório e descritivo, com amostra de conveniência. A casuística foi composta por 108 crianças com diagnóstico clínico e laboratorial de hipotireoidismo congênito, de ambos os sexos com idade ≥ 5 anos. Foi aplicado um questionário estruturado para os pais/cuidadores, formado por questões fechadas e objetivas sobre a presença ou ausência de zumbido, hipoacusia e tontura/vertigem nas crianças com hipotireoidismo congênito. Resultados: não houve associação entre fatores socioeconômicos e adesão ao tratamento ou percepção dos sintomas cócleo-vestibulares. Conclusões: os fatores socioeconômicos não influenciaram na adesão ao tratamento nem na percepção de sintomas cócleo-vestibulares pelos cuidadores de crianças com hipotireoidismo congênito.

Quality of life related to symptomatic outcomes in patients with vestibular schwannomas: A Canadian Centre perspective.

Patients with vestibular schwannomas (VS) typically present with hearing loss and tinnitus as well as variable cranial nerve dysfunctions. Surgical resection, stereotactic radiotherapy and/or conservative management employing serial magnetic resonance or computed tomography imaging serve as the main treatment options. Quality of life (QoL) may be impacted by the extent of tumour burden and exacerbated or relieved by treatment. Subjective assessment and quality of life inventories provide valuable information in client centered approaches with important implications for treatment. The intention of QoL measurements affecting VS patients within a clinical setting is to facilitate discussions regarding treatment options and objectively evaluate patient- centered clinical outcomes in a naturalistic setting.

Bony cochlear nerve canal stenosis in pediatric unilateral sensorineural hearing loss.

OBJECTIVES: This study was performed to evaluate the frequency of bony cochlear nerve canal (BCNC) stenosis and its clinical significance in pediatric patients with unilateral sensorineural hearing loss (SNHL) of unknown etiology. MATERIALS AND METHODS: We analyzed the medical records and temporal bone computed tomography (CT) results of patients less than 13 years of age with a diagnosis of unilateral SNHL of unknown etiology between July 2007 and July 2017. We compared the BCNC diameter between both sides and analyzed the age at diagnosis, degree of hearing loss, and accompanying inner ear anomalies. RESULTS: In 42 patients, the mean age at diagnosis was 7.4 ±â€¯3.6 years, and the average hearing level in the affected ear was 87.9 ±â€¯20.0 dB HL (decibels hearing level). The average diameter of the BCNC was 1.22 ±â€¯0.75 mm on the affected side and 1.96 ±â€¯0.52 mm on the normal side. The most suitable criterion for BCNC stenosis appeared to be a diameter of 1.2 mm by the recursive partitioning procedure. With application of this criterion, the rate of BCNC stenosis was significantly greater on the affected side than on the normal side (52.4% vs. 4.8%, respectively; P < 0.05). A narrow internal acoustic canal was found in two patients, and vestibular and cochlear anomalies were found in three patients each. CONCLUSIONS: Our results suggest that it is reasonable to set a diameter of 1.2 mm as a cutoff for BCNC stenosis, and also that BCNC stenosis is a common cause of unilateral SNHL of unknown etiology in childhood.

The management of pediatric hearing loss caused by auditory neuropathy spectrum disorder.

PURPOSE OF REVIEW: Auditory neuropathy spectrum disorder (ANSD) is a condition in which auditory testing reveals normal otoacoustic emissions, but auditory brainstem testing is abnormal or absent and speech discrimination is poor. This constellation of findings ostensibly suggests that the cochlea is healthy and an abnormality of conduction or processing of sound occurs along the nerve fibers. As more is learned about this condition, it is becoming clear that ANSD describes heterogeneous, distinct clinical entities that must be taken into account when devising treatment modalities. RECENT FINDINGS: Modern auditory testing, genetic testing, and neuroimaging can allow for an accurate understanding of the location of the lesion causing ANSD in the auditory pathway. Contributing causes can include genetic mutations, absent or deficient cochlear nerve, hypoxia and jaundice among others. Hearing aids can be successful in the management of ANSD. Several studies suggest that cochlear implantation can lead to successful hearing outcomes in a subset of this patient population. SUMMARY: Auditory neuropathy spectrum disorder represents a relatively rare but important diagnosis for clinicians. Treatment for this condition includes hearing aids and FM systems in more mild cases, and cochlear implants in severe cases. Cochlear implantation for many patients can lead to a good hearing outcomes but the outcome can vary greatly depending on the underlying etiology of ANSD.

Sensitivity and specificity of vestibular bed-side examination in detecting VIII cranial nerve schwannoma with sensorineural sudden unilateral hearing loss as presenting symptom.

The objectives of this study were to identify signs of vestibular nerve suffering through a bedside vestibular examination protocol in case of sudden sensorineural unilateral hearing loss without spontaneous signs of vestibular impairment and to propose a bed-side vestibular examination based protocol for the focused execution of gadolinium-enhanced magnetic resonance imaging (MRI) only if a vestibular schwannoma is suspected. 96 patients, 52 men, 44 women, mean age 57.73 +/- 12.85 years, suffering from sudden sensorineural unilateral hearing loss, which presented neither vertigo nor spontaneous nystagmus, were enrolled. Pure tone audiometry, tympanometry, measurement of acoustic reflexes and Anderson test to detect adaptation, bedside vestibular examination through head shaking test, vibration test, head impulse test, hyperventilation test and detection of nystagmus in supine and lateral decubitus to search for signs of vestibular impairment were performed. Patients with signs of vestibular impairment and pure tone audiometry threshold at high frequencies better than 70 dB nHL were subjected to auditory brainstem responses. Gadolinium enhanced MRI centred on internal acoustic canals was carried out in all patients with sudden sensorineural unilateral hearing loss. Main outcome measures were signs of vestibular impairment at vestibular bedside examination and presence of vestibular schwannoma on MRI. Signs of vestibular impairment were detected in 22/96 cases (22.9%); a vestibular schwannoma was detected by MRI in 5/96 cases (5.2%), always when vestibular impairment was present. In case of sudden sensorineural unilateral hearing loss, vestibular bedside examination seems to be useful to restrict the suspicion of a vestibular schwannoma to cases with signs of vestibular impairment, reducing the number of MRI exams, with considerable economic savings.

The Role of MRI in Diagnosing Neurovascular Compression of the Cochlear Nerve Resulting in Typewriter Tinnitus.

BACKGROUND AND PURPOSE: Typewriter tinnitus, a symptom characterized by paroxysmal attacks of staccato sounds, has been thought to be caused by neurovascular compression of the cochlear nerve, but the correlation between radiologic evidence of neurovascular compression of the cochlear nerve and symptom presentation has not been thoroughly investigated. The purpose of this study was to examine whether radiologic evidence of neurovascular compression of the cochlear nerve is pathognomonic in typewriter tinnitus. MATERIALS AND METHODS: Fifteen carbamazepine-responding patients with typewriter tinnitus and 8 control subjects were evaluated with a 3D T2-weighted volume isotropic turbo spin-echo acquisition sequence. Groups 1 (16 symptomatic sides), 2 (14 asymptomatic sides), and 3 (16 control sides) were compared with regard to the anatomic relation between the vascular loop and the internal auditory canal and the presence of neurovascular compression of the cochlear nerve with/without angulation/indentation. RESULTS: The anatomic location of the vascular loop was not significantly different among the 3 groups (all, P > .05). Meanwhile, neurovascular compression of the cochlear nerve on MR imaging was significantly higher in group 1 than in group 3 (P = .032). However, considerable false-positive (no symptoms with neurovascular compression of the cochlear nerve on MR imaging) and false-negative (typewriter tinnitus without demonstrable neurovascular compression of the cochlear nerve) findings were also observed. CONCLUSIONS: Neurovascular compression of the cochlear nerve was more frequently detected on the symptomatic side of patients with typewriter tinnitus compared with the asymptomatic side of these patients or on both sides of control subjects on MR imaging. However, considering false-positive and false-negative findings, meticulous history-taking and the response to the initial carbamazepine trial should be regarded as more reliable diagnostic clues than radiologic evidence of neurovascular compression of the cochlear nerve.

Hearing impairment in a female infant with interstitial deletion of 2q24.1q24.3.

Patients with interstitial deletions in 2q24.1q24.3 are rarely reported. These patients manifest a variety of clinical features in addition to intellectual disability, depending on the size and location of the deletion. We report a female patient with interstitial deletion of 5.5 Mb in 2q24.1q24.3, who showed intrauterine growth retardation, hypotonia, global developmental delay, microcephaly, and characteristic facial appearance. In addition, she had hearing impairment, with no auditory brainstem response. Case of 2q24.1q24.3 deletion with hearing impairment is quite rare. We suspect that hearing impairment is caused by bilateral cochlear nerve deficiency due to cochlear nerve canal stenosis. Further studies are necessary to evaluate hearing impairment as a clinical feature in patients with de novo heterozygous 2q24.1q24.3 deletion.

[Intraoperative monitoring of cochlear nerve function during cerebello-pontine angle surgery]. / Intraoperatives Monitoring des N. cochlearis bei Eingriffen im Kleinhirnbrückenwinkel.

BACKGROUND: Surgical procedures in the cerebello-pontine angle (CPA), e. g. for vestibular schwannoma, have an increased risk for damage to the cochlear nerve. Consequently, hearing deterioration up to complete deafness may result with severe impact on quality of life. Methods for intraoperative monitoring of function may minimize such risks. OBJECTIVE: Review of current methods for intraoperative monitoring of the cochelar nerve and summary of new developments. MATERIALS AND METHODS: Analysis and summary of literature, discussion of new methods. RESULTS: Early auditory evoked potentials using click stimuli remain the standard method for intraoperative monitoring of cochlear nerve function. Amplitude and latency changes indicate a risk of postoperative hearing deterioration; however demonstrate only limited further differentiation of hearing quality. As novel methods, near-field recordings may allow faster feedback and auditory steady state responses potentially enable frequency specific testing. CONCLUSIONS: Intraoperative monitoring of the cochlear nerve is an integral component of CPA surgery. It enables detection of potential nerve damage and thus contributes to avoiding postoperative functional deficits. Development and implementation of novel and additional approaches may further improve its clinical value.

Deficiencia del nervio coclear: logros obtenidos y expectativas con el implante coclear / Coclear nerve deficiency: achievements and expectations with the coclear implant / Deficiência de nervos coculares: realizações e expectativas como implante cocular

Introducción: la deficiencia del nervio coclear se define como un nervio coclear hipoplásico o aplásico, presente en más del 18% de los niños con hipoacusias neurosensoriales profundas y cuya indicación de implante coclear sigue generando controversias. Objetivo: Analizar el protocolo de estudio en pacientes con sospecha de deficiencia del nervio coclear y exponer los resultados clínico-audiológicos pos-implante coclear en nuestro servicio. Material y método: Estudio retrospectivo de historias clínicas en el período 2011-2017, analizando los estudios solicitados dentro de la evaluación preimplante coclear y el estudio extendido en pacientes con sospecha de deficiencia del nervio coclear. Resultados: Dentro de la población, un caso correspondió a un paciente con hipoacusia neurosensorial profunda bilateral con sospecha de deficiencia del nervio coclear (Birman: GRADO I y Casselman: TIPO I/IIa bilateral). El potencial evocado auditivo de tronco encefálico eléctrico permitió determinar el oído a implantar, mostrando mejor configuración de ondas para el oído derecho. Actualmente, presenta una óptima adaptación al implante (categoría de performance auditivo: 2-categoría de Moog-Geers: 3), con una puntuación de 8/40 en el cuestionario IT-MAIS. Conclusión: El protocolo de estudio prequirúrgico extendido es aplicable a pacientes con sospecha de deficiencia del nervio coclear. Estudios funcionales aportan datos de utilidad para determinar cuál de estos pacientes podrían beneficiarse tras la colocación del mismo. El asesoramiento familiar sobre las limitaciones y los objetivos reales es fundamental.

Introduction: cochlear nerve deficiency is defined as a hypoplastic or aplastic cochlear nerve present in more than 18% of children with profound sensorineural hearing loss. Cochlear implant indication continues to generate controversy. Objective: Analyze the study protocol in patients with suspected cochlear nerve deficiency and expose the clinical-audiological results after cochlear implant in our service. Material and method: Retrospective study of medical records in the period 2011-2017. Analyzing the studies requested within the cochlear pre-implant evaluation and the extended study in patients with suspected cochlear nerve deficiency. Results: Within the population, one case corresponded to a patient with bilateral profound sensorineural hearing loss with suspicion of Cochlear nerve deficiency (Birman GRADE I and Casselman TYPE I/IIa bilateral). The auditory evoked potentials by electrical stimulation allowed to determine the ear to be implanted, showing better configuration of waves for the right ear. Currently, it presents an optimal adaptation to the implant (Auditory per formance category: 2- Category of Moog-Geers: 3), with a score of 8/40 in the IT-MAIS questionnaire. Conclusion: The extended preoperative study protocol is appropriate for patients with suspected cochlear nerve deficiency. Functional studies provide useful data to determine which patients could benefit. Family counseling about real limitations and goals is critical.

Introdução: a deficiência do nervo coclear é definida como um nervo coclear hipoplásico ou aplástico presente em mais de 18% das crianças com perda auditiva neurossensorial profunda onde a indicação do implante coclear continua a gerar polêmica. Objetivo: Analisar o protocolo do estudo em pacientes com suspeita de deficiência do nervo coclear e apresentar os resultados clínico-audiológicos após o implante coclear em nosso serviço. Material e método: Estudo retrospectivo dos registros clínicos no período de 2011-2017, analisando os estudos solicitados na avaliação pré-implante coclear e o estudo prolongado em pacientes com suspeita de deficiência de nervo coclear. Resultados: Dentro da população, um caso correspondeu a um paciente com perda auditiva neurossensorial profunda bilateral com suspeita de deficiência do nervo coclear (Birman: GRADO I e Casselman: TIPO bilateral I/IIa). O potenciais evocados auditivos elétrico permitiu determinar a orelha a ser implantada, mostrando melhor configuração de ondas para a orelha direita. Atualmente, apresenta uma ótima adaptação ao implante (categoria de desempenho auditivo: 2- categoria de Moog-Geers: 3), com uma pontuação de 8/40 no questionário IT-MAIS. Conclusão: O protocolo de estudo pré-operatório estendido é aplicável a pacientes com suspeita de deficiência do nervo coclear. Estudos funcionais fornecem dados úteis para determinar quais pacientes poderiam se beneficiar do implante coclear. O aconselhamento familiar sobre limitações e metas reais é crítico.

Malignant peripheral nerve sheath tumors of the eighth cranial nerve arising without prior irradiation.

OBJECTIVE Malignant peripheral nerve sheath tumors (MPNSTs) of the eighth cranial nerve (CN) are exceedingly rare. To date the literature has focused on MPNSTs occurring after radiation therapy for presumed benign vestibular schwannomas (VSs), while MPNSTs arising without prior irradiation have received little attention. The objectives of the current study are to characterize the epidemiology, clinical presentation, disease course, and outcome using a large national cancer registry database and a systematic review of the English literature. Additionally, a previously unreported case is presented. METHODS The authors conducted an analysis of the Surveillance, Epidemiology, and End Results (SEER) database, a systematic review of the literature, and present a case report. Data from all patients identified in the SEER database with a diagnosis of MPNST involving the eighth CN, without a history of prior radiation, were analyzed. Additionally, all cases reported in the English literature between January 1980 and March 2015 were reviewed. Finally, 1 previously unreported case is presented. RESULTS The SEER registries identified 30 cases between 1992 and 2012. The average incidence was 0.017 per 1 million persons per year (range 0.000-0.0687 per year). The median age at diagnosis was 55 years, and 16 (53%) were women. Thirteen cases were diagnosed upon autopsy. Of the 17 cases diagnosed while alive, the median follow-up was 118 days, with 3 deaths (18%) observed. When compared with the incidence of benign VS, 1041 VSs present for every 1 MPNST arising from the eighth CN. Including a previously unreported case from the authors' center, a systematic review of the English literature yielded 24 reports. The median age at diagnosis was 44 years, 50% were women, and the median tumor size at diagnosis was 3 cm. Eleven patients (46%) reported isolated audiovestibular complaints typical for VS while 13 (54%) exhibited facial paresis or other signs of a more aggressive process. Treatment included microsurgery alone, microsurgery with adjuvant radiation, or microsurgery with chemoradiation. Sixty-one percent of patients receiving treatment experienced recurrence, 22% of which were diagnosed with drop metastases to the spine. Ultimately, 13 patients (54%) died of progressive disease at a median of 3 months following diagnosis. The ability to achieve gross-total resection was the only feature that was associated with improved disease-specific survival. CONCLUSIONS MPNSTs of the eighth CN are extremely rare and portend a poor prognosis. Nearly half of patients initially present with findings consistent with a benign VS, often making an early diagnosis challenging. In light of these data, early radiological and clinical follow-up should be considered in those who elect nonoperative treatment, particularly in patients with a short duration of symptoms or atypical presentation. These data also provide a baseline rate of malignancy that should be considered when estimating the risk of malignant transformation following stereotactic radiosurgery for VS.