Location and Timing of Initial Osteoid Deposition in Postmeningitic Labyrinthitis Ossificans Determined by Multiple Fluorescent Labels

Brazilian Society of Otology task force - cochlear implant ‒ recommendations based on strength of evidence

OBJECTIVE

To make evidence-based recommendations for the indications and complications of Cochlear Implant (CI) surgery in adults and children.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on cochlear implantation were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: (1) Evaluation of candidate patients and indications for CI surgery; (2) CI surgery - techniques and complications.

CONCLUSIONS

CI is a safe device for auditory rehabilitation of patients with severe-to-profound hearing loss. In recent years, indications for unilateral hearing loss and vestibular schwannoma have been expanded, with encouraging results. However, for a successful surgery, commitment of family members and patients in the hearing rehabilitation process is essential.

Neurological sequelae after childhood bacterial meningitis

The purpose of this study is to evaluate childhood bacterial meningitis (BM): incidence, clinical presentation, causative pathogens, diagnostics, and outcome (neurological sequelae, hearing loss, and death). A retrospective review of all children aged ≤ 16 years and 1 month diagnosed with BM at a tertiary children's centre in the period 2010-2020. The Glasgow Outcome Scale (GOS) was used to assess outcome, with a GOS score of 1-4 considered to be an unfavourable outcome. Logistic regression univariate analysis was used to determine predefined risk factors for death, unfavourable outcome, and long-term neurological sequelae. Seventy-four patients (44 males) with a median age of 8.0 months (range 1 day to 16 years and 1 month) and 77 BM episodes were included in the study. The average incidence rate of BM was 2.2/100,000/year, the majority (91%) being community-acquired BM. Streptococcus pneumonia and Neisseria meningitidis were the most common pathogens 12/77 (16%) each. Neurological sequelae at discharge were present in 24 (34%) patients, unfavourable outcome in 19 (25%), and hearing loss (deafness) in two (3%) survivors of BM. Seven (9%) patients died. Long-term neurological sequelae were observed in 19/60 (32%), aphasia/dysphasia being the most common in 10 (17%) BM children. No independent risk factors were identified for long-term neurological sequelae in univariate analysis.

CONCLUSION

The risk for a fatal course of BM is still remarkable. Neurological sequelae persisted in a substantial proportion of BM survivors in long-term follow-up, aphasia/dysphasia being the most common. Hearing loss (deafness) occurred in 3%. However, no specific risk factors predicting the long-term sequelae were found.

WHAT IS KNOWN

• Streptococcus pneumonia and Neisseria meningitidis were the most common pathogens causing bacterial meningitis. • Risk for fatal course of bacterial meningitis (BM) remains remarkable despite advances in modern medicine.

WHAT IS NEW

• In long-term follow-up, 1/3 of BM children suffered from neurological sequelae in the 2010s, aphasia and dysphasia being the most common sequelae. • Hearing loss was diagnosed in only two (3%) children, whom of both were deaf.

Cochlear implantation for rare Streptococcus suis meningitis with hearing loss

OBJECTIVES

This study aimed to explore the diagnostic sensitivity of 3D heavily weighted T2-weighted MRI (T2MRI) and high-resolution computed tomography (HRCT) in patients with cochlear fibrosis associated with Streptococcus suis (S. suis) meningitis and the practicality of Cochlear implantation (CI) treatments.

METHODS

Between January 2020 and December 2022, we enrolled four patients with rare cochlear S. suis meningitis with associated hearing loss despite aggressive or non-aggressive follow-up antibiotic treatment. Clinical imaging data, surgical performances and post-surgical-electrode impedance were evaluated.

RESULTS

Combined with HRCT and T2MRI, the cochlea had varying degrees of fibrosis and ossification in different cases. However, the electrodes were successfully and wholly inserted after intraoperative removal of the ossified and fibrotic foci. Post-surgical electrode impedance values of MP1 + 2 mode were normal in all 4 cases at initial activation.

CONCLUSION

In patients with S. suis meningitis and associated cochlear fibrosis, T2MRI examination of the inner ear was more sensitive than HRCT. This research highlights the feasibility of CI treatment in S. suis meningitis patients with severe cochlear fibrosis.

Cochlear Implantation by Veria Technique in Abnormal Cochlea: Our Experience

This study describes the clinical profile, operative findings, surgical technique, type of implant and complications encountered in implantation of abnormal cochlea by the transcanal (veria) technique in a tertiary care centre. This is a retrospective study done amongst 337 patients who underwent cochlear implantation by veria technique between January 2013 to August 2023. Based on pre-operative imaging with high-resolution computed tomography and magnetic resonance imaging the cochleovestibular malformations in this study were classified according to Sennaroglu classification and the cochlear ossification was graded from I to IV. Amongst the 337 patients who underwent cochlear implantation during the study period there were 79 cases (23.4%) with abnormalities of cochlea. This included 45 patients (13.4%) with congenital malformations, 20 patients (5.9%) with cochlear fibrosis and 14 patients (4.2%) with cochlear ossification. The commonest cochlear malformation was Incomplete Partition 2 which was present in 21 patients (46.7%). The other common malformations were cochlear hypoplasia (31.1%), Incomplete Partition 1(13.3%) and common cavity (8.9%). Out of the 20 patients with cochlear fibrosis, 17 patients had fibrosis only in the basal turn. Out of the 14 patients with cochlear ossification 8 patients (57.1%) had a grade 1 ossification, 2 patients (14.3%) had a grade 2 ossification and 4 patients (28.6%) had a grade 3 ossification. One of the patients required re-exploration for correcting the placement of electrode. The type of implant were chosen depending on individual malformation or length of ossification and fibrosis. In the past, inner ear anomalies were considered as a contraindication for cochlear implantation however it is now possible to implant most of these abnormal cochlea by careful planning, a modification of the surgical technique and the type of electrode used.

Cochlear Implantation in Children with Meningitis: A Multicenter Study on Auditory Performance and Speech Production Outcomes

BACKGROUND

This study aims to evaluate speech production outcomes and auditory performance in children with post-meningitis deafness who were treated with cochlear implants. Additionally, the study assesses the impact of electrode insertion depth on surgical outcomes.".

METHODS

We conducted a study on 66 pediatric patients with bilateral postmeningitis hearing loss who were being prepared for cochlear implantation at four tertiary referral academic institutions. The speech intelligibility rating (SIR) and categories of auditory performance (CAP) were evaluated after the first and second years following implantation. The patients were divided into two groups based on electrode insertion depth: one group had full electrode insertion (more than two-thirds), while the other had partial electrode insertion (less than two-thirds). We compared the SIR and CAP scores between the two groups to assess the impact of electrode insertion depth on outcomes.

RESULTS

Before implantation, the median CAP score was one, but it improved significantly to six within two years after the procedure (P-value < 0.001). Similarly, the median SIR score before implantation was one, but it improved significantly to three within two years after surgery (P-value < 0.001). However, there was no significant difference between the partial and full electrode insertion groups in terms of CAP and SIR scores during the follow-up evaluations conducted after the first and second years.

CONCLUSION

The study found that cochlear implantation significantly improved speech production skills and auditory performance in children with postmeningitis deafness. Importantly, the amount of electrode insertion at the time of implantation did not have a significant impact on the outcomes.

Cochlear implantation in patients with Streptococcus suis meningitis: clinical characteristics and postoperative evaluation

BACKGROUND

Hearing loss is a common sequala of Streptococcus suis (S. suis) meningitis, but few have addressed cochlear implantation (CI) candidates with S. suis meningitis.

OBJECTIVES

To assess the clinical characteristics and CI postoperative outcomes in S. suis meningitis patients.

MATERIAL AND METHODS

Eight S. suis meningitis patients underwent CI at Sun Yat-sen Memorial Hospital between 2020 and 2023. Control groups included (1) non-Suis meningitis patients (n = 12) and (2) non-meningitis patients (n = 35). Electrode impedances and neural response telemetry (NRT) thresholds were recorded at one month after surgery. The auditory performance-II (CAP) and speech intelligibility rating (SIR) were recorded at the last visit.

RESULTS

CAP scores of S. suis meningitis patients were significantly lower than those of non-Suis meningitis and non-meningitis patients (p = .019; p<.001). And NRT thresholds of S. suis meningitis patients were higher than those of non-Suis meningitis and non-meningitis patients (p = .006; p = .027).

CONCLUSIONS AND SIGNIFICANCE

It is recommended for S. suis meningitis CI candidates to undergo CI promptly after controlling infection, preferably within four to six weeks. CI users with S. suis meningitis tend to exhibit suboptimal hearing rehabilitation outcomes, possibly associated with the more severe damage on spiral ganglion cells after S. suis meningitis.

Postmeningitic pediatric hearing loss from non-type b Haemophilus influenzae

BACKGROUND

Postmeningitic hearing loss from Haemophilus influenzae (H. influenzae) is increasingly due to encapsulated serotypes other than type b (Hib) and nontypeable strains (collectively, nHiB H. influenzae). Pediatric hearing loss after nHib H. influenzae meningitis remains poorly described.

METHODS

Retrospecive case series of nHiB H. influenzae meningitis cases identified from a microbiologic database at Children's Hospital Colorado from 2000 to 2020. Literature regarding nHiB H. influenzae and H. influenzae postmeningitic hearing loss was also reviewed.

RESULTS

Eleven cases of nHib H. influenzae meningitis (median age 15.9 months) were identified due to serotype f (36 %), serotype a (27 %), and nontypable strains (36 %). Seven (64 %) patients were male, 55 % were white and 18 % were Hispanic or Latino. Hearing loss was initially identified in 4 children (40 %), with two patients with moderate conductive hearing loss (CHL) and one child with unilateral moderate sensorineural (SNHL) hearing loss patients recovering normal hearing. One patient with bilateral profound sensorineural hearing loss and associated labyrinthitis ossificans required cochlear implantation. All children (4) with identified hearing loss were noted to have additional intracranial sequelae, which included empyema (2), sinus thrombosis (2), and seizures (2). Of patients receiving steroids, 25 % had hearing loss on initial testing, compared to 66 % of those who did not receive steroids.

CONCLUSIONS

nHib H. influenzae can cause both transient and permanent postmeningitic hearing loss. Steroids may offer otoprotection in nHib H. influenzae meningitis similar to Hib meningitis. Given the limited literature, further study is needed to better characterize hearing outcomes after nHib H. influenzae meningitis.

Successful Cochlear Implantation for Intracochlear Fibrosis

Intracochlear fibrosis is a rare disorder that can lead to hearing loss and make cochlear implantation challenging. The etiology of intracochlear fibrosis is diverse, including infections, inflammation, and past surgical procedures. The condition causes ossification and scar tissue growth within the cochlea, leading to progressive obstruction of the cochlear turn. High-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) are sensitive diagnostic modalities for fibrosis and ossification. There is a paucity of information in the literature regarding cochlear implantation during the fibrotic stage. This case report discussed the presentation, diagnosis, and surgical management of intracochlear fibrosis in a patient with a history of sudden and severe hearing loss. A 44-year-old female patient with a 20-year history of sudden profound sensorineural hearing loss (SNHL) in both ears was successfully treated with cochlear implantation. Thorough preoperative planning for cochlear implantation, including HRCT and MRI cochlear protocol, is crucial for identifying intracochlear fibrosis, which can be missed on routine audiometry. She underwent a surgery for right cochlear implantation using postauricular approach. Drilling was done to the round window niche, and we removed an abnormal, chalky white bone we encountered by continuing to drill this abnormal bone following the scale tympani until we identified the opening of the scala tympani, then we inserted the cochlear implant device. She was doing well on the subsequent post-operative follow-up.  Intracochlear fibrosis treatment with cochlear implantation has proven successful in several studies. Audiologic outcomes vary with time to implantation, so an early attempt should be made for cochlear implantation. Follow-up is important to monitor auditory outcomes.

Simultaneous Cochlear Implantation and Salvage Translabyrinthine Resection of Vestibular Schwannoma after Radiotherapy

OBJECTIVE

To report on the novel use of simultaneous cochlear implantation (CI) during salvage translabyrinthine resection of vestibular schwannoma (VS) after failed stereotactic radiosurgery (SRS).

PATIENT

A 52-year-old woman presented with a medium-sized right VS. She experienced continued tumor growth despite previous SRS, resulting in medial extension beyond the internal auditory canal into the cerebellopontine angle. Associated symptoms included asymmetrical right moderate to severe sensorineural hearing loss, poor word recognition, tinnitus, and dizziness.

INTERVENTION

Simultaneous CI with translabyrinthine VS resection.

MAIN OUTCOME MEASURE

CI-aided pure-tone averages.

RESULTS

After 4 months of device use, CI-aided speech audiometry revealed hearing thresholds in the normal range, with a four-tone pure-tone, average of 16.3 dB. Speech perception with consonant-nucleus-consonant testing in the CI-only condition was 46%, representing a 12% improvement compared with preoperatively. Tinnitus and dizziness burden were subjectively reduced.

CONCLUSIONS

Despite challenges inherent to second procedures after radiotherapy failure, successful CI outcomes can be achieved. The current study demonstrates the feasibility of simultaneous CI during salvage VS resection after SRS. A larger study should be undertaken to further substantiate these preliminary findings.

Protocol for Evaluation and Management of Hearing Loss After Meningitis

Bacterial meningitis is the most common cause of post-natal acquired hearing loss in children. Although cochlear implantation helps in improving the hearing in these patients, the fibrosis and ossification of the cochlear lumen that occurs as a result of bacterial meningitis, limits the chances of successful implantation. In developing countries like India, the reduced awareness, limited resources, and financial constraints warrant judicial use of radiological and audiological tests to increase the rate of successful cochlear implantation. The present paper is a review of the literature and a proposed protocol for follow-up of post-meningitis patients to help clinicians diagnose and hence, intervene early when profound hearing loss occurs. Every patient who has had an episode of bacterial meningitis must be followed up for atleast 2 years for possible hearing loss with frequent audiological and radiological evaluation, as required. Cochlear implantation must be done as early as possible when profound hearing loss is detected.

Hearing impairment in Angolan children with acute bacterial meningitis with and without otitis media

AIM

Bacterial meningitis (BM) is a common cause of hearing loss in childhood. Our aim was to investigate bacterial aetiology, hearing impairment and outcome in childhood BM with vs. without otitis media (OM) in Angola.

METHODS

Hearing was tested by auditory brainstem response in 391 (76%) children with confirmed BM. The bacteria identified from the ear discharge were compared to those from cerebrospinal fluid (CSF). The hearing findings were compared among children with vs. without OM on days 1 and 7 of hospitalization, and at follow-ups of 1, 3 and 6 month(s).

RESULTS

No correlation was found in bacteriology between the ear discharge and CSF. On day 7 in hospital, hearing impairment (>40 dB) was common, regardless of whether concomitant OM or not (in 27% vs. 30%, respectively). Any hearing deficit on day 7 was associated with a higher risk of complicated or fatal clinical course (OR 2.76, CI_95% 1.43-5.29, p = 0.002).

CONCLUSION

No significant difference prevailed in hearing thresholds between children with or without OM in hospital on day 7 or at later follow-ups. Any hearing impairment during hospital stay associated with a higher risk for complicated clinical course or death.

Cochlear implantation after deafness from Pasteurella multocida meningitis

A woman in her late 40s who works as a veterinary technician represented to the emergency department with increasing headache, confusion, neck stiffness, subjective fevers and distorted hearing 2 days after diagnosis of viral infection at an outside emergency department.Diagnosis of Pasteurella multocida was made from blood cultures and lumbar puncture. Intravenous ceftriaxone was administered for 21 days. By the time of resolution of acute meningitis, she had become completely deaf bilaterally. MRI revealed faint early ossification/possible labyrinthitis ossificans of the basal cochlea, which was confirmed on surgical exploration during the placement of cochlear implants bilaterally 42 days later. We discuss how the atypical features of this infection lead to diagnostic delay and high morbidity, the unique imaging/surgical findings resulting from the infection, and the clinical utility of early and bilateral cochlear implantation in this and similar cases.

Predicting Parameters for Audiological Complications in Pediatric Patients Affected by Meningitis

Objective Meningitis is one of the most common causes of acquired sensorineural hearing loss in childhood. The aim of this study was to identify parameters predicting long-term audiological complications in meningitis.

Methods Patients under 18 years admitted to the Bambino Gesù Pediatric Hospital between March 2001 and February 2019 with a diagnosis of meningitis entered the study. Audiological complications had been investigated during hospitalization and at follow-up.

Results During the study period, 425 patients were enrolled. Sensorineural hearing loss was observed in 48 patients (11.3%). Multivariate analysis has shown that female gender predisposes to the development of permanent hearing loss after meningitis. Hearing impairment was associated with pneumococcal etiology (p < 0.001), lethargy (p = 0.027), reduced cerebrospinal fluid glucose level (26.18 mg/dL, p = 0.004), increase in both C-reactive protein (17.77 mg/dL, p = 0.001), and erythrocyte sedimentation rate (106.3 mm/h, p = 0.004). At follow-up, 19 patients had a persisting hearing damage, 7 recovered their hearing capacity and 20 were lost to follow-up. Among patients with permanent hearing damage, treatment was necessary in 16 patients. In details, 6 patients required external hearing aids and 10 patients required a cochlear implant.

Conclusions Female gender, lethargy at onset, reduced cerebrospinal fluid glucose level, increased inflammation index, and pneumococcal etiology are correlated with sensorineural hearing damage in meningitis patients.

Revision cochlear implantation using a double array device in the post-meningitis ossified cochlea

PURPOSE

To describe the surgical technique and outcome in a series of patients who underwent revision cochlear implantation using a double array or split electrode device. All patients developed ossified cochleae due to meningitis and were functioning poorly with the previous implant.

METHODS

Four patients between the ages of 4-15 years underwent revision with five double-array cochlear implant devices. One patient underwent bilateral revision surgery. All patients had previous meningitis with CT and MRI imaging studies that demonstrated completely ossified cochleae. The time interval range between the disease and the initial cochlear implantation and was 4 months to 3 years. The patient's data were retrospectively analyzed with emphasis on the surgical technique, the number of electrodes inserted, and the number of active electrodes at follow-up. In addition, pre and post-revision surgery function was compared.

RESULTS

The revision surgery was carried out 2-11 years after the initial surgery. Two tunnels, basal and apical, were drilled in the ossified cochlea. In each of the tunnels, 5 to 11 electrodes were inserted. While the number of active electrodes before revision was 0-5, after revision with the double array, it was increased to 8-12, resulting in improved auditory and speech function.

CONCLUSION

Revision cochlear implantation with a double array implant using the two tunnel technique can increase the number of active electrodes. This leads to a better outcome in post-meningitis children with completely ossified cochleae and a poor functioning previous device.

Facial nerve stimulation in a post-meningitic cochlear implant user: using computational modelling as a tool to probe mechanisms and progression of complications on a case-by-case basis

Facial nerve stimulation (FNS) is a side-effect of cochlear implantation that can result in severe discomfort for the user and essentially limits the optimal use of the implant. Three-dimensional cochlear implant modelling research has led to the progression from generic models to user-specific models with one of the intentions to develop model-based diagnostic tools. The objective of this study is to investigate the mechanisms that underlie the manifestation of FNS in the post-meningitic cochleae of a specific CI user through computational modelling. Bilateral models were created using a method previously developed for the construction of a three-dimensional user-specific volume conduction model of the cochlea and was expanded to include the facial nerve geometry. Reduced temporal bone density based on bone densitometry, cochlear duct ossification and degenerate auditory neural fibres were incorporated into a comprehensive FNS model. Auditory and facial nerve thresholds were predicted with the models showing good correspondence to perceptual thresholds and the user's FNS experience. Ossified cochlear ducts appear to aggravate the increase in thresholds caused by the otic capsule's decreased resistivity. This translational case study demonstrates the application of computational modelling as a clinical instrument in the assessment and management of complications with cochlear implantation.

Covid-19 and Otologic/Neurotologic Practices: Suggestions to Improve the Safety of Surgery and Consultations

: Since the beginning of 2020, the world has been confronted by the Covid-19 pandemic. The lock-down aims to limit the circulation of the virus and thus avoid overwhelming healthcare systems. Healthcare workers have had to adapt by postponing consultation and surgical activities. Otolaryngologists are particularly exposed to infection from the upper airway where the virus is highly concentrated. Literature has previously reported other human coronaviruses in the middle ear and mastoid, suggesting a risk of infection to staff during ear surgery where aerosolizing procedures are usually used. The aim of this article is to propose a strategy for planning consultations and surgeries for ear and lateral skull base diseases, in the context of the current active evolution of the pandemic and of the future gradual recovery to normal practice.

Otopathologic Analysis of Patterns of Postmeningitis Labyrinthitis Ossificans

OBJECTIVE

Labyrinthitis ossificans (LO) may occur following meningitis and, in cases where cochlear implantation is indicated, complicate electrode insertion. LO is critical to identify for successful cochlear implantation, and histopathology is more sensitive than imaging for identification of LO. Herein we utilize otopathologic techniques to study the timing and location of intracochlear tissue formation following meningitic labyrinthitis (ML).

STUDY DESIGN

Retrospective review.

SETTING

Academic institution.

METHODS

Temporal bone specimens with a history of bacterial ML were histologically evaluated. The location and extent of intracochlear tissue formation within the scala tympani (ST) and scala vestibuli (SV) were graded, and spiral ganglion neurons were counted.

RESULTS

Fifty-one temporal bones were identified: 32 with no intracochlear tissue formation, 9 with fibrosis alone, and 10 with LO. Fibrosis was identified as early as 1.5 weeks after ML, while ossification was found only in specimens that survived multiple years after ML. All LO cases showed ossification of the ST at the round window membrane (RWM) with continuous extension throughout the basal turn. Extent of SV ossification correlated with that in the ST but showed frequent isolated distal involvement of the cochlea. Spiral ganglion neuron counts were lower than those in age-matched controls.

CONCLUSION

In this human temporal bone study, we found that postmeningitic LO results in ossification at the RWM with continuous extension into the ST of the basal turn and variable involvement of the SV. Identification of a patent basal turn beyond RWM ossification of the ST should permit full electrode insertion.

LEVEL OF EVIDENCE

Retrospective review.

Does the practice of sports or recreational activities improve the balance and gait of children and adolescents with sensorineural hearing loss? A systematic review

BACKGROUND

Balance and gait disorders have been observed in children and adolescents with sensorineural hearing loss (SNHL), justified by vestibular dysfunctions that these children may present, due to the injury to the inner ear. Therefore, some investigations have suggested that the practice of sports or recreational activities can improve the balance and gait of this population.

OBJECTIVE

Assess the evidence quality from randomized or quasi-randomized controlled trials that used sports or recreational activities as an intervention to improve the balance and /or gait of children and/or adolescents with SNHL.

METHODS

Systematic review that surveyed articles in nine databases, published up to January 10, 2019, in any language, using the following inclusion criteria: (1) Randomized or quasi-randomized controlled trials. (2) Participants from both groups with the clinical diagnosis of SNHL, aged 6-19 years old, without physical problems, cognitive or neurological deficits, except the vestibular dysfunction. (3) Using the practice of sports or recreational activities as an intervention, to improve the balance and/or gait outcomes.

RESULTS

4732 articles were identified in the searches, after the removal of the duplicates articles and the reading of the titles and their abstracts, remained 16 articles for reading in full, being 5 trials eligible for this systematic review. Of the five eligible trials, three used sports activities and two recreational activities as intervention and presented very low-quality evidence for balance and gait outcomes.

SIGNIFICANCE

Sports and recreational practices seem to represent promising modalities to improve the balance and gait of children and adolescents with SNHL. However, due to the methodological limitations of the trials and the low quality of the current evidence on the topic, the results of the trials should be interpreted with caution. Due to the low quality of evidence observed, we suggest that new trials be proposed on this topic, with greater methodological rigor, to provide high-quality evidence on the effectiveness of sports and recreational practices to improve the balance and gait of children and adolescents with SNHL.

Human Otopathologic Findings in Cases of Folded Cochlear Implant Electrodes

HYPOTHESIS

We hypothesize that human cases of cochlear implantation (CI) with folding of the electrode array will demonstrate greater degrees of intracochlear ossification, lower spiral ganglion neuron (SGN) counts, and poorer audiometric outcomes.

BACKGROUND

CI electrode array folding, such folding of the proximal array, is a relatively common surgical complication that can occur with forceful electrode insertion and may be an important and avoidable factor affecting implant outcomes. However, otopathologic findings and audiologic outcomes of human cases where folding of the implant electrode array is observed remain undefined.

METHODS

Specimens from a human temporal bone repository having undergone CI during life were evaluated. Specimens with folding of the electrode array on histological analysis constituted study cases. Electrode-matched specimens without array folding constituted controls. All specimens were examined by light microscopy and histopathologically described. Intracochlear fibrosis and osseous tissue, and SGN counts were measured. Pre- and postoperative word recognition scores were also compared.

RESULTS

Cases with folded electrodes showed greater volumes of intracochlear osseous tissue than controls, which was most prominent in areas adjacent to array folding. Both cases and controls demonstrated similar amounts of fibrous tissue. Folded cases showed decreased SGNs when compared with the contralateral ear, whereas controls showed stable SGN populations between ears. In this small cohort, postoperative hearing outcomes were similar between groups.

CONCLUSION

Atypical fibro-osseous changes and lower SGN counts are observed in cases of CI electrode folding. Future studies are necessary to determine if recognition and correction of folding can prevent long-term intracochlear changes.

Cochlear Implant

Cochlear implant is the first approved cranial nerve stimulator that works by directly stimulating the cochlear nerve. The medical and societal impact of this revolutionary device cannot be understated. This article reviews the evolving indications for cochlear implant, patient assessment, surgical approach, and outcomes for pediatric and adult cochlear implant that demonstrate its impact. Future concepts in cochlear implant are introduced briefly. This article covers a breadth of information; however, it is not intended be entirely comprehensive. Rather, it should serve as a foundation for understanding cochlear implant.

Balance performance of children and adolescents with sensorineural hearing loss: Repercussions of hearing loss degrees and etiological factors

INTRODUCTION

Some studies have demonstrated a parallelism between the extent of hearing loss and the frequency of vestibular dysfunction in children with sensorineural hearing loss (SNHL). Despite this, little is known about the repercussion of degrees of hearing loss and etiological factors on the balance performance in this children.

OBJECTIVE

Compare the balance performance between normal hearing (NH) children and those with SNHL, considering the sex and age range of the sample, and analyze balance performance according to the degrees of hearing loss and etiological factors in the latter group.

METHODS

Cross-sectional study that assessed 96 children (48 NH and 48 with SNHL), aged between 7 and 18 years old. The balance performance was assessed by the Brazilian version of the Pediatric Balance Scale, validated for Brazilian child population and the Mann-Whitney test used for statistical analysis.

RESULTS

The group with SNHL showed lower average balance performance compared to NH (p = 0.000). This was also observed when the children were grouped by sex: female and male (p = 0.001). The same difference occurred when the children were stratified by age group: 7-14 years old (p = 0.000). There were no differences between the balance performance of the groups according to the degrees of hearing loss (p = 0.236) and the children with prematurity or post-natal meningitis as an etiological factor demonstrated the worst balance performance.

CONCLUSION

The children with SNHL showed worse balance performance compared to NH of the same sex and age range between seven to fourteen years. There were no differences between balance performance and hearing loss degrees, and those children with prematurity or post-natal meningitis as an etiological factor demonstrated the worst balance performances.

Systematic Review: Incidence and Course of Hearing Loss Caused by Bacterial Meningitis: In Search of an Optimal Timed Audiological Follow-up

OBJECTIVE

The objective of this study was to clarify the incidence and course of hearing loss after bacterial meningitis to optimize the audiological follow-up.

DATA SOURCES

The databases Embase, Medline (OvidSP), Web-of-science, Scopus, Cinahl, Cochrane, PubMed publisher, and Google Scholar were used. Only articles written in English were included.

STUDY SELECTION

Articles published from 1985 until March 2015 describing the incidence, risk factors, or course of hearing loss after meningitis were used.

DATA EXTRACTION

The quality of the studies was assessed on three aspects: quality of audiometry, number of patients, and methodological quality.

DATA SYNTHESIS

For each publication, data were entered in spreadsheet software for analysis. The data were analyzed and interpreted using best evidence synthesis.

CONCLUSIONS

The overall quality of the included studies was poor. A major drawback was the quality of the (description of) audiometry, severity, and timing of hearing loss.A systematic review of the literature showed an incidence of hearing loss (>25 ± 5  dB) of 14% and an incidence of 5% for profound hearing loss (>90  dB). Patients with initial normal hearing after meningitis showed stable normal hearing over time. However, initial hearing loss related to meningitis can improve or deteriorate over time.We therefore recommend early audiological testing of all patients who suffered bacterial meningitis. However, long-term audiological follow-up is only needed for patients with early onset hearing loss and not for patients with normal hearing at the first hearing test.

Correlation between word recognition score and intracochlear new bone and fibrous tissue after cochlear implantation in the human

Cochlear implantation is an effective, established procedure for patients with profound deafness. Although implant electrodes have been considered as biocompatible prostheses, surgical insertion of the electrode induces various changes within the cochlea. Immediate changes include insertional trauma to the cochlea. Delayed changes include a tissue response consisting of inflammation, fibrosis and neo-osteogenesis induced by trauma and an immunologic reaction to a foreign body. The goal of this study was to evaluate the effect of these delayed changes on the word recognition scores achieved post-operatively. Seventeen temporal bones from patients who in life had undergone cochlear implantation were prepared for light microscopy. We digitally calculated the volume of fibrous tissue and new bone within the cochlea using Amira(®) three-dimensional reconstruction software and assessed the correlations of various clinical and histologic factors. The postoperative CNC word score was positively correlated with total spiral ganglion cell count. Fibrous tissue and new bone were found within the cochlea of all seventeen specimens. The postoperative CNC word score was negatively correlated with the % volume of new bone within the scala tympani, scala media/vestibuli and the cochlea, but not with the % volume of fibrous tissue. The % volume of new bone in the scala media/vestibuli was positively correlated with the degree of intracochlear insertional trauma, especially trauma to the basilar membrane. Our results revealed that the % volume of new bone as well as residual total spiral ganglion cell count are important factors influencing post-implant hearing performance. New bone formation may be reduced by limiting insertional trauma and increasing the biocompatibility of the electrodes.

Contralateral implantation in children affected by postimplant meningitis

This study was designed to investigate the indication and advantages of contralateral implantation after postimplant meningitis (piM). Speech perception assessment, most comfortable levels and high-resolution computer tomography were used to monitor cochlear fibrosis/ossification and clinical changes in outcomes in 5 children affected by meningitis after a variable-time post-cochlear implantation. Ipsilateral ossification was found in 3 children, 1 of whom developed delayed contralateral ossification. These children were implanted on the contralateral side as they all showed deterioration of hearing performance. Results from the present paper and literature analysis suggest that, (1) piM can induce ipsilateral and contralateral ossification, (2) meningitis-induced cochlear ossification is more prone to develop in the presence of a normal cochlear structure and (3) contralateral implantation after piM has proven to be effective in restoring performance when a full electrode insertion is accomplished.

Significant sequelae after bacterial meningitis in Niger: a cohort study

BACKGROUND

Beside high mortality, acute bacterial meningitis may lead to a high frequency of neuropsychological sequelae. The Sahelian countries belonging to the meningitis belt experience approximately 50% of the meningitis cases occurring in the world. Studies in Africa have shown that N. meningitidis could cause hearing loss in up to 30% of the cases, exceeding sometimes measles. The situation is similar in Niger which experiences yearly meningitis epidemics and where rehabilitation wards are rare and hearing aids remain unaffordable. The aim of this study was to estimate the frequency of neuropsychological sequelae after acute bacterial meningitis in four of the eight regions of Niger.

METHODS

Subjects exposed to acute bacterial meningitis were enrolled into a cohort with non exposed subjects matched on age and gender. Consenting subjects were interviewed during inclusion and at a control visit two months later. If clinical symptoms or psychological troubles persisted at both visits among the exposed subjects with a frequency significantly greater than that observed among the non exposed subjects, a sequelae was retained. The comparison of the frequency of sequelae between non exposed and exposed subjects to bacterial meningitis was also calculated using the Fisher exact test.

RESULTS

Three persisting functional symptoms were registered: headaches, asthenia, and vertigo among 31.3, 36.9, and 22.4% respectively of the exposed subjects. A significant motor impairment was retrieved among 12.3% of the exposed versus 1.6% of the non exposed subjects. Hearing loss significantly disabled 31.3% of the exposed subjects and 10.4% exhibited a serious deafness.

CONCLUSIONS

This study carried out in Niger confirms two serious neurological sequelae occurring at high frequencies after bacterial meningitis: severe and profound hearing loss and motor impairment. Cochlear implantation and hearing aids are too expensive for populations living in developing countries. Neurological sequelae occurring after meningitis should sensitize African public health authorities on the development of rehabilitation centers. All these challenges can be met through existing strategies and guidelines.

Cochlear ossification in patients with profound hearing loss following bacterial meningitis

CONCLUSION

Cochlear ossification following bacterial meningitis is related to causative pathogen, but not age at disease or time point of evaluation. However, progression may occur over time, especially in case of primary signs of ossification.

OBJECTIVE

To investigate the occurrence and degree of cochlear ossification on CT and MRI in patients with bilateral profound hearing loss following bacterial meningitis, in relation to causative pathogen, age at disease, and time point of evaluation. Progression of ossification in cases that underwent more than one scan was evaluated.

METHODS

In the period 1982-2008, 47 cochlear implantations were performed in 34 consecutive candidates suffering from bilateral profound hearing loss following bacterial meningitis. A retrospective review of patient files and preoperative CT and MR images was performed.

RESULTS

Cochlear ossification was observed in 35% of patients and 26% of ears on CT. The corresponding values for MRI were 44 and 30% (difference not significant). Streptococcus pneumoniae infection caused ossification more frequently than Neisseria meningitidis. No difference was found between pediatric and adult cases, and the occurrence of ossification was not related to the time point of evaluation. Signs of progressive ossification were found in cases with two CT scans, especially if ossification was present at the first scan.

Cochlear implantation after bacterial meningitis in infants younger than 9 months

Objective. To describe the audiological, anesthesiological, and surgical key points of cochlear implantation after bacterial meningitis in very young infants. Material and Methods. Between 2005 and 2010, 4 patients received 7 cochlear implants before the age of 9 months (range 4-8 months) because of profound hearing loss after pneumococcal meningitis. Results. Full electrode insertions were achieved in all operated ears. The audiological and linguistic outcome varied considerably, with categories of auditory performance (CAP) scores between 3 and 6, and speech intelligibility rating (SIR) scores between 0 and 5. The audiological, anesthesiological, and surgical issues that apply in this patient group are discussed. Conclusion. Cochlear implantation in very young postmeningitic infants is challenging due to their young age, sequelae of meningitis, and the risk of cochlear obliteration. A swift diagnostic workup is essential, specific audiological, anesthesiological, and surgical considerations apply, and the outcome is variable even in successful implantations.

Pathogenesis and pathophysiology of pneumococcal meningitis

Pneumococcal meningitis continues to be associated with high rates of mortality and long-term neurological sequelae. The most common route of infection starts by nasopharyngeal colonization by Streptococcus pneumoniae, which must avoid mucosal entrapment and evade the host immune system after local activation. During invasive disease, pneumococcal epithelial adhesion is followed by bloodstream invasion and activation of the complement and coagulation systems. The release of inflammatory mediators facilitates pneumococcal crossing of the blood-brain barrier into the brain, where the bacteria multiply freely and trigger activation of circulating antigen-presenting cells and resident microglial cells. The resulting massive inflammation leads to further neutrophil recruitment and inflammation, resulting in the well-known features of bacterial meningitis, including cerebrospinal fluid pleocytosis, cochlear damage, cerebral edema, hydrocephalus, and cerebrovascular complications. Experimental animal models continue to further our understanding of the pathophysiology of pneumococcal meningitis and provide the platform for the development of new adjuvant treatments and antimicrobial therapy. This review discusses the most recent views on the pathophysiology of pneumococcal meningitis, as well as potential targets for (adjunctive) therapy.

Effects of ultrasound on osteotomy healing in a rabbit fracture model

This study investigated the effects of ultrasound (US) at different frequencies on fracture healing over a three-week period in a rabbit fibular fracture model. Forty-five adult New Zealand White rabbits were divided into five groups: a control group and four groups treated with US frequencies of 0.5, 1.0, 1.5 and 2.0 MHz (0.5 W/cm(2), 200-μs burst, pulsed 1:4). After anesthesia, transverse osteotomy was performed on the fibula bone. This was followed by intravital staining and fluorescence microscopic examination of new bone formation and biomechanical tests of torsional stiffness at the osteotomy site. Results showed that total new bone formation and torsional stiffness of the fibula were greater in all US-treated groups than in the control group. No significant difference was found between any of the four US-treated groups. The US treatment also enhanced bone growth of the sham-treated contralateral fracture site. These results suggest that US treatment at 0.5, 1.0, 1.5 or 2.0 MHz can enhance fracture healing in a rabbit model. Furthermore, the effects of US on fracture healing at present parameters might not be confined locally.

Early prediction of postmeningitic hearing loss in children using magnetic resonance imaging

OBJECTIVE

To determine whether early gadolinium-enhanced magnetic resonance imaging (GdMRI) can reliably detect meningitic labyrinthitis and thereby predict which children are at high risk for hearing loss. Permanent sensorineural hearing loss (SNHL) remains a common sequela of bacterial meningitis, and early diagnosis of the associated suppurative labyrinthitis can be difficult, especially in critically ill, sedated patients and young children.

DESIGN

Retrospective cohort study.

SETTING

Tertiary pediatric hospital.

PARTICIPANTS

Twenty-three survivors of bacterial meningitis (median age, 15 months [range, 3 months-14 years]) who had undergone brain GdMRI during the acute disease and had subsequent ear-specific audiometric data.

MAIN OUTCOME MEASURE

Blinded to disease and outcome, a neuroradiologist rated the relative enhancement of each cochlea on T1-weighted images using a 4-point scale. Scores were then correlated with the degree of hearing loss on subsequent testing.

RESULTS

Sensorineural hearing loss occurred in 15 of 46 ears (8 of 23 patients). Enhancement on GdMRI was detected in 13 of the 15 ears that later developed SNHL but was absent in all 31 unaffected ears. Thus, GdMRI was 87% sensitive and 100% specific for predicting which ears would develop permanent SNHL. In the subgroup with pneumococcal meningitis (n = 15), GdMRI was 100% sensitive and 100% specific. Labyrinthine enhancement was detectable as early as 1 day after diagnosis.

CONCLUSION

Gadolinium-enhanced MRI detected meningitic labyrinthitis at early stages and accurately predicted which patients would later develop hearing loss.

Reduced spiral ganglion neuronal loss by adjunctive neurotrophin-3 in experimental pneumococcal meningitis

Background

Hearing loss is a frequent long-term complication of pneumococcal meningitis (PM). Its main pathological correlate is damage to the organ of Corti and loss of spiral ganglion neurons. The only current treatment option is cochlear implants which require surviving neurons. Here, we investigated the impact of systemically applied neurotrophin-3 (NT-3) on long-term hearing loss and the survival of neurons.

Methods

Eighteen hours after infection with S. pneumoniae, C57BL/6 mice were treated with a combination of ceftriaxone with NT-3 or dexamethasone or placebo. Hearing, cochlear damage, and brain damage were assessed by audiometry and histology.

Results

The main findings from immunohistochemical visualization of neurotrophins (NT-3, BDNF) and their receptors (TrkB, TrkC, and p75) in the cochlea were (i) enhanced staining for the cell survival-promoting receptor TrkB and (ii) increased NT-3 staining in NT-3 treated mice, showing that systemically applied NT-3 reaches the cochlea. The major effects of adjunctive NT-3 treatment were (i) a reduction of meningitis-induced hearing impairment and (ii) a reduction of spiral ganglion neuronal loss. The efficacy of NT-3 therapy was comparable to that of dexamethasone.

Conclusion

Systemically applied NT-3 might be an interesting candidate to improve hearing outcome after pneumococcal meningitis.

Labyrinthitis ossificans: How accurate is MRI in predicting cochlear obstruction?

Objective: To determine the accuracy of preoperative MRI in predicting cochlear obstruction in pediatric patients with a history of bacterial meningitis.

Methods: A case series with chart review was performed at a tertiary care multidisciplinary cochlear implant program. Forty-five children with hearing loss that resulted from bacterial meningitis were implanted from 1991 to 2006. Twenty-five children had preoperative MRI with high-resolution axial T2-weighted images to assess for cochlear patency.

Results: Seventeen of 25 patients (68%) had surgical evidence of cochlear obstruction. Six patients (37.5%) required circummodiolar drill-outs, and one patient (6.25%) underwent placement of a double array cochlear implant. The nine remaining patients (56%) with cochlear obstruction required removal of fibrous tissue or drilling of the inferior basal turn, but did not require manipulation of the ascending basal turn to achieve full electrode insertion. The sensitivity, specificity, and positive and negative predictive value of MRI predicting intraoperative cochlear obstruction with 95 percent confidence intervals was 94.1 percent (71–99), 87.5 percent (47–99), 94.1 percent (71–99) and 87.5 percent (47–99), respectively.

Conclusion: Preoperative high-resolution T2 MRI may be useful in predicting cochlear obstruction in patients with a prior history of bacterial meningitis.

Nitrogen and oxygen molecules in meningitis-associated labyrinthitis and hearing impairment

Pneumococcal meningitis remains a serious disease with a case fatality rate of 15%-25%. Furthermore, long-term residues affect up to 50% of survivors. One of the most frequent sequelae is sensorineural hearing loss, which occurs in 26% of survivors of pneumococcal meningitis. Unfortunately, sufficient treatment regimens are still missing. New insights into the pathology and pathophysiology of meningitis-associated hearing loss have come from animal models of bacterial meningitis. Most likely, bacteria reach the cochlea through the cochlear aquaeduct. Once arrived in the perilymphatic spaces, they induce a severe suppurative labyrinthitis. The blood-labyrinth barrier breaks, hair cells are damaged, and neurons in the spiral ganglion undergo cell death, leading to meningitis-associated hearing loss. Reactive oxygen and nitrogen species, in particular peroxynitrite, seem to be among the crucial mediators of cochlear damage and hearing loss during meningitis. In our rat model of pneumococcal meningitis, adjunctive therapy with the antioxidants and peroxynitrite scavengers Mn(III)tetrakis(4-bencoic acid)-porphyrin (MnTBAP) and N-Acetyl-L-Cystein (NAC) significantly attenuated acute and long-term hearing loss. In several other animal studies of pneumococcal meningitis, adjunctive antioxidant therapy also protected infected animals from intracranial complications. Therefore, the use of antioxidants seems to be a promising future treatment option in pneumococcal meningitis.

Analysis of intracochlear new bone and fibrous tissue formation in human subjects with cochlear implants

OBJECTIVES

In this study we aimed to evaluate new bone and new fibrous tissue formation in the inner ear following cochlear implantation.

METHODS

Twelve temporal bones from patients who underwent cochlear implantation during life were prepared for histologic study. The specimens were reconstructed by both 2-dimensional and 3-dimensional methods. These reconstructions were used to calculate the total volume and distribution of new bone and new fibrous tissue in the cochlea, the number of spiral ganglion cells, and other histopathologic parameters. Clinical data, including the last-recorded word recognition scores, were obtained from the patients' medical records.

RESULTS

New bone and new fibrous tissue were found in all 12 specimens, particularly at the site of cochleostomy. There was a significant correlation between overall damage to the lateral cochlear wall and the total volume of intracochlear new tissue (Spearman rho = .853; p = .0004). The total volume of new tissue did not correlate with word recognition scores or spiral ganglion cell counts.

CONCLUSIONS

These preliminary results suggest that the degree of damage to the lateral cochlear wall may play an important role in influencing the amount of new tissue formation following cochlear implantation. Intracochlear new tissue does not appear to be an important determinant of performance as measured by word recognition scores or the total number of remaining spiral ganglion cells.