Otopathologic Analysis of Patterns of Postmeningitis Labyrinthitis Ossificans

Preventive Effect of Controlled-Release Dexamethasone on Cochlear Ossification in Meningitis Model

OBJECTIVE

Despite vaccination and early antibiotic treatment, pneumococcal meningitis remains a disease with significant mortality and morbidity. The resulting inflammatory response can lead to cochlear fibrosis, ossification where cochlear implant surgeries are far challenging. Our study aimed to investigate the preventive effect of controlled-release dexamethasone implant in such cases in terms of structural integrity.

METHODS

Twenty-four rats were induced with pneumococcal meningitis and randomized into study (n = 16) and control (n = 8) groups. Controlled-release dexamethasone implants were placed transbullarly into the right round window of the study group. Bilateral cochleas underwent histological examination 3 months post-infection.

RESULTS

In the study, cochlear effects of pneumococcal meningitis were evaluated. The basal turn was significantly more affected by fibrosis and ossification (P = .013 and .010, respectively). Compared with control ears, the dexamethasone implant group showed less fibrosis in all turns and less ossification in the basal turn (P = .014, .003, .044, and .035, respectively).

CONCLUSION

In pneumococcal meningitis, fibrosis and ossification occur more intensively in the basal turn of the cochlea. Controlled-release dexamethasone implants are effective in preventing cochlear ossification and fibrosis. The prevention from the structural damage indicates the potential role of these dexamethasone implants in post-meningitic hearing loss and easing cochlear implant surgeries.

Comparative Histopathologic Analysis of Inner Ear Damage in Meningitis: Otogenic Versus Meningogenic Routes

OBJECTIVE

To distinguish the patterns of inner ear changes between meningogenic and otogenic routes in meningitis cases. Our hypothesis is that pinpointing distinct patterns linked to each route could aid in the development of diagnostic strategies and targeted therapies.

METHODS

Temporal bones (TBs) from patients with a history of meningitis and histopathological evidence of labyrinthitis were divided into two groups (otogenic and meningogenic). Inner ear histopathological examination was performed to identify qualitative and semi-quantitative changes. This assessment encompassed inflammation patterns, indications of early ossification, hair cell loss, and alterations in the lateral wall, round window membrane, cochlear aqueduct and vestibular aqueduct.

RESULTS

Thirty-six TBs were included in the study (otogenic, 21; meningogenic, 15). Generalized labyrinthitis was more common in otogenic cases (100% vs. 53%, p < 0.001). Early signs of cochlear ossification were exclusively observed in otogenic cases (9 TBs). The spiral ligament of otogenic cases has shown a uniform loss of fibrocytes across all cochlear turns, while meningogenic cases showed more severe loss in the apical turn. Otogenic cases exhibited a higher prevalence of severe inflammation of the cochlear aqueduct and endolymphatic sac. Meningogenic cases showed more severe loss of vestibular hair cells in the otolithic organs.

CONCLUSION

Otogenic cases displayed a higher prevalence of changes in the spiral ligament and signs of early ossification, whereas meningogenic cases were associated with a higher degree of vestibular damage. Our findings emphasize the importance of considering the infection route and its implications for timely diagnosis and development of pathology-oriented treatment strategies.

LEVEL OF EVIDENCE

NA Laryngoscope, 135:864-872, 2025.

Long-term outcomes of pediatric temporal bone fractures with hearing loss: Results of a multinational database analysis

INTRODUCTION

Pediatric temporal bone fractures (TBFs) can result in adverse outcomes including meningitis, significant sensorineural hearing loss requiring cochlear implantation (CI), facial nerve weakness, cerebrospinal fluid (CSF) leak, and labyrinthitis. The objective of this study is to determine the risks of these outcomes for TBFs with hearing loss.

METHODS

Using the multinational TriNetX database, a retrospective cohort study was performed of patients less than 18 years old with diagnostic codes for other fracture of base of skull and hearing loss to serve as an approximation of TBF. This classification excluded all TBFs without hearing loss. An age- and sex-matched control cohort was selected without the above-mentioned diagnostic codes. More than 95 % of patient data used is from 2006-present, with an average of 12-14 years of data per health care organization. Measured outcomes included meningitis, CI, facial nerve disorders (including facial nerve weakness, lagophthalmos, and eyelid weight placement for lagophthalmos), CSF leak and labyrinthitis after TBF. Risk ratios were calculated after 1:1 propensity-score matching (PSM) for age and sex.

RESULTS

TriNetX identified 2739 pediatric patients (mean age of 7.61 ± 4.39 years) with TBF and an age- and sex-matched cohort of 2739 pediatric patients without TBF (mean age of 7.58 ± 4.37 years). Those with TBF had a greater risk of developing meningitis (RR: 2.90, 95 % CI: 1.42-5.94) and facial nerve disorders (RR: 13.44, 95 % CI: 8.83-20.45) at any time than those without TBF. Matched results were not available for labyrinthitis, CI or CSF leak, as there were multiple instances in the Pediatric TBF cohort versus zero instances in the Control cohort. Results prior to PSM demonstrated an increased risk for labyrinthitis (RR: 43.12, 95 % CI: 23.17-80.27), CI (RR: 21.61, 95 % CI: 13.03-35.84) and CSF leak (89.08, 95 % CI: 67.71-117.20) in the pediatric TBF cohort compared with the cohort without TBF.

DISCUSSION

Pediatric patients who sustain TBF with hearing loss are at increased risk of subsequent meningitis and facial nerve disorders and may also be at increased risk of labyrinthitis, CSF leak, and undergoing CI.

Cochlear Implant Infections

Cochlear implants (CIs) are associated with a range of infections. These infections present unique considerations because of their position relative to the respiratory tract and the central nervous system, as well as the propensity for biofilms to form on CIs. This article reviews infections related to CIs, including otitis media, mastoiditis, meningitis, and deep CI infection. High-quality evidence on the prevention and management of CI infections is lacking; however, best practices regarding prevention and management are provided.

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 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.

Non-Syndromic Sensorineural Hearing Loss in Children

Pediatric hearing loss is common with significant consequences in terms of language, communication, social and emotional development, and academic advancement. Radiological imaging provides useful information regarding hearing loss etiology, prognosis, therapeutic options, and potential surgical pitfalls. This review provides an overview of temporal bone imaging protocols, an outline of the classification of inner ear anomalies associated with sensorineural hearing loss and illustrates some of the more frequently encountered and/or important causes of non-syndromic hearing loss.

Cochlear Ossification After Vestibular Schwannoma Surgery: A Temporal Bone Study

OBJECTIVE

This study aims to investigate patterns of cochlear ossification (CO) in cadaveric temporal bones of patients who underwent vestibular schwannoma (VS) surgery via the translabyrinthine (TL), middle cranial fossa (MF), or retrosigmoid (RS) approaches.

STUDY DESIGN

Histopathologic analysis of cadaveric temporal bones.

SETTING

Multi-institutional national temporal bone repository.

METHODS

The National Institute of Deafness and Communication Disorders and House Temporal Bone Laboratory at the University of California, Los Angeles and the Massachusetts Eye and Ear Otopathology Laboratory were searched for cadaveric temporal bones with a history of VS for which microsurgery was performed. Exclusion criteria included non-VS and perioperative death within 30 days of surgery. Temporal bones were analyzed histologically for CO of the basal, middle, and apical turns.

RESULTS

Of 92 temporal bones with a history of schwannoma from both databases, 12 of these cases met the inclusion criteria. The approaches for tumor excision included 2 MF, 4 RS, and 6 TL approaches. CO was observed in all temporal bones that had undergone TL surgery. Among temporal bones that had undergone MF or RS surgeries, 5/6 had no CO, and 1/6 had partial ossification. This single case was noted to have intraoperative vestibular violation after RS surgery upon histopathologic and chart review.

CONCLUSION

In this temporal bone series, all temporal bones that had undergone TL demonstrated varying degrees of CO on histological analysis. MF and RS cases did not exhibit CO except in the case of vestibular violation. When cochlear implantation is planned or possible after VS surgery, surgeons may consider using a surgical approach that does not violate the labyrinth.

Labyrinthitis Ossificans in a Post-Splenectomy Patient With Meningitis: A Case Report and Review of Literature

This report describes a case of cochlear implantation to treat profound deafness three months after a diagnosis of bacterial meningitis in a patient with a remote history of splenectomy. A 71-year-old woman with a remote history of a splenectomy over 20 years before presented with bilateral profound deafness that occurred as sequela from pneumococcal meningitis three months prior. The patient had been vaccinated against the 23-valent polysaccharide pneumococcal vaccine (PPV-23). The audiometric evaluation revealed no response in either ear. Imaging was suggestive of complete ossification of the right cochlea with partial ossification of the basal turn of the left cochlea. She underwent successful left-sided cochlear implantation. Standard post-implantation speech outcomes include consonant-nucleus-consonant (CNC) word and phoneme scores and Az-Bio in quiet and noise. The patient noted subjective improvement in her hearing. Performance measures markedly improved when compared to her pre-operative evaluation, which showed no aided sound detection. This case report highlights the possibility of meningitis many years after splenectomy that can result in profound deafness with labyrinthitis ossificans and the potential for hearing rehabilitation for cochlear implantation.

An optically-guided cochlear implant sheath for real-time monitoring of electrode insertion into the human cochlea

In cochlear implant surgery, insertion of perimodiolar electrode arrays into the scala tympani can be complicated by trauma or even accidental translocation of the electrode array within the cochlea. In patients with partial hearing loss, cochlear trauma can not only negatively affect implant performance, but also reduce residual hearing function. These events have been related to suboptimal positioning of the cochlear implant electrode array with respect to critical cochlear walls of the scala tympani (modiolar wall, osseous spiral lamina and basilar membrane). Currently, the position of the electrode array in relation to these walls cannot be assessed during the insertion and the surgeon depends on tactile feedback, which is unreliable and often comes too late. This study presents an image-guided cochlear implant device with an integrated, fiber-optic imaging probe that provides real-time feedback using optical coherence tomography during insertion into the human cochlea. This novel device enables the surgeon to accurately detect and identify the cochlear walls ahead and to adjust the insertion trajectory, avoiding collision and trauma. The functionality of this prototype has been demonstrated in a series of insertion experiments, conducted by experienced cochlear implant surgeons on fresh-frozen human cadaveric cochleae.

Auditory and speech outcomes of cochlear implantation in post-meningitis deafness

PURPOSE

This study aims to identify the auditory, speech, and surgical outcomes of cochlear implantation in patients with profound SNHL following bacterial meningitis.

METHODS

Subjects with bilateral severe to profound SNHL who underwent unilateral cochlear implantation from 2003 to 2020 were included in this historical cohort study. The main outcomes were assessed using Categories of Auditory Performance (CAP) and Speech Intelligibility Ratings (SIR) scores. The CAP and SIR outcomes were collected as three-time points after surgery: 6, 12, and 24 months. In order to achieve the strength of the relationship and for computing the Risk Ratio (RR) by log-binominal regression method, we used two binary categorizations of CAP and SIR in our analyses.

RESULTS

The mean of age at implantation of the study and control group were 144.30 (156.90) and 121.10 (133.70) months, respectively. In the study group, 19 of 35 (54.3%) patients were male, and 16 (45.7%) were female. In the control group, 34 of 81 (42.0%) patients were male and 47 (58.0%) were female. The mean scores of CAP and SIR in our study improved significantly during the time in both groups. All p-values (p) were significant in both groups (T2 vs T1, T3 vs T1, and T3 vs T2). Our analysis by log-binomial regression and computing the RR based on the first and second categorization of CAP and SIR showed moderate to strong relationships between the presence of a history of meningitis and inappropriate CAP and SIR outcomes in these patients.

CONCLUSIONS

Although subjects who were deafened due to meningitis benefit significantly from cochlear implantation, we found moderate to strong relationships between the history of meningitis and inappropriate CAP and SIR outcomes in these patients.