A New Pathogenic Variant in POU3F4 Causing Deafness Due to an Incomplete Partition of the Cochlea Paved the Way for Innovative Surgery.

Incomplete partition type III (IP-III) is a relatively rare inner ear malformation that has been associated with a POU3F4 gene mutation. The IP-III anomaly is mainly characterized by incomplete separation of the modiolus of the cochlea from the internal auditory canal. We describe a 71-year-old woman with profound sensorineural hearing loss diagnosed with an IP-III of the cochlea that underwent cochlear implantation. Via targeted sequencing with a non-syndromic gene panel, we identified a heterozygous c.934G > C p. (Ala31Pro) pathogenic variant in the POU3F4 gene that has not been reported previously. IP-III of the cochlea is challenging for cochlear implant surgery for two main reasons: liquor cerebrospinalis gusher and electrode misplacement. Surgically, it may be better to opt for a shorter array because it is less likely for misplacement with the electrode in a false route. Secondly, the surgeon has to consider the insertion angles of cochlear access very strictly to avoid misplacement along the inner ear canal. Genetic results in well describes genotype-phenotype correlations are a strong clinical tool and as in this case guided surgical planning and robotic execution.

New Classification of Cochlear Hypoplasia Type Malformation: Relevance in Cochlear Implantation.

OBJECTIVES: This paper attempts to create a new classification type of cochlear hypoplasia (CH)-type malformation taking into consideration of vestibular section and internal auditory canal (IAC). MATERIALS AND METHODS: Preoperative computed-tomography (CT) scans of cochlear implant (CI) candidates (N=31) from various clinics across the world with CH type malformation were taken for analysis. CT dataset were loaded into 3D-slicer freeware for three-dimensional (3D) segmentation of the inner-ear by capturing complete inner-ear structures from the entire dataset. Cochlear size in terms of diameter of available cochlear basal turn and length of cochlear lumen was measured from the dataset. In addition, structural connection between IAC and cochlear portions was scrutinized, which is highly relevant to the proposed CH classification in this study. RESULTS: CH group-I has the normal presence of IAC leading to cochlear and vestibular portions, whereas CH group-II is like CH group-I but with some degree of disruption in vestibular portion. In CH group-III, a disconnection between IAC and the cochlear portion irrespective of other features. Within all these three CH groups, the basal turn diameter varied between 3.1 mm and 9.6 mm, and the corresponding cochlear lumen length varied between 3 mm and 21 mm for the CI electrode array placement. CONCLUSION: A new classification of CH mainly based on the IAC connecting the cochlear and vestibular portions is presented in this study. CI electrode array length could be selected based on the length of the cochlear lumen, which can be observed from the 3D image.

Cochlear Patency after Translabyrinthine and Retrosigmoid Vestibular Schwannoma Surgery.

OBJECTIVES: To assess the incidence and onset of cochlear obliteration after translabyrinthine and retrosigmoid vestibular schwannoma surgery. MATERIALS AND METHODS: We retrospectively identified a consecutive series of eighty ears in eighty vestibular schwannoma patients who were treated via a translabyrinthine or retrosigmoid approach by a single neuro-otological surgical team in a tertiary referral center from May 2011 to January 2018. Postoperative, high- resolution T2-weighted turbo spin echo three-dimensional magnetic resonance (MR) images of the posterior fossa were evaluated at the level of the membranous labyrinth and internal auditory canal. Perilymphatic patency of the vestibule, basal, and apical cochlear turns were scored and classified as patent, hypointense, partially obliterated, or completely obliterated. RESULTS: Twenty-five vestibular schwannomas were treated with surgery via a translabyrinthine approach, and fifty-five were treated using a retrosigmoid approach; of these, 8% and 65%, respectively, showed no signs of perilymphatic alterations in the basal or apical turns, while 84% and 20%, respectively, showed partial or complete obliteration in the basal or apical turns with a mean postoperative interval of 127 and 140 days, respectively. All the patients who underwent multiple MR scans and had a completely patent perilymphatic system on the first postoperative scan remained patent during subsequent scans; 16% of the patients showed worsened perilymphatic appearance. The onset of cochlear obliteration occurred within 2-7 months in most translabyrinthine patients. CONCLUSION: These findings may support the need for simultaneous cochlear electrode or dummy implantation in translabyrinthine surgery. Second-stage implantation could be feasible in cases where a retrosigmoid approach is used; however, the implantation should be considered within the initial months to avoid cochlear obliteration. Findings on the first postoperative MR could indicate the need for intensified MR follow-up and may even predict the occurrence of cochlear obliteration.

Pattern of cochlear obliteration after vestibular Schwannoma resection according to surgical approach.

OBJECTIVES/HYPOTHESIS: To investigate the prevalence and course of cochlear obliteration according to microsurgical approach to inform clinical decision making regarding optimal timing of cochlear implantation. STUDY DESIGN: Retrospective radiologic review and chart review. METHODS: Patients who underwent microsurgical resection of vestibular schwannoma (VS) with a minimum of two available postoperative magnetic resonance imaging (MRI) scans were analyzed. The prevalence and timing of cochlear and labyrinthine obliteration was classified using relevant MRI sequences. RESULTS: MRI studies in 60 patients were analyzed: 20 translabyrinthine (TL), 20 retrosigmoid, and 20 middle fossa (MF) cases. The first and last postoperative MRI was obtained a median of 3.4 months (interquartile range (IQR), 3.0-3.7 months) and 35 months (IQR, 27-83 months) after surgery, respectively. At the time of the first postoperative MRI, 21 (35%) patients had partial basal turn obliteration, and none of the patients had complete basal turn obliteration. At the time of the last postoperative MRI, six (10%) patients had partial basal turn obliteration and 17 (28%) patients had complete basal turn obliteration. The pattern of partial or complete basal turn obliteration differed significantly among all three surgical approaches (P < .001). Specifically, the risk of partial or complete obliteration of the basal turn was highest in the TL cohort and lowest in the MF cohort. CONCLUSIONS: The prevalence and timing of cochlear obliteration after VS microsurgery varies significantly according to surgical approach. The risk of early and complete obliteration is highest in the TL group and lowest in the MF cohort. These data may inform clinical decision making regarding optimal timing of cochlear implantation in patients with advanced hearing loss after microsurgical resection. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:474-481, 2020.

Auditory brainstem implantation (ABI) in children without neurofibromatosis type II (NF2): communication performance and safety after 24 months of use.

Objectives: To assess the safety and communication performance of auditory brainstem implant (ABI) provision in children who were contraindicated for cochlear implantation and do not have neurofibromatosis type II (NF2).Methods: Communication performance was assessed via a battery of tests up to 24 months after first fitting. Safety was assessed intra-operatively and via post-operative adverse event reports.Results: Ten children participated in the study. The mean communication skills on all 8 tests for which inferential statistics were possible increased significantly from pre-operatively to 12 months and either again increased significantly or remained stable from 12 to 24 months. Communication development was variable: some children achieved high scores while others did not. Two serious adverse events that were device or procedure-related were reported and successfully resolved.Discussion: ABI provision in this population group was safe. Participants' auditory abilities were significantly better after 24 months of ABI use than at pre-implantation. Development was slower than that of children with a cochlear implant but may continue progressing after 24 months of use.Conclusion: ABI provision and use is safe and allows significant auditory development in children without NF2 who are contradicted for cochlear implantation.

Cochlear implantation in patients with ossified cochleas.

PURPOSE: The timing of CI for postmeningitic deafness is controversial and differential outcomes have been reported. To review and share our surgical and auditory outcomes. MATERIALS AND METHODS: 17 patients with ossified cochleas who received CI were enrolled. Clinical data including the cause of cochlear ossification, preoperative examination, onset of deafness, age at implantation, surgical findings, and relevant auditory outcomes was analysed. RESULTS: Cochlear ossification was observed in 53% of patients with HRCT, whereas the corresponding value for MRI was 59%. Patients in both stage I and II received complete insertion of the electrode array, however, stage III patients only received partial insertion. 1 patient in stage II received bilateral CI. Hearing tests showed increased average hearing threshold for stage III patients than those in stage I and II (P < 0.05). CAP scores were much lower for stage III patients than those in stage I and II (P < 0.05). Postlingual deafness patients showed higher SIR scores than prelingual deafness children (P < 0.05). CONCLUSIONS: HRCT and MRI have comparable value in predicting the occurrence of ossification in cochleas. We recommend fast surgical intervention in the patients with bilateral profound postmeningitic deafness. If possible, bilateral cochlear implantation is recommended.

Cochlear obliteration following a translabyrinthine approach and its implications in cochlear implantation.

The most frequent sequelae following a translabyrinthine approach for vestibular schwannoma resection is complete hearing loss on the affected side. Such patients could benefit from a cochlear implant, provided that two essential requisites are met before surgery: a preserved cochlear nerve and a patent cochlea to accommodate the electrode array. The goal of our study is to determine the prevalence and extent of cochlear ossification following a translabyrinthine approach. Postoperative MRI of 41 patients were retrospectively reviewed. Patients were classified according to the degree of cochlear obliteration into three groups (patent cochlea, partially obliterated cochlea and totally obliterated cochlea). The interval between surgery and the first MRI was studied as well as its relationship with the rate of cochlear ossification. At first postoperative MRI (mean interval of 20 months), 78% of patients showed some degree of cochlear ossification. Differences were found in the time interval between surgery and first MRI for each group, showing a smaller interval of time the patent cochlea group (p > 0.05). When MRI was performed before the first year after surgery, a larger rate of patent cochlea was found (p > 0.05). The present study suggests that cochlear ossification is a time-depending process, whose grounds are still to be defined.

[The results of bilateral cochlear implantation in the children who survived meningitis]. / Rezul'taty bilateral'noi kokhlearnoi implantatsii u detei, perenesshikh meningit.

The objective of the present study was the prospective analysis of the results of bilateral cochlear implantation (CI) in the children presenting with bilateral ossification of the cochlea after they had survived meningitis. A total of 15 patients underwent the surgical intervention. In those exhibiting bilateral ossification of the basal cochlear helix over the 5 mm segment (up to first bend of the cochlear turn) and partial ossification of the second helix (in 6 children), the affected portions were removed with the placement of two choleostomies, the lower one (from the ossified membrane of the cochlear window) and the upper one (toward the second helix). Activation of the speech processors of the CI systems was carried out within 4-6 weeks after surgery. The hearing abilities of the children were evaluated in accordance with the 'Estimation of the auditory perception categories', 'Estimation of the child's apprehension capacity', and 'Analysis of speech intelligibility rating' guidelines. In all the children with ossification over less than 5 mm of the basal cochlear helix, it proved possible to introduce the whole intracochlear electrode grid whereas only half of the electrode array was implanted in the cases of overall ossification of the basal helix. The first results obtained by telemetry and surdopedagogical testing gave evidence of the possibility of identifying various sources of non-verbal and speech stimuli in all the treated children at a small (up to 3 meters) distance.

[The fistula of the round window of the cochlea]. / Fistula okna ulitki.

This article presents the data on the frequency, diagnostics, and variants of the surgical treatment of the fistula of the round window of the cochlea. A case of this pathology is reported with the special emphasis placed on the approaches to the diagnostics and surgical management of this condition.

Audiological outcome of stapes surgery for far advanced cochlear otosclerosis.

BACKGROUND: Patients with advanced otosclerosis can present with hearing thresholds eligible for cochlear implantation. This study sought to address whether stapes surgery in this patient group provides a clinically significant audiological benefit. OBJECTIVES: To assess pre- and post-operative hearing outcomes of patients with advanced otosclerosis, and to determine what proportion of these patients required further surgery including cochlear implantation. METHODS: Between 2002 and 2015, 252 patients underwent primary stapes surgery at our institution. Twenty-eight ears in 25 patients were deemed to have advanced otosclerosis, as defined by pure audiometry thresholds over 80 dB. The patients' records were analysed to determine audiological improvement following stapes surgery, and assess whether any further surgery was required. RESULTS: The audiological outcome for most patients who underwent primary stapes surgery was good. A minority of patients (7 per cent) required revision surgery. Patients who underwent cochlear implantation after stapes surgery (10 per cent) also demonstrated a good audiological outcome. CONCLUSION: Stapes surgery is a suitable treatment option for patients with advanced otosclerosis, and should be considered mandatory, before offering cochlear implantation, for those with a demonstrable conductive component to their hearing loss. A small group of patients get little benefit from surgery and subsequently a cochlear implant should be considered.

Delayed-onset haematoma formation after cochlear implantation.

OBJECTIVE: This paper presents our experience on delayed-onset haematoma formation after cochlear implantation, a topic which has not been well discussed in the literature. METHOD: Retrospective case review study. RESULTS: Five children who had undergone cochlear implant surgery at 1.5 to 4 years of age (median, 2.5 years) were studied. The haematoma episodes occurred 2-12 years (median, 6 years) after cochlear implantation. Two patients had recurrent episodes. Two of the seven haematoma episodes were managed by needle aspiration alone, four by incision and drainage alone, and one by both needle aspiration and incision and drainage. Other than one patient with coagulopathy, there were no obvious predisposing factors, including trauma. CONCLUSION: The majority of delayed-onset haematomas occurred without obvious predisposing factors. Needle aspiration can differentiate a haematoma from an abscess or cerebrospinal fluid leakage, and it provides an effective immediate therapeutic solution. However, aseptic techniques are emphasised to minimise the chances of an uncomplicated haematoma converting into a septic one.

Auditory and audio-visual processing in patients with cochlear, auditory brainstem, and auditory midbrain implants: An EEG study.

There is substantial variability in speech recognition ability across patients with cochlear implants (CIs), auditory brainstem implants (ABIs), and auditory midbrain implants (AMIs). To better understand how this variability is related to central processing differences, the current electroencephalography (EEG) study compared hearing abilities and auditory-cortex activation in patients with electrical stimulation at different sites of the auditory pathway. Three different groups of patients with auditory implants (Hannover Medical School; ABI: n = 6, CI: n = 6; AMI: n = 2) performed a speeded response task and a speech recognition test with auditory, visual, and audio-visual stimuli. Behavioral performance and cortical processing of auditory and audio-visual stimuli were compared between groups. ABI and AMI patients showed prolonged response times on auditory and audio-visual stimuli compared with NH listeners and CI patients. This was confirmed by prolonged N1 latencies and reduced N1 amplitudes in ABI and AMI patients. However, patients with central auditory implants showed a remarkable gain in performance when visual and auditory input was combined, in both speech and non-speech conditions, which was reflected by a strong visual modulation of auditory-cortex activation in these individuals. In sum, the results suggest that the behavioral improvement for audio-visual conditions in central auditory implant patients is based on enhanced audio-visual interactions in the auditory cortex. Their findings may provide important implications for the optimization of electrical stimulation and rehabilitation strategies in patients with central auditory prostheses. Hum Brain Mapp 38:2206-2225, 2017. © 2017 Wiley Periodicals, Inc.

[The non-damaging method for the insertion of a standard electrode for cochlear ossification].

The objective of the present study was to develop the non-damaging method for the insertion of a standard electrode for cochlear ossification with a view to improving the results of hearing and speech rehabilitation of the patients presenting with grade IV sensorineural impairment of hearing. Twenty preparations of the cadaveric temporal bone were used to investigate topographic and anatomical relationships in the main structures of the middle and internal ears, viz. the second cochlear coil, vestibulum and its windows, processus cochleaformis, spiral lamina, and modiolus. The optimal method for the insertion of a standard electrode into the spiral canal of the cochlea after the removal of the ossified structures is proposed. The optimal site for constructing the second colostomy is determined that allows the spiral plate and modiolus to be maximally preserved. The proposed method was employed to treat 11 patients with grade IV sensorineural impairment of hearing and more than 5 mm ossification of the basal cochlear coil. With this method, it proved possible to insert the maximum number of electrodes into the cochlear spiral canal and thereby to obtain excellent results of hearing and speech rehabilitation in the patients with the ossified cochlea.

Perilymphatic fistula after underwater diving: a series of 11 cases.

INTRODUCTION: Onset of cochleovestibular symptoms (hearing loss, dizziness or instability, tinnitus) after a dive (scuba or breath-hold diving) warrants emergency transfer to an otology department. One priority is to investigate the possibility of the development of decompression sickness with a view to hyperbaric oxygen treatment of bubble-induced inner-ear damage. If this injury is ruled out, inner-ear barotrauma should be considered together with its underlying specific injury pattern, perilymphatic fistula. METHODS: We report on a series of 11 cases of perilymphatic fistula following ear barotrauma between 2003 and 2015, eight after scuba diving and three after free diving. All patients underwent a series of laboratory investigations and first-line medical treatment. RESULTS: Seven patients had a perilymphatic fistula in the left ear and four in the right. Eight cases underwent endaural surgical exploration. A fistula of the cochlear fenestra was visualised in seven cases with active perilymph leakage seen in six cases. After temporal fascia grafting, prompt resolution of dizziness occurred, with early, stable, subtotal recovery of hearing in seven. Of six patients in whom tinnitus occurred, this disappeared in two and improved in a further two. Two patients were not operated on because medical treatment had been successful, and one patient refused surgery despite the failure of medical treatment. Median follow-up time was 7.4 years (range 0.3 to 12). CONCLUSION: The diagnosis of perilymphatic fistula is based on clinical assessments and various laboratory findings. When there was strong evidence of this condition, surgery yielded excellent functional outcomes in all patients treated early.

Perilymph fistula: the patients' experience.

OBJECTIVE: This study aimed to assess the experiences and outcomes of patients who underwent surgical repair of a perilymph fistula in Norfolk, UK. METHODS: The study involved a retrospective questionnaire-based patient survey and case note review of patients who had undergone tympanotomy and perilymph fistula repair between 1998 and 2012 in two district general hospitals. RESULTS: Fourteen patients underwent 20 procedures, of whom 7 completed the pre- and post-operative Vertigo Symptom Scale. In five patients, there was no obvious precipitating cause. Perilymph fistula was precipitated by noise in one patient, by a pressure-increasing event in six patients and by trauma in two patients. The Vertigo Symptom Scale scores showed a statistically significant improvement following surgical repair, from a median of 67 (out of 175) pre-operatively to 19 post-operatively. CONCLUSION: In selected patients with vertigo, perilymph fistula should be considered; surgical repair can significantly improve symptoms.

The role of fissula ante fenestram in unilateral sudden hearing loss.

The cause of unilateral sudden sensorineural hearing loss (SNHL) remains unclear in many clinical cases. Perilymphatic leakage through a fissula ante fenestram (FAF) fistula is one possible reason. We present four clinical cases with proven FAF fistula, discovered during surgical exploration. All patients experienced partial hearing recovery after surgical coverage of the fistula. We suggest FAF as a possible site for perilymphatic leakage, representing an anatomical correlate for sudden unilateral SNHL. We recommend early exploratory tympanotomy with special attention to the bony region, anterior to the oval window, in cases of severe sudden SNHL and suspected FAF.

Experiences from Auditory Brainstem Implantation (ABIs) in four paediatric patients.

INTRODUCTION: Indications for auditory brainstem implants (ABIs) have been widened from patients with neurofibromatosis type 2 (NF2) to paediatric patients with congenital cochlear malformations, cochlear nerve hypoplasia/aplasia, or cochlear ossification after meningitis. We present four ABI surgeries performed in children at Uppsala University Hospital in Sweden since 2009. METHODS: Three children were implanted with implants from Cochlear Ltd. (Lane Cove, Australia) and one child with an implant from MedEl GMBH (Innsbruck, Austria). A boy with Goldenhar syndrome was implanted with a Cochlear Nucleus ABI24M at age 2 years (patient 1). Another boy with CHARGE syndrome was implanted with a Cochlear Nucleus ABI541 at age 2.5 years (patient 2). Another boy with post-ossification meningitis was implanted with a Cochlear Nucleus ABI24M at age 4 years (patient 3). A girl with cochlear aplasia was implanted with a MedEl Synchrony ABI at age 3 years (patient 4). In patients 1, 2, and 3, the trans-labyrinthine approach was used, and in patient 4 the retro-sigmoid approach was used. RESULTS: Three of the four children benefited from their ABIs and use it full time. Two of the full time users had categories of auditory performance (CAP) score of 4 at their last follow up visit (6 and 2.5 years postoperative) which means they can discriminate consistently any combination of two of Ling's sounds. One child has not been fully evaluated yet, but is a full time user and had CAP 2 (responds to speech sounds) after 3 months of ABI use. No severe side or unpleasant stimulation effects have been observed so far. There was one case of immediate electrode migration and one case of implant device failure after 6.5 years. CONCLUSION: ABI should be considered as an option in the rehabilitation of children with similar diagnoses.

Cochlear Nerve Stimulation in the Internal Auditory Canal in Ossified Cochlea: A Case Study.

OBJECTIVE: To present the first reported case of intraneural direct cochlear nerve stimulation in a human being. STUDY DESIGN: This is a case report. RESULTS: A 23-year-old patient with bilateral progressive hearing loss associated with bilateral complete semicircular canal aplasia and ossified cochleas underwent cochlear implantation. During surgery, a patent cochlear lumen could not be found, and the array was positioned in the internal auditory canal adjacent to the cochlear nerve. Against our expectations, an assiduous rehabilitation and frequent fitting adjustments have led to a word recognition score, in open set speech with lip reading, of 18/25 and acceptable frequency discrimination. CONCLUSIONS: We are aware that this was an anomalous use of the cochlear implant, and it is not our aim to suggest a new indication for cochlear array positioning. However, this case shows that auditory perception, to some degree, can be obtained with intraneural direct cochlear nerve stimulation.

Cochlear obliteration after translabyrinthine vestibular schwannoma surgery.

The objective of the study was to determine the temporal occurrence of cochlear obliteration following translabyrinthine vestibular schwannoma resection. A retrospective chart review, cross-sectional study, and sequential analysis of the time series were performed. The retrospective study included patients undergoing translabyrinthine resection for stage T1-T2 vestibular schwannoma from 2007 to 2010 without prior therapy and postoperative follow-up including MRI of the brain and the cerebellopontine angle. Already 3 months after surgery a radiographic labyrinthine change was observed in 66.7 %, a partial obstruction in 50 %, and an obstruction limited to the saccule in 16.7 %. Only 33.3 % of the patients showed an unchanged inner ear. In consideration of early cochlear obstruction after translabyrinthine vestibular schwannoma resection, temporary follow-up is necessary. Since the indications for cochlear implantation (CI) have been extended, especially concerning patients with single-side deafness, a simultaneous or early second-stage CI after tumour removal should be discussed.

Surgical methods and postoperative results of cochlear implantation in 79 cases of ossified cochlea.

CONCLUSION: A man-made bone tunnel of 1.5 turns around the modiolus can be created in cases of total cochlear ossification. Patients with ossified cochlea types I and II achieved satisfactory hearing results after cochlear implantation (CI). Patients with ossified cochlea type III, in which the modiolus is damaged by the ossification, showed poor hearing results after CI. OBJECTIVES: To introduce a new CI surgical technique for ossified cochlea and to summarize postoperative hearing results. METHODS: A total of 79 patients with ossified cochlea who underwent CI were analyzed. Cases were divided into three types: type I, round window ossification; type II, partial cochlear ossification; and type III, complete cochlear ossification. Four surgical methods were used: method A, applicable to type I; methods B and C, applicable to type II; and method D, applicable to type III. Sound field audiometric and speech tests were performed 6 months postoperatively. RESULTS: All surgeries were successful. The average hearing thresholds for warble tone were 35 dB hearing level (HL) in types I and II and 75 dB HL in type III. The average recognition rates of Mandarin speech were 100% (single finals) and 91% (single initials) in types I and II and 20% (single finals) and 0% (single initials) in type III.