Genetic Etiology of Nonsyndromic Hearing Loss in Hungarian Patients.

Hearing loss is the most prevalent sensory disorder worldwide. The majority of congenital nonsyndromic hearing loss (NSHL) cases are caused by hereditary factors. Previously, the majority of NSHL studies focused on the GJB2 gene; however, with the availability of next-generation sequencing (NGS) methods, the number of novel variants associated with NSHL has increased. The purpose of this study was to design effective genetic screening for a Hungarian population based on a pilot study with 139 NSHL patients. A stepwise, comprehensive genetic approach was developed, including bidirectional capillary sequencing, multiplex ligation-dependent probe amplification (MLPA), and an NGS panel of 108 hearing loss genes. With our results, a genetic diagnosis was possible for 92 patients. Sanger sequencing and MLPA identified the genetic background of 50% of these diagnosed cases, and the NGS panel identified another 16%. The vast majority (92%) of the diagnosed cases showed autosomal recessive inheritance and 76% were attributed to GJB2. The implementation of this stepwise analysis markedly increased our diagnostic yield and proved to be cost-effective as well.

A new method of preoperative assessment of correct electrode array alignment based on post-operative measurements in a cochlear implanted cohort.

PURPOSE: During cochlear implantation surgery, a range of complications may occur such as tip fold-over. We recently developed a method to estimate the insertion orientation of the electrode array. The aim of the study was to determine the optimal angle of orientation in a cohort of cochlear implanted patients. METHODS: On eighty-five CT scans (80 uncomplicated insertions and 5 cases with tip fold-over), location of the electrode array's Insertion Guide (IG), Orientation marker (OM) and two easily identifiable landmarks (the round window (RW) and the incus short process (ISP)) were manually marked. The angle enclosed by ISP-RW line and the Cochlear™ Slim Modiolar electrode array's OM line determined the electrode array insertion angle. RESULTS: The average insertion angle was 45.0-47.2° ± 10.4-12° SD and was validated with 98% confidence interval. Based on the measurements obtained, patients' sex and age had no impact on the size of this angle. Although the angles of the tip fold-over cases (44.9°, 46.9°, 34.2°, 54.3°, 55.9°) fell within this average range, the further it diverted from the average it increased the likelihood for tip fold-over. CONCLUSION: Electrode array insertion in the individually calculated angle relative to the visible incus short process provides a useful guide for the surgeon when aiming for the optimal angle, and potentially enhances good surgical outcomes. Our results show that factors other than the orientation angle may additionally contribute to failures in implantation when the Slim Modiolar electrode is used.

A novel intraoperative imaging tool to follow the cochlear implant electrode array insertion dynamics / Új mutéti képalkotó lehetoség a belsofül-implantátum elektródasorának dinamikus helyzetmeghatározására.

Összefoglaló. Bevezetés: A cochlearis implantátum egy mutétileg behelyezett elektromos eszköz, amely az akusztikus hanghullámokat elektromos jelekké alakítja, közvetlenül a hallóideget stimulálja, így segíti a súlyos fokú hallássérüléssel vagy teljes hallásvesztéssel élok életét. Cochlearis implantációt követoen a legjobb rehabilitációs eredmény elérésének technikai feltétele többek között az esetre szabott elektródaválasztás és az elektródasor teljes, kontrollált, szövodménymentes bejuttatása a scala tympaniba, miközben a cochlea belso struktúrája a leheto legkisebb mértékben sérül. A rutin intraoperatív elektrofiziológiai tesztek fontos információt adnak a készülék muködoképességérol és a hallóideg stimulációjáról, azonban nem hagyatkozhatunk rájuk az elektródasor cochleán belüli helyzetének igazolásában. Mivel elofordulhat, hogy a rendelkezésre álló elektrofiziológiai vizsgálatok eredménye megfelelo, és mégis rendellenes helyzetbe kerül az elektróda, az arany standardot a képalkotó vizsgálatok jelentik. Módszer: Közleményünkben egy modern, hibrid muto által nyújtott technológiai háttér új alkalmazási területét mutatjuk be. Szimultán kétoldali cochlearis implantációt végeztünk Cochlear Nucleus Slim Modiolar típusú perimodiolaris elektródasorral, a belso fül fejlodési rendellenességével rendelkezo betegen. Az intraoperatív képalkotást Siemens Artis pheno C-karos robot digitális szubtrakciós angiográfiás rendszer biztosította valós ideju átvilágító és volumentomográfiás funkcióval. Eredmények: Az intraoperatív képalkotás által dinamikusan követheto az elektródasor bevezetésének folyamata, ellenorizheto az elektródasor statikus helyzete, így kiváltható a rutinnak számító posztoperatív képalkotó vizsgálat. A rendellenes helyzetbe kerülo elektródasor pozíciója egy ülésben korrigálható, az újból bevezetheto, így elkerülheto az újabb altatással járó, bizonytalan kimenetelu revíziós mutét. Következtetés: A hibrid muto jól kontrollált, minimálisan invazív eljárások elvégzését biztosítja. Különösen a hallószerv fejlodési rendellenessége vagy egyéb, az elektródának a cochleába vezetését nehezíto rendellenesség esetén javasolt a mutoi képalkotó diagnosztika. Orv Hetil. 2021; 162(22): 878-883. INTRODUCTION: The cochlear implant is a surgically inserted electrical device that converts acoustic sound waves into electrical signals to stimulate the cochlear nerve, thus helps the rehabilitation of people with severe to total hearing loss. One of the most important technical conditions for achieving the best rehabilitation result after cochlear implantation is the personalized choice of electrodes. Additionally, it is vital that there is a complete, controlled, uncomplicated delivery of the electrode array to the scala tympani while minimizing damage to the inner structures of the cochlea. Routine electrophysiological tests provide important information about device functionality and auditory nerve stimulation. However, they probably do not show an abnormal position of the electrode array within the cochlea. Thus, imaging studies remain the gold standard. METHOD: In our paper, we present a novel application field of the modern technological background provided by a hybrid operating room. Simultaneous bilateral cochlear implantation was performed with cochlear implants with perimodiolar electrode array (Nucleus Slim Modiolar) in a patient with cochlear malformation. Intraoperative imaging was provided by a Siemens Artis pheno C-arm robot digital subtraction angiography system with real-time fluoroscopy and volume tomography function. RESULTS: Intraoperative imaging ensures dynamic follow-up of the introduction and static determination of the position of the electrode array and replaces routine postoperative imaging. If the electrode array was inserted in an abnormal position, the revision can be performed in the same sitting. Also, the revision surgery with a potential risk of uncertain outcome, alongside additional anaesthesia, can be prevented. CONCLUSION: The hybrid operating room ensures that well-controlled, minimally invasive procedures are performed. Intraoperative imaging can be imperative in malformed cochleae and conditions that may complicate electrode insertion. Orv Hetil. 2021; 162(22): 878-883.

Late simultaneous carcinomatous meningitis, temporal bone infiltrating macro-metastasis and disseminated multi-organ micro-metastases presenting with mono-symptomatic vertigo - a clinico-pathological case reporT.

BACKGROUND AND PURPOSE: Although vertigo is one of the most common complaints, intracranial malignant tumors rarely cause sudden asymmetry between the tone of the vestibular peripheries masquerading as a peripheral-like disorder. Here we report a case of simultaneous temporal bone infiltrating macro-metastasis and disseminated multi-organ micro-metastases presenting as acute unilateral vestibular syndrome, due to the reawakening of a primary gastric signet ring cell carcinoma. Purpose - Our objective was to identify those pathophysiological steps that may explain the complex process of tumor reawakening, dissemination. The possible causes of vestibular asymmetry were also traced. METHODS: A 56-year-old male patient's interdisciplinary medical data had been retrospectively analyzed. Original clinical and pathological results have been collected and thoroughly reevaluated, then new histological staining and immunohistochemistry methods have been added to the diagnostic pool. RESULTS: During the autopsy the cerebrum and cerebellum was edematous. The apex of the left petrous bone was infiltrated and destructed by a tumor mass of 2x2 cm in size. Histological reexamination of the original gastric resection specimen slides revealed focal submucosal tumorous infiltration with a vascular invasion. By immunohistochemistry mainly single infiltrating tumor cells were observed with Cytokeratin 7 and Vimentin positivity and partial loss of E-cadherin staining. The subsequent histological examination of necropsy tissue specimens confirmed the disseminated, multi-organ microscopic tumorous invasion. Discussion - It has been recently reported that the expression of Vimentin and the loss of E-cadherin is significantly associated with advanced stage, lymph node metastasis, vascular and neural invasion and undifferentiated type with p<0.05 significance. As our patient was middle aged and had no immune-deficiency, the promoting factor of the reawakening of the primary GC malignant disease after a 9-year-long period of dormancy remained undiscovered. The organ-specific tropism explained by the "seed and soil" theory was unexpected, due to rare occurrence of gastric cancer to metastasize in the meninges given that only a minority of these cells would be capable of crossing the blood brain barrier. CONCLUSION: Patients with past malignancies and new onset of neurological symptoms should alert the physician to central nervous system involvement, and the appropriate, targeted diagnostic and therapeutic work-up should be established immediately. Targeted staining with specific antibodies is recommended. Recent studies on cell lines indicate that metformin strongly inhibits epithelial-mesenchymal transition of gastric cancer cells. Therefore, further studies need to be performed on cases positive for epithelial-mesenchymal transition.

Clinical aspects of otosclerotic ossicular chain fixations. / Az otoscleroticus eredetu hallócsontláncolati fixatiók klinikuma.

Otosclerosis is a human-specific ear disease characterised by complex bone-remodelling with multifactorial aetiology. It affects the bony labyrinth capsule and consequently fixates the stapes to the oval window rim. The fixation of the ossicular chain leads to a decrease in the middle ear's acoustic impedance-fitting and amplifier function that leads to conductive hearing loss. The process is progressive and when it involves the inner ear structures, it deteriorates the sensorineural function as well. The course of the illness can be prevented or delayed if hearing reconstructive surgery is performed on time. The development of stapes surgery spans the 20th century, and despite the major surgical steps - laid down by Shea and Marquet in the 1960s - are quite conservative, fine adjustments are still being made mainly due to technical progress. Several studies confirm that stapedotomy remained the first-to-offer therapeutic option in otosclerosis. With an adequate surgical technique, significant improvement can be achieved in the air conduction threshold, the air-bone gap may be minimalized or ceased over the speech frequencies, which significantly improves the quality of life of the patients. In this quest, we reviewed the Hungarian and the international literature as well in context with otosclerosis, with special attention to the newest methods in diagnostics and treatment management. Orv Hetil. 2020; 161(19): 780-788.

Review of electrode placement with the Slim Modiolar Electrode: identification and management.

Background - Several cochlear implant recipients experience functionality loss due to electrode array mal-positioning. The application of delicate perimodiolar electrodes has many electrophysiological advantages, however, these profiles may be more susceptible to tip fold-over. Purpose - The prompt realization of such complication following electrode insertion would be auspicious, thus the electrode could be possibly repositioned during the same surgical procedure. Methods - The authors present three tip fold-over cases, experienced throughout their work with Slim Modiolar Electrode implants. Implantations were performed through the round window approach, by a skilled surgeon. Standard intraoperative measurements (electric integrity, neural response telemetry, and electrical stapedial reflex threshold tests) were successfully completed. The electrode position was controlled by conventional radiography on the first postoperative day. Results - Tip fold-over was not tactilely sensated by the surgeon. Our subjects revealed normal intraoperative telemetry measurements, only the postoperative imaging showed the tip fold-over. Due to the emerging adverse perception of constant beeping noise, the device was replaced by a CI512 implant after 6 months in one case. In the two remaining cases, the electrode array was reloaded into a back-up sheath, and reinserted into the scala tympani successfully through an extended round window approach. Discussion - Future additional studies using the spread of excitation or electric field imaging may improve test reliability. As all of these measurements are still carried out following electrode insertion, real-time identification, unfortunately, remains questionable. Conclusion - Tip fold-over could be reliably identified by conventional X-ray imaging. By contrast, intraoperative electrophysiology was not sufficiently sensitive to reveal it.

[The distance from the modiolus of perimodiolar electrode arrays of cochlear implants. A radiological study to evaluate the difference in perimodiolar properties]. / Cochlearis implantátumok különbözo, elore görbített elektródasorainak elhelyezkedése a cochlea tengelyéhez viszonyítva. Radiológiai vizsgálat a perimodiolaritás mértékének megállapítására.

Introduction: The cochlear implants vary in electrodes in terms of length, width and proximity to the modiolus. The precurved electrode arrays could be placed closer to the modiolus and the ganglion cells compared to straight electrodes. The two types of electrode arrays provide different electrophysiological characteristics; however, proximity to the modiolus may lead to better hearing performance. Aim: To investigate our preliminary electrophysiological results that suggest that the Slim Modiolar (SM) electrode array has the potential to elicit similar neural responses as the thicker perimodiolar (Contour Advance, CA) electrode from the same generation of implants. Method: Subjects that were implanted either with CA or SM electrodes were enrolled, 54 consecutive subjects in each group. All electrodes were introduced into the cochlea via the round window. The diameter of the largest turn of the electrode arrays within the cochlea was measured through postoperative radiography. The energy consumption parameters were estimated 2 months after implantation. Results: The mean of the largest turns of the arrays within the cochlea was 4.2 ± 0.5 mm in the SM group and 4.9 ± 1.1 mm in the CA group. 'Auto power' was 44.81 ± 5.05% and 50.85 ± 8.35% with SM and CA, respectively. Estimated energy consumption was lower with SM. The differences were statistically significant. Conclusion: Our measurements for a large cohort in each group suggest that the SM electrode array takes a significantly closer position to the modiolus than the CA. This finding supports our earlier electrophysiological result and indicates better performance abilities. Orv Hetil. 2019; 160(31): 1216-1222.

[Possibilities for residual hearing preservation with Nucleus CI532 Slim Modiolar electrode array. Case report]. / A maradványhallás megorzésének lehetoségei cochlearis implantáció során Nucleus CI532 Slim Modiolar elektródasorral.

During the rehabilitation of hearing-impaired patients, the preservation of residual acoustic hearing following cochlear implantation by minimizing the implantation trauma allows for improved hearing performance. To achieve this, minimally invasive, soft surgery methods and thinner, atraumatic electrodes were required. In our present study, we reported a case where Cochlear® Nucleus CI532 Slim Modiolar electrode was implanted in a patient with residual hearing. Our aim was to study the possible preservation of postoperative acoustic residual hearing by audiological monitoring. Since childhood, due to her congenital hearing loss, she has been wearing a conventional, airborne hearing correction device on both ears. Six months before cochlear implantation, we measured the progression on both sides of the hearing loss, so we decided to perform cochlear implantation. The patient had residual hearing on both ears prior to surgery thus the Cochlear® Nucleus CI532 Slim Modiolar Implant was used. The minimally invasive surgery was performed on the patient's right ear through the round window approach. Compared to the preoperative hearing threshold (average 85 dBHL) in the 4th postoperative week, an initial hearing threshold progression of 20-25 dBHL was observed between 0.25 and 1.0 kHz, while of 5-10 dBHL between 2.0-4.0 kHz. Hearing threshold measured in the 6th month showed a slight progression in the range above 1 kHz, but improved by the 12th month, to the results achieved at the 4th week. The effects of cochlear implantation on residual hearing have been studied in numerous studies, in which several key surgical and technical factors have been identified. Nucleus CI532 is a Slim Modiolar electrode profile that is close to the modiolus, so it is expected to have a lower endocochlear hydrodynamic load since it lies in the covering of the osseus spiral lamina, thus less influencing the dynamics of the basilar membrane. However, the perimodiolar location of the electrode array allows the adjacent nerve elements of the spiral ganglion to be stimulated with a lower electrical intensity and a reduced surface that may be neuroprotective. Preservation of acoustic residual hearing following cochlear implantation improves the patient's speech perception and the sound localization skills, particularly in difficult circumstances. Long-term residual hearing preservation may also be of great importance in the subsequent feasibility for regenerative procedures and drug treatments. Orv Hetil. 2018; 159(41): 1680-1688.

[The role of laryngeal electromyography in the diagnosis of vocal cord movement disorders]. / A laryngealis electromyographia szerepe a hangszalag-mozgászavarok diagnosztikájában és az alkalmazott kezelés kiválasztásában.

The development of the therapeutic possibilities of vocal cord immobility necessitated the parallel renewal of diagnostic methods. In the last years, laryngeal electromyography, which was first introduced more than 70 years ago, has been re-discovered. After reviewing the international literature and their own experience, the authors present the indications, technical requirements, method and, particularly, the evaluation of the results of this procedure. Laryngeal electromyography makes the differentiation between mechanical fixation and immobility with neurological origin of the vocal folds possible. In case of laryngeal paralysis/paresis it also evaluates objectively the severity of neural injury, the prognosis of the disease and the necessity of any glottis-widening procedure. The widespread application of dynamic rehabilitation interventions is not conceivable without the routine application of laryngeal electromyography, so this sensitive diagnostic tool has to be introduced in all laryngological centers. Orv Hetil. 2018; 159(8): 303-311.

[Pediatric hearing rehabilitation with the Baha® Attract implant system]. / Fiatalkori hallásrehabilitáció Baha® Attract implantátumrendszerrel.

INTRODUCTION: Baha® Attract is a new transcutaneous bone-conduction hearing aid, which is more preferable in childhood than the conventional percutaneous systems. AIM: Our aim was to demonstrate the possibilities of application in childhood. METHOD: Eight children have undergone surgeries (mean age of 13.2 ± 3.2 years; "posterosuperior" incision technique, 5 mm implants). The thickness of the skull bone was determined in 72 children (1-8 years old) at the recommended implant site, based on CT scans. RESULTS: The average duration of surgeries was 30 minutes. There were no intra- and postoperative complications observed. Sound processors were fitted at the postoperative 4th week. Hearing measurements proved 51.58±11.22SD dBHL gain in warble tone thresholds, and 43.3 ± 16.02 SD dB in speech discrimination thresholds. The skull bone thickness was measured as 3.39 ± 1.05 SD mm. CONCLUSION: The Baha Attract system is a new tool for hearing rehabilitation in pediatric population. Preoperative CT provides valuable knowledge about skull bone thickness. Orv. Hetil., 2017, 158(8), 304-310.

Vascular mapping of the retroauricular skin - proposal for a posterior superior surgical incision for transcutaneous bone-conduction hearing implants.

BACKGROUND: Passive transcutaneous osseointegrated hearing implant systems have become increasingly popular more recently. The area over the implant is vulnerable due to vibration and pressure from the externally worn sound processor. Good perfusion and neural integrity has the potential to reduce complications. The authors' objective was to determine the ideal surgical exposure to maintain perfusion and neural integrity and decrease surgical time as a result of reduced bleeding. METHODS: The vascular anatomy of the temporal-parietal soft tissue was examined in a total of 50 subjects. Imaging diagnostics included magnetic resonance angiography in 12 and Doppler ultrasound in 25 healthy subjects to reveal the arterial network. Cadaver dissection of 13 subjects formed the control group. The prevalence of the arteries were statistically analyzed with sector analysis in the surgically relevant area. RESULTS: The main arterial branches of this region could be well identified with each method. Statistical analysis showed that the arterial pattern was similar in all subjects. The prevalence of major arteries is low in the upper posterior area though large in proximity to the auricle region. CONCLUSIONS: Diverse methods indicate the advantages of a posterior superior incision because the major arteries and nerves are at less risk of damage and best preserved. Although injury to these structures is rare, when it occurs, the distal flow is compromised and the peri-implant area is left intact. Hand-held Doppler is efficient and cost-effective in finding the best position for incision, if necessary, in subjects with a history of surgical stress to the retroauricular skin. TRIAL REGISTRATION: This was a non-interventional study.

Laser-Doppler microvascular measurements in the peri-implant areas of different osseointegrated bone conductor implant systems.

The objective of this study was to evaluate the impact of hydroxyapatite coating of newly designed osseointegrated fixtures' abutments on the postoperative complication rates. The integrity of peri-implant microcirculation was used as a marker to compare tissue viability after different surgical techniques. Laser-Doppler Flowmetry (LDF) measures alone, and coupled with heat provocation tests were applied to test the different microcircular patterns. Measures for 17 consecutively implanted patients (8 women, 9 men, ages ranged from 18 to 77 years) were recruited; seven with soft tissue reduction (STR); and 10 with soft tissue preservation (STP).Thirteen non-operated retro-auricular areas were examined as naive controls. In isotherm conditions the baseline blood flow remained stable in all groups. The naive control patients demonstrated significant changes of blood flux in the intact skin. The non-implanted yet previously operated contralateral sides of the patients demonstrated marginally lower (p = 0.09) blood flux index. The STR sides however, showed significantly lower (average 217 %) provoked blood flux compared to controls (p < 0.001). At the STP sides a maladaptation could be observed (average 316 %) compared to the contralateral sides (p = 0.53). STP sides demonstrated a significantly better blood flow improvement compared to the STR sides (p = 0.02). These results suggest a favorable postoperative condition of vascular microcirculation after STP, than after STR surgery. The possibly faster wound healing and lower potential complication rate may widen the inclusion criteria and maybe beneficial for the patient compliance with a better quality-of-life.

[New method for measuring the cortical auditory evoked potentials: the HEARLab]. / Új lehetoség az akusztikusan kiváltott corticalis válaszok mérésére: a HEARLab.

INTRODUCTION: Cortical auditory evoked potentials can provide objective information about the highest level of the auditory system. AIM: The purpose of the authors was to introduce a new tool, the "HEARLab" which can be routinely used in clinical practice for the measurement of the cortical auditory evoked potentials. In addition, they wanted to establish standards of the analyzed parameters in subjects with normal hearing. METHOD: 25 adults with normal hearing were tested with speech stimuli, and frequency specific examinations were performed utilizing pure tone stimuli. RESULTS: The findings regarding the latency and amplitude analyses of the evoked potentials confirm previously published results of this novel method. CONCLUSIONS: The HEARLAb can be a great help when performance of the conventional audiological examinations is complicated. The examination can be performed in uncooperative subjects even in the presence of hearing aids. The test is frequency specific and does not require anesthesia.

Minimally invasive genetic screen for GJB2 related deafness using dried blood spots.

OBJECTIVE: Nonsyndromic hearing loss is one of the most abundant human sensory disorders, and can be found in 1 out of 1000 newborns. In 60-70% of the cases this disorder is hereditary. The phenotype varies from moderate hearing loss to almost complete deafness, often only revealed in late childhood. Early detection of hearing related genetic variations in the first few weeks of life would allow planning of the audiological and logopedical procedures to maintain the children's normal audiological and speech development, and if required a cochlear implantation can be planned in time. We wanted to evaluate, whether the blood samples collected from neonates onto Guthrie cards (dried blood spots, or DBS), and blood collected from people of various ages into blood collecting tubes is equally usable for genetic testing. The quality of the samples on DBS's for genetic tests after an extended period of storage was evaluated. The methods for sample preparation and analysis were also evaluated. METHODS: Two DNA extraction methods were compared on the samples. We extracted DNA from whole blood with the Versagene Blood Kit from Gentra, and from DBS's with boiling. Allele-specific PCRs (AS-PCR) were carried out on each sample. Samples were analyzed with AS-PCR and sequencing, for the 35delG mutation in the GJB2 (Cx26) gene. Freshly drawn and dried blood spot samples stored for several years were used in the experiments. RESULTS: An AS-PCR method for detecting 35delG mutation on DNA extracted from Guthrie cards was validated. Blood samples up to 10 years of storage were applicable in the screen. 84 patients were found with 35delG mutations, both heterozygous (with no detected hearing related phenotypical discrepancies), and homozygous (phenotipically with moderate to severe hearing loss) forms. CONCLUSIONS: The dried blood spots on Guthrie cards require only three drops of blood to be collected from children, which causes less stress than taking 3 ml of blood. The blood stored on Guthrie cards can be used to store DNA samples for at least 10 years. Even under suboptimal storage conditions the samples' DNA remains intact for genetic testing. Compared to blood collection tubes Guthrie cards cost less, are easier to transport and store.

Two subgroups of schizophrenia identified by systematic cognitive neuropsychiatric mapping.

The description of the heterogeneous phenomenological, pathophysiological, and etiological nature of schizophrenia is under way; however, the relationships between heterogeneity levels are still unclear. We performed a robust cross-sectional study, including a systematic neuropsychological battery, assessment of clinical symptoms, neurological soft signs, morphogenetic anomalies and smell identification, and measurement of event-related potentials on 50 outpatients with schizophrenia in their compensated states. An explorative fuzzy cluster analysis revealed two subgroups in this sample that could be distinguished from each other on symptomatological, cognitive and neurological levels. The patterns of cognitive dysfunctions and neurological developmental anomalies equally indicate that there may be hemispherical differences between the patients belonging to the different clusters.

Recurrent bacterial meningitis after cochlear implantation in a patient with a newly described labyrinthine malformation.

Authors report on a so far undescribed bilateral inner ear malformation with congenital deafness where a defect of both the medial and lateral bony labyrinthine wall allowed the herniation of a cerebrospinal fluid-filled endosteum sac into the tympanic cavity. The story of cochlear implantation in this ear and the series of following meningitis demonstrates the dilemma of indicating implantation in labyrinthine dysplasia and the difficulties of treating postimplantation meningitis. Routes of bacterial invasion from inner ear to intracranium is discussed regarding normal, dysplastic and surgically "disturbed" inner ear anatomy.

Cochlear implantation for treatment-induced ototoxic deafness in Langerhans cell histiocytosis. A case report.

A case is presented where the authors carried out a cochlear implantation on a girl whose deafness was induced by cytostatic agents. The normally hearing child was diagnosed with Langerhans cell histiocytosis at the age of 3 years and received polychemotherapy for almost 2 years. By her 5th year, she started to develop a bilateral, progressive sensorineural hearing loss, necessitating a hearing aid in both ears. While her histiocytosis was cured, her hearing ultimately deteriorated to total deafness on the right and profound hearing loss on the left ear. After 3 years, her hearing aids no longer provided adequate hearing for the postlingually deafened girl. At the age of 14, a cochlear implantation was performed on her right ear with excellent results.

Successful cochlear implantation in a child after recovery from a head and neck malignancy: a case report.

We present the case of a successful pediatric cochlear implantation that was carried out following bilateral perilingual deafness caused by meningitis during the treatment of a childhood malignant tumor. A rhabdomyosarcoma localized in the frontobasal area was removed from the child at the age of 2 years. He then received 11 months of postoperative cytostatic treatment. A purulent meningitis developed at the end of the chemotherapy, resulting in a major-grade, bilateral sensorineural hearing loss (practically a perilingual deafness). After 6 tumor-free years and a meticulous preoperative assessment, a Nucleus 24 M cochlear implant was successfully implanted in the child's left ear. Two years after the operation, the child shows excellent hearing results and moderate speech development.