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.

[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.

Rhinophototherapy in persistent allergic rhinitis.

Previous published results have revealed that Rhinolight® intranasal phototherapy is safe and effective in intermittent allergic rhinitis. The present objective was to assess whether phototherapy is also safe and effective in persistent allergic rhinitis. Thirty-four patients with persistent allergic rhinitis were randomized into two groups; twenty-five subjects completed the study. The Rhinolight® group was treated with a combination of UV-B, UV-A, and high-intensity visible light, while the placebo group received low-intensity visible white light intranasal phototherapy on a total of 13 occasions in 6 weeks. The assessment was based on the diary of symptoms, nasal inspiratory peak flow, quantitative smell threshold, mucociliary transport function, and ICAM-1 expression of the epithelial cells. All nasal symptom scores and nasal inspiratory peak flow measurements improved significantly in the Rhinolight® group relative to the placebo group and this finding persisted after 4 weeks of follow-up. The smell and mucociliary functions did not change significantly in either group. The number of ICAM-1 positive cells decreased non-significantly in the Rhinolight® group. No severe side-effects were reported during the treatment period. These results suggest that Rhinolight® treatment is safe and effective in persistent allergic rhinitis.

[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.

[Endoscopic, posterior transseptal pituitary surgery--learning curve of the surgical technique and equipment in 61 operations]. / Endoszkópos posterior transseptalis hypophysismutét. A sebészi technika fejlodése a teljes endoszkópos tumoreltávolításig 61 eset elemzése alapján.

INTRODUCTION: The removal of hypophyseal tumor by transsphenoidal pituitary surgery using microsurgical instruments was first performed over 100 years ago. Operating techniques for this surgery are constantly being renewed, first by using a microscope and later on with the use of an endoscop. The authors provide an overview of the minimal invasive posterior transseptal-transsphenoidal aproach with the combined utilization of classical techniques with the assistance of the endoscop. METHOD: Sixty-one patients (33 female, 28 male, 21-84 yrs) were treated for sellar region tumor resection using an endonasal transsphenoidal aproach with the help of an endoscope. Follow ups were performed within 2-21 months. RESULTS: Total tumor resection was successful in 91.8%, and partial resection in 8.2% of the patients. The rate of complications using the endoscopic method was not higher compared to that of the classical microscopic method. There was no major bleeding in any of the cases. Adverse events such as minor epistaxis occurred in 4.9%, transitional diabetes insipidus in 6.5%, inraoperative CSF leak in 16.67%, postoperative CSF leak in 11.5% and meningitis in 8.2% of the patients. After the operation the pathological hormonal production stoped in all patients except in two patients who were acromegalic. However their GH level normalized and they did not require further treatment, the IGF-1 still remained high. CONCLUSION: The success of the surgical treatment is based on both, the proficient pre- and postoperative endocrinological care, and the minimal invasive surgical technique. The endoscope was used partially or continuously during the operation for better visualization of the operation field in multiple angles (30 degrees, 45 degrees). It was useful in differentiating between normal and tumorous glandular tissue, and also offered an enhanced view of the intrasellar (via hydroscopy) and parasellar region. Moreover the endoscopic method is able to decrease the operating time, reduce blood loss. In different stages of the surgery, depending on the anatomical and pathological situation, switching back and forth from microscope to endoscope technique, gives us the benefit of a clearer view in each situation.

Transoral CO2 laser management for selected supraglottic tumors and neck dissection.

This study aimed to evaluate transoral laser resection as a method of choice for conservation surgery for supraglottic laryngeal carcinoma in carefully selected patients. Between 1987 and 2006, 55 patients with early supraglottic carcinoma were selected for transoral laser surgery. The outcome of the endoscopic CO(2) laser resection and larynx-sparing functional results without tracheotomy was evaluated. Fifty-five patients with T1, T2 supraglottic carcinomas underwent transoral CO(2) laser resection and seven patients with manifest neck metastasis required a neck dissection at one session with additional postoperative radiation therapy. There was no need for tracheotomy; deglutition was moderately disturbed. Forty of the 55 (73%) patients had no signs of recurrence to date. Fifteen patients with local recurrences underwent salvage therapies: six repeated laser excisions, three radiotherapies, four supraglottic laryngectomies and two total laryngectomies. Laser-specific survival is 84% and larynx preservation is 96%. The overall 5-year-survival after salvage treatment is 98%. Development of late metastasis required five radical neck dissections (RND) and radiation therapy. The results indicated that transoral laser resection can control early supraglottic cancer in selected patients and can be combined with simultaneous neck dissection with less morbidity than "open surgery".

Intranasal PUVA phototherapy in nasal polyposis--a pilot study.

Nasal polyposis (NP) affects 4% of the general population, representing a major health problem. In spite of complex (surgical and medical) treatment, the relapse rate is high and it has a negative impact on the quality of life. Recently we found that intranasal photochemotherapy with ultraviolet A light (PUVA) is effective in allergic rhinitis. In the present study PUVA was administered for 6 weeks in 7 patients with NP. Nasal lavages were performed in all patients before and at the end of the treatment; from four patients a biopsy specimen was also collected. Eosinophils significantly decreased in patients with NP and slightly in a patient who had associated aspirin sensitivity. IL-5 and eosinophil cationic protein (ECP) levels showed a decreasing trend in patients with NP and an increasing trend in patients with associated aspirin sensitivity. Our results suggest that intranasal PUVA might represent a future therapeutic method in a subset of patients with NP.

Minimally invasive peroral endoscopic removal of a regurgitated giant polysegmented fibrovascular polyp of the esophagus.

Giant fibrovascular polyps (FVP) are relatively rare benign neoplasms of the upper part of the esophagus. Without a previous history, their diagnosis might be difficult because the endoscopic findings are sometimes misinterpreted. The present report describes a case in which the patient regurgitated a giant polypoid mass into his mouth and captured it between his teeth and buccal surface until emergency endoscopic removal. Although the adequate therapy for these lesions is open surgical resection, most often via cervical esophagotomy, in our case the polyp was removed successfully by peroral endoscopy with minimally invasive surgery. After 5 years of follow-up the patient is doing well, without recurrence.

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.

Peroral endoscopic removal: as a minimally invasive long-term surgical treatment of a regurgitated giant polisegmented fibrovascular polyp of the esophagus.

Giant fibrovascular polyps (FVP) are relatively rare benign neoplasm of the upper part of the esophagus. Without previous history, their diagnosis might be difficult as the endoscopic findings are sometimes misinterpreted. The present report describes a case, in which the patient regurgitated his giant polypoid mass into his mouth and captured it between his teeth and buccal surface until the emergency endoscopic removal. Although the adequate therapy for these lesions is mainly the open surgical resection, most often via cervical esophagotomy, in our case the polyp was removed successfully by peroral endoscopic operation, as a minimally invasive surgical treatment. After 5 years of follow-up, the patient is doing well, without recurrence of his polyp.

[Dimensions of the human temporal bone that are relevant to cochlear implantation surgery in infants and toddlers. A clinical-radiological study]. / Az emberi halántékcsontnak a csecsemo- és kisgyermekkori cochlearis implantáció szempontjából kiemelkedoen fontos dimenziói. Klinikoradiológiai vizsgálat.

Introduction: Early cochlear implantation enables prelingual deaf individuals to become full members of the hearing society. Although early diagnostics are widely accessible and enable early rehabilitation, implant surgery often may be delayed due to a candidate's young age. Aim: The authors' objectives were to determine the anatomical parameters of the pediatric and adult temporal bone that are relevant to cochlear implantation and to ascertain the differences between them in order to assess whether the anatomical differences could influence the surgical technique and the timing of surgery. Method: Along with a survey of the literature, findings from the authors own cochlear implantees were assessed with respect to the most relevant dimensions of the internal electronic package, including the stimulating electrode of the cochlear implant, by measuring the squama of the temporal bone, the mastoid cavity and the facial recess on high resolution computed tomographic images. Results: The skull and the overlying soft tissues proved to be thinner and the mastoid cavity was less developed in children than in adults, while no significant changes were noted in the size of the facial recess. Conclusions: It is recommended to choose modern, thin implants that do not require sinking the implant package into a bone bed. Less bone work in infants and children enables excellent visualization of the round window through the underdeveloped mastoid cavity, which makes the procedure less time-consuming and minimally invasive. Indeed, a young age should alert ear surgeons to be cautious, but no higher risk of injury to important structures is predicted for young subjects than those that might occur in adults. Orv Hetil. 2019; 160(24): 936-943.

[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.

Detection of osteoprotegerin and TNF-alpha mRNA in ankylotic Stapes footplates in connection with measles virus positivity.

HYPOTHESIS: Otosclerosis is a bone remodeling disorder of the otic capsule causing conductive and sensorineural hearing loss. Persistent measles virus infection of the temporal bone with increased tumor necrosis factor (TNF)-alpha and decreased osteoprotegerin mRNA expression is supposed to be the main etiologic factor in otosclerosis. BACKGROUND: Determinants of measles virus infection and reactive inflammation were studied in otosclerosis. The presence of measles virus was shown in otosclerotic patients by reverse transcriptase-polymerase chain reaction (RT-PCR) amplification of the viral RNA. No report is available, however, about the role and interactions of bone-specific cytokines in otosclerosis. METHODS: : Nucleic acid was extracted from stapes footplates of clinically otosclerotic patients. Measles virus nucleoprotein RNA was amplified by seminested RT-PCR. TNF-alpha and osteoprotegerin mRNA coexpression was detected by RT-PCR in otosclerotic bone and was correlated to measles virus positivity. RESULTS: Among 154 clinically stapes fixation otosclerotic patients, 99 stapedes contained measles virus RNA. TNF-alpha mRNA was detectable in 88 virus-positive and in 6 virus-negative stapes footplates. Osteoprotegerin mRNA expression was significantly lower in the TNF-alpha-positive specimens (P < .0001) that was independent from virus positivity. CONCLUSION: Detection of TNF-alpha mRNA demonstrates activated osteoclast functions and inflammatory pathways in otosclerotic stapes footplates associated with measles virus presence. Increased expression of TNF-alpha and its action on RANK production inhibits the protective functions of osteoprotegerin on normal bone turnover in the otic capsule.

Activated osteoclasts with CD51/61 expression in otosclerosis.

HYPOTHESIS: Stapes ankylosis is supposed to be a disease with variable histopathology caused by otosclerosis or pseudo-otosclerosis. Persistent measles virus infection of the otic capsule could induce reactivation of quiescent embryonic osteoclasts in otosclerosis. BACKGROUND: Presence of measles virus RNA was demonstrated in the footplates of otosclerotic patients by reverse-transcription polymerase chain reaction (RT-PCR). Histology of active otosclerosis is featured by the presence of numerous osteoclasts with unknown phenotype. METHODS: Nucleic acid was extracted from stapes footplates of clinically otosclerotic patients (n = 261). Genomic RNA of measles virus was amplified by RT-PCR. Amplification results were correlated to postoperative histologic and CD51/61 specific immunohistologic findings. A parallel alcalic phosphatase activity assessment was performed to evaluate the metabolic activity of osteoclasts in each section. RESULTS: Among 261 stapes fixation cases, 175 otosclerotic stapes contained measles virus RNA. Histology for virus negative stapes (n = 86) represented nonotosclerotic, degenerative disorders. Histologically confirmed otosclerosis was featured by the presence of osteoclasts with renewed, embryonic phenotype. In otosclerosis, alcalic phosphatase activity was significantly higher compared with nonotosclerotic stapes ankylosis (P < .001). CONCLUSION: The presence of CD51/61 positive osteoclasts in otosclerotic bone containing viral sequences provides the basis for an inflammatory bone remodeling disorder. Otosclerosis is a disease caused by persistent measles virus infection and reactivation of resting embryonic osteoclasts in the otic capsule.

Antimeasles immunoglobulin g for serologic diagnosis of otosclerotic hearing loss.

HYPOTHESIS: Persistent measles virus infection of the otic capsule is suggested to be an etiologic factor in otosclerosis. Otosclerosis is a disease of complex unknown etiology causing progressive conductive and/or sensorineural hearing loss (HL). BACKGROUND: Diagnostic methods of otosclerosis are sensitive to ossicular chain fixation with low specificity for otosclerotic stapes ankylosis. METHODS: Nucleic acid was extracted from stapes foot plates of clinically stapes fixation patients (N = 213). Measles virus nucleoprotein RNA was amplified by reverse-transcriptase polymerase chain reaction. Amplification results were correlated to histologic findings in 49 cases. Antimeasles IgG levels of all clinically stapes fixation as well as control sera specimens were measured by enzyme-linked immunosorbent assay. RESULTS: Among clinically stapes fixation patients, 141 stapes foot plates contained measles virus RNA. Among 49 histologic specimens, viral RNA was detectable only in histologically otosclerotic stapes foot plates (n = 35). Histology for virus-negative foot plates (n = 14) excluded otosclerosis. Antimeasles IgG levels were significantly lower in the sera of patients with virus-positive stapes than in control sera. CONCLUSIONS: Combination of decreased antimeasles IgG serum level and conductive HL has a great specificity and sensitivity as a diagnostic method in the preoperative evaluation of ossicular chain fixations otosclerosis. Low antimeasles IgG level indicates otosclerosis, whereas high level suggests non-otosclerotic ossicular chain fixations. Preoperative elucidation of the cause of a conductive HL may suggest optional medical treatment in preference to surgical methods.

Two subgroups of stapes fixation: otosclerosis and pseudo-otosclerosis.

HYPOTHESIS: Stapes ankylosis is a disease with variable histopathology and can be caused by otosclerosis or pseudo-otosclerosis. Viral pathogenesis of otosclerosis could be established only by correlative analysis: histologic examination of the stapes footplate and reverse-transcriptase polymerase chain reaction (RT-PCR) amplification of the viral RNA. BACKGROUND: Presence of the RNA genome of measles virus was demonstrated in the footplates of clinically otosclerotic patients by RT-PCR, and also viral proteins were detected by immunohistochemistry. METHODS: Nucleic acids were extracted from ankylotic stapes footplates of clinically stapes fixation patients (n = 104). Measles virus genomic nucleoprotein (NP) RNA was amplified by seminested RT-PCR. Amplification results were correlated to postoperative histologic and audiologic findings. RESULTS: Measles virus RNA was detectable only in histologically otosclerotic stapes footplates (n = 67). Histology for virus negative footplates (n = 37) excluded otosclerosis. Virus negative stapes footplates showed nonotosclerotic, degenerative disorders. CONCLUSIONS: Stapes ankylosis is a heterogeneous disease causing conductive hearing loss with different etiologies. Nonotosclerotic stapes fixations could be established as pseudo-otosclerosis and may belong to nonspecific, degenerative disorders with variable and noncharacteristic histopathology. Otosclerosis is an inflammatory disease caused by persisting measles virus infection of the otic capsule.

Codetection of measles virus and tumor necrosis factor-alpha mRNA in otosclerotic stapes footplates.

HYPOTHESIS: Otosclerosis is a disease of unknown etiology causing conductive or sensorineural hearing loss. Persistent measles virus infection of the otic capsule is considered to be one of the etiologic factors in otosclerosis. BACKGROUND: Determinants of measles virus infection and reactive inflammation were studied in otosclerosis. The presence of measles virus was shown in otosclerotic patients by reverse-transcription polymerase chain reaction (RT-PCR) amplification of the viral RNA. No report is available, however, on the types and features of paracrine cytokines in otosclerosis. METHODS: Nucleic acid was extracted from stapes footplate samples of clinically otosclerotic patients. Measles virus nucleoprotein RNA was amplified by seminested RT-PCR. Tumor necrosis factor (TNF)-alpha mRNA expression was detected by RT-PCR in otosclerotic bone and was correlated with preoperative audiologic findings and measles virus positivity. RESULTS: Among 154 clinically otosclerotic patients, 99 stapes footplate specimens contained measles virus RNA. TNF-alpha mRNA was detectable in 88 virus-positive and in 6 virus-negative stapes footplates. There was no detectable TNF-alpha mRNA expression in virus negative cases. CONCLUSION: The etiologic role of measles virus in the pathogenesis of otosclerosis should be considered. Detection of TNF-alpha mRNA demonstrates activated osteoclast functions and inflammatory pathways in otosclerotic stapes footplates associated with measles virus presence. Virus-associated and virus-negative pathomechanisms of otosclerosis should be distinguished.

Effects of noise on the intensity of distortion product otoacoustic emissions.

Distortion product otoacoustic emission (DPOAE) is a widely used differential diagnostic method for diagnosing inner ear disorders. It provides us information on the condition of the outer hearing cells (OHCs). Otoacoustic emission occurs only when the OHCs are functioning normally. Changes in thresholds of DPOAE curves can provide us important information on the activity of the OHCs. The inner ear shows nonlinear properties if the OHCs are functioning normally. If OHCs are injured and thus function improperly, the system stops showing nonlinear properties. If we have a system with periodic excitation and, with the addition of white noise, the signal-to-noise ratio on the output increases (at least for small noise intensities), we have witnessed what is called phenomenon stochastic resonance. Our goal was to elucidate how white noise influences the intensity of DPOAE. If there is emission, that specific ear surely exhibits nonlinear behavior, which in turn is the basic property needed for stochastic resonance.

Investigation of auditory brainstem function in diabetic patients.

We performed brainstem auditory evoked potential (BAEP) examinations in 15 patients with long-standing type 1 diabetes mellitus. We applied cardiovascular reflex tests for assessment of autonomic neuropathy. The aim of our investigation was to compare the BAEP results of this patient group with those of controls and to look for the possible correlation between alteration of the auditory brainstem function and cardiovascular autonomic neuropathy. Analysis of the latencies (waves I, II, III, and V) and the interpeak latencies (I-III and I-V) of BAEP revealed a significant difference between those of diabetics and those of healthy controls. The amplitudes of waves I, III, and V were definitely lower in comparison with amplitudes of healthy controls. We observed a positive correlation between the overall autonomic score and the latencies (waves III and V) and interpeak latencies (I-III, I-V). These data support the hypothesis that long-standing diabetes mellitus and diabetic neuropathy might be revealed as a cause of certain dysfunctions of the central auditory pathways.

Neural response telemetry in cochlear implant users.

Programming of multichannel cochlear implants requires subjective responses to a series of sophisticated psychophysical percepts. It is often difficult for cochlear implant patients (especially young prelinguistically deaf children) to provide adequate responses for device fitting. However, the neural response telemetry (NRT) system renders possible the measurement of the compound action potential threshold. We performed NRT examinations in 27 cochlear implant users with Nucleus 24-channel cochlear implants. Measurements were obtained from five electrodes (3, 5, 10, 15, and 20) in each patient. Our goal was to look for correlation between behavioral subjective thresholds and compound action potentials. The action potentials could be elicited in 23 patients in all measured electrodes. The NRT threshold values were highly correlated with electrical threshold levels obtained through subjective responses. Our results suggest that the electrically elicited neural responses may yield very important information for device fitting in patients with cochlear implants.