Comparison of Two Measurement Paradigms to Determine Electrically Evoked Cochlear Nerve Responses and Their Correlation to Cochlear Nerve Cross-section in Infants and Young Children With Cochlear Implant

INTRODUCTION

Electrically evoked compound action potentials (ECAPs) are used for intra-/postoperative monitoring with intracochlear stimulation of cochlear implants. ECAPs are recorded in MED-EL (Innsbruck, Austria) implants using auditory response telemetry (ART), which has been further developed with automatic threshold determination as AutoART. The success of an ECAP measurement also depends on the number of available spiral ganglion cells and the bipolar neurons of the cochlear nerve (CN). It is assumed that a higher population of spiral ganglion cell implies a larger CN cross-sectional area (CSA), which consequently affects ECAP measurements.

METHODS

Intraoperative ECAP measurements from 19 implanted ears of children aged 8 to 18 months were retrospectively evaluated. A comparison and correlation of ART/AutoART ECAP thresholds/slopes at electrodes E2 (apical), E6 (medial), E10 (basal), and averaged E1 to E12 with CN CSA on magnetic resonance imaging was performed.

RESULTS

A Pearson correlation of the ART/AutoART ECAP thresholds/slopes for E2/E6/E10 and the averaged electrodes E1 to E12 showed a significant correlation. The CN CSA did not correlate significantly with the averaged ART/AutoART ECAP thresholds/slopes across all 12 electrodes.

SUMMARY

AutoART provides reliable measurements and is therefore a suitable alternative to ART. No significant influence of CN CSA on ECAP thresholds/slopes was observed. A predictive evaluation of the success of ECAP measurements based on CN CSA for a clinical setting cannot be made according to the present data.

Significance of endolymphatic sac surgery with and/or without simultaneous cochlea implant surgery in respect of vertigo control and speech perception in patients with Menière's disease

PURPOSE

The focus on treating patients with Menière's Disease (MD) lies on the reduction of vertigo attacks and the preservation of sensory function. Endolympathic hydrops is considered as an epiphenomenon in MD, which can potentially be altered by endolymphatic sac surgery (ESS). Purpose of the study was to investigate the influences on vertigo control through manipulation of the perilymphatic system with or without ESS.

METHODS

Retrospective data analysis of 86 consecutive patients with MD according to current diagnostic criteria after endolymphatic sac surgery alone (ESSalone; n = 45), cochlear implantation (CI) alone (CIalone; n = 12), and ESS with CI (ESS + CI; n = 29), treated at a tertiary referral center.

MAIN OUTCOME MEASURES

vertigo control, speech perception pre- and postoperatively.

RESULTS

Gender, side, and preoperative treatment were similar in all groups. Age was younger in the ESSalone-group with 56.2 ± 13.0 years (CIalone = 64.2 ± 11.4 years; ESS + CI = 63.1 ± 9.7 years). Definitive MD was present in all the CIalone, in 79.3% of the ESS + CI and in 59.6% of the ESSalone-patients. Likewise, vertigo control rate was 100% in the CIalone, 89.7% in the ESS + CI and 66.0% in the ESSalone-group.

CONCLUSIONS

Vertigo control was improved in all three groups, however, superior in groups treated with CI, potentially contributed by the manipulation of both the endo- and perilymphatic systems. A more systematic characterization of the patients with larger case numbers and documentation of follow up data would be needed to evaluate a clinical effect more properly.

ART and AutoART ECAP measurements and cochlear nerve anatomy as predictors in adult cochlear implant recipients

PURPOSE

The purpose of this retrospective study is to compare the results of electrically evoked compound action potential (ECAP) measurements using automatic auditory response telemetry (AutoART) with those obtained by ART in adults. The study also aimed to evaluate the predictive value of intraoperative ART and AutoART ECAPs for speech intelligibility (SI) and hearing success (HS), and to determine if cochlear nerve (CN) cross-sectional area (CSA) obtained preoperatively by magnetic resonance imaging (MRI) scans could predict ART and AutoART ECAPs and SI and HS outcome.

METHODS

The study analyzed and correlated ART and AutoART ECAP thresholds at electrodes E2, E6, and E10, as well as averaged ECAP thresholds over electrodes E1-E12, using data from 32 implants. Correlations were also examined for ART and AutoART ECAP slopes. In addition, averaged ART and AutoART ECAP thresholds and slopes over all 12 electrodes for each participant were correlated with CN CSA measured from MRI sequences. SI of the monosyllabic Freiburg Speech Test at 65 dB sound pressure level was examined along with averaged ART and AutoART thresholds and slopes over all 12 electrodes. A parallel analysis was performed for HS, derived from the difference between baseline and 6-month SI. Finally, correlations between CN CSA and SI, as well as CN CSA and HS were examined.

RESULTS

The results of the study showed a significant positive correlation between ART and AutoART ECAP thresholds and as well as slopes for E2, E6, E10 and averaged thresholds and slopes of E1-E12. However, no significant correlation was observed between ART and AutoART averaged ECAP thresholds and slopes and either SI and HS or CN CSA. Furthermore, no significant correlation was found between CN CSA and SI and HS.

CONCLUSION

While AutoART is a reliable and safe program for measuring ECAPs in adults, the study found no preoperative prognostic information on intraoperative ECAP results using parameters extracted from current MRI sequences or pre-/intraoperative information on subsequent hearing outcome using ECAP and CN CSA.

Comparison of speech perception in bimodal cochlear implant patients with respect to the cochlear coverage

BACKGROUND

The hearing success of patients with bimodal fitting, utilizing both a cochlear implant (CI) and a hearing aid (HA), varies considerably: While some patients benefit from bimodal CI and HA, others do not.

OBJECTIVES

This retrospective study aimed to investigate speech perception in bimodally fitted patients and compare it with the cochlear coverage (CC).

METHODS

The CC was calculated with the OTOPLAN software, measuring the cochlear duct length on temporal bone CT scans of 39 patients retrospectively. The patients were categorized into two groups: CC ≤ 65% (CC500) and CC > 65% (CC600). Monaural speech intelligibility for monosyllables at a sound pressure level (SPL) of 65 dB in a free-field setting was assessed before and after CI at various time points. The two groups, one with preoperative HA and one with postoperative CI, were compared. Additionally, speech intelligibility was correlated with CC in the entire cohort before CI and at the last available follow-up (last observation time, LOT).

RESULTS

Overall, there was no significant difference in speech intelligibility between CC500 and CC600 patients, with both groups demonstrating a consistent improvement after implantation. While CC600 patients tended to exhibit earlier improvement in speech intelligibility, CC500 patients showed a slower initial improvement within the first 3 months but demonstrated a steeper learning curve thereafter. At LOT, the two patient groups converged, with no significant differences in expected speech intelligibility. There was no significant relationship between unimodal/unilateral free-field speech intelligibility and CC. Interestingly, patients with a CC of 70-75% achieved the highest speech intelligibility.

CONCLUSION

Despite of the lack of a significant correlation between CC and speech perception, patients appeared to reach their maximum in unimodal/unilateral speech perception primarily at a coverage level of 70-75%. Nevertheless, further investigation is warranted, as CC500 was associated with shorter cochlear duct length, and different types of electrodes were used in both groups.

Evaluation of auditory pathway excitability using a pre-operative trans-tympanic electrically evoked auditory brainstem response under local anesthesia in cochlear implant candidates

OBJECTIVE

Subjective promontory stimulation is used to evaluate cochlear implant (CI) candidacy, but the test reliability is low. Electrically evoked auditory brainstem response (EABR) can verify the function of the auditory system objectively. This study's procedure uses a trans-tympanic rounded bent-tip electrode to perform pre-operative EABR under local anaesthesia (LA-TT-EABR) using MED-EL Software and Hardware. This study aimed to determine usability and effectiveness for CI candidates.

DESIGN

We hypothesised that LA-TT-EABR waveforms of good quality would be related to successful hearing outcomes. We assumed that the duration of hearing loss/deafness was a confounding factor to study outcomes.

STUDY SAMPLE

19 borderline CI candidates.

RESULTS

Positive LA-TT-EABR results were confirmed in 14 patients. LA-TT-EABR's mean latency was 2.05 ± 0.31 ms (eII/eIII) and 4.24 ± 0.39 ms (eIV/eV). Latencies weren't statistically different from intra-operative EABR elicited by basal CI contacts. All positive LA-TT-EABR patients benefitted from CI and speech performance improved one year after implantation. One patient with negative LA-TT-EABR was cochlear-implanted and had no hearing sensation.

CONCLUSIONS

LA-TT-EABR is a tool in the frame of pre-operative objective testing the auditory pathway. It seems useful for clinical testing CI candidacy. Based on this study's outcomes, LA-TT-EABR should be recommended for uncertain CI candidates.

[Speech perception as a function of cochlear coverage-comparison in bimodally hearing cochlear implant patients. German version]

BACKGROUND

Hearing success in bimodally hearing patients with a cochlear implant (CI) and a hearing aid (HA) exhibits different results: while some benefit from bimodal CI and HA, others do not.

OBJECTIVE

The aim of this study was to investigate hearing success in terms of speech perception in bimodally fitted patients in relation to the cochlear coverage (CC) of the CI electrodes.

MATERIALS AND METHODS

Using the OTOPLAN software (CAScination AG, Bern, Switzerland), CC was retrospectively measured from CT scans of the temporal bone of 39 patients, who were then categorized into two groups: CC ≤ 65% (CC⁵⁰⁰) and CC > 65% (CC⁶⁰⁰). Monaural speech intelligibility for monosyllables at a sound pressure level (SPL) of 65 dB in open field was assessed at various timepoints, preoperatively with HA and postoperatively with CI, and compared between the groups. In addition, speech intelligibility was correlated with CC in the entire cohort before surgery and during follow-up (FU).

RESULTS

Overall, no significant differences in speech intelligibility were found between CC⁵⁰⁰ and CC⁶⁰⁰ patients at any of the FU timepoints. However, both CC⁵⁰⁰ and CC⁶⁰⁰ patients showed a steady improvement in speech intelligibility after implantation. While CC⁶⁰⁰ patients tended to show an earlier improvement in speech intelligibility, CC⁵⁰⁰ patients tended to show a slower improvement during the first 3 months and a steeper learning curve thereafter. The two patient groups converged during FU, with no significant differences in speech intelligibility. There was no significant relationship between unimodal/unilateral free-field speech intelligibility and CC. However, patients with a CC of 70-75% achieved maximum speech intelligibility.

CONCLUSION

Despite a nonsignificant correlation between CC and speech discrimination, patients seem to reach their maximum in unimodal/unilateral speech understanding mainly at 70-75% coverage. However, there is room for further investigation, as CC⁵⁰⁰ was associated with a shorter cochlear duct length (CDL), and long and very long electrodes were used in both groups.

The RonchAP® palatinal device: A conservative approach in treating obstructive sleep apnea syndrome—a randomized, controlled study

Purpose

The aim of the present study was to assess the efficacy of the Ronch®AP palatal device in treating patients with moderate and severe forms of obstructive sleep apnea syndrome.

Methods

In a randomized controlled trial 22 patients were examined with the Ronch®AP palatal device after 4 weeks of usage. Their results were compared to a control group of 30 patients who did not receive any treatment during this time. All patients included did not tolerate CPAP therapy. Among other parameters the apnea–hypopnea index (AHI) was measured using nocturnal cardiorespiratory polysomnography. Daytime sleepiness was assessed using Epworth Sleepiness Scale. Pittsburgh Sleep Quality Index was used to analyze sleep quality.

Results

Using the Ronch®AP palatal device AHI was reduced from an average of 35.34 ± 14.9/h to 19.18 ± 14.93/h, whereas the control group only showed a minimal mean reduction from 31.32 ± 12.76/h to 29.37 ± 17.11/h. The difference in reduction between the two randomized groups was highly significant (d = − 14.2, 95% CI 5.9–22.6, t = 3.4, df = 49.9, p = 0.001). Epworth Sleepiness Scale score was lowered from 9.18 ± 4.73 to 7.82 ± 4.14 on average and sleep quality improved by − 1.91 ± 2.31. Both changes were also statistically relevant (p < 0.005).

Conclusions

The Ronch®AP device is an effective alternative treatment option for patients suffering from moderate and severe forms of obstructive sleep apnea syndrome and not tolerating CPAP therapy.

Trial registration number

407-16 with approval from the local ethical committee (Ethikkommission der Medizinischen Fakultät der LMU München).

LA-TT-EALR / PromCERA: Comparison of preoperatively performed electrically evoked auditory potentials at the brainstem and cortical level during local anesthesia

Introduction: In the past years, some groups established methods to use promontory stimulation and subjective responses as a tool for preoperative stimulation of the cochlea before cochlear implant (CI) surgery by a temporary transtympanic needle placed on the middle ear. Our research group tested CI candidates when the presence of the auditory nerve could not be confirmed by other pre-operative tests and analyzed objective results of electrical auditory brainstem response recorded with trans-tympanic promontory stimulation in local anesthesia (LA-TT-EABR) with a “golfclub” electrode placed on the round window niche (Polterauer et al. 2018). However, EABR recording suffers from an electrical artifact from the stimulation and focuses on the excitability of the solely auditory nerve. We hypothesize that late evoked potential response (EALR) can be used for the assessment of the auditory pathway up to the cortical area with less electrical artifact interference. Methods: The trans-tympanic electrically evoked auditory late response in local anesthesia (LA-TT-EALR) was added to our protocol right after the LA-TT-EABR in a unique recording session. In this study, we investigated the feasibility of LA-TT-EALR using MED-EL hardware and software. These two pre-operative trans-tympanic measurements, LATT- EABR and LA-TT-EALR, were compared. Results: In a total n=18 tested subjects, it could be possible to record LA-TT-EABR in 10 and LA-TT-EALR in 13. In contrast to the fact that acoustically evoked auditory late responses are often hard to detect, and an electrical artifact heavily affects LA-TT-EABR, we did not experience these problems on LA-TT-EALR recordings. The matching between two measurements was present in 67% of the cases. Conclusion: LA-TT-EALR may be a complement to the existing state-of-the-art LA-TT-EABR for pre-operative assessment before cochlear implantation offering information about auditory pathways in the auditory brainstem and cortex with a small increase of recording time. The equivalency of these two methods is encouraging.

Multicenter Results With an Active Transcutaneous Bone Conduction Implant in Patients With Single-sided Deafness

OBJECTIVE

To evaluate the audiological and subjective benefit from hearing rehabilitation with an active bone conduction implant in subjects with single-sided sensorineural deafness (SSD).

STUDY DESIGN

Prospective, multicenter, single-subject repeated measures.

SETTING

Tertiary referral center, five clinics in Germany and Switzerland.

PATIENTS

Seventeen subjects aged 18 years and older with severe to profound unilateral sensorineural hearing loss and contralateral normal hearing were followed up for 24 months.

INTERVENTION

Active bone conduction implant.

MAIN OUTCOME MEASURES

Speech understanding in noise was assessed in three situations: with signal from front, deaf, or normal hearing side (with noise from front in all set-ups). Subjective benefit was evaluated using the Speech, Spatial, and Qualities of Hearing (SSQ-B) and Bern Benefit in Single-Sided Deafness (BBSS) questionnaire.

RESULTS

When the signal was coming from the deaf side the mean improvement of the speech reception threshold in noise ranged from 1.5 up to 2.2 dB with the device and was statistically and clinically significant at all tested timepoints. No significant difference between the aided and unaided situation was found when signal and noise were coming from the front. With the signal from the normal hearing side no clinically significant difference, that is, greater than 1 dB between the aided and unaided situation was found. The SSQ-B and BBSS questionnaire showed an overall improvement with no significant difference between time points.

CONCLUSIONS

The study demonstrates long-term efficacy and benefit of the device in adults with SSD. Patients reported substantial and persistent subjective benefit from the active bone conduction implant.

Cochlear Implant Electrode Tip Fold-Over: Our Experience With Long and Flexible Electrode

OBJECTIVE

The aim of this study was to retrospectively investigate if there is any incidence of electrode tip fold-over with 31.5 mm long and flexible lateral wall electrodes implanted in two high-volume Cochlear Implant (CI) centers in Germany. In addition, a detailed literature review was performed to capture all the peer-reviewed publications reporting on tip fold-over with CI electrodes from different CI brands for comparison.

METHODS

Post-operative X-ray images of FLEX SOFT electrode from MED-EL in Stenver's view were retrospectively investigated for the presence of electrode tip fold-over from 378 consecutive cases in two high-volume CI centers in Germany. All patients were implanted between 2010 and 2018 by three individual experienced CI surgeons using round window and extended round window approach for CI electrode insertion. A literature review was performed following a thorough PubMed (https://www.ncbi.nlm.nih.gov/pubmed/) search using the keywords "cochlear implant electrode tip fold-over" or "cochlear implant electrode tip roll-over" to capture articles that were published until December 2020 in English language only. Articles selection was based on electrode-related issues investigated only in-patient cases applying imaging modality. Those studies investigated tip fold-over in cadaveric temporal bones and cases with inner-ear malformation excluded.

RESULTS

No single case of tip fold-over was clinically detected from the retrospective investigation of post-operative X-ray images from 378 consecutive cases. The electrode angular insertion depth as measured applying the cochlear coordinate system, varied from a minimum of 560° to a maximum of 720°. The literature review on the tip fold-over issue resulted in 24 peer-reviewed published articles in total. Tip fold-over with pre-curved modiolar-hugging electrodes was reported in 85 cases out of 1,606 implantations making an incidence rate of 5.3%. With the straight lateral wall electrodes, the tip fold-over was reported in four cases out of 398 implantations making an incidence rate of 1%, not including the number of implantations reported in the current study. Otherwise it would be 0.5%.

CONCLUSION

Electrode tip fold-over with 31.5 mm long flexible lateral wall electrodes is highly exceptional and this can be generalized to any of the straight lateral wall electrodes from any CI brand. The literature review on tip fold-over revealed an incidence rate of 5.3% with pre-curved or modiolar-hugging electrodes and 1% with straight lateral wall electrodes from CI brands. Including this series of 0% tip fold-over, the incidence rate of electrode tip fold-over with LW electrode type would be 0.5%.

Outcome of Auricular Reconstruction with Porous Polyethylene Frameworks: Our 10 Years of Experience with 113 Children and Adults

This study evaluates the surgical outcome and patient benefit after auricular reconstruction with porous polyethylene frameworks and temporoparietal fascia flaps in both children and adults. A total of 161 patients who had undergone auricular reconstruction between 2003 and 2014 by doctors in our department were asked to answer both a validated health-related quality-of-life questionnaire (Glasgow Benefit Inventory or Glasgow Children's Benefit Inventory) and a questionnaire reporting satisfaction, complaints, and complications with the reconstructed pinna. Furthermore, postoperative surgical complications were recorded. A total of 113 patients (89 individuals older than 14 and 24 children under the age of 14) returned the questionnaires. About 80% of the patients were satisfied with the results of their auricular reconstruction. The main complaints concerned scars and the shape. Patients' quality of life was correlated with their postoperative aesthetic satisfaction. Thus, framework extrusion was the principal factor affecting patients' satisfaction, whereas treatable postoperative complications did not interfere with the overall quality of life. Interestingly, children indicated greater benefit from auricular reconstruction than older patients. With regard to the patient's feeling of being physically healthy after auricular reconstruction, partial pinna reconstruction and reconstruction without simultaneous hearing restoration should be very carefully considered. Auricular reconstruction using a porous polyethylene framework significantly increases the patients' health-related quality of life and leads to significant patient satisfaction, especially in the case of younger patients.

Variation of the cochlear anatomy and cochlea duct length: analysis with a new tablet-based software

Purpose

In cochlear implantation, thorough preoperative planning together with measurement of the cochlear duct length (CDL) assists in choosing the correct electrode length. For measuring the CDL, different techniques have been introduced in the past century along with the then available technology. A tablet-based software offers an easy and intuitive way to visualize and analyze the anatomy of the temporal bone, its proportions and measure the CDL. Therefore, we investigated the calculation technique of the CDL via a tablet-based software on our own cohort retrospectively.

Methods

One hundred and eight preoperative computed tomography scans of the temporal bone (slice thickness < 0.7 mm) of already implanted FLEX28™ and FLEXSOFT™ patients were found eligible for analysis with the OTOPLAN software. Measurements were performed by two trained investigators independently. CDL, angular insertion depth (AID), and cochlear coverage were calculated and compared between groups of electrode types, sex, sides, and age.

Results

Mean CDL was 36.2 ± 1.8 mm with significant differences between sex (female: 35.8 ± 0.3 mm; male: 36.5 ± 0.2 mm; p = 0.037), but none concerning side or age. Differences in mean AID (FLEX28: 525.4 ± 46.4°; FLEXSOFT: 615.4 ± 47.6°), and cochlear coverage (FLEX28: 63.9 ± 5.6%; FLEXSOFT: 75.8 ± 4.3%) were significant (p < 0.001).

Conclusion

A broad range of CDL was observed with significant larger values in male, but no significant differences concerning side or age. Almost every cochlea was measured longer than 31.0 mm. Preoperative assessment aids in prevention of complications (incomplete insertion, kinking, tipfoldover), attempt of atraumatic insertion, and addressing individual necessities (hearing preservation, cochlear malformation). The preferred AID of 720° (two turns of the cochlea) was never reached, opening the discussion for the requirement of longer CI-electrodes versus a debatable audiological benefit for the patient in his/her everyday life.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00405-021-06889-0.

Surgical management of choroid plexus papilloma of the cerebellopontine and cerebellomedullary angle: classification and strategy

Choroid plexus papillomas (CPPs) are primary neuroectodermal neoplasms that usually arise in the fourth ventricle in adults. In this study, we present 12 patients with CPP arising from the cerebellopontine angle (CPP-CPA) and/or of the cerebellomedullary angle (CPP-CMA) that were treated in our department. Patients who underwent surgery for the treatment for CPP-CPA/CMA from January 2004 to March 2020 were identified by a computer search of their files from the Department of Neurosurgery, Tübingen. CPPs were classified according to their location into type 1 (tumor portion only in the CPA,), type 2 (tumor portions only in the CMA), and type 3 (tumor portions both in the CPA and CMA). Patients were evaluated for initial symptoms, previous therapies in other hospitals, extent of tumor resection, recurrence rate, and complications by reviewing patient documents. Of approximately 1500 CPA lesions, which were surgically treated in our department in the last 16 years, 12 patients (mean age 42 ± 19 years) were found to have CPP-CPA/CMA. Five were male, and seven were female patients. Gross total resection was achieved in nine cases, and a subtotal resection was attained in three cases. Tumor recurrence in the same location after the first surgery in our hospital was observed in 2 patients after 15 and 40 months of follow-up, and in another patient, distant metastases (C3/4 and L3 levels) were observed. Surgical removal of CPP is the treatment of choice, but additional therapeutic options may be necessary in case of remnant tumor portions, recurrence, or malignant transformation.

[Hearing rehabilitation with the Vibrant Soundbridge in patients with congenital middle ear malformation]

BACKGROUND

Congenital aural atresia, which is usually unilateral, causes hearing loss and aesthetic impairment. Besides tympanoplasty with/without canalplasty and bone conduction devices, active middle ear implants are also available for functional rehabilitation.

OBJECTIVE

This article aims to present a contemporary review on the treatment possibilities for middle ear malformations, with a focus on audiological rehabilitation with the Vibrant Soundbridge.

MATERIALS AND METHODS

A selective literature search for treatment possibilities was performed in PubMed up to October 2020, and personal clinical experiences are reported.

RESULTS

The Vibrant Soundbridge, which is approved for children ≥ 5 years, is suitable for treatment of middle ear malformations with a Jahrsdoerfer score ≥ 5. Although implantation of a Vibrant Soundbridge is surgically more demanding than implantation of a bone conduction device, the method is safe, delivers good auditory results (superior to bone conduction devices in terms of speech understanding and spatial hearing), does not involve intensive postsurgical care, and rarely requires revision surgery. The Vibrant Soundbridge can be coupled to (remnants of) the ossicular chain or the round window.

CONCLUSION

The Vibrant Soundbridge is an appropriate treatment method in patients with middle ear malformations who have suitable anatomical preconditions.

Image-guided robotic radiosurgery for glomus jugulare tumors-Multicenter experience and review of the literature

BACKGROUND

Glomus jugulare tumors (GJTs) are challenging to treat due to their vascularization and location. This analysis evaluates the effectiveness and safety of image-guided robotic radiosurgery (RRS) for GJTs in a multicenter study and reviews the existing radiosurgical literature.

METHODS

We analyzed outcome data from 101 patients to evaluate local control (LC), changes in pretreatment deficits, and toxicity. Moreover, radiosurgical studies for GJTs have been reviewed.

RESULTS

After a median follow-up of 35 months, the overall LC was 99%. Eighty-eight patients were treated with a single dose, 13 received up to 5 fractions. The median tumor volume was 5.6 cc; the median treatment dose for single-session treatments is 16 Gy, and for multisession treatments is 21 Gy. Fifty-six percentage of patients experienced symptom improvement or recovered entirely.

CONCLUSIONS

RRS is an effective primary and secondary treatment option for GJTs. The available literature suggests that radiosurgery is a treatment option for most GJTs.

Single-session image-guided robotic radiosurgery and quality of life for glomus jugulare tumors

BACKGROUND

Limited data are available on the efficacy and impact on the quality of life (Qol) of single-session image-guided robotic radiosurgery (RRS) for glomus jugulare tumors (GJTs). This study investigates the role of RRS in the management of GJTs and reviews the RRS literature.

METHODS

We analyzed 53 GJT patients treated with RRS to evaluate the safety, local control, clinical outcome, and Qol assessed by the SF12v2.

RESULTS

The local control was 98% at a median follow-up of 38 months. The median tumor volume was 4.3 cc and tumors were treated with a median dose of 16.5 Gy. At the last follow-up, 35 patients had recovered from their symptoms or experienced symptom improvement. Qol analyses showed no significant decline while bodily pain significantly decreased.

CONCLUSIONS

RRS is a safe and efficient tool for the treatment of GJTs. Qol of patients after treatment is stable and tends to improve over time.

Comparison of ABR and ASSR using NB-chirp-stimuli in children with severe and profound hearing loss

INTRODUCTION

Objective techniques for hearing threshold estimation in infants and children with profound or severe hearing loss play a key role in pediatric audiology to prevent speech acquisition disorders by choosing the adequate therapy. Auditory brainstem responses and auditory steady-state responses are available for frequency-dependent hearing threshold estimations and both techniques show strong correlations. However, various systems and stimuli are available, which is one reason why comparison is challenging, and, so far, no single "gold standard" could be established for hearing threshold estimation in children suffering from profound or severe hearing loss. The aim of the study was to compare hearing threshold estimations in children with profound or severe hearing loss derived with narrow-band CE-chirps evoked auditory brainstem responses and auditory steady-state response.

SUBJECTS

and Methods: 71 children (121 ears) with an age from 3 month to 15 years were measured with the Interacoustics Eclipse EP25 ABR system® (Denmark) with narrow-band CE-chirps® at 500, 1000, 2000 and 4000 Hz under identical conditions.

RESULTS

Auditory brainstem responses and auditory steady-state responses highly correlate (r = 0.694, p < 0.001). Correlation coefficients differ depending on the center frequency and patient age. Generally, auditory steady-state responses show a better hearing threshold than auditory brainstem responses or a remaining hearing threshold when auditory brainstem responses could not be obtained. In approximately 15% of cases this would have affected the therapeutic strategy when only taking one technique into account.

CONCLUSION

Auditory brainstem responses and auditory steady-state responses should be jointly used in the diagnostic approach in children with suspected profound or severe hearing loss.

PromBERA: A preoperative eABR: An update

Prior to cochlear implantation, audiological tests are performed to determine candidacy in subjects with a hearing loss. This is usually done by measuring the acoustic auditory brainstem response (ABR). Unfortunately, for some subjects, a reproducible ABR recording cannot be obtained, even at high acoustic levels. Having a healthy stimulating auditory nerve is required for cochlear implantation in order to benefit from the electrical pulses that are generated by the implant and to improve speech comprehension. In some subjects, this prerequisite cannot be measured using routine audiological tests. In this study, the feasibility of recording electrically evoked auditory brainstem responses (eABR) using a stimulating transtympanic electrode, placed on the round window niche, together with MED-EL clinical system is investigated. The results show that it is possible to record reproducible eABR measurements using PromBERA. The response was also confirmed with intraoperative eABR measurements that were stimulated using the implanted CI electrode array. Similarities between the intraoperative measurements and the preoperative recorded waveforms were observed. In summary, the integrity and excitability of the auditory nerve can be objectively measured using the PromBERA in subjects where standard clinical testing procedures are unable to provide the information required.

[Impact of Microsurgical Exstirpation of Vestibular Schwannomas on the Sense of Taste]

Patients with single sided vestibular schwannoma may report about a taste dysfunction apart from the well known cardinal symptoms. Very few data are published so far on that topic. The aim of this study was to investigate the influence of microsurgery for vestibular schwannomas on taste perception prospectively using a well validated taste test. 25 patients could be included in the study. No ageusia was claimed by the patients. In average a decrease of the taste score postoperatively could be detected on the tumor as well as on the non treated side. The differences were not statistically significant. But a subgroup of ¼ of the subjects revealed a new onset of side difference in the taste score that was not present before surgery. In all those cases the treated side showed a clinically significant reduced taste score of 6,2 in average. Within this subgroup the temporal access was overpresented in contrast to the whole group. This may indicate an influence of the choosen approach and that for the position of the tumor to the change of the taste score. The observations should be verified on a greater collective.

Comparison between ABR with click and narrow band chirp stimuli in children

OBJECTIVE

Click and chirp-evoked auditory brainstem responses (ABR) are applied for the estimation of hearing thresholds in children. The present study analyzes ABR thresholds across a large sample of children's ears obtained with both methods. The aim was to demonstrate the correlation between both methods using narrow band chirp and click stimuli.

METHODS

Click and chirp evoked ABRs were measured in 253 children aged from 0 to 18 years to determine their individual auditory threshold. The delay-compensated stimuli were narrow band CE chirps with either 2000 Hz or 4000 Hz center frequencies. Measurements were performed consecutively during natural sleep, and under sedation or general anesthesia. Threshold estimation was performed for each measurement by two experienced audiologists.

RESULTS

Pearson-correlation analysis revealed highly significant correlations (r=0.94) between click and chirp derived thresholds for both 2 kHz and 4 kHz chirps. No considerable differences were observed either between different age ranges or gender. Comparing the thresholds estimated using ABR with click stimuli and chirp stimuli, only 0.8-2% for the 2000 Hz NB-chirp and 0.4-1.2% of the 4000 Hz NB-chirp measurements differed more than 15 dB for different degrees of hearing loss or normal hearing.

CONCLUSION

The results suggest that either NB-chirp or click ABR is sufficient for threshold estimation. This holds for the chirp frequencies of 2000 Hz and 4000 Hz. The use of either click- or chirp-evoked ABR allows a reduction of recording time in young infants. Nevertheless, to cross-check the results of one of the methods, we recommend measurements with the other method as well.

[Prospective assessment of quality of life after auricular reconstruction with porous polyethylene]

BACKGROUND

Microtia is associated with increased psychosocial morbidity. The literature contains three purely retrospective studies using validated tools. These studies show that auricular reconstruction leads to a significant improvement in health-related quality of life in affected children and adults.

METHODS

In a prospective approach, the authors assessed 21 consecutive microtia patients (return rate 81 %; 7 children and 10 adults) before and after auricular reconstruction with porous polyethylene using the following validated questionnaires: Glasgow Health Status Inventory (GHSI), Short Form 36 Health Survey Questionnaire (SF-36), Childhood Experiences Questionnaire (CEQ) and Kidscreen-52.

RESULTS

An improved health-related quality of life was detected with all applied instruments.

CONCLUSION

A subjective benefit of auricular reconstruction with porous polyethylene can be shown using prospective, as well retrospective tools.

[Correlation of pure tone thresholds and hearing loss for numbers. Comparison of three calculation variations for plausibility checking in expertise]

BACKGROUND

The present study analyzes the best combination of frequencies for the calculation of mean hearing loss in pure tone threshold audiometry for correlation with hearing loss for numbers in speech audiometry, since the literature describes different calculation variations for plausibility checking in expertise. Three calculation variations, A (250, 500 and 1000 Hz), B (500 and 1000 Hz) and C (500, 1000 and 2000 Hz), were compared.

METHODS

Audiograms in 80 patients with normal hearing, 106 patients with hearing loss and 135 expertise patients were analyzed in a retrospective manner. Differences between mean pure tone audiometry thresholds and hearing loss for numbers were calculated and statistically compared separately for the right and the left ear in the three patient collectives.

RESULTS

We found the calculation variation A to be the best combination of frequencies, since it yielded the smallest standard deviations while being statistically different to calculation variations B and C. The 1- and 2.58-fold standard deviation (representing 68.3% and 99.0% of all values) was ±4.6 and ±11.8 dB for calculation variation A in patients with hearing loss, respectively.

CONCLUSIONS

For plausibility checking in expertise, the mean threshold from the frequencies 250, 500 and 1000 Hz should be compared to the hearing loss for numbers. The common recommendation reported by the literature to doubt plausibility when the difference of these values exceeds ±5 dB is too strict as shown by this study.

Botulinum toxin A prolongs functional durability of voice prostheses in laryngectomees with pharyngoesophageal spasm

PURPOSE

Laryngectomized patients with pharyngoesophageal spasm frequently have poor voice quality and dysphagia. Local botulinum toxin A (BTA) injection can relieve muscular hypertonicity and improve symptoms. This procedure should also prolong the functional life span of the tracheoesophageal voice prosthesis.

MATERIALS AND METHODS

This study evaluates 33 BTA treatments in 11 laryngectomees. All patients were having poor voice quality; 6 patients had additional dysphagia. In 10 patients, the BTA injection has been carried out during rigid pharyngoscopy under general anesthesia. One patient was treated in local anesthesia.

RESULTS

A subjective improvement of voice quality was reported in 94%. This lasted on average for 20 weeks. The swallowing function improved moderately. For the first time, the functional life span of voice prostheses was examined. After treatment of pharyngoesophageal spasm, their durability was almost tripled. The BTA therapy has a significant effect.

CONCLUSIONS

The BTA treatment improves voice quality and prolongs functional durability of voice prostheses in laryngectomees with pharyngoesophageal spasm. The success of treatment is of limited duration but can be repeated in the long-term.

Trigeminal perception is necessary to localize odors

The human ability to localize odorants has been examined in a number of studies, but the findings are contradictory. In the present study we investigated the human sensitivity and ability to localize hydrogen sulphide (H(2)S), which in low concentrations stimulates the olfactory system selectively, the olfactory-trigeminal substance isoamyl acetate (IAA), and the trigeminal substance carbon dioxide (CO(2)). A general requirement for testing of localization was the conscious perception of the applied stimuli by the participants. Using Signal Detection Theory, we determined the human sensitivity in response to stimulation with these substances. Then the subjects' ability to localize the three different substances was tested. We found that humans can detect H(2)S in low concentration (2 ppm) with moderate sensitivity, and possess a high sensitivity in response to stimulation with 8 ppm H(2)S, 17.5% IAA, 50% v/v CO(2). In the localization experiment, subjects could localize neither the low nor the high concentration of H(2)S. In contrast, subjects possessed the ability to localize IAA and CO(2) stimuli. These results clearly demonstrate that humans, in spite of the aware perception, are not able to localize substances which only activate the olfactory system independent of their concentration, but they possess an ability to localize odorants that additionally excite the trigeminal system.

Prevalence and Characteristics of Preoperative Balance Disorders in Cochlear Implant Candidates

Objectives:

The aim of this study was to elucidate the frequency and characteristics of preoperative vertigo symptoms in patients who undergo cochlear implantation (CI), in order to differentiate them from CI-related symptoms.

Methods:

In a prospective observational study, 47 adult CI candidates were asked about vertigo problems on a questionnaire. A subdivision into 3 groups was done: Group A (probable otogenic vertigo), group B (possible otogenic vertigo), and group C (not otogenic vertigo). Horizontal semicircular canal function was measured. Patients with vertigo complaints were compared to patients without vertigo with regard to the presence of abnormal vestibular function findings.

Results:

Twenty-five patients (53%) reported preoperative vertigo problems. In 21 (84%), the patient's history suggested a probable (group A) or possible (group B) otogenic origin. Patients with vertigo more often had abnormal findings on vestibular function testing than did patients without vertigo. This difference, however, was not statistically significant.

Conclusions:

A considerable number of CI candidates have preoperative vertigo symptoms. These cannot be explained by horizontal semicircular canal function alone. In order to understand why CI patients develop postoperative vertigo, analysis of prospective preoperative vestibular function test findings and vertigo symptoms is necessary.

Ototoxicity of artemether/lumefantrine in the treatment of falciparum malaria: a randomized trial

Background

Due to increasing drug resistance, artemisinin-based combination chemotherapy (ACT) has become the first-line treatment of falciparum malaria in many endemic countries. However, irreversible ototoxicity associated with artemether/lumefantrine (AL) has been reported recently and suggested to be a serious limitation in the use of ACT. The aim of the study was to compare ototoxicity, tolerability, and efficacy of ACT with that of quinine and atovaquone/proguanil in the treatment of uncomplicated falciparum malaria.

Methods

Ninety-seven patients in south-west Ethiopia with slide-confirmed malaria were randomly assigned to receive either artemether/lumefantrine or quinine or atovaquone/proguanil and followed-up for 90 days. Comprehensive audiovestibular testing by pure tone audiometry (PTA), transitory evoked (TE) and distortion product (DP) otoacoustic emissions (OAE) and brain stem evoked response audiometry (BERA) was done before enrolment and after seven, 28 and 90 days.

Results

PTA and DP-OAE levels revealed transient significant cochlear hearing loss in patients treated with quinine but not in those treated with artemether/lumefantrine or atovaquone/proguanil. TE-OAE could be elicited in all examinations, except for three patients in the Q group on day 7, who suffered a transient hearing loss greater than 30 dB. There was no evidence of drug-induced brain stem lesions by BERA measurements.

Conclusion

There was no detrimental effect of a standard oral regimen of artemether/lumefantrine on peripheral hearing or brainstem auditory pathways in patients with uncomplicated falciparum malaria. In contrast, transient hearing loss is common after quinine therapy and due to temporary outer hair cell dysfunction.

Effect of atorvastatin on progression of sensorineural hearing loss and tinnitus in the elderly: results of a prospective, randomized, double-blind clinical trial

OBJECTIVE

To test whether the 3-hydroxy-3-methylglutaryl- coenzyme A reductase inhibitor atorvastatin can slow down the progression of presbycusis.

PATIENTS

Fifty patients 60- to 75-years-old with presbycusis and moderately elevated serum cholesterol.

INTERVENTION(S)

In a double-blind design, patients were randomly assigned to treatment with either atorvastatin (40 mg/d orally) or placebo.

MAIN OUTCOME MEASURE(S)

Pure-tone audiometry and tinnitus evaluation at enrolment and after 7 and 13 months.

RESULTS

Development of hearing thresholds after 7 and 13 months showed no significant differences between the groups. Tinnitus score continuously improved in the atorvastatin group (34.8 at 7 and 27.6 at 13 mo), whereas it slightly deteriorated in the placebo group (24.8 at 7 and 26.8 at 13 mo). The effect on tinnitus was a tendency without statistic significance (p = 0.0833).

CONCLUSION

Atorvastatin had no effect on the development of hearing thresholds, but resulted in a trend toward a relief of tinnitus.

[The hard-of-hearing patient--what should the general practitioner do?]

When assessing hardness of hearing, the physician must in the first instance differentiate between an acute event--for example sudden loss of hearing--and chronic deafness. Otoscopy, tuning fork testing and measurement of hearing distance provide importance information for the differentiation of hardness of hearing. In the case of noise deafness, the general physician has a preventive task. With regard to the provision of a hearing aid he can play a supportive role as a mediator between the hearing aid wearer, the ENT specialist and the acoustician.

Functional outcome after gamma knife treatment in vestibular schwannoma

Radiosurgery (RS) is a noninvasive, ambulatory special neurosurgical procedure for the treatment of vestibular schwannoma (VS). We treated 123 patients with unilateral schwannomas between 1994 and 2000 at the gamma knife (GK) center in Munich using a primary stereotactic procedure. These patients were followed up until June 2004 in respect to audiological, neurological, neurootological and radiological features before and after radiosurgical intervention. The actual tumor control rate of 8.2 years (mean) after GK surgery for all patients and a single treatment was calculated to be 96.7%. The impairment of hearing was on average 18% after GK, ranking from 0% gain of hearing loss up to 90%. Facial nerve function, graded according to the House-Brackmann scale, deteriorated in none of the patients; 5.8% reported a trigeminal neuralgia. Tinnitus developed in 4.1% of the patients after RS; 13.3% had vertigo for the first time after the treatment, age apparently being a predisposing factor. Radiosurgical treatment for VS is an alternative to microsurgery (MS). It is associated with a lower rate of facial and trigeminal neuropathy, postoperative complications and hospital stay. The hearing preservation rate is equivalent to MS.

[Diagnosing hearing impairment in children]

Failure to recognize the presence of a hearing impairment in early childhood can severely harm the development of the child. A differentiation is made between sound conduction deafness and sensorineural.deafness. The former may be temporary or permanent. The latter may be inherited or acquired. Inherited sensorineural deafness occurs within the framework of syndromes, or may be monosymptomatic. Acquired sensorineural deafness may occur prenatally, perinatally or postnatally. A range of subjective and objective audiological tests is available, which, depending on the age and state of developmental of the child, can be used in combination. Cases of syndromal deafness are investigated on an interdisciplinary basis and involve the pediatrician, geneticist, laboratory physician and radiologist.

Niikawa-Kuroki-Syndrom

Niikawa-Kuroki syndrome (Kabuki make-up syndrome) is a congenital disorder with characteristic facial features and possibly anomalies of the skeletal system and internal organs. There is an increasing number of reports of patients with combined hearing impairment, inner ear deformities or sensorineural hearing impairment. In addition, the patients often suffer from therapy-resistant chronic otitis media. In addition to multiple cardiac and renal deformities, our 3 year old patient has a hearing impairment due to chronic otitis media with chronic otorrhea, and requires a hearing aid. A high-definition CT scan of the petrosal bone revealed, for the first time in a patient with Niikawa-Kuroki syndrome, a large vestibular aqueduct syndrome and deformities of the vestibular system. We examine the problems involved with treating chronic otorrhea in chronic otitis media and providing patients with BTE hearing aids.

Outpatient gamma knife surgery for vestibular schwannoma: definition of the therapeutic profile based on a 10-year experience

Object. The purpose of the study was to define the therapeutic profile of outpatient gamma knife surgery (GKS) for vestibular schwannoma (VS) by using sequential tumor volumetry to quantify changes following treatment.

Methods. A total of 111 patients met the inclusion criteria. The median follow-up duration was 7 years (range 5–9.6 years). Thirty-seven patients (33%) had undergone surgery before GKS and 10 (9%) had neurofibromatosis Type 2 (NF2). The median VS volume was 1.6 cm3 (range 0.08–8.7 cm3).

The actuarial 6-year tumor control rate after a single GKS treatment was 95%. Tumor swelling was observed in 43 patients (38.7%). Recurrence was significantly associated with NF2 (p < 0.003) and the reduced dose (p < 0.03) delivered to these tumors. The incidence of facial nerve neuropathy was mainly determined by surgery prior to GKS (p < 0.0001). Facial nerve radiation toxicity was mild and transient. No permanent facial nerve toxicity was observed. Trigeminal neuropathy occurred in 13 patients, and this was correlated with the VS volume (p < 0.02). The median hearing loss was −10 dB (range + 20 dB to −70 dB). The risk of hearing loss was correlated with age and transient tumor swelling (p < 0.05) but not with dose parameters or NF2.

Conclusions. Outpatient GKS is feasible, effective, and safe. Its therapeutic profile compares favorably with that of microsurgery.

Outpatient gamma knife surgery for vestibular schwannoma: definition of the therapeutic profile based on a 10-year experience

Object.The purpose of the study was to define the therapeutic profile of outpatient gamma knife surgery (GKS) for vestibular schwannoma (VS) by using sequential tumor volumetry to quantify changes following treatment.

Methods.A total of 111 patients met the inclusion criteria. The median follow-up duration was 7 years (range 5–9.6 years). Thirty-seven patients (33%) had undergone surgery before GKS and 10 (9%) had neurofibromatosis Type 2 (NF2). The median VS volume was 1.6 cm3(range 0.08–8.7 cm3).

The actuarial 6-year tumor control rate after a single GKS treatment was 95%. Tumor swelling was observed in 43 patients (38.7%). Recurrence was significantly associated with NF2 (p < 0.003) and the reduced dose (p < 0.03) delivered to these tumors. The incidence of facial nerve neuropathy was mainly determined by surgery prior to GKS (p < 0.0001). Facial nerve radiation toxicity was mild and transient. No permanent facial nerve toxicity was observed. Trigeminal neuropathy occurred in 13 patients, and this was correlated with the VS volume (p < 0.02). The median hearing loss was −10 dB (range + 20 dB to −70 dB). The risk of hearing loss was correlated with age and transient tumor swelling (p < 0.05) but not with dose parameters or NF2.

Conclusions.Outpatient GKS is feasible, effective, and safe. Its therapeutic profile compares favorably with that of microsurgery.

Outpatient gamma knife surgery for vestibular schwannoma: definition of the therapeutic profile based on a 10-year experience

OBJECT

The purpose of the study was to define the therapeutic profile of outpatient gamma knife surgery (GKS) for vestibular schwannoma (VS) by using sequential tumor volumetry to quantify changes following treatment.

METHODS

A total of 111 patients met the inclusion criteria. The median follow-up duration was 7 years (range 5-9.6 years). Thirty-seven patients (33%) had undergone surgery before GKS and 10 (9%) had neurofibromatosis Type 2 (NF2). The median VS volume was 1.6 cm3 (range 0.08-8.7 cm3). The actuarial 6-year tumor control rate after a single GKS treatment was 95%. Tumor swelling was observed in 43 patients (38.7%). Recurrence was significantly associated with NF2 (p < 0.003) and the reduced dose (p < 0.03) delivered to these tumors. The incidence of facial nerve neuropathy was mainly determined by surgery prior to GKS (p < 0.0001). Facial nerve radiation toxicity was mild and transient. No permanent facial nerve toxicity was observed. Trigeminal neuropathy occurred in 13 patients, and this was correlated with the VS volume (p < 0.02). The median hearing loss was -10 dB (range + 20 dB to -70 dB). The risk of hearing loss was correlated with age and transient tumor swelling (p < 0.05) but not with dose parameters or NF2.

CONCLUSIONS

Outpatient GKS is feasible, effective, and safe. Its therapeutic profile compares favorably with that of microsurgery.

Labyrinth dysfunction 8 months after cochlear implantation: a case report

OBJECTIVE

Investigate whether the cochleostomy is a possible port of entry for pneumolabyrinth and a resulting vertigo in patients provided with a cochlear implant.

STUDY DESIGN

Retrospective case review.

SETTING

Ludwig-Maximilians University of Munich, Hospital Grosshadern.

PATIENT

62-year-old patient who underwent implantation of a HiFocus II cochlear implant with positioner from Advanced Bionics (CLARION). Eight months postoperatively, the patient reported rotatory vertigo and right-side tinnitus after he had blown his nose harder than usual during an episode of rhinitis.

INTERVENTIONS

Preoperative and postoperative testing of both the petrosal bone with a CT scan and of balance function.

MAIN OUTCOME MEASURE

Air inclusion in the labyrinth.

RESULTS

In contrast to the preoperative high resolution computed tomography (CT) scan, air inclusion was seen in the labyrinth during the episode of vertigo. At the same time, balance function tests with Frenzel glasses revealed both spontaneous and provoked horizontal nystagmus to the right side. At follow-up 8 weeks later, the level of vertigo had significantly decreased. Twelve months later, the control CT showed the cochlear implant positioned correctly and no visible air in the labyrinth.

CONCLUSION

It is known that placement of the HiFocus II with Positioner from CLARION requires a relatively large cochleostomy of 1.5 mm. Moreover, in the connective tissue seal between the electrode and the positioner, the latter reaches into the tympanic cavity, and this is possibly the weak point. Further investigation will be needed to determine whether the large cochleostomy with the HiFocus II with positioner increases the predisposition to labyrinth dysfunction.

[Localized invasive intracranial aspergillosis with multiple cranial nerve failure -- case report and review of the literature]

Contrary to the more frequent hematogenously spread cerebral aspergillosis, localized invasive intracranial aspergillosis is a fungal infection that can also occur in patients who are not severely immunosuppressed. This illness can be effectively treated in some of these patients by early and rigorous therapy. Localized invasion of the fungus, generally from one of the nasal sinuses, causes intracranial growth mainly along the base of the skull and larger vessels,where fibrous, granulomatous tissue develops. This generally leads to damage of the cranial nerves (primarily I-VI) as well as localized pain syndromes. We report on the clinical course documented by MRI of a patient with localized invasive intracranial aspergillosis who had multiple failure of cranial nerves following surgery for an aspergilloma of the maxillary sinus. Clinical course, imaging findings, and treatment of the illness are discussed with a review of the relevant literature.

[Detection of humoral immune response to inner ear proteins in patients with sensorineural hearing loss]

BACKGROUND

The precise mechanism of inner ear disease is still unknown. An autoimmune reaction could be one of several possible pathogenic factors involved in progressive sensorineural hearing loss. Heat shock protein 70 is suggested to play an important role in the development of autoimmune diseases. The aim of this study is the investigation of humoral immune reactivity to inner ear components in patients with sensorineural hearing loss.

METHODS

The presence of antibodies to inner ear components was determined by immuno-blotting extracted bovine or human inner ear proteins. Study groups consisted of patients with idiopathic progressive sensorineural hearing loss (group A), patients with Menière's disease (group B), patients with sudden hearing loss (group C), patients with otosclerosis (group D), patients with Cogan's disease (group E), and individuals without hearing problems (group F).

RESULTS

40% of the patients with progressive sensorineural hearing loss showed reactivity against a 68-kDa protein extracted from bovine inner ear. In contrast to this, only 5% of healthy individuals and 10% with Menière's disease showed reactivity against the 68-kDa protein from bovine inner ear or against bovine heat shock protein 70. Some of the patients who showed reactivity against bovine inner ear proteins were tested with human inner ear and human heat shock protein 70; all of these showed reactivity. Approximately 6% of the patients with sudden hearing loss (group C), otosclerosis (group D), and Cogan's disease (group E) showed reactivity to inner ear proteins. A non-specific humoral immune reaction against inner ear proteins with molecular weights of 30, 40, 50, 60, and 220 kDa was observed in all patients.

DISCUSSION

These results indicate a humoral immune reactivity against heat shock protein 70, which might be responsible for the pathogenesis of progressive sensorineural hearing loss.

Tertiary trisomy in a human kindred containing an E/G translocation

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