Christoph Arnoldner

Publications of Christoph Arnoldner

• Electron microscopy changes of cochlear implant electrodes with permanently high impedances.

  Authors: Martin Durisin, Christian Krause, Christoph Arnoldner, Georgios Kontorinis, Andreas Buechner, Thomas Lenarz, Anke Lesinki-Schiedat, Oliver Profant, Juergen Neuburger

  Cochlear implants international. 11/2011; 12(4):228-33.

  Impedance measurements by means of telemetry have provided us with an objective test of cochlear implant function. Unmeasurable impedance suggests a possible defect on the corresponding channel ofImpedance measurements by means of telemetry have provided us with an objective test of cochlear implant function. Unmeasurable impedance suggests a possible defect on the corresponding channel of the electrode. However, increasing impedances could suggest inflammatory and/or proliferating processes along the electrode. In this report we examined correlations between high impedance, measured in vivo and in vitro findings on the electrode surfaces. We describe recurrent increases in cochlear implant electrode impedance in the same channels, which could initially be reversed by reprogramming the implant, and with anti-inflammatory treatment using cortisone and antibiotics. Subsequently, however, the impedances remained consistently high, indicating a cochlear implant defect. After the removal of the cochlear implant, the electrodes were examined using light and scanning electron microscopy. Examination of the electrodes with normal impedance values revealed, in the great majority of the electrodes, silver shining surfaces. On the other hand, electrodes with high impedances were found coated with tissue. Further analysis of these electrodes using scanning electron microscopy also demonstrated surface changes. Persistently high impedances were related to changes on the electrodes' surface and to coating with tissue in this case. These changes can result in adhesive processes and technical malfunction, leading to explantation and difficult re-implantation. Therefore, close and professional supervision of cochlear implant patients is needed.

• Envelope versus fine structure speech coding strategy: a crossover study.

  Authors: Dominik Riss, Jafar-Sasan Hamzavi, Andreas Selberherr, Alexandra Kaider, Michaela Blineder, Veronika Starlinger, Wolfgang Gstoettner, Christoph Arnoldner

  Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 09/2011; 32(7):1094-101.

  The transmission of fine structure information to cochlear implant users is an expanding area of research. Previous studies comparing the fine structure processing (FSP) speech coding strategy to theThe transmission of fine structure information to cochlear implant users is an expanding area of research. Previous studies comparing the fine structure processing (FSP) speech coding strategy to the envelope-based continuous interleaved sampling (CIS) strategy indicated improved speech perception when using the fine structure strategy. Those investigations were performed with an extended frequency spectrum in the low frequencies together with the fine structure strategy. The current study addresses the question whether these improvements are due to the presentation of fine structure per se or rather the extended frequency spectrum. Hence, this cross over study compares the two strategies using an identical frequency spectrum. Randomized crossover study. 31 patients were randomly assigned to two groups. One group was fitted with a CIS map for 4 weeks, tested and subsequently fitted with a FSP map for 4 weeks. The other group followed the same pattern in reverse. Test material consisted of sentence tests in noise, monosyllables in quiet and melody recognition. No statistical significance was noted between the different speech coding strategies at an identical frequency spectrum. This study shows that there is no difference in speech perception with FSP compared to CIS at an extended frequency spectrum. Therefore, the extended frequency spectrum in the low frequencies might explain a benefit of FSP observed in previous studies.

• Residual hearing preservation using the suprameatal approach for cochlear implantation.

  Authors: Christoph Arnoldner, Wolfgang Gstoettner, Dominik Riss, Jens Wagenblast, Clemens Honeder, Michaela Blineder, Jafar-Sasan Hamzavi, Alexandra Jappel, Wolf-Dieter Baumgartner

  Wiener klinische Wochenschrift. 08/2011; 123(19-20):599-602.

  Cochlear implantation of patients with high-frequency hearing loss and residual low-frequency hearing has become a new treatment standard within the last years. The objective of this study was toCochlear implantation of patients with high-frequency hearing loss and residual low-frequency hearing has become a new treatment standard within the last years. The objective of this study was to evaluate the rate of hearing preservation in cochlear implantation for electric-acoustic stimulation using the suprameatal approach. Five patients (mean age 48.2 years) who were supplied with Med El (Combi 40+, Pulsar) cochlear implants and various different electrodes (Custom made, Flex soft, Flex EAS) were evaluated for residual hearing preservation after a mean follow-up time of 35.6 months (range 24 to 77 months). Three patients showed partial hearing preservation, whereas 2 patients experienced a complete loss of residual hearing. Although hearing preservation rates in this series of patients operated on using the suprameatal approach were inferior as compared with a series using the standard mastoidectomy approach, this study shows that it is in fact possible to preserve residual hearing using a non-mastoidectomy surgical technique for cochlear implantation. Nevertheless, more experience is necessary to answer the question whether this technique can be thoroughly recommended in cochlear implantation for electric-acoustic stimulation.

• Effects of fine structure and extended low frequencies in pediatric cochlear implant recipients.

  Authors: Dominik Riss, Jafar-Sasan Hamzavi, Michaela Katzinger, Wolf-Dieter Baumgartner, Alexandra Kaider, Wolfgang Gstoettner, Christoph Arnoldner

  International journal of pediatric otorhinolaryngology. 02/2011; 75(4):573-8.

  In recent years, new speech coding strategies have been developed with the aim of improving the transmission of temporal fine structure to cochlear implant recipients. This study reports on theIn recent years, new speech coding strategies have been developed with the aim of improving the transmission of temporal fine structure to cochlear implant recipients. This study reports on the implementation of one such strategy (fine structure processing, FSP) in children. This was a prospective study investigating the upgrade to a new speech processor. The upgrade used a repeated measures design with an alternating order of conditions (A-B-A-B design). Twelve pre- and perilingually deaf children with MED-EL C40+ cochlear implants were enrolled in the study. Patients were upgraded from their Tempo+ speech processor, which used continuous interleaved sampling (CIS) in combination with a frequency spectrum of 200-8500 Hz, to an Opus speech processor, which used FSP with an extended frequency spectrum of 70-8500 Hz. The primary means of testing was an HSM (Hochmair, Schulz and Moser) sentence test at 65 and 80 dB in quiet. In addition, the "Mainzer Kindersprachtest" (Mainz audiometric speech test for children) was applied at 65 and 70 dB. When the new FSP speech processor was used together with the extended low frequency range, HSM sentence tests at 65 and 80 dB resulted in scores indicating statistically significant improvements of 7.1 and 9.9 percentage points, respectively. Scores in the "Mainzer Kindersprachtest" at 65 and 70 dB indicated statistically significant improvements of 9.3 and 6.1 percentage points, respectively. The present study clearly shows that children benefit from the fine structure speech coding strategy in combination with an extended frequency spectrum in the low frequencies, as is offered by the Opus speech processors. This should be taken into consideration when fitting pre- and perilingually deaf children implanted almost a decade previously.

• Cochlear osteoneogenesis after meningitis in cochlear implant patients: a retrospective analysis.

  Authors: Martin Durisin, Soenke Bartling, Christoph Arnoldner, Melanie Ende, Jana Prokein, Anke Lesinski-Schiedat, Heinrich Lanfermann, Thomas Lenarz, Timo Stöver

  Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 09/2010; 31(7):1072-8.

  Retrospective clinical study. Academic tertiary referral center at the Medical University of Hannover. Computed tomographic findings of 126 patients (95 children and 31 adults) profoundly deafened byRetrospective clinical study. Academic tertiary referral center at the Medical University of Hannover. Computed tomographic findings of 126 patients (95 children and 31 adults) profoundly deafened by meningitis during a period of 20 years were evaluated. Children were defined as up to 12 years old at the onset of meningitis. No patients showed any relevant bilateral auditory brainstem response thresholds at the time of admission to our clinic. Patient histories, surgical findings, and imaging results were analyzed by experienced surgeons/neuroradiologists. Of 95 children, 30 (32%) displayed symptoms of labyrinthitis ossificans, whereas 11 (36%) of 31 adults showed changes of the bony structure of the cochlea. High-resolution computed tomography (HRCT) evaluation indicated that the ossification was detected more frequently if there was a larger time interval between onset of meningitis and high-resolution computed tomographic scan. Bilateral ossification at various stages was observed in 67% of children and 55% of adults with obliteration. In the comparison of cochlear ossification found in computed tomographic scans and intraoperative obliteration, HRCT showed a specificity of 73% and a sensitivity of 88%. The intraoperative evaluation revealed various stages of cochlear obliteration in 44% of children and 39% of adults. In our study, the earliest onset of labyrinthitis ossificans was found in high-resolution computed tomographic scans as early as 4 weeks after the onset of meningitis. In most cases, ossification occurred bilaterally with predominantly asymmetric involvement of both ears. The rate of osteoneogenesis increases significantly over time after meningitis. This leads to the conclusion that cochlear ossification can start very early and increase over time with unpredictable speed. Cochlear ossification typically develops bilaterally. From these results, we conclude that cochlear implantation should be performed bilaterally as soon as possible after meningitis and deafness have been diagnosed. HRCT offers good specificity but only limited sensitivity. Preoperative diagnostics should include magnetic resonance imaging to optimize preparation for cochlear implantation.

• Tenth and twelfth nerve palsies in a patient with internal carotid artery dissection mistaken for cervical mass lesion.

  Authors: Christoph Arnoldner, Dominik Riss, Jens Wagenblast, Veronika Starlinger, Jafar-Sasan Hamzavi

  Skull base : official journal of North American Skull Base Society ... [et al.]. 07/2010; 20(4):301-4.

  Among the multiple causes for cranial nerve palsies, internal carotid artery dissection is rather uncommon. Patients usually present with unilateral head pain, Horner's syndrome, and signs ofAmong the multiple causes for cranial nerve palsies, internal carotid artery dissection is rather uncommon. Patients usually present with unilateral head pain, Horner's syndrome, and signs of cerebral ischemia. We present the case of a 52-year-old male patient, who showed isolated palsies of the tenth and twelfth nerve without any other symptoms. Magnetic resonance imaging (T1) depicted a hyperintense lesion surrounding the internal carotid artery, which was mistaken for a cervical mass, and the patient underwent unnecessary surgical exploration of the neck. Angiography performed afterward could reveal the dissection of the internal carotid artery. This case shows that even in cases with mild and atypic symptoms, internal carotid artery dissection has always to be ruled out in lower cranial nerve palsies.

• Does dexamethasone inhibit the antineoplastic effect of cisplatin and docetaxel in head and neck cancer cells?

  Authors: Jens Wagenblast, Christoph Arnoldner, Wolfgang Gstöttner, Sotirios Bisdas, Susanne Mörtel, Angelika May, Markus Hambek

  Anticancer research. 01/2010; 30(1):123-7.

  Comedication with glucocorticoids such as dexamethasone is frequently given to head and neck cancer patients treated with chemotherapy. However, an increasing body of evidence suggests thatComedication with glucocorticoids such as dexamethasone is frequently given to head and neck cancer patients treated with chemotherapy. However, an increasing body of evidence suggests that dexamethasone may induce resistance to antineoplastic agents. The present study was the first to investigate the effect of dexamethasone on the antiproliferative activity of cisplatin and docetaxel in vitro in squamous cell carcinoma of the head and neck (SCCHN) cell lines. The cytotoxic effect of cisplatin and docetaxel on eight SCCHN cell lines was determined for each drug alone or with increasing concentrations of dexamethasone. Cell growth inhibition and viability were measured quantitatively after 24, 48, 72 hours of treatment using water-soluble-tetrazolium-test and lactate dehydrogenase assays. Absolute tumor cell numbers were determined by cell counting in a Rosenthal chamber. Cisplatin and docetaxel alone inhibited the growth of all eight SCCHN cell lines significantly (p=0.012). The antiproliferative activity of both agents was not decreased by the addition of dexamethasone in any of the cell lines (p>0.05). Dexamethasone does not interfere with the cytotoxic action of cisplatin or docetaxel in the investigated SCCHN cell lines.

• Electric Acoustic Stimulation in Patients with Postlingual Severe High-Frequency Hearing Loss: Clinical Experience.

  Authors: Christoph Arnoldner, Silke Helbig, Jens Wagenblast, Wolf-Dieter Baumgartner, Jafar-Sasan Hamzavi, Dominik Riss, Wolfgang Gstoettner

  Advances in oto-rhino-laryngology. 01/2010; 67:116-124.

  Background/Aims: The aim of this study was to describe audiological outcomes and surgical considerations in electric acoustic stimulation for patients with severe to profound high-frequency hearingBackground/Aims: The aim of this study was to describe audiological outcomes and surgical considerations in electric acoustic stimulation for patients with severe to profound high-frequency hearing loss. Methods: In this latest series of patients in our center, all patients were supplied with the new (atraumatic) Flex EAS MED-EL electrode. Eleven patients (age 7.62-71.32 years) with profound high-frequency hearing loss were implanted with this electrode, which was designed to preserve residual hearing despite the intracochlear insertion of an electrode array. All patients were operated on by the same surgeon (W.G.). Results: The rate of complete or partial hearing preservation was 100% after a mean follow-up period of 7.85 months (range 0.95-15.65 months). Conclusion: This study proves that both refined surgical techniques and atraumatic electrodes are mandatory to preserve residual hearing after cochlear implantation. Flexible, thin, and free-fitting straight electrodes, such as the MED-EL Flex EAS electrode used in this study, seem to most accurately meet the requirements for hearing preservation in electric acoustic stimulation.

• Cochlear implant reference electrode migration to dura mater.

  Authors: Christoph Arnoldner, Silke Helbig, Jens Wagenblast, Wolfgang Gstoettner

  Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 10/2009; 30(7):1013-4.

• Does dexamethasone inhibit anticancer activity of cetuximab in squamous cell carcinoma cell lines of the head and neck?

  Authors: Jens Wagenblast, Mehran Baghi, Susanne Mörtel, Daniel Hirth, Laura Thron, Christoph Arnoldner, Wolfgang Gstöttner, Angelika May, Markus Hambek

  Oncology reports. 07/2009; 22(1):171-6.

  Glucocorticoids such as dexamethasone are widely used as comedication in the treatment of head and neck cancer, e.g., to improve appetite and decrease weight loss and fatigue in patients withGlucocorticoids such as dexamethasone are widely used as comedication in the treatment of head and neck cancer, e.g., to improve appetite and decrease weight loss and fatigue in patients with advanced disease or as antiallergic and antiemetic prophylaxis during anti-EGFR therapy. However, the literature suggests that dexamethasone induces resistance to antineoplastic agents in many solid tumor models in vitro and in vivo. Since this phenomenon has never been investigated in head and neck cancer, the present study was conducted to investigate the effect of dexamethasone on the antiproliferative activity of cetuximab in vitro in squamous cell carcinoma of the head and neck (SCCHN) cell lines. The antiproliferative effect of the anti-EGFR agent cetuximab alone and in combination with increasing concentrations of dexamethasone was examined in eight SCCHN cell lines at three different time-points (24, 48 and 72 h). Cell growth inhibition and viability were measured quantitatively using WST and LDH assays. Absolute tumor cell numbers were determined by cell counting in a Rosenthal chamber. Cetuximab alone inhibited the growth of all eight SCCHN cell lines significantly (p=0.008). In some cases the addition of dexamethasone reduced the antiproliferative activity of cetuximab (p</=0.038) but remained significant in all of the eight SCCHN cell lines compared with untreated controls (p</=0.028) at each drug concentration and each time-point. In contrast to the results reported for other tumor models, in our study dexamethasone showed in the majority of the evaluated dexamethasone drug concentrations and time-points no inhibition of the cytotoxic activity of cetuximab. The reasons for these discrepant findings are unclear but may be related to the degree of tumor cell differentiation or proliferation rate. Thus, further studies are required to elucidate the molecular mechanisms underlying the interaction between dexamethasone and cetuximab in different tumors.

• A new electrode for residual hearing preservation in cochlear implantation: first clinical results.

  Authors: Wolfgang Gstoettner, Silke Helbig, Claudia Settevendemie, Uwe Baumann, Jens Wagenblast, Christoph Arnoldner

  Acta oto-laryngologica. 02/2009;

  Conclusion. A so far unattained high rate (100%) of residual hearing preservation in cochlear implantation for electric-acoustic stimulation could be achieved using sophisticated surgical techniquesConclusion. A so far unattained high rate (100%) of residual hearing preservation in cochlear implantation for electric-acoustic stimulation could be achieved using sophisticated surgical techniques in combination with the MedEl Flex EAS electrode. Objectives. This study aimed to gather first audiological and surgical results from the experience gained with the new MedEl Flex EAS electrode array. Patients and methods. Nine patients (aged 7.62-71.32 years) with profound high frequency hearing loss were supplied with this atraumatic electrode, which was designed to preserve residual hearing despite intracochlear insertion of an electrode array. All patients were implanted by the same surgeon. Results. Hearing preservation was achieved in all patients (complete preservation 44.44%) after a mean follow-up period of 9.73 months. Mean monosyllabic test scores improved from 9% correct with the hearing aid alone to 48% with the cochlear implant and to 65% in the electric-acoustic mode.

• 1-year results using the Opus speech processor with the fine structure speech coding strategy.

  Authors: Dominik Riss, Christoph Arnoldner, Sonja Reiss, Wolf-Dieter Baumgartner, Jafar-Sasan Hamzavi

  Acta oto-laryngologica. 01/2009;

  Conclusion: In contrast to the Tempo+ the new Opus speech processor stimulates with the new fine structure programming (FSP) speech coding strategy and offers an extended frequency spectrum. AConclusion: In contrast to the Tempo+ the new Opus speech processor stimulates with the new fine structure programming (FSP) speech coding strategy and offers an extended frequency spectrum. A significant improvement in speech perception for sentences at 10 dB SNR (signal to noise ratio) was observable. Objectives: The aim of this study was to investigate the long-term effects on speech perception in quiet and in noise with the Opus speech processor using FSP. Subjects and methods: Eight post-lingually deaf patients implanted with Pulsar cochlear implants and fitted with Tempo+ speech processors (both MED-EL) for a minimum of 1 year were tested at baseline with Tempo+ using continuous interleaved sampling (CIS), and at 1 year follow-up with the Opus speech processor using FSP. Monosyllables and sentence tests were performed in quiet, and sentence tests (HSM) in noise with 15, 10 and 5 dB SNR. Results: Mean speech perception scores showed a trend towards improvement for all tests. A statistically significant (p<0.05) improvement was only observed for the sentence test in noise at 10 dB SNR.

• Effects of combination treatment of bortezomib and dexamethasone in SCCHN cell lines depend on tumor cell specificity.

  Authors: Jens Wagenblast, Mehran Baghi, Christoph Arnoldner, Sotirios Bisdas, Wolfgang Gstöttner, Angelika May, Rainald Knecht, Markus Hambek

  Oncology reports. 11/2008; 20(5):1207-11.

  Bortezomib has recently become the new treatment standard for relapsed or refractory multiple myeloma. We previously demonstrated that bortezomib also had a significant growth-inhibiting andBortezomib has recently become the new treatment standard for relapsed or refractory multiple myeloma. We previously demonstrated that bortezomib also had a significant growth-inhibiting and apoptotic effect on squamous cell carcinoma of the head and neck (SCCHN) cells in vitro. Preclinical evidence has provided a rationale for combining bortezomib with dexamethasone in multiple myeloma, suggesting that the therapeutic effects of the two agents might be additive. These findings are in contrast with the results achieved in solid tumor models where the addition of dexamethasone reduced the efficacy of other antineoplastic drugs. In the present study, we investigated the effect of dexamethasone in combination with bortezomib in SCCHN cell lines for the first time. The antiproliferative effect of bortezomib alone or in combination with increasing concentrations of dexamethasone was investigated in four SCCHN cell lines. Cell growth inhibition and viability were measured quantitatively using WST and LDH assays. Bortezomib alone inhibited the growth of all four SCCHN cell lines significantly (p<0.047). The addition of dexamethasone leads to a clear tumor cell decline and showed a trend in enhancing the growth-inhibitory effect of bortezomib although the difference failed to reach statistical significance (p>0.05). Our first results show that dexamethasone increased the cytotoxic activity of bortezomib in most SCCHN cell lines investigated. These findings might be dependent on molecular factors such as the degree of tumor cell differentiation and proliferation rate. Therefore, further studies will be required to elucidate these molecular factors to substantiate our findings from a cancer biological point of view.

• A new fine structure speech coding strategy: speech perception at a reduced number of channels.

  Authors: Dominik Riss, Christoph Arnoldner, Wolf-Dieter Baumgartner, Alexandra Kaider, Jafar-Sasan Hamzavi

  Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 10/2008; 29(6):784-8.

  OBJECTIVE: One of the most commonly used speech coding strategies for cochlear implants is continuous interleaved sampling (CIS), which codes the envelope information of an acoustic signal. Based onOBJECTIVE: One of the most commonly used speech coding strategies for cochlear implants is continuous interleaved sampling (CIS), which codes the envelope information of an acoustic signal. Based on this strategy, MED-EL has recently developed the new fine structure processing (FSP) speech coding strategy, which also transmits subtle pitch and temporal cues. The aim of this study was to investigate the number of active channels necessary for good speech perception with FSP and whether there is an advantage for FSP compared with CIS at a reduced number of channels. METHODS: Ten postlingually deafened patients using MED-EL Pulsar cochlear implants participated in this study. Patients were tested with all 12, 8, 5, 3, and 2 channels with CIS and FSP strategy, resulting in a total of 10 conditions. Performance was tested with numbers, monosyllables, and sentence tests. RESULTS: Our results showed an improvement in speech perception, with up to 5 channels for numbers and for monosyllables and sentence tests. Statistically significant increases in performance were noted from 3 to 8 channels for numbers, from 3 to 5 channels for monosyllables, and from 5 to 8 channels for sentence tests. No statistical significance was observed whether FSP or CIS was used. CONCLUSION: Based on these findings, the number of channels necessary for speech perception with FSP is similar to published results using CIS. There seems to be no advantage for FSP compared with CIS in the conditions of the present experiment.

• Cetuximab enhances the efficacy of bortezomib in squamous cell carcinoma cell lines.

  Authors: Jens Wagenblast, Mehran Baghi, Christoph Arnoldner, Sotirios Bisdas, Wolfgang Gstöttner, Hanns Ackermann, Angelika May, Markus Hambek, Rainald Knecht

  Journal of cancer research and clinical oncology. 10/2008;

  PURPOSE: Proteasome inhibition has been shown to be effective in multiple myeloma and solid tumor models. In this in vitro study, we investigated the antitumor effect of bortezomib (Velcade((R))) inPURPOSE: Proteasome inhibition has been shown to be effective in multiple myeloma and solid tumor models. In this in vitro study, we investigated the antitumor effect of bortezomib (Velcade((R))) in combination with cetuximab in squamous cell carcinoma cell lines (SCC). METHODS: Dose-escalation studies were performed in five squamous cell carcinoma cell lines using bortezomib or cetuximab alone or in combination. Cell survival and growth inhibition were measured quantitatively using an MTT and LDH assay. RESULTS: Bortezomib alone showed a significant antiproliferative activity in all SCC cell lines (P < 0.042), and the activity was further significantly enhanced by the addition of cetuximab (P < 0.043). CONCLUSIONS: Our results indicate that cetuximab increases the cytotoxic activity of bortezomib in SCC cell lines. Combination therapy of SCC with bortezomib and cetuximab might be less toxic than conventional drug regimens used in the treatment of these tumors.

• Surgical revision of hemorrhage in 8388 patients after cold-steel adenotonsillectomies.

  Authors: Christoph Arnoldner, Matthäus Ch Grasl, Dietmar Thurnher, Jafar-Sasan Hamzavi, Alexandra Kaider, Markus Brunner, Boban M Erovic

  Wiener klinische Wochenschrift. 07/2008; 120(11-12):336-342.

  PURPOSE OF THE INVESTIGATION: Tonsillectomy and adenoidectomy are the most common surgical procedures in otorhinolaryngology. The most serious complication is postoperative hemorrhage, with a 2-4%PURPOSE OF THE INVESTIGATION: Tonsillectomy and adenoidectomy are the most common surgical procedures in otorhinolaryngology. The most serious complication is postoperative hemorrhage, with a 2-4% risk of substantial bleeding. The aim of this study was to evaluate the incidence of and possible predictive factors for postoperative hemorrhage requiring surgical revision in patients undergoing cold dissection tonsillectomy/adenoidectomy. BASIC PROCEDURES: We performed a single-institution retrospective study of 8388 patients who underwent tonsillectomy and/or adenoidectomy between 1994 and 2006. Tonsillectomy was performed using only cold-steel dissection with bipolar diathermy for hemostasis. MAIN FINDINGS: Hemorrhage occurred in 114 patients (1.78%) after tonsillectomy and in seven patients (0.35%) after adenoidectomy. After tonsillectomy 85.09% of the hemorrhages were secondary, occurring between the postoperative days 1 and 15, whereas in the adenoidectomy group 85.71% of the bleeding episodes were primary. Two patients (0.03%) required blood transfusions, none of the patients required an external carotid artery ligation, and there were no cases of death in our series. On the basis of logistic regression analysis, patient age was found to be a statistically significant risk factor (P = 0.007): the highest incidence was found in patients over 16 years of age (2.19%). At warmer times of year the incidence was higher (1.98%) than at colder times (1.63%). The resident surgeons caused a hemorrhage incidence of 1.75% and the consultant surgeons one of 1.84%. The incidence was significantly higher in male patients (2.2%) than in female patients (1.4%; P = 0.016). PRINCIPAL CONCLUSIONS: Our data show that whereas adenoidectomy can be safely performed as a one-day procedure, tonsillectomy complications due to postoperative hemorrhages might be avoided only if patients were to stay in hospital until postoperative day 15, which would clearly be impractical for economic, organizational and social reasons. A crucial factor for increasing the safety of this procedure is the provision of meticulous education and information for the patient and/or parents.

• The Intensity-Pitch Relation Revisited: Monopolar Versus Bipolar Cochlear Stimulation.

  Authors: Christoph Arnoldner, Dominik Riss, Alexandra Kaider, Alois Mair, Jens Wagenblast, Wolf-Dieter Baumgartner, Wolfgang Gstöttner, Jafar-Sasan Hamzavi

  The Laryngoscope. 06/2008;

  OBJECTIVE/HYPOTHESIS:: The very high speech perception scores now being achieved with cochlear implants have led to demands for similar levels of achievement in music perception and perception inOBJECTIVE/HYPOTHESIS:: The very high speech perception scores now being achieved with cochlear implants have led to demands for similar levels of achievement in music perception and perception in noisy environments. One of the crucial factors in these fields is pitch perception. The aim of the present study was to investigate the extent to which pitch perception is influenced by the intensity of the stimulus, through the use of different stimulation modes (monopolar, bipolar) and different electrodes (lateral and perimodiolar). STUDY DESIGN:: Sixteen postlingually deafened patients with an average implant use of 3.1 years were included in this study. All patients were using a Cochlear (CI24M, CI24R, CI24RE) cochlear implant. METHODS:: Subjects were asked to compare the pitch of an intensity-constant reference tone with the pitch of a test tone of varying intensity. The test was repeated for apical, mediocochlear, and basal channel locations, and also for monopolar and bipolar stimulation. RESULTS:: It was found that in monopolar stimulation 87.5% and in bipolar stimulation 85.7% of the patients perceived a clear pitch change with changing intensity of the stimulus (Spearman correlation coefficients r < -0.3 or r > 0.3, respectively). A total of 73.1% of these patients perceived lower pitches with increasing intensity, 26.9% reported the opposite effect. No statistically significant difference in the intensity-pitch correlation could be found between mono- and bipolar stimulation. Neither the mean dynamic range nor the type of electrode used was found to be related to the correlation coefficient. CONCLUSION:: Although the majority of today's cochlear implant recipients perform well and the intensity-pitch relation in cochlear implant recipients is still poorly understood, rising demands on speech-coding strategies may soon make a compensation of the pitch shifts desirable. Although the results of our study tend to argue against a peripheral mechanism, the exact origin of this phenomenon remains unclear.

• RE: REIMPLANTATION OF HYBRID COCHLEAR IMPLANT USERS WITH A FULL-LENGTH ELECTRODE AFTER LOSS OF RESIDUAL HEARING.

  Authors: Wolfgang Gstoettner, Christoph Arnoldner

  Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 05/2008;

• Speech and music perception with the new fine structure speech coding strategy: preliminary results.

  Authors: Christoph Arnoldner, Dominik Riss, Markus Brunner, Martin Durisin, Wolf-Dieter Baumgartner, Jafar-Sasan Hamzavi

  Acta oto-laryngologica. 01/2008; 127(12):1298-303.

  CONCLUSIONS: Taking into account the excellent results with significant improvements in the speech tests and the very high satisfaction of the patients using the new strategy, this firstCONCLUSIONS: Taking into account the excellent results with significant improvements in the speech tests and the very high satisfaction of the patients using the new strategy, this first implementation of a fine structure strategy could offer a new quality of hearing with cochlear implants (CIs). OBJECTIVE: This study consisted of an intra-individual comparison of speech recognition, music perception and patient preference when subjects used two different speech coding strategies with a MedEl Pulsar CI: continuous interleaved sampling (CIS) and the new fine structure processing (FSP) strategy. In contrast to envelope-based strategies, the FSP strategy also delivers subtle pitch and timing differences of sound to the user and is thereby supposed to enhance speech perception in noise and increase the quality of music perception. PATIENTS AND METHODS: This was a prospective study assessing performance with two different speech coding strategies. The setting was a CI programme at an academic tertiary referral centre. Fourteen post-lingually deaf patients using a MedEl Pulsar CI with a mean CI experience of 0.98 years were supplied with the new FSP speech coding strategy. Subjects consecutively used the two different speech coding strategies. Speech and music tests were performed with the previously fitted CIS strategy, immediately after fitting with the new FSP strategy and 4, 8 and 12 weeks later. The main outcome measures were individual performance and subjective assessment of two different speech processors. RESULTS: Speech and music test scores improved statistically significantly after conversion from CIS to FSP strategy. Twelve of 14 patients preferred the new FSP speech processing strategy over the CIS strategy.

• Cochlear implant channel separation and its influence on speech perception--implications for a new electrode design.

  Authors: Christoph Arnoldner, Dominik Riss, Wolf-Dieter Baumgartner, Alexandra Kaider, Jafar-Sasan Hamzavi

  Audiology & neuro-otology. 02/2007; 12(5):313-24.

  There are a variety of factors which can influence cochlear implantation outcome. Channel interaction is one of the variables responsible for audiological performance deterioration in multichannelThere are a variety of factors which can influence cochlear implantation outcome. Channel interaction is one of the variables responsible for audiological performance deterioration in multichannel implants. Electrode design is--among others--one way to decrease the incidence of channel interaction. At present, electrodes differ in overall length, diameter, contact design and distribution, but none of the electrodes available have a distinct variability in the amount of space between contacts across the length of the electrode. The aim of this study was to investigate whether a new electrode design featuring larger contact spacing in the apical part of deeply inserted electrodes would lead to an increase in speech perception. Eighteen postlingually deafened patients fitted with MedEl Combi 40+ or MedEl Pulsar cochlear implants using the MedEl implementation of continuous interleaved sampling participated in this study. Patients were tested in 6 conditions, in which the channel spacing and distribution of electrode contacts in each patient were artificially varied by activating or deactivating different channels. Performance was tested immediately after each change in setup with a monosyllable and sentence test (Hochmaier, Schultz and Moser). Our results showed that the condition with the highest distance between contacts in the apical part (up to 6.4 mm instead of 2.4 mm) is the most effective for the matched map condition: the results improved statistically significantly for the sentence test from 72% in the standard 12-channel condition to 83.2% and from 40.8 to 50% for the monosyllable test. Based on these findings, we present a new electrode design which can help achieve further increases in speech perception with cochlear implants.