C. von Ilberg

Evaluation of Performance with the COMBI 40 Cochlear Implant in Adults: A Multicentric Clinical Study

The present multicentric clinical study involves 19 centres, 16 of them in German-speaking countries, 1 British, 1 Polish and 1 Hungarian. 60 postlingually deafened adults with a mean age of 47.5 years (20-70) and mean duration of deafness of 5.3 years (0.5-20) have been evaluated with the MED-EL COMBI 40 cochlear implant which implements a high-rate continuous-interleaved-sampling strategy with 8 channels. Safety and effectiveness data have been collected. Speech perception tests include a 16-consonant, an 8-vowel, a sentence and a monosyllabic-word test in all languages and a 2-digit figure test in all languages but English. Test intervals are 1, 3, 6 months and 1 year after first fitting. 41 of the 60 postlingually deafened adult study patients have completed their 6-month evaluation. While their pre-operative monosyllabic-word score was 0%, their mean monosyllabic-word score 6 months after first fitting was 48% (8-90) with a median of 50%. The mean sentence understanding was 84% (24-100) with a median of 90%. The respective values for the 1-year evaluations with 25 patients are a mean of 50% (5-85), with a median of 60% for the monosyllables and a mean of 89% (30-100), with a median of 97%, for the sentences.

Speech understanding in quiet and in noise with the CIS speech coding strategy (MED-EL combi-40) compared to the multipeak and spectral peak strategies (nucleus)

This study compares sentence understanding in quiet and in noise with 3 different speech coding strategies for cochlear implants. The results show that the spectral-peak (SPEAK) and continuous-interleaved-sampling (CIS) coding strategies, based on spectral signal analysis, allow for better speech understanding in quiet as well as in noise, than the multipeak (MPEAK) coding strategy, which relys on speech feature extraction. In the intrasubject comparison of the MPEAK and SPEAK strategies, the SPEAK coding strategy provided a considerable improvement in quiet and in noise for the majority of patients using the Nucleus 22 Mini-implant. In the intersubject comparisons, the mean results in noise with the CIS strategy were superior to both the MPEAK and the SPEAK strategies. The difference was greatest for the most difficult tests in noise. Understanding in noise was least reduced for the CIS strategy. Understanding in quiet was not significantly different between the CIS and the SPEAK strategies; both strategies were significantly better than the MPEAK strategy in quiet. These results are still preliminary, due to the relatively small number of patients and the great inherent intersubject variability of results.

Comparison of the TEMPO+ ear-level speech processor and the cis pro+ body-worn processor in adult MED-EL cochlear implant users.

A study was conducted to compare the new MED-EL TEMPO+ ear-level speech processor with the CIS PRO+ body-worn processor in the COMBI 40/COMBI 40+ implant system. Speech tests were performed in 46 experienced subjects in two test sessions approximately 4 weeks apart. Subjects were switched over from the CIS PRO+ to the TEMPO+ in the first session and used only the TEMPO+ in the time between the two sessions. Speech tests included monosyllabic word tests and sentence tests via the telephone. An adaptive noise method was used to adjust each subject’s scores to approximately 50%. Additionally, subjects had to complete a questionnaire based on their 4 weeks of experience with the TEMPO+. The speech test results showed a statistically significant improvement in the monosyllabic word scores with the TEMPO+. In addition, in the second session, subjects showed a significant improvement when using the telephone with the TEMPO+, indicating some learning in this task. In the questionnaire, the vast majority of subjects found that the TEMPO+ allows equal or better speech understanding and rated the sound quality of the TEMPO+ higher. All these objective and subjective results indicate the superiority of the TEMPO+ and are mainly attributed to a new coding strategy called CIS+ and its implementation in the TEMPO+. In other words, based on the results of this study, it appears that after switching over from the CIS PRO+ to the TEMPO+, subjects are able to maintain or even improve their own speech understanding capability.

Autoradiographical Distribution of Locally Applied Dihydrostreptomycin in the Inner Ear

H3-labelled dihydrostreptomycin (DHS) in isosmolar solution is perfused through the cochlea of guinea pigs. After varying incubation periods the distribution of the radioactivity in the cochlear duct is shown by autoradiography. Because of the water solubility of DHS, freeze drying of the tissue is applied. Maximum radioactivity is clearly seen over the inner and outer hair cells and over the nerve tissue of ossetis spiral lamina. This seems to indicate that the specific sensitivity of the sensory cells to DHS is not only due to thz long persistence of the substance in the perilymph but also to a specific affinity of the drug to their cytoplasm. Presumably DHS is attached reversibly to the ribosomes of the hair cells as described in bacteria.

Immunoglobulin deficiency and determination of pneumococcal antibody titers in patients with therapy-refractory recurrent rhinosinusitis

Abstract We examined 245 patients with chronic rhinosinusitis not responding to prolonged antibiotic treatment and tested each patient for humoral antibody deficiencies. Low immunoglobulin levels were found in 22 patients. Five of them had defects of two or more immunoglobulin isotypes that were diagnosed as common variable immunodeficiency (CVI). Seventeen had an IgG-subclass deficiency. Before and after immunization with pneumococcal vaccine, serotype-specific pneumococcal antibody levels were determined to further evaluate the relevance of the underlying deficiency. Significantly reduced antibody titers of pneumococcal serotypes were found in CVI patients (n = 5), while immunization of 17 patients with IgG-subclass deficiency gave different results. Three of the 17 patients responded poorly to pneumococcal immunization and were prone to a polysaccharide specific immunodeficiency. Patients with CVI or IgG-subclass deficiency failing to produce protective antibody levels in more than five serotypes were chosen for antibiotic and/or immunoglobulin substitution therapy. Since recurrent sinusitis in these patients did not resolve with adequate conservative therapy, endonasal microsurgery was then performed and was seen to be a valuable therapeutic option. Our study suggests that an IgG-subclass deficiency may be the first sign of a basic immunological change, resulting in persisting sinus infections.

Scala vestibuli Insertion in Cochlear Implantation: A Valuable Alternative for Cases with Obstructed Scala tympani

Insertion of a sufficient number of electrodes is important for a successful use of cochlear implants. We investigated the results of scala vestibuli insertion for cochlear implantation in cases of obstructed scala tympani. In a series of 200 cochlear implantations, scala vestibuli insertion was successfully performed in 4 cases with obstruction of the scala tympani. Etiologies included a temporal bone fracture, severe otosclerosis and malformations of the cochlea. The maximum insertion depth obtained via the scala vestibuli was 30 mm. Postoperative results were comparable to patients in whom conventional scala tympani insertion was performed. No adverse effects related to the site of insertion were observed. Scala vestibuli insertion offers a valuable alternative in cases of obstructed scala tympani that can be employed for a variety of etiologies.

A follow-up study of long-term results after cochlear implantation in children and adolescents

The time course of speech development in children after cochlear implantation may extend over many years, thus making long-term studies necessary to evaluate any outcome. We report our long-term results after cochlear implantation in children and adolescents. Mean follow-up was 28 months, ranging from 1 to 5 years. After at least 1 year of experience all children were found to benefit from their cochlear implants. The majority of children scored above chance in speech identifcation tasks requiring closed set word and sentence understanding). At the 4-year interval, all children tested including prelingually deaf children had developed open set sentence understanding. The most relevant factor accounting for differences in the results was the duration of implant use in all groups. Even beyond 3 years the results continued to improve. Peri- or postlinguallly deafened children tended to have favorable results. For prelingually deaf children, duration of deafness and age at implantation were correlated negatively with the results.

Bone replacement by ionomer cement in osteoplastic frontal sinus operations

Ionomer-based cement is a new bone replacement material. After promising results in middle ear and skull base surgery, we started to use Ionocap as an alternative to metal osteosynthesis material. Between 1992 and 1995, 20 men and 9 women were treated with an osteoplastic approach for complicated frontal sinus diseases at Johann Wolfgang Goethe University. Ionocap as bonding material for bone was used in 22 of the patients. The indications for osteoplastic surgery were recurrent frontal rhinosinusitis, mucoceles, skull base fractures, osteomas and meningocele. The surgical procedure using bone cement was found to be much easier and shorter, the functional stability achieved was at least equal and the cosmetic outcome was clearly superior when compared to cases done with metal osteosynthesis. No rejection of the material or osteonecrosis was observed. In no case was the cement placed in direct contact to dura mater. Our findings show that ionomer-based cement can be recommened in osteoplastic frontal sinus surgery, but Ionocap should only be used strictly according to the guidelines of the supplier.

Indication and technique of transnasal microscopic orbital decompression for endocrine ophthalmopathy.

If endocrine ophthalmopathy progresses despite conservative treatment then indications for surgical decompression are: loss of visual acuity, increasing strabism, and severe keratopathy. Endonasal microsurgery ensures a binocular view onto the intranasal landmarks of the orbital walls and allows simultaneous decompression of the medial and inferior wall as well as a good relief of pressure at the orbital apex. Surgical decompressions were performed on 29 orbits in 19 patients, 16 by using the endonasal microsurgical, 3 via external approach. The microscopic approach was entirely comparable with regard to the reduction of proptosis with a mean improvement of 4.2 mm against a mean of 4.7 mm by external approach and a mean 0.2 of better visual acuity in both procedures. The microsurgical technique is considered superior to an external approach avoiding external scars, neural pain, and reportedly less diplopia. The healing phase and the hospitalization time are shorter.

Chloridleitfähigkeit nasaler Fibroblasten von Polyposis-Patienten mit zystischer Fibrose und Patienten ohne zystische Fibrose Relevanz für den HNO-Arzt

ZusammenfassungZum komplexen Krankheitsbild der zystischen Fibrose (CF) gehören überdurchschnittlich häufig auftretende Rhinosinusitiden und Nasenpolypenbildung. Der Basisdefekt dieser Erkrankung ist im cAMP-abhängigen Chloridkanal lokalisiert. Elektrophysiologische Untersuchungen zur Chloridleitfähigkeit am nasalen Fibroblasten liegen noch nicht vor. Da der Fibroblast das Grundgerüst des Nasenpolypen bildet, erscheint es wichtig zu untersuchen, ob eine cAMP-abhängige Chloridleitfähigkeit auch im nasalen Fibroblasten nachzuweisen ist, und ob diese Leitfähigkeit bei CF-Fibroblasten defekt ist. Wir haben deshalb mit Hilfe konventioneller Mikroelektroden Potentialmessungen an Fibroblasten aus Primärkulturen von Nasenpolypen durchgeführt. Unsere Untersuchungen zeigen, daß der Nicht-CF-Fibroblast eine cAMP-regulierte Chloridleitfähigkeit besitzt, die bei CF-Fibroblasten fehlt. Die cAMP-regulierte Chloridleitfähigkeit, die in der Epithelzelle für den transepithelialen Chloridtransport und somit für die Atemwegsbefeuchtung erforderlich ist, hat im Fibroblasten offenbar eine andere Bedeutung. Sie ist wahrscheinlich an der Regulation der Zellproliferation beteiligt und könnte auf diese Weise in die Polypengenese eingreifen.SummaryCystic fibrosis (CF) is a complex systemic disease that has pathological alterations in the upper airways, including the recurrent formation of nasal polyps. Although the fibroblast is the predominant cell type in nasal stroma and nasal polyps, little is known about the electrophysiological properties of nasal fibroblasts. We investigated whether fibroblasts possess a cAMP-regulated chloride conductance which is impaired in patients with CF. Thus far the few studies concerning conductance in fibroblasts have been performed on skin fibroblasts using indirect methods and have yielded conflicting results. Therefore we studied chloride conductance in fused nasal fibroblasts by employing conventional microelectrodes. We have demonstrated that a cAMP-regulated chloride conductance is present in fibroblasts. However, this chloride conductance cannot be activated in fibroblasts from CF-patients. Thus, we present direct evidence that the impairment of the cAMP-regulated chloride conductance in CF is not confined to epithelial cells but also affects the fibroblast. We discuss how this conductance might modulate fibroblast proliferation to produce polyp formation.