International consensus on meningitis and cochlear implants.
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Adult↗
Biomedical subjects
T Lenarz
Publications and source records attributed to T Lenarz.
[Characterisation of the gene expression profiles in the inner ear and the colliculus inferior of normal and deafened rats by gene-array-technology].
BACKGROUND: The phenotype of deafness and its mechanisms are morphologically and electrophysiologically well characterised. However, the molecular mechanisms and the consequences of deafness are poorly understood. METHODS: In this study we investigated changes in gene expression profiles in subfractions of the cochlea and the colliculus inferior, a non-cochlear tissue, of normal and deafened (10 % Neomycin) rats using the gene-array-technology. RNA was prepared from modiolus (Mo) und sensorineural epithel/lateral wall (SnE/Lw) und Colliculus inferior (IC), reverse transcribed with gene specific primers, labeled with (32)P-dATP and hybridised with its complementary sequences of 1200 rat ESTs. RESULTS: Similar gene expression profiles were detected in Mo- and SnE/Lw in normal as well in deafened rats differing significantly from those found in IC. In deafened animals differences in mRNA levels were determined in IC for 8 genes, in Mo für 17 genes and in SnE/Lw for 25 genes in comparison to those of normal rats. By using gene-arrays many genes described in the literature previously could be detected. Otherwise most of the genes found in the cochlea are unknown. CONCLUSIONS: The gene-array-technology is a valuable tool in otological research for gene expression analysis and, therefore, for comprehensive understanding of molecular processes in the inner ear. Furthermore gene screening for candidate genes could be a big step ahead in developing therapies of diseases of the inner ear.
Animals↗
[The interesting case -- case no. 65].
Bilateral Osteomyelitis following frontal sinusitis is a rare complication in the antibiotic era. The main risk of a progredient course is mainly the formation of external subperiostal, epidural, subdural abscesses or brain abscesses with potentially life-threatening complications. This is a report on a patient who presented in our department with progredient cephalgia and swelling in the area around the glabella and frontal sinus. Macroscopical examination revealed septum deviation to the right side and nasal polyposis of the right nasal passage. A computed tomography of the paranasal sinuses showed subtotal soft tissue obstruction of all sinuses with the exception of the sphenoidal sinus. Bilateral osteolysis of the ventral osseous borders of the frontal sinus with accompanying osteosclerosis was also observed. The therapy consisted of radical frontal sinus surgery via Unterberger approach. This case demonstrates a rare case of bilateral frontal osteomyelitis together with the necessary diagnostic and therapeutic measures. The management consisted of the removal of all osteomyelitic bone and antibiotic therapy. Differential diagnostic procedures must be carried out in order to exclude orbital and intracranial complications. Regular follow-up examinations and a CT scan of the paranasal sinuses are part of the standard therapy.
Adult↗
[Universal hearing screening for babies--recommendations for the organization and performance of the universal screening of babies for hereditary hearing disorders in Germany].
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Genetic Testing↗
Co-expression of transforming growth factor-beta1 and glial cell line-derived neurotrophic factor in vestibular schwannoma.
HYPOTHESIS: Transforming growth factor-beta1, glial cell line-derived neurotrophic factor, and their receptors are expressed in vestibular schwannoma, and the expression data correlate with the proliferation activity (Ki-67 labeling index) and the clinical growth rate of vestibular schwannoma tissue. BACKGROUND: Glial cell line-derived neurotrophic factor is a potent growth factor for the central and peripheral nervous system. Recent results demonstrate that glial cell line-derived neurotrophic factor requires transforming growth factor-beta to exert its trophic effect on neural tissue. A functional role, including that in Schwann cell proliferation, is discussed for both transforming growth factor-beta1 and glial cell line-derived neurotrophic factor. METHODS: Immunohistochemical analysis for transforming growth factor-beta1 and glial cell line-derived neurotrophic factor and their receptors TbetaR II, GFRalpha-1, and Ret was performed on formalin-fixed, paraffin-embedded archival surgical specimens. The Ki-67 labeling index (mean Ki-67 labeling index and highest Ki-67 labeling index for Antoni Type A and Type B regions) and the clinical growth rate of vestibular schwannoma were determined and correlated with the expression patterns of the examined neurotrophic factors and their receptors. RESULTS: Results demonstrate co-expression of transforming growth factor-beta1 and glial cell line-derived neurotrophic factor with higher levels in Antoni Type A than in Antoni Type B regions. Ninety-five percent of vestibular schwannomas exhibited transforming growth factor-beta1 immunoreactivity, and glial cell line-derived neurotrophic factor expression was found in 100% of vestibular schwannoma specimens. Fifty percent of vestibular schwannoma displayed TbetaR II immunostaining, 100% showed positive reactions for GFRalpha-1, and 86% showed positive reactions for Ret. Statistical analysis revealed no significant correlation in neurotrophin expression related to sex, age, tumor size, clinical growth rate, or Ki-67-labeling indices. CONCLUSIONS: Expression of transforming growth factor-beta1 and glial cell line-derived neurotrophic factor may suggest a biological role for both growth factors in vestibular schwannomas. Trophic transforming growth factor-beta/glial cell line-derived neurotrophic factor synergism seems possible and is underscored by co-expression of both neurotrophic factors and their receptors.
Glial Cell Line-Derived Neurotrophic Factor↗
[Model project of hearing screening in new-born in Hanover (preliminary results)].
In Germany, congenital hearing disorders are usually detected too late resulting in insufficient therapy of the disorder. To investigate these problems, the Federal Ministry of Health and the principal associations of statutory health insurance commissioned a pre-operative study. The study's aim is to verify whether introduction of a universal new-born hearing screening results in earlier diagnosis of hearing disorders and thus improves medical care for children with impaired hearing. Feasibility, effectiveness and economic tenability of this hearing screening programme will be investigated. The study is realised in the Hanover region and aims at carrying out a hearing test in all new-born during the first days of life. The tests will be performed in all 10 birth clinics and 2 paediatric clinics in the relevant region and in 24 otolaryngological practices. Hearing ability is controlled via an automated screening device measuring otoacoustic emissions. Sensitivity and specificity of the test is more than 95%. Economical feasibility is investigated by cost-effectiveness analyses. During a 6-month period the screening has been implemented in all clinics in every day routine. The mean coverage rate in the clinics has been stabilised to 97% of the total number. 4.7% of the children were presumed to suffer from unilateral hearing disorders and 2.3% from bilateral. In 13 cases the diagnosis of hearing disorder was confirmed. The mean age of diagnosis in these children was 3.7 months. The average age of therapy onset was 4.4 months. According to the present experience, area-wide implementation of hearing screening seems feasible in existing health care structures. The intention to advance the time of diagnosis and the therapy onset can be achieved by this method. Systematic training, introduction and quality assurance measures of screening are mandatory. Tracking of suspicious cases is necessary, even if it challenges data privacy regulations.
Cost-Benefit Analysis↗
[Navigation-supported surgery in the head and neck region].
Few of the pioneering manufacturers who attempted to develop navigation systems have been able to establish themselves within the market long-term. The same applies to the technological basis of these systems which aid intraoperative anatomical orientation. The first few systems registered the mechanical displacement of the navigational instrument's axes. Optoelectronic and electromagnetic methods are now prevalent. In contrast to electromagnetic systems, the "line of sight" between the camera system, the reference markers placed on the patient's head and the navigation instruments must remain unobstructed during the navigation process when using electrooptical navigation systems. Whereas, in the past, only preoperative CT scans were used for navigation, the integration of MRI and sonography--whose images can now be fused with each other and with those provided by other intraoperative imaging techniques such as fluoroscopy and endosonography--has become increasingly popular. Navigation systems require input of information about spatial conditions. This is carried out via procedures of registration and referencing, by means of which the relative position of reference markers at the head of the patient is correlated with the image data. The equipment is calibrated in the same way. Headsets, headbands and bone-anchored adapters are available for the fixation of the markers in the patient's head. Whereas the use of a headband or headset requires considerably less time, bone-anchored referencing increases the precision of the navigation system. The surgeon must be able to manage the different methods. In order to reduce the time required for preoperative preparation and to enhance the handling of the navigation processor for the surgeon, it is essential to have a clear menu. The surgeon is able to plan the steps involved in the surgery using the processor, define the access to the surgical site and control the surgery intraoperatively. Preoperative segmentation of functionally and clinically relevant structures enables minimally invasive surgery to be carried out, such as procedures with the aim of acquiring biopsy tissue and the search for foreign bodies. Following the technical development of the systems, the manufacturers are endeavouring to simplify their handling in close coordination with the users. The next step has to be the clinical evaluation of the navigation systems in accordance with the EBM standard, in order to establish this assistive method as routine clinical practice while applying meaningful medical criteria.
Endosonography↗
Technical report: modification of a cochlear implant electrode for drug delivery to the inner ear.
OBJECTIVE: To investigate the possibility of modifying a cochlear implant electrode for the purpose of drug delivery to the cochlea. BACKGROUND: Animal experiments suggest that local therapy of the inner ear could be a promising new approach to the interventional treatment of inner ear disease, and that pharmacologic intervention could possibly enhance cochlear implant performance. One of the key aspects is the deployment of a means of drug delivery to the human inner ear. METHODS: The tip of the Contour electrode array was cut to open the lumen of the array, and a connecting piece was developed to connect the electrode to a pump. The feasibility of using the array for drug delivery was tested using both an Alzet mini-osmotic pump and a mechanical pump. The connection was tested for its stability in terms of leakage and resistance to tractive forces. The system was also applied to temporal bones to evaluate its applicability to the human cochlea. RESULTS: The modified Contour electrode is easy to handle in temporal bones and can be used to simulate drug delivery to the inner ear. The connection to the pump was sealed for all tested pump rates and resisted tractive forces up to 50 N. CONCLUSIONS: The described modified electrode could provide a safe and easy-to-handle means of combining electrical stimulation with the beneficial effects of a local drug therapy applied to the inner ear.
Cochlear Implantation↗
[Pyoderma gangraenosum. Case report and comparison with necrotizing fasciitis].
The differential diagnosis of patients with ulcerative trachelophyma repeatedly causes difficulties. Particularly in view of the possibly fatal outcome, early differentiation between two clinical pictures is very important. Necrotizing fasciitis is often misdiagnosed or the diagnosis is delayed with a mortality rate of approximately 25-40%. It is characterized by local disintegration of the subcutaneous fascia and extensive gangrene of the skin. Sometimes it is not even possible to control the disease using combined antibiotics. Early surgical exploration is mandatory to stop progression of the disease. Pyoderma gangrenosum develops following an initial lesion with pustules and bullae in an ulceration with slight bleeding. Therapy consists of i.v. glucocorticoids (60-200 mg prednisolone/day) administered as early as possible. In complete contrast to the therapy for necrotizing fasciitis, surgical intervention should be strictly avoided in cases of pyoderma gangrenosum.
Adult↗
[Application of Optical Coherence Tomography (OCT) in middle ear surgery].
BACKGROUND: Middle ear surgery has reached an advanced stage of development over the last few decades. The use of biocompatible materials offers new possibilities in ossiculoplasty. The exact calculation concerning the length of the implant to be used, however, still poses considerable difficulties and is an additional cause for a remaining air conduction difference or a further surgical intervention. METHODS: Optical coherence tomography (OCT) is a non-invasive imaging procedure for the imaging of tissue structures with a resolution accurate to micrometres. OCT can be operated touch-free and for this reason does not require any means of contact between applicator and sample. In the present study an optical coherence inferometre was coupled to an operating microscope and used in 5 stapedoplasties and 5 tympanoplasties type III in order to determine the length of the prosthesis to be used. RESULTS: The use of OCT implies an intraoperative measuring time of only a few seconds. The coupling in the optical path of an operating microscope allows trouble-free handling. The measurement of middle ear structures has an accuracy of 30 micrometer. The postoperative audiological results show a good auditory performance. CONCLUSIONS: Initial experience with OCT indicates that the technology will be extremely interesting for otosurgery. Improvements in functional pattern will enable routine intervention in connection with an operating microscope. Further OCT applications for tissue differentiation will have to follow.
Equipment Design↗
[Test set for the evaluation of hearing and speech development after cochlear implantation in children].
BACKGROUND: Since autumn 1998 the multicenter interdisciplinary study group "Test Materials for CI Children" has been compiling a uniform examination tool for evaluation of speech and hearing development after cochlear implantation in childhood. METHODS USED: After studying the relevant literature, suitable materials were checked for practical applicability, modified and provided with criteria for execution and break-off. For data acquisition, observation forms for preparation of a PC-version were developed. RESULTS: The evaluation set contains forms for master data with supplements relating to postoperative processes. The hearing tests check supra-threshold hearing with loudness scaling for children, speech comprehension in silence (Mainz and Göttingen Test for Speech Comprehension in Childhood) and phonemic differentiation (Oldenburg Rhyme Test for Children), the central auditory processes of detection, discrimination, identification and recognition (modification of the "Frankfurt Functional Hearing Test for Children") and audiovisual speech perception (Open Paragraph Tracking, Kiel Speech Track Program). The materials for speech and language development comprise phonetics-phonology, lexicon and semantics (LOGO Pronunciation Test), syntax and morphology (analysis of spontaneous speech), language comprehension (Reynell Scales), communication and pragmatics (observation forms). The MAIS and MUSS modified questionnaires are integrated. CONCLUSIONS: The evaluation set serves quality assurance and permits factor analysis as well as controls for regularity through the multicenter comparison of long-term developmental trends after cochlear implantation.
Child↗
Telomerase activity, telomere length, and apoptosis: a comparison between acquired cholesteatoma and squamous cell carcinoma.
BACKGROUND: Cholesteatoma disease is characterized by accumulation of keratinizing epithelium. Several molecular markers of tumor formation have been found in cholesteatoma (e.g. upregulation of matrix metalloproteinases, c and activation of angiogenesis). Other molecular findings clearly distinguish between cholesteatoma and malignant tumors (e.g., lack of chromosomal instability, intact checkpoint responses). To further distinguish the molecular mechanisms in cholesteatoma from malignant tumors, the authors determined telomerase activity and telomere length in both tissue types. METHODS: To evaluate the role of telomerase activation and telomere length in cholesteatoma, 29 cholesteatoma samples and 9 squamous cell carcinomas were analyzed for telomerase activity and telomere length. In addition, the rate of apoptosis was determined in both groups, using the TdT-mediated dUTP nick end labeling technique. RESULTS: As previously described, a high proportion of squamous cell carcinoma exhibited telomerase activity (6/9, 66%). By contrast, a significantly lower rate of telomerase activity was found in cholesteatoma samples (1/29, 3.4%, p = 0.0002). Despite the differences in telomerase activity, the telomere length was similar in cholesteatoma (mean length 7.43 kb) and in squamous cell carcinoma (mean length 7.99 kb; difference not significant, p = 0.1364). The low rate of telomerase activity in cholesteatoma was accompanied by significantly higher rates of apoptosis in cholesteatoma (mean 30%) compared with squamous cell carcinoma tissue (mean 3%, p = 0.0031). CONCLUSIONS: Taken together, these data show that telomerase activation is a rare event in cholesteatoma and that the absence of telomerase activity is accompanied by high rates of apoptosis in cholesteatoma. It is proposed that the absence of telomerase limits the proliferative capacity of cholesteatoma by induction of apoptosis, whereas the presence of telomerase allows immortal growth of squamous cell carcinoma.
Adult↗
Measurement method for the assessment of transmission properties of implantable hearing aids.
Over the last five years the Symphonix Vibrant soundbridge (VSB), an implantable hearing device, has proven an effective alternative treatment modality for patients suffering from moderate to severe sensorineural hearing loss. The results from the majority of our 40 patients are very encouraging but reveal clinical variations in benefit influenced by the coupling of the transducer to the ossicular chain. This study describes a set-up for measuring the sound pressure level in the external auditory canal when the middle ear implant is activated. The reverse transfer function allows the transducer performance to be determined both intra- and postoperatively. The sound pressure level shows a strong correlation with the stapes footplate displacement and free-field audiometry.
Adult↗
[Rheologic infusion therapy, neurotransmitter administration and lidocaine injection in tinnitus. A staged therapeutic concept].
BACKGROUND AND OBJECTIVE: Cochlear dysfunction and tinnitus are treated by means of hemorrheological infusions in order to increase the cochlear oxygen supply and restore function of hair cells, neurotransmission and central processing of auditory information. PATIENTS/METHODS: In a retrospective analysis of the charts of 123 patients treated between February 1993 and May 1994, we analyzed effectiveness and safety of a gradual therapeutic regimen, consisting of dextrane/procaine infusions, lidocaine i.v. injection and infusion therapy with the neurotransmitter glutamic acid. RESULTS: Tinnitus decreased in 83.7% of patients with acute tinnitus (AT) and 16.1% of patients with chronic tinnitus (CT) during dextrane/procaine infusion. The majority (89%) experienced their tinnitus relief during the first 5 days. Treatment with glutamic diethylester and glutamic acid resulted in a 26.5% overall improvement. Application of lidocaine intravenously over a period of 10 min diminished tinnitus loudness or frequency in 16.7% (AT) and 38.9% (CT) of cases respectively. The long-term effects of therapy were investigated by a follow-up mailing action: 66.7% of the AT and 15.6% of the CT sufferers stated a clear therapy effect over time. Nonserious side effects were noted in 4% of the treated patients. Therefore safety was excellent. CONCLUSIONS: For acute and chronic tinnitus a gradual therapeutic regimen is recommended: (1) infusions with dextrane and procaine over 5 days; (2) intravenous application of 100 mg lidocaine over 10 min; and if necessary (3) administration of glutamic diethylester and glutamic acid for 3 days. This resulted in overall tinnitus relief in 95.3% of the acute and 26.7% of the chronic tinnitus sufferers.
Adolescent↗
[Skull base surgery with an opto-electronic navigation system].
BACKGROUND AND OBJECTIVE: The exact localization of pathological anatomy is the basis of a successful operation. Malformations, tumors, or previous operations can make intraoperative orientation considerably more difficult. Navigation systems can be useful tools in such cases. METHODS: The OTS is an optoelectrical navigation system which was used on 34 patients with disorders of the skull base region. Clinical accuracy, practicability, and intraoperative usefulness of the system were evaluated. RESULTS: In clinical use, an accuracy of approximately 1.5 mm could only be achieved with the use of head fixation and bone-anchored reference markers. When using the VBH mouthpiece for dynamic referencing with flexible head positioning, deviations of less than 2 mm were observed. The preoperative preparation time was 15-25 min, depending on the operation schedule. CONCLUSIONS: The intraoperative orientation system represents a significant aid for orientation, particularly where anatomical alterations are present. Further modifications to improve both accuracy and the integration of the system into working practice are, however, essential.
Adult↗
[Sudden deafness and tinnitus].
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Acute Disease↗
Multicenter audiometric results with the Vibrant Soundbridge, a semi-implantable hearing device for sensorineural hearing impairment.
The Vibrant Soundbridge, a semi-implantable hearing device for subjects with moderate to severe sensorineural hearing impairment was introduced commercially. First audiologic results are presented on 63 patients from 10 European implant centers. Hearing loss was at 0.5, 1, 2, and 4 kHz varying between 43 and 81 dB HL. The patients used the analogue audio processor, type 302. Measured sound-field gain was compared with NAL-R target values. For most patients an acceptable agreement was found. There was a subgroup of patients, however, with relatively low gain. The results suggest that this was related to the suboptimal positioning and fixation of the transducer to the incus.
Audiometry, Speech↗
The effect of an adjuvant mistletoe treatment programme in resected head and neck cancer patients: a randomised controlled clinical trial.
The effect of an adjuvant mistletoe extract treatment was tested in a prospective, randomised controlled clinical trial involving 477 patients with head and neck squamous cell carcinoma. The patients were stratified into two treatment groups that underwent surgery or surgery followed by radiotherapy and both groups were randomised for additional treatment with mistletoe extract. Patients treated with a mistletoe lectin-1 (ML-1) standardised mistletoe preparation had no lower risk of local/locoregional recurrences, distant metastases or second primaries. In the main analysis based on 202 patients treated with surgery and 275 patients treated with surgery and radiotherapy the adjusted hazard ratio for the disease-free survival (DFS) was 0.959 (95% confidence interval (CI) 0.725-1.268). The 5-year survival rates of patients from the mistletoe group were no better than the survival rates of patients from the control group. Furthermore, no significant changes in the cellular immune reaction or in quality of life could be detected. We conclude that the used mistletoe preparation has no indication in the adjuvant treatment of patients with head and neck cancer.
Adult↗