Biomedical subjects

A Lesinski-Schiedat

Publications and source records attributed to A Lesinski-Schiedat.

17 recordsLinked to original sources

PubMed2006

[Paediatric cochlear implantation in the first year of life: preliminary results].

BACKGROUND: The success of cochlear implants in children was followed by a stepwise reduction in age at time of surgery. As a result of newborn hearing-screening (NHS) and the reliable audiologic diagnostic procedure, the question is raised as to whether an implantation before the age of 1 year is effective and safe in terms of surgery and rehabilitation. METHOD AND PATIENTS: This retrospective study included 27 children implanted before the age of 1 year (Gr. 1) and 89 children implanted between the age of 1 and 2 years (Gr. 2). Patient related data were analysed for individual history, surgery, rehabilitation and speech understanding. RESULTS: The incidence of complications was not increased in Gr. 1. The fitting of a speech processor was effective and uneventful in all children. The development of hearing and speech understanding showed better results after 2 years in Gr. 1. This development is more obvious for absolute age and not to rehabilitation time. CONCLUSION: In order to achieve an optimal timing for the development of speech understanding, cochlear implantation should be performed before the age of 2 years. This study revealed no additional risks for children in Gr. 1, but the development of speech understanding was better. As a consequence, cochlear implantation should be considered for very young children with an identified bilateral profound hearing loss.

Cochlear Implantation↗

PubMed2006

[Diagnosis and therapy of auditory synaptopathy/neuropathy].

Pathological auditory brainstem responses (lack of responses, elevated thresholds and perturbed waveforms) in combination with present otoacoustic emissions are typical audiometric findings in patients with a hearing impairment that particularly affects speech comprehension or complete deafness. This heterogenous group of disorders first described as "auditory neuropathy" includes dysfunction of peripheral synaptic coding of sound by inner hair cells (synaptopathy) and/or of the generation and propagation of action potentials in the auditory nerve (neuropathy). This joint statement provides prevailing background information as well as recommendations on diagnosis and treatment. The statement focuses on the handling in the german language area but also refers to current international statements.

Brain Stem↗

PubMed2005

[Malignant transformation of a juvenile papilloma in a 11 year old boy].

BACKGROUND: The juvenile laryngeal papilloma is the most common benign neoplasm in children. Often the entity shows an elongated recurrent course of disease with an expansion into the tracheo-bronchial system. Sporadic malignant transformation in adults with a papilloma was reported after treatment with radiotherapy alone or in combination with the intake of additional toxins (e. g. nicotine). Similar reports of a malignant transformation of juvenile papillomas without additional risk factors is very rarely reported. CASE REPORT: We report about an 11 year old boy, who suffered from a juvenile laryngeal papilloma. The multiple laser surgical procedures and a therapy with interferon resulted in a short-term remissions. A tracheotomy was inevitable. Seven months after the first diagnosis of the papilloma a regional metastatic squamous cell carcinoma was found. In spite of combined radiotherapy and chemotherapy the boy died 11 months later. CONCLUSIONS: The spontaneous malignant transformation of a juvenile papilloma in a squamous cell carcinoma is extremely rare. The surgical intervention as well the radiotherapy and chemotherapy using interferon was unsuccessful due to the high grade of malignancy. In view of the very short time interval between first diagnosis of juvenile papilloma and the subsequent malignant transformation, one must consider either the potential presence of a very aggressive form of papilloma or alternative two coincident independent diseases.

Antineoplastic Agents↗

PubMed2003

[Pediatric cost-benefit analysis].

BACKGROUND: The aim of this study was to explore the cost-benefit-ratio of pediatric cochlear implantation for congenitally deaf and prelingually deafened children compared to children with hearing aids. The payers' perspective was chosen as this is the most relevant for cost discussions. The study should verify the hypothesis that educational and associated full costs increase with the age at implantation and that these can be below costs for children with hearing aids. METHODS: Children implanted at different ages (group 1: 0 - 1.9 yr., group 2: 2 - 3.9 yr., group 3: 4 - 6.9 yr.) were compared with deaf children using hearing aids (group 4). Payers were sick funds and public authorities, the first paying for medical and indirect costs, the latter paying for education. Educational settings were used as measure for benefit. All costs related to the hearing deficiency were included up to the age of 16 years (end of primary education) based on 1999 costs. RESULTS: Discounted medical and indirect costs for a pediatric cochlear implant user varied between DM 112,000 (53,300 US dollars) and DM 91,000 (43,300 US dollars) depending on the age at implantation. Costs for a hearing aid user added up to DM 36,000 (17,100 US dollars). These costs were paid by the sick funds. Costs for education varied between DM 159,000 (75,700 US dollars) for group 1 and DM 257,000 (122,400 US dollars) for group 3 compared to DM 277,000 (131,900 US dollars) for hearing aid users. These differences are mainly based on the use of mainstream schools. Total costs for sick funds and public authorities ad up to DM 271,000 (129,000 US dollars), DM 334,000 (159,000 US dollars) and DM 348,000 (165,700 US dollars), respectively, for the three age groups of implanted children compared to DM 313,000 (148,600 US dollars) for hearing aid users. CONCLUSION: This study supports the view that pediatric cochlear implantation provides positive cost-benefit ratios compared to hearing aid users depending on the age at implantation. From a societal/payer perspective implantation of prelingually deafened children is especially recommended for children under the age of 2 years. Implantation between ages 2 and 3,9 can be recommended from an educational perspective. Implantation at ages >7 years must be based on individual decisions considering psychosocial environment, speech and language status and type of communication.

Adolescent↗

PubMed2002

[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↗

PubMed2002

The results in patients implanted with the nucleus double array cochlear implant: pitch discrimination and auditory performance.

OBJECTIVE: In patients with total or surgically inaccessible cochlear obliteration, only a reduced number of active electrodes can be inserted with standard cochlear implants, resulting in below average auditory performance. Therefore, a special implant with two electrode arrays was developed on the basis of the Nucleus 22 cochlear implant, the socalled Double Array. One electrode array with 11 active electrodes is inserted into the basal turn of the cochlea, while the second array with 10 active electrodes is inserted into the second turn. The Double Array is now available on the basis of the more advanced Nucleus 24 with 11 active electrodes on each array and two reference electrodes, one at the case and the second one an additional ball electrode, which is placed under the temporalis muscle. For device description and surgical technique see Lenarz et al. (2001). This paper presents psychophysical data on pitch discrimination and auditory performance of patients implanted with a Double Array on the basis of the Nucleus 22. STUDY DESIGN: A prospective intra-individual study using a Latin square paradigm was performed in six adult patients with obliterated cochlea who received the Nucleus 22 Double Array. After appropriate fitting and loudness balancing, patients were tested either with the basal, the apical or both electrode arrays. Apart from auditory performance tests including numbers and monosyllable word tests, pitch discrimination was determined with a defined procedure. RESULTS: When activating each array alone, auditory performance was better with the basal array than with the apical array. Both arrays together showed marked improvement compared with the basal array, indicating an additional effect of the second array. Pitch discrimination was significantly better for the electrodes in the basal turn than in the second turn, indicating differences in electrical excitation of the auditory nerve fibers. Pitch discrimination was positively correlated with auditory performance data. CONCLUSION: The additional apical array leads to significant improvement in auditory performance in patients with obliterated cochleae by increasing the number of intracochlear electrodes. Despite reduced pitch discrimination, the apical array provides important information for speech recognition. For this reason the Double Array provides a profound advantage for patients with obliterated or surgically inaccessible cochleae.

Acoustic Stimulation↗

PubMed2001

[Subjective deafness in case of peri-synaptic audiopathy. Isolated defects of the inner haircells?].

BACKGROUND: Damage to or functional impair of the inner hair cells, synapsis or dendrites of the ganglion cells of the auditory nerve result in specific audiometric findings. Due to the normal function of the outer hair cells otoacoustic emissions can be registered, ABR and ECochG show at least elevated thresholds or are absent. PATIENTS: We demonstrate 5 cases with these audiological findings described in the literature as Auditory Neuropathy. RESULTS: All patients have profound to severe hearing loss with poor speech understanding under best aided conditions with conventional hearing aids. 3 patients, which were implanted with a cochlear implant have speech understanding but one prelingually adult, also implanted, has only sound identification. CONCLUSIONS: Hypoxia, carboplatin, ototoxicity and metabolic disorders are possible etiologies for damage to the inner hair cells or synapsis. The results will be discussed with reference to the localisation of the pathology and the definition as Auditory Neuropathy.

Adult↗

PubMed2001

The nucleus double array cochlear implant: a new concept for the obliterated cochlea.

OBJECTIVE: To increase the number of intracochlear electrodes that may be inserted into a totally obliterated cochlea, a special implant has been developed in collaboration with Cochlear Limited. This implant features two separate electrode carriers containing 11 and 10 active electrodes, respectively, as well as a reference electrode located on the receiver-stimulator package. The potential stimulation modes available with this device therefore include monopolar and bipolar stimulation, and stimulation between both arrays. SURGICAL TECHNIQUE: A cochleostomy anterior to the round window provides access to the basal turn (both the scala tympani and the scala vestibuli), and new built connective tissue and bone can be removed until the anterior wall of the basal turn is approached. A second cochleostomy is performed at the second turn caudal of the cochleariform process and 2 mm anterior of the oval window after removal of the incus. New tissue should also be removed if necessary. The two electrode carriers are then placed into the scala tympani of the basal and the scala vestibuli of the second turn, respectively. The remaining surgical procedure is identical with that used for cochlear implantation in patients without obliterated cochleas. PATIENTS: In this clinical study, 10 patients aged 32 to 66 years with an obliterated cochlea each received a double array cochlear implant. All patients had total obliteration of the basal turn either on preoperative imaging or during surgery. Intraoperatively, the second turn was not obliterated in only 4 of 10 patients. Postoperatively, a standard audiologic test battery was used to determine auditory improvement over time. POSTOPERATIVE RESULTS: All patients achieved significantly improved speech understanding when the additional apical electrode array was used, compared with the use of each electrode array independently. No complications occurred. CONCLUSION: In patients with a totally obliterated cochlea, the number of intracochlear electrodes can be increased by use of the Nucleus double array implant. As a result, patients achieve significantly better auditory results.

Adult↗

PubMed2001

Auditory brainstem implant: part I. Auditory performance and its evolution over time.

OBJECTIVE: Evaluation of auditory performance and its evolution over time in patients with the auditory brainstem implant. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. PATIENTS AND METHODS: Between May 1996 and April 2000, 14 patients with neurofibromatosis type 2 underwent implantation with a multichannel auditory brainstem implant. Auditory performance data were obtained in 13 patients who had used their device on a regular daily basis for 1 to 41 months (average 19 months). Hearing evaluation was based on the results of four tests (vowel confusion, consonant confusion, Freiburger numbers, and speech-tracking test), which were performed with and without lip-reading at regular intervals after device activation. RESULTS: 12 patients received auditory sensation through the auditory brainstem implant immediately after device activation. In one patient, because of postoperative electrode migration, device activation was not successful. In this case, after the electrode array was repositioned, activation was successful. The results of the audiovisual mode 2 weeks after device activation revealed a lip-reading enhancement above the chance level in about 50% of the patients in the vowel confusion and speech-tracking tests and in 70% of the patients in the consonant confusion test. Lip-reading enhancement improved within the first 6 months and then entered a plateau phase, which was more prominent in the monosyllabic vowel and consonant tests. In the auditory alone mode, more than half of the patients showed their first positive result in the vowel test 3 months after device activation, but it took about 6 months until half of the patients revealed a result above the chance level in the consonant and Freiburger numbers tests. Open set speech recognition in the auditory alone mode (in the speech-tracking test) was not common and happened relatively late (within 1 year or later). DISCUSSION AND CONCLUSION: Although auditory sensation appeared immediately after device activation, a period of 6 months was necessary for relearning and adaptation of the central auditory system to the altered form of auditory information presented by the auditory brainstem implant.

Adult↗

PubMed2000

Auditory brainstem implants: current neurosurgical experiences and perspective.

The objective of this study was to present aspects of the current treatment protocol, such as patient evaluation and selection for therapy, multimodality monitoring for optimal auditory brainstem implant (ABI) positioning and radiological evaluation, that might have an impact on the functional results of ABI. Out of a series of 145 patients with bilateral vestibular schwannomas 10 patients received an ABI, eight of which are reported here. Patient selection was based on disease course, clinical and radiological criteria (according to the Hannover evaluation and prognosis scaling of neurofibromatosis type 2 (NF2)), extensive otological test battery and psycho-social factors. ABI placement was controlled by multimodality electrophysiological monitoring in order to activate the auditory pathway and to prevent false stimulation of the cranial nerve nuclei or long sensory or motor tracts. Results of hearing function were correlated with patients' ages, duration of deafness, tumour extension, tumour-induced compression or deformation of the brainstem, and numbers of activated electrodes without any side-effects. Out of 59 patients with pre-operative deafness eight patients received an ABI of the Nucleus 22 type. All these patients became continuous users without any side effects and experienced improved quality of life. Speech reception in combination with lip-reading was markedly improved, with further improvement over a long period. A short duration of deafness may be favourable for achieving good results, while age was not a relevant factor. Lateral recess obstruction may necessitate a more meticulous dissection, but did not prevent good placement of the ABI in the lateral recess. Pre-existing brainstem compression did not prevent good results, but brainstem deformation and ipsi- and contralateral distortion were followed by a less favourable outcome. Among the factors that can be influenced by the therapy management are the selection of patients with a slow progressing NF2 disease, a short duration of deafness, a careful analysis of brainstem deformation and consideration of either side for implantation. Long-standing brainstem deformation might not lead to recovery, but instead lead to a low number of active electrodes and possibly only moderate results. ABI treatment is a safe procedure that can increase a patient's quality of life considerably. ABI placement along with neurophysiological control helps to prevent side effects and to improve acoustic activation. Further studies on structural and functional changes of the brainstem after previous tumour compression and distortion should increase our understanding and facilitate a decision on the best side for ABI implantation.

Adult↗

PubMed2000

Extensive monitoring during auditory brainstem implant surgery.

In patients with reduced auditory nerve function, for example due to tumour removal or an accident, hearing rehabilitation can be elicited by an auditory brainstem implant (ABI). The electrode array of the ABI manufactured by Cochlear Ltd., Sydney, consists of 21 circled contacts in a silicon carrier. This is inserted in the lateral recess of the fourth ventricle. Since 1996, in Hannover eight patients have been implanted with a cochlear ABI Nucleus 21 + 1. All of them were profoundly deaf on both sides due to neurofibromatosis type 2 (NF2). To find the optimal electrode position during surgery, a multimodal monitoring by auditory evoked potentials (AEP), electromyography (EMG) and somatosensory evoked potentials (SEP) was performed. When monitoring AEPs, the function of the implant can be checked first by the stimulus artefact. By analysing the AEPs in more detail, the optimal positioning of the electrode on the cochlear nucleus can be found. If systems other than the auditory system are stimulated this will be revealed in one or more of the AEP, EMG and SEP recordings. According to the literature, AEPs stimulated by an ABI consist of three vertex positive peaks with latencies shorter than 4 ms. Typical AEPs are correlated with good post-operative hearing sensation. Comparing these AEPs with AEPs stimulated acoustically or electrically at different sites of the auditory system, it can be assumed that the first peak corresponds to J3, the second to J4 and the last to J5. From this comparison it can also be concluded that no potentials should occur later than 5 ms. This corresponds to our findings. Post-operatively, side-effects occurred when areas of the electrode array were stimulated that showed potentials with latencies longer than 5 ms intra-operatively. Our results indicate that monitoring is an essential aid for the surgeon in finding the optimal electrode position. Positioning solely with reference to anatomical landmarks may not be enough to find the optimal functional position.

Adult↗

PubMed2000

Auditory brainstem implant in auditory rehabilitation of patients with neurofibromatosis type 2: Hannover programme.

An auditory brainstem implant (ABI) is indicated for patients suffering from bilateral neural deafness. The most affected patients are those with neurofibromatosis type 2 (NF2). An implantation is possible either at the same time as, or after, surgical removal of an acoustic neuroma. This paper demonstrates the results of eight out of 11 patients with NF2, seven of whom received an ABI after tumour removal. Pre-operatively, all of them were deaf. Post-operatively, the first fitting served to determine the individual stimulation parameters for each electrode. The stimulation-dependent side-effects were eliminated by reducing the stimulus intensity without causing negative effects on the hearing with the ABI. Only in one case was an open set understanding achieved within the first year. However, all patients had a better speech understanding when they combined their hearing with the ABI and their lip-reading abilities. There is no correlation between the performance with ABI and the tumour size or the duration of deafness.

Adolescent↗

PubMed1999

[Temporal bone fracture after head trauma causing rhinoliquorrhea and meningitis].

We report our experience in managing a temporal bone fracture after head trauma that had no apparent clinical signs. Recurrent CSF rhinorrhea and meningitis lead to extensive diagnostic procedures. Operative exploration of the temporal bone demonstrated a fracture line along the horizontal part of the carotid artery. The location of the fracture did not cause such typical symptoms as hearing impairment, facial paralysis, vertigo or tinnitus. Only CSF liquorrhea through the Eustachian tube indicated a fracture at the lateral skull base.

Cerebrospinal Fluid Rhinorrhea↗

PubMed1999

[The Nucleus Double Array Cochlear Implant: a new concept in obliterated cochlea].

AIM: In order to increase the number of intracochlear electrodes to be inserted into a totally obliterated cochlea a special implant has been developed in collaboration with Cochlear Ltd. The implant features two separate electrode carriers containing 11 and 10 active electrodes, respectively, and a reference electrode on the receiver stimulator package. The potential stimulation modes include monopolar and bipolar stimulation as well as stimulation between both arrays. SURGICAL TECHNIQUE: A cochleostomy at the round window provides access to the scala tympani. Newly formed bone is removed as far as the anterior portion of the basal turn. Care is taken to identify and preserve the osseous border of the cochlea. A second cochleostomy is performed immediately caudal to the cochleariform process after removal of the incus. New tissue can be removed here in the same way. The two electrode carriers are then placed into the first and the second turn respectively. The remaining procedure corresponds to the procedure for cochlear implantation in cases in which the cochlea is not obliterated. PATIENTS: For the purpose of a clinical study n = 10 patients aged between 32-66 years with an obliterated cochlea were fitted with a double array cochlear implant. All patients showed signs of total obliteration of the basal turn either in preoperative imaging or during surgery. Intraoperative inspection revealed that the second turn was not obliterated in 4 of 10 patients. POSTOPERATIVE RESULTS: Postoperatively, a standard test battery was used to determine auditory performance over a period of time. All patients achieved significantly better speech understanding due to the additional apical electrode array. No complications occurred. CONCLUSION: In cases involving an obliterated cochlea, the number of intracochlear electrodes can be increased with the double array implant. As a result, the patients achieve significantly better auditory results.

Adult↗

PubMed1999

Speech perception results for children implanted with the CLARION cochlear implant at the Medical University of Hannover.

The perception of speech of 167 children implanted with a CLARION Multi-Strategy Cochlear Implant (1.2 device) was evaluated preimplantation and at 3, 6, 12, 18, and 24 months postimplantation. The children were between 15 months and 15 years of age. The test materials consisted of 8 tests involving syllable structure, single- and 2-syllable words, differentiation of word pairs, and sentences. Two difficulty levels were used, depending on developmental age (<7, and 7 to 15 years). There was an improvement in test scores over time for both age groups. The younger children (particularly those under age 4) improved steadily over the first 2 years, while the older children tended to plateau between 12 and 18 months after implantation. These findings demonstrate that deaf children up to 15 years old benefit from cochlear implants. Children under 4 years of age may even have the ability to compensate for delays in speech development before they reach school age.

Adolescent↗

PubMed1999

Cochlear implantation in children under the age of two: the MHH experience with the CLARION cochlear implant. Medizinische Hochschule Hannover.

This paper examines reports on the selection criteria, the surgical procedure, and the postoperative performance for children under the age of 2 implanted with the CLARION Multi-Strategy Cochlear Implant (1.2 device). Eighteen children have been implanted since 1996 with a mean age at implantation of 18 months (range 11 to 23 months). All children were selected by means of a standardized preoperative diagnostic protocol. The surgical procedure used in older children was modified depending on the head and mastoid size, skull thickness, and recurrent otitis media. Auditory perception was tested prior to as well as 3, 6, 12, and 18 months following implantation by means of a standardized age-adapted test protocol. The electrode array was inserted without difficulty in all cases, with no complications to date. On average, auditory performance improved over time up to 18 months after implantation. Closed-set test scores increased by 25% to 55% in 18 months. Open-set test scores began to show improvement between 6 and 12 months postoperatively. Overall, our experience indicates that cochlear implantation in children under the age of 2 is relatively safe and reliable. The Clarion 1.2 device surgery can be performed without complications. Auditory performance results support the effectiveness of early implantation.

Cochlear Implantation↗

PubMed1999

The influence of ionizing radiation on the CLARION 1.2 cochlear implant during radiation therapy.

OBJECTIVE: This study aimed to determine the maximum dose of radiation the CLARION 1.2 cochlear implant can withstand safely. INTRODUCTION: Cochlear implants restore functional hearing to patients with sensorineural deafness. Because some patients may need radiation therapy, it is important to investigate the influence of ionizing radiation on cochlear implant function. METHODS: This study tested the function of four CLARION 1.2 implants (Advanced Bionics, Sylmar, CA, U.S.A.) after varying radiation treatments with gamma rays. The first implant received a cumulative dosage of 69 Gy over nine treatments (single doses between 0.1-30 Gy). The second was irradiated with a total of 90 Gy, receiving three treatments of 30 Gy each. The third and fourth received doses more typical of patient therapy (i.e., 2 Gy) approximately 30 times, for a cumulative dosage of approximately 60 Gy. Implant function was tested after every treatment; the CLARION implant incorporates a back-telemetry system, allowing impedance and current output testing. RESULTS: Despite the type of treatment, the results were quite consistent: difficulties in function occurred when the cumulative dosage inside the implant was approximately 60 Gy. The first implant recovered completely and the second recovered partially. DISCUSSION: The CLARION 1.2 cochlear implant seems to safely withstand approximately 60 Gy of radiation before experiencing functional difficulties. In a clinical situation, the implant would not likely be in the target volume irradiated, and thus the patient's therapeutic cumulative dosage might be higher.

Cochlear Implants↗