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ABSTRACT: High doses of acetylsalicylic acid (ASS) induce tinnitus and hearing loss. This ototoxic side effect of ASS is characterized by a decrease in spontaneous and evoked otoacoustic emissions. A decrease in otoacoustic emissions is found not only in mammals, but also in non-mammalian ears without electromotile outer hair cells. The molecular mechanism underlying ASS ototoxicity seems to be competitive binding to and a block of the motor molecule prestin. In non-mammalian species, ASS ototoxicity is possibly explained by an effect on the hair bundle.
The present data from the outer hair cells of the adult guinea pig cochlea show a reduction in the membrane capacitance by maximally 42%, probably as a result of ASS binding competitively to the motor molecule. However, spontaneous and evoked receptor currents were not modulated by ASS.
The results suggest an influence of ASS on outer hair cell somatic electromotility, without a concomitant effect on hair-bundle function.
HNO 10/2006; 54(9):670-6. · 0.40 Impact Factor
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ABSTRACT: HintergrundAzetylsalizylsure (ASS) induziert in hohen Dosen zuverlssig reversibel eine Schwerhrigkeit und einen Tinnitus. Die ototoxische Wirkung von ASS ist neben anderen Phnomenen von einer Unterdrckung der spontanen und evozierten otoakustischen Emissionen gekennzeichnet. Diese Unterdrckung der otoakustischen Emissionen lsst sich bei Sugetieren, aber auch bei Tierspezies ohne elektromotile kochlere uere Haarzellen nachweisen. Der zugrunde liegende Pathomechanismus in der Sugetierkochlea ist eine kompetitive Hemmung des Motormolekls Prestin durch ASS. Bei Nichtsugetierhaarzellen wird eine Beeinflussung des Haarbndels als Angriffspunkt fr ASS diskutiert.ErgebnisseIn der vorliegenden Arbeit konnte bei adulten ueren Haarzellen der Meerschweinchenkochlea eine Abnahme der Membrankapazitt (um maximal 42%) als Zeichen fr die Beeinflussung der Motorproteine gefunden werden. Der spontane und evozierte Rezeptorstrom in den Zellen blieb jedoch von ASS unbeeinflusst.SchlussfolgerungDie Ergebnisse sprechen fr eine Wirkung von ASS auf die somatische Elektromotilitt uerer Haarzellen und gegen eine Modulation der Haarbndelfunktion bei Sugetierhaarzellen.BackgroundHigh doses of acetylsalicylic acid (ASS) induce tinnitus and hearing loss. This ototoxic side effect of ASS is characterized by a decrease in spontaneous and evoked otoacoustic emissions. A decrease in otoacoustic emissions is found not only in mammals, but also in non-mammalian ears without electromotile outer hair cells. The molecular mechanism underlying ASS ototoxicity seems to be competitive binding to and a block of the motor molecule prestin. In non-mammalian species, ASS ototoxicity is possibly explained by an effect on the hair bundle.ResultsThe present data from the outer hair cells of the adult guinea pig cochlea show a reduction in the membrane capacitance by maximally 42%, probably as a result of ASS binding competitively to the motor molecule. However, spontaneous and evoked receptor currents were not modulated by ASS.ConclusionThe results suggest an influence of ASS on outer hair cell somatic electromotility, without a concomitant effect on hair-bundle function.
HNO 08/2006; 54(9):670-676. · 0.40 Impact Factor
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ABSTRACT: Data on the prevalence of otorhinolaryngological (ORL) symptoms in patients with cystic fibrosis (CF) are limited. A standard annual examination would be useful for definition of risk factors and/or management alternatives for these symptoms.
Prospective observational study of an unselected group of CF patients.
Between 1997 and 2004, 123 CF patients were routinely examined. The examinations included nasal endoscopy and audiological evaluation.
All patients who were approached to take part in the study gave their consent and were extremely cooperative. In 40% of the patients nasal polyps were found endoscopically. In 22% rhinological surgery had already been performed. Of the 123 patients, 13 (12%) showed different grades of sensorineural hearing loss, and all of these patients had received aminoglycoside antibiotics.
CF patients demonstrate a high prevalence of ORL symptoms. Therefore, an annual standard examination would provide data for identifying potential risk factors and for optimizing the management of these symptoms in CF patients.
HNO 06/2006; 54(5):361-4, 366, 368. · 0.40 Impact Factor
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ABSTRACT: HintergrundBisher existieren wenige Daten zur Prvalenz von HNO-Symptomen bei Mukoviszidose- (CF-)Patienten.ZielHNO-Symptome von CF-Patienten aufzuzeigen und einen Standard einer jhrlichen Untersuchung zu definieren.Patienten und MethodenVon 1997 bis 2004 wurden 123 CF-Patienten untersucht. Es wurden eine Spiegeluntersuchung, einschlielich Endoskopie der Nase, sowie audiologische Messungen durchgefhrt.ErgebnisseDie Patienten und deren Eltern waren nach Aufklrung ber die Hintergrnde der Studie sehr kooperativ. Bei 40% aller Patienten war endoskopisch eine Polyposis nasi nachweisbar. Bei 22% der Patienten war bereits mindestens eine Operation erfolgt. 13 Patienten (12%) zeigten eine unterschiedlich stark ausgeprgte Innenohrschwerhrigkeit (IOS). Alle Patienten mit einer IOS waren zu unterschiedlichen Zeiten mit Aminoglykosiden behandelt worden.SchlussfolgerungHNO-Symptome zeigen eine hohe Prvalenz bei CF-Patienten. Daher empfehlen wir eine jhrliche Endoskopie der Nase und einen audiometrischen Ausschluss von ototoxischen Innenohrschden, um stichhaltige Daten fr eine Optimierung der Behandlung zu erhalten.ObjectivesData on the prevalence of otorhinolaryngological (ORL) symptoms in patients with cystic fibrosis (CF) are limited. A standard annual examination would be useful for definition of risk factors and/or management alternatives for these symptoms.Study designProspective observational study of an unselected group of CF patients.Patients and methodsBetween 1997 and 2004, 123 CF patients were routinely examined. The examinations included nasal endoscopy and audiological evaluation.ResultsAll patients who were approached to take part in the study gave their consent and were extremely cooperative. In 40% of the patients nasal polyps were found endoscopically. In 22% rhinological surgery had already been performed. Of the 123 patients, 13 (12%) showed different grades of sensorineural hearing loss, and all of these patients had received aminoglycoside antibiotics.ConclusionsCF patients demonstrate a high prevalence of ORL symptoms. Therefore, an annual standard examination would provide data for identifying potential risk factors and for optimizing the management of these symptoms in CF patients.
HNO 04/2006; 54(5):361-368. · 0.40 Impact Factor
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ABSTRACT: Nosocomial infection is generally regarded as the most important postoperative complication. Therefore, on 28 December 2002 a German law was implemented requiring the surveillance of postoperative infections in all hospitals.
The authors propose using stapes and thyroid surgery to monitor the infection rate in a typical Head and Neck Department. A versatile software (CISS) based on MS Word and MS Excel was developed for this purpose.
Postoperative infections were retrospectively analyzed for three subsequent years. The present data confirm the results of previous studies that surveillance itself is a powerful tool in reducing the postoperative infection rate.
The newly developed software provided an easy tool for the collection of infection data. The reported infection rates in stapes and thyroid surgery are representative of ENT clinics in Germany.
HNO 05/2005; 53(4):325-8, 330-2. · 0.40 Impact Factor
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ABSTRACT: HintergrundNosokomiale Infektionen gelten als hufigste postoperative Komplikation, daher wird im deutschen Infektionsschutzgesetz vom 23.12.2002 eine Erfassung der Infektionsrate nach Operationen gefordert.Material und MethodenDie Stapesplastik und die Strumaoperation werden als HNO-typische Indikatoroperationen vorgeschlagen. Fr die Erfassung wurde eine Software (CISS) basierend auf den Programmen MS Word und MS Excel neu entwickelt.ErgebnisseRetrospektiv wurden die Infektionsraten fr die 2Indikatoroperationen ber 3Jahre aufgearbeitet. Die vorliegenden Daten besttigen die Ergebnisse frherer Studien, dass allein die Surveillance von Infektionen zu einer Senkung der Infektionsrate fhrt.SchlussfolgerungDie vorgestellte Software erwies sich als geeignet fr die Erfassung der Infektionsdaten. Die 2Indikatoroperationen Stapesplastik und Strumaoperation spiegeln die Infektionsrate einer typischen Hals-Nasen-Ohren-Klinik gut wider.BackgroundNosocomial infection is generally regarded as the most important postoperative complication. Therefore, on 28 December 2002 a German law was implemented requiring the surveillance of postoperative infections in all hospitals.MethodsThe authors propose using stapes and thyroid surgery to monitor the infection rate in a typical Head and Neck Department. A versatile software (CISS) based on MS Word and MS Excel was developed for this purpose.ResultsPostoperative infections were retrospectively analyzed for three subsequent years. The present data confirm the results of previous studies that surveillance itself is a powerful tool in reducing the postoperative infection rate.ConclusionThe newly developed software provided an easy tool for the collection of infection data. The reported infection rates in stapes and thyroid surgery are representative of ENT clinics in Germany.
HNO 03/2005; 53(4):325-332. · 0.40 Impact Factor
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H P Zenner,
H-G Freitag,
C Linti,
U Steinhardt,
J Rodriguez Jorge, S Preyer,
P-S Mauz,
M Sürth,
H Planck,
I Baumann,
R Lehner,
A Eiber
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ABSTRACT: The purpose of the study was to identify acoustcomechanical properties of various biostable and biocompatible materials to create a middle ear prosthesis with the following properties: (i) improved handling including a good view of the head of the stapes or footplate and adjustable length, (ii) improved acoustical characteristics that are adequate for ossiculoplastic. The identified material should serve to build CE and FDA approved prostheses for clinical use in patients.
Test models made of Teflon, polyetheretherketone, polyethylenterephtalate, polysulfone, gold, Al2O3 ceramics, carbon and titanium were investigated for their potential to fulfill the requirements. Acoustical properties were investigated by laser Doppler velocimetry (LDV) in mechanical middle ear models (MMM). Measured data were fed in to a recently created computer model of the middle ear (multibody systems approach, MBS). Using computer-aided design (CAD) measured and computed data allowed creation and fine precision of titanium prostheses (Tübingen Titanium Protheses, TTP). Their handling was tested in temporal bones. Acoustomechanical properties were investigated using the MBS and mechanical middle ear models.
Input impedance, mass, stiffness, and geometry of test models and prostheses were determined. Furthermore, their influence on the intraprosthetic transfer functions and on coupling to either tympanic membrane or stapes was investigated.
Final results were FDA- and CE-approved filigreed titanium prostheses with an open head that fulfilled the four requirements detailed above. The prostheses (TTP) were developed in defined lengths of between 1.75 and 3.5 mm (partial) and 3.0 and 6.5 mm (total) as well as in adjustable lengths (TTP-Vario).
The results suggest acoustomechanical advantages of TTPs because they combine a significantly low mass with high stiffness. In contrast to closed prostheses, the open head and filigreed design allow an excellent view of the prosthesis foot during coupling to the head or footplate of stapes, contributing to an improved intraoperative reliability of prosthesis coupling.
Hearing Research 07/2004; 192(1-2):36-46. · 2.70 Impact Factor
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HNO 06/2002; 50(5):488-9. · 0.40 Impact Factor
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ABSTRACT: Epidemiological and experimental studies suggest that hypercholesterolemia promotes the development of sensorineural hearing loss; however, the underlying cellular pathomechanism remains obscure. In the present study, 20 healthy subjects and 20 patients with familial hypercholesterolemia were compared with respect to their hearing function. None of the 40 persons reported any history of hearing disorder. In accordance with this subjective impression, mean hearing thresholds were within the normal, age-dependent ranges in both groups. In contrast, the single-generator distortion product otoacoustic emissions (sgDPOAE) were reduced at and above 4 kHz. Input-output functions of DPOAE could be subdivided into three groups: (i) normal, with unity slope at low intensities and slope less than unity (0.24+/-0.07 dB/dB at higher intensities; (ii) pathologic, described by a single straight line; (iii) ill-defined, with data usually indistinguishable from the background noise level. The ill-defined DPOAE behavior was only found in patients with hypercholesterolemia; namely, for 25% of patients at f(2)=1.5 kHz and for 50% at f(2)=4 kHz. Patients belonging to the pathologic and ill-defined DPOAE groups had significantly (P<0.05) higher total serum cholesterol and LDL-cholesterol levels compared with subjects from the normal DPOAE group. While hearing thresholds of patients with ill-defined growth functions were not statistically different from those of normal subjects, speech scores were significantly reduced in these cases. The data imply that nonlinear mechanical processes in the cochlea are compromised in hypercholesterolemic patients.
Hearing Research 03/2001; 152(1-2):139-51. · 2.70 Impact Factor
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ABSTRACT: We report about ectopic glial tissue of the skull base and the parapharyngeal space presenting as a soft tissue mass in the middle ear. An 11-year-old boy presented with bilateral conductive hearing loss since early childhood. The history included previously removed lesions consistent with ectopic neuroglial tissue of the tongue and the parapharyngeal space soon after birth, as well as surgery for cleft palate. High resolution computed tomography of the petrous bone and magnetic resonance imaging were useful in identifying the skull base defect and in characterizing the lesion's relation to the brain. There was no clinical, radiological or surgical evidence of any associated dural defect. The lesion was removed via a modified infratemporal approach. Histology revealed neuroglial tissue with calcifications without any signs of mesodermal or entodermal origin. On the basis of this case the pathogenesis and diagnosis of ectopic brain tissue and its relation to the more commonly encountered meningoencephalic herniations are reviewed. Furthermore therapeutical implications are discussed.
International Journal of Pediatric Otorhinolaryngology 01/2001; 56(2):141-7. · 1.17 Impact Factor
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HNO 11/1998; 46(10):882-3. · 0.40 Impact Factor
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HNO 01/1998; 46(10):882-883. · 0.40 Impact Factor
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ABSTRACT: The overall aim of the present investigation was to develop a technique for endoscopic investigation of the cochlea. In the experiments reported here, the possible effect of the endoscope-called the "cochleoscope"-on the electrophysiology of the cochlea was investigated by recording the cochlear action potential (CAP) threshold tuning curve from (0.1-34 kHz). The dorsolateral bulla of anesthesized guinea pigs (with ketamine 60 mg/kg and Rompun 12 mg/kg) was opened, after which the cochleoscope was introduced under micromanipulator control through the round window membrane. Three cochleoscopes were used and had diameters of 0.29 mm, 0.7 mm and 0.89 mm, respectively, containing 2000, 3000 and 3000 fibers each. Experiments in 7 animals showed that the cochleoscope did not influence CAP thresholds. Although the present resolution of the endoscopes is limited, the basilar membrane can be clearly distinguished from the osseous spiral lamina. It is anticipated that improved resolution will allow the cochleoscope to be used for diagnostic purposes in cases of sensorineural hearing loss.
HNO 05/1997; 45(4):216-21. · 0.40 Impact Factor
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Ear, nose, & throat journal 04/1997; 76(3):151-8, 160, 162-3. · 0.66 Impact Factor
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ABSTRACT: Die Verbesserung der endoskopischen Aufnahmetechnik macht heute eine endoskopische Inspektion der Cochlea möglich. Die Untersuchungstechnik
erfolgte bisher über eine intraoperative Cochleotomie im Rahmen von Cochleaimplantoperationen bei surden Patienten. Wünschenswert
wäre eine diagnostische Endoskopie des geschädigten, noch hörenden Innenohrs. Die Ziele der vorliegenden Arbeit waren daher
zum einen die Verfeinerung der Cochleoskopie am Säugetierohr und des weiteren, die Auswirkung der Ruptur des runden Fensters
und das Eindringen des Endoskops in die Cochlea mit Hilfe der Summenaktionspotentiale zu untersuchen.
Anhand von Untersuchungen der Schwellen des Summenaktionspotentials (SAP) am Meerschweinchen wissen wir, daß die vorsichtige
Öffnung des runden Fensters zu keiner signifikanten SAP-Schwellenerhöhung führt; daher wurde das Endoskop durch das runde
Fenster eingeführt. Als Versuchsmodell diente die Cochlea des Meerschweinchen (350–450 g). Die Tiere wurden mittels Ketanest
(60 mg/kg) und Rompun (12 mg/kg) intramuskulär in Narkose operiert. Das Monitoring der Narkosetiefe erfolgte an den tracheotomierten
und beatmeten Tieren über EKG und Pfotenreflex.
Zur Darstellung des runden Fensters wurde ein dorsaler Zugangsweg unter Resektion der Bulla gewählt. Das weitere Vordringen
in Richtung rundes Fenster erfolgte hierbei über ein per Mikromanipulator gesteuertes Endoskop (Durchmesser 0,29 mm mit 2000
Fasern; 0,7 mm mit 3000 Fasern; 0,89 mm mit 3000 Fasern). Die räumliche Lage konnte des weiteren über ein Operationsmikroskop
verfolgt werden. Dabei diente als Zustandskontrolle der Cochlea die Messung der SAP-Schwelle vor und während wesentlicher
Versuchsphasen.
Die gewonnenen Ergebnisse zeigen hierbei, daß eine Cochleoskopie an Ohren des Meerschweinchens ohne Beeinträchtigung der SAP-Schwellen
möglich ist. Der Versuchsaufbau soll Baustein für künftige endoskopische In-vivo-Untersuchungen der Cochlea vom runden Fenster
aus sein.
Anhand der vorliegenden Resultate besteht die Hoffnung, daß durch die weitere Miniaturisierung der Endoskope mit verbesserter
Auflösung eine diagnostische Endoskopie der Cochlea durch die Tuba Eustachii oder über einen Parazenteseschnitt durch das
Trommelfell am Menschen möglich sein wird.
The overall aim of the present investigation was to develop a technique for endoscopic investigation of the cochlea. In the
experiments reported here, the possible effect of the endoscope – called the ”cochleoscope”– on the electrophysiology of the
cochlea was investigated by recording the cochlear action potential (CAP) threshold tuning curve from (0.1–34 kHz). The dorsolateral
bulla of anesthesized guinea pigs (with ketamine 60 mg/kg and Rompun 12 mg/kg) was opened, after which the cochleoscope was
introduced under micromanipulator control through the round window membrane. Three cochleoscopes were used and had diameters
of 0.29 mm, 0.7 mm and 0.89 mm, respectively, containing 2000, 3000 and 3000 fibers each. Experiments in 7 animals showed
that the cochleoscope did not influence CAP thresholds. Although the present resolution of the endoscopes is limited, the
basilar membrane can be clearly distinguished from the osseous spiral lamina. It is anticipated that improved resolution will
allow the cochleoscope to be used for diagnostic purposes in cases of sensorineural hearing loss.
HNO 03/1997; 45(4):216-221. · 0.40 Impact Factor
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S Preyer
HNO 01/1997; 44(12):658-60. · 0.40 Impact Factor
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Lymphology 10/1996; 29(3):91-4. · 1.02 Impact Factor
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S Preyer
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ABSTRACT: The etiology of sudden idiopathic hearing loss is not known. Among other causes, vascular disease is discussed as a possible pathomechanism in sudden hearing loss. Since other vascular diseases such as myocardial infarction, migraine, and open-angle glaucoma show a clear meteorotropy, it was the aim of the present prospective study to investigate the dependence of sudden hearing loss on weather parameters.
The incidence, the extent, and the remission of sudden idiopathic hearing loss in 128 patients were correlated with atmospheric pressure and temperature during a period of 12 months.
The group of patients with a complete recovery of hearing thresholds was characterized by the smallest changes of atmospheric pressure and temperature, whereas patients with no recovery of hearing had the highest values for atmospheric pressure and temperature changes. However, a statistically significant correlation of sudden hearing loss with absolute values or relative changes of atmospheric air pressure or temperature was not found. Likewise, there was no seasonal dependence.
The results indicate that sudden idiopathic hearing loss occurs independently of weather parameters.
Laryngo-Rhino-Otologie 09/1996; 75(8):443-6. · 0.97 Impact Factor
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ABSTRACT: The etiology of sudden hearing loss is still not known. Among other pathomechanisms, vascular disorders have been proposed as an underlying cause. We investigated patients with sudden hearing loss for signs of microcirculation disorders.
Thirty-one patients (15 males and 16 females, mean age 37.5 years) were admitted because of sudden hearing loss. In addition, all patients underwent thorough ophthalmologic examination.
Refraction, vision, intraocular pressure and excavation of the optic nerve were normal. In 81% of all cases abnormal conjunctival vascular ectasia were detected. The fundus of 53% of the patients was characterized by slight tortuosity of arterial retinal vessels. The first 11 patients received an ocular electrophysiological examination and showed normal ERG, P-VEP and dark adaptation. Standard perimetry (TAP 2000 ct) revealed no abnormalities in 29 patients, 2 glaucoma patients had small arcuate scotomas. However, 90% of all 29 scotoma-free patients were abnormal in the white-noise campimetry (TEC, Oculus). Testing for color vision (Roth 28 HUE, desat.) revealed abnormally high values (right 120, left 131).
Although patients with sudden hearing loss appeared healthy in the standard eye examination, the more sensitive tests of white-noise campimetry and color vision, together with the conjunctival vascular ectasia and the tortuosity of arterial retinal vessels, indicated a disturbed microcirculation.
Der Ophthalmologe 09/1996; 93(4):433-9. · 0.62 Impact Factor
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S Preyer
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ABSTRACT: It is believed that the sound-induced travelling wave in the mammalian cochlea is enhanced and sharpened by a positive feedback mechanism. This causes the passive linear basilar membrane growth function to become non-linear. The present paper shows that nonlinear basilar membrane vibration is due to the nonlinear growth function of the receptor potential of outer hair cells, which can be described by a 2nd-order Boltzmann function. Since intensity coding in the inner ear depends on an interaction of nonlinear basilar membrane motion and nerve fibers with three different types of synaptic threshold and growth function, the process is directly dependent on an intact mechanoelectrical transduction of outer hair cells. According to the proposed model, a loss in efficiency of outer hair cell mechanoelectrical transduction must lead to both a reduction in gain (i.e., hearing loss) and a linearizing of the response. As a result, once above threshold, the changes of stereociliary displacement, basilar membrane displacement and neural firing rate per unit change of sound intensity must be larger than for the healthy cochlea with its compressive nonlinearity.
HNO 06/1996; 44(5):246-53. · 0.40 Impact Factor
