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Biomedical subjects

M Gersdorff

Publications and source records attributed to M Gersdorff.

At least 19 recordsLinked to original sources

Tragal cartilage in tympanic membrane reconstruction.

INTRODUCTION: Management of chronic perforation and severe posterior and/or attic Retraction Pocket (RP) or atelectasis of the tympanic membrane continues to be one of the most difficult problems for otologists. AIM OF THE STUDY: To analyse the usefulness of the tympanic membrane reconstruction with tragal cartilage. MATERIALS AND METHODS: The study included 27 patients with chronic perforation or severe RP operated by the same surgeon, using tragal cartilage tympanoplasty. Seven supplementary procedures were required for recurrent cholesteatoma (second-look surgery). RESULTS: There has been no recurrence of the retraction and the perforation. Nineteen ossicular reconstructions were necessary with acceptable hearing results. CONCLUSIONS: Tragal cartilage has made a significant improvement in the tympanic membrane reconstruction procedure. A large thin cartilage combined with a titanium prosthesis can provide an excellent anatomical result, perfect stability and good functional outcome. When the eardrum is intact, we still use allografts of costal cartilage for the management of the retraction pocket or titanium prosthesis.

Adolescent↗

[The art of tympanoplasty and its clinical illustration].

INTRODUCTION: The development of tympanic membrane surgery is based on 150 years of surgical experiences, medical and technological innovations. There are two major techniques of tympanic membrane reconstruction depending on the graft related to the different anatomic layers of the eardrum. AIM OF THE STUDY: We evaluate different risk factors of the tympanoplasty such as the age of the patient, the tubal function, the middle ear inflammation, the status of the contra-lateral ear, the localization and the size of the perforation, the surgical techniques and the type of the graft. METHODS: We illustrate and comment on those risk factors considering 122 simple tympanoplasties and a large overview of the literature. RESULTS: We show that the graft position doesn't interfere with the surgical results and we specify our attitude to control the risk factors. CONCLUSION: To obtain excellent results, surgical indications have to be extremely rigorous as with surgical techniques.

Adult↗

Overlay versus underlay tympanoplasty. Comparative study of 122 cases.

INTRODUCTION: In tympanoplasty, the most common two techniques for positioning the graft relative to the remnant of both the tympanic membrane and of the annulus, are the "overlay" and the "underlay" techniques. Each technique has advantages and disadvantages. METHODS: One hundred and twenty-two cases over the age of 8 years who had undergone a tympanoplasty for tympanic membrane perforation secondary to chronic otitis media were included. All patients had a minimum 3-month postoperative otoscopic and audiometric follow-up. RESULTS: of 122 cases, 115 tympanoplasties (94%) were anatomically successful. At frequencies of 0.5, 1, 2, and 4 kHz, the mean air-bone gap improved significantly from 21.7 dB preoperatively to 8.4 dB postoperatively giving a mean gain of 13.3 dB. CONCLUSION: In our series the underlay or overlay positioning of the graft does not significantly influence the rate of postoperative perforations or complications with the exception of epithelial pearls, which occur significantly more frequently following the overlay technique for perforations that require fibro-epidermal cleaving across a large area.

Adolescent↗

No evidence of auditory dysfunction in guinea pigs immunized with myelin P0 protein.

Recent data have focused on the peripheral nerve myelin glycoprotein P0 as a putative autoantigen involved in the autoimmune etiology of some cases of Meniere's disease, idiopathic sensorineural hearing loss and sudden deafness. To determine whether antibodies to myelin P0 can alter cochlear function, 13 healthy guinea pigs were immunized with purified porcine myelin P0 while 10 controls were injected with saline water. The animals were then evaluated for evidence of evolving inner ear disease using immunological, electrophysiological and morphological methods. Twenty-six experimental ears were tested weekly with a brainstem auditory evoked potential technique for a period of 4 months and were compared to 20 control ears. Uniformly, all P0-sensitized guinea pigs showed antibodies to myelin protein P0 as evidenced by ELISA. Clinical signs of inflammatory demyelination were not discernible in P0-sensitized guinea pigs and all the animals were qualitatively normal. No significant increase of evoked potential thresholds was found in the P0-sensitized animals when compared to controls (P>0.05). Peak latencies of waves I, II, III, IV and V and inter-peak latencies in P0-sensitized guinea pigs did not significantly differ from those of controls (P>0.05). Histological sections of inner ear and peripheral nerves were free of disease in both groups. These findings indicate that the sole presence of antibodies to myelin P0 in the sera of guinea pigs or patients suspected of having autoimmune inner ear diseases is unlikely to elicit auditory abnormalities and that additional factors are necessary for the pathogenic development of these disorders.

Animals↗

Inner ear autoantibodies and their targets in patients with autoimmune inner ear diseases.

Immunological mechanisms are thought to play an important role in the pathogenesis of some cochleo-vestibular diseases. This study attempts to present further evidence of autoantibodies reactive against guinea pig inner ear proteins found in patients with autoimmune inner ear diseases (AIED) and specifically identifies the main target antigens of these antibodies. Sera from 110 patients with a clinical diagnosis of either rapidly progressive sensorineural hearing loss (n = 32). Ménière's disease (n = 41), sudden deafness (n = 6) or other aetiologies of hearing loss (n = 11) were screened by the Western blot technique. Forty-four percent of the patients' sera had antibodies to several inner ear proteins, of which the 30, 42 and 68 kDa proteins were found to be the most reactive. These highly reactive proteins were identified by gas-phase micro sequencing after digestion with trypsin and separation of peptide fragments by high-performance liquid chromatography. A partial sequence of each protein was determined. These data, together with those obtained from 2-dimensional gel electrophoresis followed by Western blotting, demonstrated that the 30 and 42 kDa inner ear proteins are the major peripheral myelin protein P0 and the beta-actin protein, respectively, while sequence analysis indicated that the 68 kDa protein is novel. These findings further support the hypothesis that several populations of antibodies may contribute to the enhanced immunological activity of AIED patients. They also add a new dimension to our knowledge of AIED and may open new avenues in the development of simple serological assays, which are easier to perform and more rapid than Western blotting.

Animals↗

Autoimmune sensorineural hearing loss in young patients: an exploratory study.

OBJECTIVES: P0 protein is expressed exclusively in myelinating Schwann cells of the peripheral nervous system. In a previous study from our laboratory, 27% of patients with sensorineural hearing loss (SNHL) had antibodies to P0 protein in their serum. The purpose of the present exploratory study was to examine the relationship between the clinical presentation of SNHL among children and young adults (age range, 5-30 y) and the presence of serum anti-P0 antibodies. STUDY DESIGN: The data were collected by retrospective questionnaires from Belgian otolaryngologists. METHODS: Patients were divided for comparison into two groups according to the presence or absence of anti-P0 antibodies. RESULTS: Analyses of clinical data and audiometric results indicated that a progressive hearing loss was more frequently recorded in the patients in the anti-P0 antibody-positive group (82% [14 of 17]) than in those in the anti-P0 antibody-negative group (35% [6 of 17]) (P <.005). CONCLUSIONS: Thus, in the age group in the present study, autoimmune SNHL (as measured in the present study by the presence of anti-P0 antibodies) is more frequently associated with progressive than with sudden hearing loss. The implications of this finding for preventive screening of hearing loss in children and young adults are discussed.

Adolescent↗

COCH5B2 is a target antigen of anti-inner ear antibodies in autoimmune inner ear diseases.

OBJECTIVE: This study was designed to identify the 58-kDa inner ear protein against which the sera of some patients with idiopathic, progressive sensorineural hearing loss or Ménière's disease strongly react. BACKGROUND: We and other groups have previously demonstrated that a 58-kDa protein extracted from guinea pig or bovine inner ear tissue is a target of antibodies in serum samples from some patients with autoimmune inner ear diseases. METHODS: After separation of inner ear proteins by 10% sodium dodecyl sulfate polyacrylamide gel electrophoresis, the bands corresponding to 58 kDa were localized and excised from the gel. The concentrated protein was then digested with trypsin, and the peptide fragments were separated by high-pressure liquid chromatography. Three fractions were subjected to amino acid sequencing by the classic Edman degradation. RESULTS: The sequence of a stretch of 14 amino acids of the first fragment was identical to that of amino acids 526 to 539 of the COCH5B2 protein. The sequences of 11 and 10 amino acids of the second and third fragments, respectively, also were identical to residues 417 to 427 and 396 to 405 of the COCH5B2 protein. These data, together with two-dimensional gel electrophoresis followed by Western blot experiments, confirmed that the 58-kDa inner ear protein is the COCH5B2 protein. DISCUSSION: These findings indicate that the 58-kDa target protein of antibodies in serum samples of patients with autoimmune inner ear diseases is the COCH5B2 protein, a molecule that is highly and specifically expressed in the cochlea and vestibule.

Animals↗

Tinnitus and otosclerosis.

Fifty patients with otosclerosis and tinnitus were studied for the course of the tinnitus after stapes surgery. Tinnitus disappeared in 64% of the cases, improved in 16%, was unchanged in 14%, and worsened in 6%. The reduction in tinnitus was more favorable after a small fenestra stapedotomy than after a partial stapedectomy with removal of the posterior half of the footplate. An unfavorable postoperative course of tinnitus did not appear to be linked to the postoperative audiometric result. In our study the subjective evaluation of pitch and loudness of the tinnitus did not provide significant information regarding its prognosis.

Adult↗

Identification of beta-actin as a candidate autoantigen in autoimmune inner ear disease.

It has been shown that sera from patients with autoimmune inner ear disease contain antibodies to several inner ear antigens. We report here the characterization of the 42-43 kDa protein against which a significant number of patients' sera react strongly. After separation of inner ear proteins from guinea-pig cochleas by SDS-PAGE, the band corresponding to the 42-43 kDa protein was digested with trypsin and the peptide fragments were separated by high-performance liquid chromatography. Two fractions were then subjected to amino acid sequencing by the classical automated Edman degradation. The sequence of a stretch of 15 amino acids of the first fragment was identical to that of amino acids 148-162 of beta-actin. The sequence of the 10 amino acids of the second fragment was also identical to beta-actin. On Western blots, monoclonal antibody directed against beta-actin reacted with the inner ear 42-43 kDa proteins. The serum samples from the patients and the monoclonal antibody reacted with the non-muscle actin used as antigen in Western blotting. Immunoblot analysis of inner ear proteins after two-dimensional gel electrophoresis showed a spot, corresponding to the region of the 43 kDa as compared to the protein standards. On the basis of these data it is concluded that the target 42-43 kDa protein for antibodies in sera of patients with autoimmune inner ear disease is beta-actin, a molecule, which has important and numerous functions inside cells. This is the first report to identify the cytoskeletal protein beta-actin as a candidate autoantigen in autoimmune inner ear disease.

Actins↗

Results of cerebellopontine space imaging by magnetic resonance during one year.

The authors present the results of a retrospective study concerning 231 magnetic resonance imaging (MRI) of the cerellopontine space requested by the otologists of the department between September 1996 and September 1997. The motives of imaging were sensorineural hearing loss (44%), vertigo and unsteadiness (25.5%), tinnitus (16.5%) and other (13%). The MRI was abnormal in 18% of the cases and the diagnosis of acoustic schwannoma was made in 10% of the cases.

Belgium↗

[Functional results of velopharyngoplasty: apropos of 55 cases].

From 1991 until 1998, 55 three to twelve year-old patients underwent a velopharyngoplasty to correct velopharyngeal insufficiency. They had indeed severe hypernasality with or without gross reflux of food matter into the nasal cavities or behavioural disturbances. Eighty-two percent had a closed cleft palate. Forty percent presented with mental retardation, heart diseases or multiple syndromal defects. They all had had a previous speech therapy for a long (months) or a very long (years) period of time. In the post operative period, hypernasality disappeared totally or partially in eighty-five percent; reflux disappeared in almost all cases. Middle ear pathologies were not more frequent and were also less severe. Behavioral disturbances associated with a severe speech defect were also less pronounced.

Age Factors↗

Our classification of tympanic retraction pockets.

A classification of tympanic retraction pockets is indispensable in order to standardise their evaluation. In this manner, the evolution of the pathology can be carefully followed and the most appropriate therapy chosen. The authors propose adapting their classification to endoscopy which permits the inspection of the depths of certain pockets, otherwise invisible to examination under microscope, thus ensuring a better follow-up.

Ear Diseases↗

Imaging and cochlear implant.

The auditory pathway imaging may be morphologic and/or functional. The high resolution computed tomography and the magnetic resonance imaging (MRI) provide an evaluation of the anatomical and structural landmarks useful for a safe and successful cochlear implantation. The electrical stimulations supplied by the cochlear implant give rise to ascending electrochemical activities reaching the cortex. These activities can be recorded with scalp electrodes by Evoked Potentials (EP) or fields techniques and eventually translated in isochronic or isopotential brain mapping. These techniques provide a very sharp temporal resolution with an imprecise spatial resolution. The late auditory EP of implantees are closely comparable to the responses of normal hearing people. The neuronal metabolism's increase is associated with a cerebral blood flow increase. Comparing regional cerebral blood flow (rCBF) between two or more conditions allows the localisation of brain areas involved in a fixed task. Single photon or positron emission tomography and functional MRI (fMRI) demonstrate cBF changes associated with an auditory stimulation. (f)MRI is contraindicated in cochlear implantees.

Brain↗

Role of speech therapy and sign language prior to cochlear implantation.

The speech therapist should assess and develop the communication skills of the deaf child prior and after a cochlear implantation. The goals are first the acquisition of a useful communication system by the deaf child (for avoiding a cognitive stimulation lack) and parallely the acquisition of good oral language competencies. The different modes of communication useable in the profoundly deaf education are presented. Exclusive sign language use is not indicated in implanted children. It is well demonstrated that an exclusive oral communication is associated with an insufficient knowledge of the oral language. The total communication (combination of listening, speech reading, signing with or without finger spelling) is a defective communication mode with a bad representation of the morpho-syntactic and the phonologic aspects of the oral language. The best choice seems to be the simultaneously use of a spoken language and a manually coding of their phonological structures. The limits of this alternative are discussed.

Child↗

Cochlear implantation in patients with Cogan's syndrome: a review of four cases.

Cogan's syndrome is a rare disorder that is characterized by a rapid onset of bilateral severe sensorineural hearing loss associated with vertigo and tinnitus, ocular involvement (most commonly an interstitial keratitis) and variable systemic symptoms. We review our experience with four cases treated in our department. We describe their symptoms, the evolution of their disease, the diagnosis, and the radiological investigations with computed tomography and/or magnetic resonance imaging. When medical treatment with corticosteroids failed and no benefit could be obtained with hearing aids at each patient's end stage, all patients received a cochlear implant with excellent results. The considerations for implantation in these patients are discussed.

Adult↗

Use of costal cartilage in middle ear surgery.

Use of costal cartilage in middle ear surgery. Tympanic membrane retraction often occurs in otologic pathology. In an effort to reduce this pathology, the surgical procedure considered incorporates the use of a new material which diminishes retraction and allows freer movement of the eardrum. Since 1991, we have been using costal cartilage allograft obtained from donors and treated to prevent disease transmission. The allografts were used for tympanoplasty, retraction pockets and attic reconstruction. More than 150 patients were treated and the results evaluated in order to determine the indications of this new material.

Cartilage↗