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Biomedical subjects

M Gersdorff

Publications and source records attributed to M Gersdorff.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Limits of the study of early auditory brainstem responses in the diagnoses of childhood deafness].

The author presents the results of his experience concerning brain stem evoked response in children. 122 cases are put forth. It shows that although behavioral audiometry is impossible in 7% of the cases, the BERA (Brain stem Evoked Response Audiology) is not reliable in 26.5% of the treble frequencies and 36% of the bass frequencies. Thus, it is not possible to equip children with hearing aids based on this given alone.

Adolescent↗
PubMed1991

Ossiculoplasty: some physical and physiological considerations.

Numerous techniques and many materials are available to the surgeon for the reconstruction of defects of the tympano-ossicular system. The author would like modestly to recall certain aspects of middle-ear physiology and physics, and the impact that a knowledge of these ought to have in the mind and in the action of a surgeon about to practise an ossiculoplasty. The ideal for an ossiculoplasty would be to respect the ossicular joints, to remember that sound transmission at the level of the footplate falls within the field of quantic mechanics. The stapes transmits sound energy to the inner ear virtually without movement. Let us pay the greatest respect to the malleus and make use of the tympano-mallear complex during ossicular reconstruction. Let us remember that the middle ear is an adaptor for acoustic impedance. Let us respect the resonance frequencies of the ear, by avoiding an increase in the mass with unnecessarily heavy devices, or an increase in the stiffness, and let us seek to have a well-ventilated middle ear and a reconstruction without excessive tension. Let us use materials that are as physiological as possible in the field of impedance and speed of sound transmission. Finally, let us try to reconstitute the most physiological ossicular chain possible, using three ossicles whenever we can, using the malleus and avoiding if possible direct drum footplate contacts.

Acoustics↗
PubMed1990

Long-term results of various surgical treatments for cholesteatoma.

The authors have studied 11 series of results following cholesteatoma surgery by closed or open technique. The closed technique was performed in 77%. The notion of surgical revision is not accepted by all surgeons; it is practised with an average of 59% for the whole series. Residual cholesteatoma and/or recurrences are observed in 34% of the cases of which 20% have been discovered at the time of revision surgery. Surgical revision appears mandatory to the authors.

Cholesteatoma↗
PubMed1989

Bone allografts in reconstructive middle ear surgery.

The authors present their current experience with stored bone grafts, using allografts shaped from the cortices of long bones for reconstructing the tympano-ossicular chain. The materials and the methods are described. The anatomical results have been good in 97% of the cases, while the functional results are as satisfactory as those obtained with bioceramics. In addition to ossiculoplasty, the bone allografts can also be used in otology for reconstructing large bony defects of the temporal bone.

Bone Transplantation↗
PubMed1989

New perspectives on lyophilized bone allografts.

In 1987, at the Congress of Implants in Otology in Venice, Italy, we first presented our experiences with stored lyophilized bone allografts for reconstruction of the tympano-ossicular chain. Since then, we have extended our experiences to include reconstruction of the external bony ear canal, the filling of defects in the mastoid bone, reconstructive nasal surgery and rehabilitation of major bony defects of the face. Additionally, we have tried to improve the preparation of the bony implants used clinically and have started a multicenter collaboration with other European universities.

Bone Transplantation↗
PubMed1989

[Lyophilized homologous bone grafts in middle ear surgery: new perspectives].

The authors share their experience of the use of allografts in the reconstruction of the tympano-ossicular chain. The implants were cut from the cortical substance of the long bone in patients deceased for a maximum of six hours; the donors were tested for syphilis, hepatitis, AIDS, systemic diseases or a neoplasm. These bone allografts were cut to size, degreased, demineralized, frozen and then lyophilized in order to be presented to the surgeon in a sterile container (Bone Bank). The implants were all tolerated well. The anatomical results were satisfactory. Optical microscopic studies showed that the implant was: a) covered with mucosa, b) full of osteoblasts and c) the site of a bone neoformation. Experimental research is currently underway in order to perfect the implant preparation methodology.

Bone Transplantation↗
PubMed1989

[Osseous reconstruction in microsurgery of the middle ear].

The authors report their technique and results about the use of bone allografts in tympano-ossicular reconstruction. They use a mixture of bone dust and fibrin sealant for repairing small bone defects. Furthermore, the results of cavity reconstruction techniques with hydroxylapatite and tricalcium phosphates are compared.

Bone Transplantation↗
PubMed1988

[Cytomegalovirus and acquired congenital deafness].

Cytomegalovirus (CMV) is nowadays a frequent causal agent in pediatric acquired hearing loss and should become the principal one in the next few years. CMV is a herpes like virus. Eighty percent of all adults are carriers of this virus in the salivary glands, without any symptom. In the pregnant women, CMV can act by reactivation and give a placental and foetal infection. The pregnant woman is generally asymptomatic when infected. In the infant, besides death in utero, the CMV can produce two clinical types. Ten percent of the congenitally infected infants presented symptoms at birth. In a quarter of them the clinical picture is a severe ictero-hemorrhagic syndrome with infaust prognosis. Most often the clinical picture is an incomplete syndrome with serious neurological, hepatic, developmental, ophthalmic and auditory sequelae. The subclinical form represents 90% of the infected infants. Normal at birth, about 20% of these develop hypoacusis. During the antenatal period, a rise in titre in serologic examination signals a reactivation of the virus. At birth, the diagnosis is by cytodiagnosis and the identification of specific foetal CMV antibodies. The postnatal diagnosis--the most frequent for the otolaryngologist--is based on the concommitant raised titers in both mother and child and/or the presence of other neurological or ophthalmic signs by the child. The prevention is practically impossible. Many medical treatments are studied and nowadays the follow up of a high risk group seems to remain the best attitude.

Cytomegalovirus Infections↗
PubMed1988

[The MSR-UCL cochlear implant: new adaptations].

The authors describe the further modifications made to the MSR-UCL cochlear implant since its creation in September 85, i.e. the transformation of the MSR-UCL monocanal apparatus into a bicanal implant, and the isolation of the pick-up from the amplifier. The technical and audiophonological advantages of these new adjustments are brought into evidence by the authors.

Cochlear Implants↗
PubMed1987

A clinical correlation between hypozincemia and tinnitus.

We examined a group of 115 patients suffering from tinnitus and have attempted to find a statistically significant correlation between the tinnitus experienced and low blood zinc levels (hypozincemia). No particular correlation could be made between the nature of the tinnitus experienced and hypozincemia except for the continuation of head noises, these being more frequently associated with hypozincemia when they are intermittent. Two hypotheses of pathogenesis are proposed to explain this phenomenon and are based on the importance of zinc to the syntheses of enzymes and proteins.

Adolescent↗