Abstract Otology 2000 B16-1

Rudolf Kuhweide Dr.med., Geert Vanhooren Dr.med., Jan W. Casselman Dr.

ENT Department AZ St.Jan Hospital B-Brugge

Low-frequency sensorineural hearing loss and tinnitus have recently been recognized as a mostly temporary complication after lumbal puncture, myelography or spinal anesthesia. The presumed mechanism involves a persistent cerebrospinal fluid leak from the dural puncture site and a patent cochlear aqueduct, which transmits the intracranial hypotension to the inner ear. The lowering of the perilymphatic pressure relative to the endolymphatic pressure would induce a compensatory elevation of the endolymphatic pressure, resulting in a clinical picture of cochlear Ménière's disease. Spontaneous intracranial hypotension is a rare condition with less than a hundred cases reported, limited to the neurological literature. As gadolinium-enhanced MRI reveals a striking and initially perplexing meningeal enhancement, it is being increasingly diagnosed. The accepted pathogenic hypothesis is a minor trauma- or pressure-related cerebrospinal fluid leak from a spinal meningeal defect. It characteristically induces postural headache. Associated symptoms include postural tinnitus, vertigo and hearing loss. Treatment is empirical with emphasis on strict bed rest. In the majority the disease is self-limiting, reserving epidural blood patching or saline infusion for refractory cases. We believe the following case of spontaneous intracranial hypotension to be unique, in that it is - to the best of our knowledge - the first one reported to the otolaryngologic community, that the patient presented with ear symptoms rather than headache, and that by using her audiogram (peak-type) we can complete the neurological literature and clarify the ear symptoms by postulating a mechanism similar to the one seen in post dural puncture endolymphatic hydrops.

Abstract Otology 2000 B16-2

Gregor Bachmann Dr.med., Jiping Su Dr.med., Christoph Zumegen Dr.med., Claus Wittekind Dr.med., Olaf Michel MD

HNO-Klinik Universität D-Köln

Prednisolone is the drug of first choice for the treatment of acute cochleovestibular disorders, such as sudden hearing loss. By intravenous administration, the drug efficient levels to be achieved in inner ear fluids are limited. Aim of the study was to determine the concentration of prednisolone-21-succinate in the perilymph, which was applied on the round window membrane. Levels of prednisolone-21-succinate in perilymph of the guinea pig were measured by isocratic HPLC. Variable was the time between application to the round window and taking specimens of perilymph from the cochlea. Application of prednisolone (5 mg in 0.1 ml) to the round window membrane was performed in anesthesia under microscopic view. Specimens of perilymph were obtained after 15, 20, 80, 180, 330 and 960 min (each group 10 specimens, n=60) by dissecting the cochlea and opening the apex cochleae. The highest levels of prednisolone-21-succinate were found after 180 min 952.3 mg/l (95% confidence interval: 382.7). After 960 min the level was 18.72 mg/l (95% confidence interval: 16.9). The results demonstrate that high levels of prednisolone-21-succinate in perilymph are achievable by local application of a single dose. Therefore, a selective therapy of the inner ear using prednisolone-21-succinate is possible by application to the round window membrane.

Abstract Otology 2000 B16-3

Alexis Bozorg Grayeli MD, P. Palmer MD, Patrice Tran Ba Huy MD, J. Soudant MD, Olivier Sterkers MD, P. Lebon MD, E. Ferrary MD, PhD

INSERM U. 426 Faculté Xavier Bichat Université Paris 7 F-Clichy

The hypothesis of a persistent infection by the measles virus in otosclerosis has been postulated based on electron microscopy observations, immuno-histochemical studies, and PCR techniques. The aim of the present work was to confirm the role of the measles virus in the etiology of otosclerosis. Pathologic stapes samples were obtained from 36 patients suffering from otosclerosis. The measles virus detection was realised by: i. assessment of cytopathogenic effect during 4 weeks in cocultures of VERO (monkey kidney) cells and primary cell cultures of bone samples (n=6), ii. immunohistochemical study of these cocultures (n=3) using monoclonal antibodies against measles virus and other paramyxovirus, iii. reverse transcription and polymerase chain reaction (RT-PCR) on RNA directly obtained from fresh frozen samples (n=30) and on RNA extracted from cultures (n=2). For each sample, two different viral genomic regions coding for N protein (nucleoprotein) and M protein (matrix) were amplified by separate PCR. These amplified regions are known to be highly conserved in different acute and persistent infection strains. PCR sensitivity tests were realised on an Edmondson B laboratory strain yielding 0.1 TCID50 for the protein M and 0.01 TCID50 for the protein N. A single step PCR amplifying GAPDH, an ubiquitous enzyme, was used as positive control. Southern-blot assays were performed on PCR products to enhance sensitivity and specificity. We could not evidence the presence of the measles virus in any of our 36 stapes samples by the different methods described. Our observations do not confirm the hypothesis of persistent measles virus infection in otosclerosis. This work was supported by a research grant from Synthélabo, Meudon-la-Forêt, France.

Abstract Otology 2000 B16-4

Poul Bretlau DMSc, MD

Dept. of Oto-laryng, Head & Neck S. Univ. Hosp. Rigshospitalet DK-Copenhagen

Clinical results in 85 Argon-laser stapedotomies and 48 Erbium-YAG-laser stapedotomies are evaluated with special attention to high tone hearing loss at 4 kHz and 8 kHz. Closure of the Air-Bone gap in 20 dB was 98% resp. 90% in the two groups with a more pronounced high tone hearing loss in the Erbium-Yag-laser treated group. Sound pressure measurements at the footplate level indicate noise induced high tone hearing loss using the Erbium-YAG-laser.

Abstract Otology 2000 B16-5

Dusan R. Milisavljevic MD, Zare Rankovic Dr., Ljiljana Milisavljevic MD, PhD, Milan Stankovic MD, PhD, Zoran Dimic MD, Zoran Radovanovic MD

University Clinic of ENT YU-Nis

Hearing loss is one of the serious complications of bacterial meningitis. The bacterial organisms most commonly associated with generalized meningitis having a sensorineural hearing loss sequela are Streptococcus pneumonia, Haemophilus influenzae, Streptococcus pyogenes, in most cases sensory neural hearing loss is bilateral and severe to profound. The audiometry and tympanometry were used to detect this complication in fifteen patients who recovered from meningitis treated at the Clinic for infectious diseases and Otolaryngology Clinic Nis in the last year. Out of 15 patients 6 were infected by Pneumococcal, 4 with H. Influenzae, 2 with Listeria and 3 with Meningecoccal. There was a high incidence of Streptococcus and H. Influenza meningitis which resulted in high incidence of hearing impairment. The degree of hearing loss was varied from mild to profound. Out of 15 patients six patients had mild hearing loss (25 to 40dB), 4 had moderate (40 to 55 dB), 2 moderately-severe (55 to 70 dB) and 3 very severe hearing loss (70 to 100 dB). The nature of antibiotic therapy, duration of illness, age and sex of patients were not significant risk factors in the development of hearing loss. The site of disease resulting in hearing loss cannot be stated with certainty, but the involvement of the inner ear or auditory nerve was suspected. Early hearing loss in purulent meningitis does not always constitute an irreversible lesion. Bacterial meningitis is the single most important cause of acquired sensorineural hearing loss in patients and every attempt should be made to assess the patients hearing as soon after their recovery possible.