Bulent Serbetcioglu

The protective effect of intratympanic dexamethasone on cisplatin-induced ototoxicity in guinea pigs

Objective The purpose of this study was to investigate the effectiveness of intratympanic dexamethasone injection as a protection agent against cisplatin-induced ototoxicity. Study Design and Setting The four groups of guinea pigs were injected as follows: 1) cisplatin, 2) intratympanic dexamethasone, 3) cisplatin following intratympanic dexamethasone, and 4) cisplatin after intratympanic saline. Before and 3 days following injections, the ototoxic effect was measured with distortion product otoacoustic emissions (DPOAEs). Results The DPOAEs amplitudes and signal-to-noise ratio (SNR) values at 1 to 6 kHz frequencies for group 1 animals after injections significantly decreased over those before injections (P < 0.05). In group 2, there were no significant differences in DPOAE amplitude and SNR values between before and after intratympanic dexamethasone injections (P > 0.05). Considering group 3, there were also no significant differences in DPOAEs amplitudes and SNR values before and after of dexamethasone and cisplatin injections (P > 0.05). Conclusions Intratympanic dexamethasone injection did not cause any ototoxic effect; in contrast, it might have a significant protective effect after cisplatin injection.

The frequency of auditory neuropathy detected by universal newborn hearing screening program

OBJECTIVE Auditory neuropathy/auditory dyssynchrony (AN/AD) has become a well-accepted clinical entity. The combined use of oto-acoustic emissions (OAEs) and auditory brainstem response (ABR) testing in the universal newborn hearing screening (UNHS) has led to the easy recognition of this disorder. Although, we are now able to diagnose AN/AD reliably, little is known about its epidemiology, etiology, and especially the frequency of its occurrence. The primary goal of this study was to determine the frequency of AN/AD in the Western Anatolian region of Turkey. The secondary goal was to compare the detection rate of AN/AD before and after the implementation of the UNHS in the audiology department of Dokuz Eylul University Hospital. METHOD Between 2005 and 2007, among the 23,786 newborns who were screened by automated click evoked oto-acoustic emissions (a-CEOAE) and automated auditory brainstem responses (a-ABRs), 2236 were referred to our department. All necessary audiological tests were performed for all the referred newborns. Among them, babies with deficient or abnormal ABR in combination with normal OAEs were considered as having AN/AD. These babies were evaluated with additional diagnostic audiological tests. Furthermore, comparison of the incidence of children diagnosed with AN/AD before and after the implementation of UNHS in our audiology department was also performed. RESULTS Among the referred newborns, 65 had abnormal or deficient ABR test results. Ten of these 65 newborn babies (mean diagnostic age: 5.7 months) with hearing impairment showed electrophysiological test results that were consistent with AN/AD. The frequency of AN/AD in these 65 children with hearing loss was 15.38%. Moreover, the frequency of AN/AD within UNHS was found to be 0.044%. Seven of the 10 babies with AN/AD had hyperbilirubinemia as a risk factor, which is a high rate to be emphasized. On the other hand, the retrospective investigation of children diagnosed with AN/AD in the same audiology department between 1999 and 2005 (i.e. before the implementation of UNHS) revealed only 7 children, with an average diagnostic age of 34 months. CONCLUSION After implementing the UNHS, the incidence of AN/AD in the audiology department increased from 1.16 to 4.13. Furthermore, the age of diagnosis of AN/AD decreased from 34 months to 5.7 months. This study shows that AN/AD, when screened, is a comparatively common disorder in the population of hearing-impaired infants. While newborn hearing screening provides early detection of babies with hearing loss, it also helps to differentiate AN/AD cases when the screening is performed with both a-ABR and automated oto-acoustic emission (a-OAE) tests. Thus, the routine combined use of a-ABR and a-OAE tests in UNHS programs, especially for the high-risk infants, can provide better detection of newborns with AN/AD. Furthermore, hyperbilirubinemia is merely an association and maybe etiologically linked.

Investigation of topical ciprofloxacin ototoxicity in guinea pigs.

Antibiotic eardrops mostly contain potentially ototoxic aminoglycosides. Ciprofloxacin is an alternative, and there is limited experience in its topical use. To investigate the topical ototoxicity of ciprofloxacin, 11 guinea pigs have been operated on. Transbullae silicone drug delivery tubes were placed to both ears of the animals. After the operation the guinea pigs were divided into two groups. The first group of animals received 0.2 ml of 4% gentamicin in one ear and 0.2 ml of 0.9% sodium chloride solution in the other. The second group received 0.2 ml of 0.2% ciprofloxacin in the test ear and 0.2 ml of 0.9% sodium chloride solution in the control ear. All drugs were given once a day on 7 consecutive days. Auditory brainstem response thresholds were recorded using click, 4 and 8 kHz logon stimuli before and after the operation, and after topical drug application. Results were statistically compared using Wilcoxon matched pairs signed-ranks test. Comparison of the thresholds before and after the operation, physiological saline application, as well as ciprofloxacin application yielded no statistically significant differences, whereas application of gentamicin resulted in total hearing loss. The results indicate that topical use of 0.2% ciprofloxacin is not ototoxic in guinea pigs.

Discussion of the dizziness handicap inventory

PURPOSE A review of the Dizziness Handicap Inventory (DHI). NUMBER OF STUDIES: Seventy-four studies. MATERIALS/METHODS Articles published between January 1990 and May 2012 were identified by searches in PubMed electronic database. Of the 227 articles meeting the inclusion criteria 74 were reviewed. These articles are discussed under nine topics; Reliability, validity and internal consistency of the original version of DHI, relationship between vestibular/balance tests and DHI, association between DHI and the other scales related to balance impairments, exploratory factor analysis of the DHI, screening version of DHI, translations of DHI into other languages, the role of DHI to assess the success of the treatment of balance disorder, DHI results in various vestibular disorders, general characteristics of DHI in patients with balance impairment. CONCLUSIONS Self reported measures represent unique pieces of the information important for the management of dizzy patients. DHI is the most widely used self reported measurement of patients with dizziness. It has been translated into fourteen languages, so it is widely accepted.

Protective effect of acetyl‐l‐carnitine against cisplatin ototoxicity: role of apoptosis‐related genes and pro‐inflammatory cytokines

Cisplatin is an anti‐neoplastic agent treatment with which causes many side effects including ototoxicity. The aim of this study was to investigate whether acetyl‐l‐carnitine would have protective effects on cisplatin‐induced ototoxicity in vitro, and if present, to reveal roles of apoptotic gene expressions and pro‐inflammatory cytokines.

Evaluation of the Effect of Acetyl L-Carnitine on Experimental Cisplatin Ototoxicity and Neurotoxicity

Introduction: Cisplatin (CDDP) is an effective and widely used chemotherapeutic agent for pediatric tumors, and ototoxicity is one of the dose-limiting side effects. Objective: It was the aim of our study to investigate the effect of acetyl L-carnitine (ALCAR) on experimental CDDP ototoxicity by audiologic tests, histomorphologic, immunohistochemical and ultrastructural examinations and to investigate the apoptotic pathways. Materials and Methods: Wistar albino rats (n = 28) were studied. Baseline audiological tests were performed in 4 groups: group 1, control; group 2, ALCAR; group 3, CDDP; group 4, CDDP + ALCAR-administered rats. Control audiological tests were performed on the 3rd day, and then the rats were sacrificed. Ear and brain specimens were examined by transmission electron microscopy, and caspase 3, 8 and 9 activities were investigated. Results: The CDDP-administered rats showed significant auditory brainstem response threshold shifts using all stimuli (clicks, 6-kHz and 8-kHz tone burst) compared with the control groups. The CDDP + ALCAR-administered rats showed significant auditory brainstem response threshold shifts by only click stimuli compared with the control groups. In the brain, spiral ganglion and organ of Corti, ultrastructural damage was prominent in group 3; the number of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling)-positive cells and caspase 3, 8 and 9 immunostaining cells was significantly high in group 3. Conclusion: ALCAR improves CDDP-induced auditory impairment, and also antioxidative and antiapoptotic properties of ALCAR on CDDP ototoxicity were supported by the findings.

Friend or foe? Effect of oral resveratrol on cisplatin ototoxicity

Our objectives were to study effects of orally administered resveratrol (RV) against cisplatin (CDDP) ototoxicity in different doses and to investigate ultrastructural changes in the cochlea and brainstem.

Results of multiple-frequency tympanometry measures in normal and otosclerotic middle ears

Tympanometry is a non-invasive, quick, and inexpensive method for examining the middle-ear function. Its limited value in differentiating otosclerotic from normal middle ears caused researchers to develop new methods for evaluation of middle ears. Resonant frequency had been found to be higher in otosclerotic middle ears than normals. We conducted multiple-frequency tympanometry measurements in 25 surgically confirmed otosclerotic ears and 100 normal ears. Mean middle-ear resonant frequency for the otosclerotic group was found to be 1190 Hz and mean middle-ear resonant frequency of the control group was 934.6 Hz (p<0.001). With a cut off value of 1025 Hz (based on 95% confidence interval), sensitivity was 80% and specificity was 82%. The present findings confirm the advantage of the resonant frequency estimation over conventional tympanometry in detecting middle-ear status and mechanics in patients with otosclerosis. As a conclusion, detecting resonant frequency when evaluating patients for otosclerosis must be an essential part of examination. Nevertheless, further investigation is necessary for better diagnosis of otosclerosis preoperatively.

Features of unilateral hearing loss detected by newborn hearing screening programme in different regions of Turkey.

OBJECTIVE Newborn hearing screening (NHS) works well for babies with bilateral hearing loss. However, for those with unilateral loss, it has yet to be established some standard rules like age of diagnose, risk factors, hearing loss degree. The aim of this study is to identify the demographic characteristics of newborns with unilateral hearing loss to obtain evidence based data in order to see what to be done for children with unilateral hearing loss (UHL). METHOD Newborn hearing screening data of 123 babies with unilateral hearing loss, 71 (57.7%) male and 52 (42.3%) female, were investigated retrospectively. Data provided from the archives of six referral tertiary audiology centers from four regions in Turkey. Data, including type of hearing loss; age of diagnosis; prenatal, natal and postnatal risk factors; familial HL and parental consanguinity was analyzed in all regions and each of the Regions 1-4 separately. RESULT The difference between data obtained in terms of gender and type of hearing loss was detected as statistically significant (p<0.05). While UHL was significantly higher in females at Region 1, and in males at other Regions of 2-4; SNHL was the most detected type of UHL in all regions with the rate of 82.9-100.0%. There were not significant differences between regions in terms of the degree of hearing loss, presence of risk factors, family history of hearing loss, age at diagnosis and parental consanguinity (p>0.05). Diagnosis procedure was completed mostly at 3-6 months in Region 4; whereas, in other regions (Regions 1-3), completion of procedure was delayed until 6 months-1 year. CONCLUSION This study indicates that the effect of postnatal risk factors, i.e. curable hyperbilirubinemia, congenital infection and intensive care is relatively high on unilateral hearing loss, precautions should be taken regarding their prevention, as well as physicians and other health personnel should be trained in terms of these risks. For early and timely diagnosis, families will be informed about hearing loss and NHS programme; will be supported, including financial support of diagnosis process. By dissemination of the NHS programme to the total of country by high participation rate, risk factors can be determined better and measures can be increased. Additionally, further studies are needed with more comprehensive standard broad data for more evidence based consensus.

Cochlear implantation in neurobrucellosis.

Objective: To report the first successful cochlear implantation (CI) in neurobrucellosis. Patient: A patient with bilateral total sensorineural hearing loss and other neurologic sequela due to neurobrucellosis from a country in which the disease is epidemic was successfully rehabilitated with CI. Interventions: Clinical, laboratory, radiodiagnostics, and audiological. Main Outcome Measures: Sensorineural hearing loss due to neurobrucellosis may be the result of an injury anywhere along the auditory pathway, and candidacy for CI should be thoroughly evaluated and promontory stimulation test seems to be most helpful in this regard. Results: Cochlear implantation may be successful in patients with sensorineural hearing loss due to neurobrucellosis. Conclusion: Positive promontory stimulation test is useful for selecting patients for CI deafened by neurobrucellosis.