Shi Nae Park

Comparison of Cochlear Morphology and Apoptosis in Mouse Models of Presbycusis

OBJECTIVESnMorphological studies on presbycusis, or age-related hearing loss, have been performed in several different strains of mice that demonstrate hearing loss with auditory pathology. The C57BL/6 (C57) mouse is a known model of early onset presbycusis, while the CBA mouse is characterized by relatively late onset hearing loss. We performed this study to further understand how early onset hearing loss is related with the aging process of the cochlea.nnnMETHODSnWe compared C57 cochlear pathology and its accompanying apoptotic processes to those in CBA mice. Hearing thresholds and outer hair cell functions have been evaluated by auditory brainstem response (ABR) recordings and distortion product otoacoustic emission (DPOAE).nnnRESULTSnABR recordings and DPOAE studies demonstrated high frequency hearing loss in C57 mice at P3mo of age. Cochlear morphologic studies of P1mo C57 and CBA mice did not show differences in the organ of Corti, spiral ganglion, or stria vascularis. However, from P3mo and onwards, a predominant early outer hair cell degeneration at the basal turn of the cochlea in C57 mice without definitive degeneration of spiral ganglion cells and stria vascularis/spiral ligament, compared with CBA mice, was observed. Additionally, apoptotic processes in the C57 mice also demonstrated an earlier progression.nnnCONCLUSIONnThese data suggest that the C57 mouse could be an excellent animal model for early onset sensory presbycusis in their young age until P6mo. Further studies to investigate the intrinsic or extrinsic etiologic factors that lead to the early degeneration of organ of Corti, especially in the high frequency region, in C57 mice may provide a possible pathological mechanism of early onset hearing loss.

Clinical experience of 71 cases of congenital middle ear cholesteatoma.

Conclusions. As congenital middle ear cholesteatoma (CMC) is a different disease entity from acquired cholesteatoma, early diagnosis is important for good treatment results. Preoperative computed tomography (CT) imaging is a useful modality for both evaluation of the extent of the disease and selection of appropriate surgical methods. Some modification should be considered based on the findings of the actual operative field for complete removal of CMC. Objectives. To present the results of surgical treatment of 71 cases of CMC and investigate the applicability of preoperative CT for the treatment of CMC. Patients and methods. A retrospective study over an 11-year period was performed. The presenting symptoms, tympanic membrane findings, surgical findings, methods, and results were investigated retrospectively. Results. CMC was found incidentally in 38 cases (53.5%). A whitish mass medial to the tympanic membrane was observed in 62 cases (87%). Postoperative air–bone gap changes were not statistically significant. There was no predominance of localized lesions of the middle ear. The recurrence rate was 9.9% (seven cases), and higher in open type. Staging by CT and surgical staging matched in 70.4%. Positive predictive value for mastoid involvement of CT staging was 72.7%, with sensitivity and specificity of 68.6% and 87.5%, respectively.

Effect of Nitric Oxide and Peroxynitrite on Mucociliary Transport Function of Experimental Otitis Media

OBJECTIVES: To determine the role of nitric oxide (NO) and peroxynitrite on mucociliary activity in experimental otitis media with effusion (OME). STUDY DESIGN AND SETTING: Twenty guinea pigs were divided into 1 control and 3 experimental groups; lipopolysaccharide (LPS), NG -nitro-L-arginine methyl ester (L-NAME), and uric acid (UA) groups. Ten ears were used in each group. OME was induced by transtympanic injection of LPS in experimental groups. Twenty-four hours after the transtympanic injection, dye transfer time (DTT) was measured and the temporal bone was taken for histopathologic examination. Expression of peroxynitrite was determined by immunohistochemical stain for 3-nitrotyrosine (3-NT). RESULTS: Dye transfer time was significantly delayed in LPS group compared to control group; by contrast it was significantly reduced in L-NAME or UA treated groups (P < 0.01). Histopathologic examination showed reduced inflammation and mucosal thickening in the treatment groups when compared to LPS group. These findings, however, were not statistically significant. Immunoreactivity to 3-NT was intense in LPS group and decreased in the treatment groups (P < 0.05). CONCLUSIONS: It is suggested that LPS induced mucociliary dysfunction in the middle ear by NO and peroxynitrite-mediated pathways.

Renexin as a rescue regimen for noise-induced hearing loss

Renexin, a compound of cilostazol and ginkgo biloba extract, has been reported to produce neuroprotective effects through antioxidant, antiplatelet, and vasodilatory mechanisms. This study was designed to investigate the protective effects of renexin on hearing, the organ of Corti (OC), and medial olivocochlear efferents against noise-induced damage. C57BL/6 mice were exposed to 110 dB SPL white noise for 60 min and then randomly divided into three groups: high- and low-dose renexin-treated groups and noise only group. Renexin were administered for 7 days: 90 mg/kg to the low-dose, and 180 mg/kg to the high-dose groups. All mice, including the controls underwent hearing tests on postnoise day 8 and were killed for cochlear harvest. We compared the hearing thresholds and morphology of the OC and cochlear efferents across the groups. The renexin-treated groups recovered from the immediate threshold shifts in a dose-dependent manner, while the noise group showed a permanent hearing loss. The renexin-treated ears demonstrated less degeneration of the OC. The diameters of the efferent terminals labeled with α-synuclein were preserved in the high-dose renexin-treated group. In the western blot assay of the cochlear homogenates, the treated groups displayed stronger expressions of α-synuclein than the noise and control groups, which may indicate that noise-induced enhanced activity of the cochlear efferent system was protected by renexin. Our results suggest that pharmacologic treatment with renexin is hopeful to reduce or prevent noise-induced hearing loss as a rescue regimen after noise exposure.

Clinical and audiologic characteristics of patients with sensorineural tinnitus and its association with psychological aspects: an analytic retrospective study

This study was performed to analyze clinical and audiologic characteristics of sensorineural tinnitus and to investigate the associating factors reflecting psychological aspects of stress and depression of the patients. This is a retrospective analytical study conducted in a tinnitus clinic of a tertiary referral center of a university hospital. The medical records of 216 patients suffering from sensorineural tinnitus were thoroughly evaluated to determine correlations between clinical and audiological characteristics, including age, sex, predisposing or etiologic factors, hearing levels up to extended high frequencies, and tinnitus severity. Psychological aspects of stress and depression were also evaluated and analyzed to seek the associations with tinnitus severity. All data were stored in our database bank and were statistically analyzed. Our study subjects showed a slight male predominance. The highest percentage of tinnitus was found in patients of 60–80xa0years old. Only 32.5xa0% of tinnitus patients were subjectively aware of their hearing loss, whereas 73xa0% of subjects had hearing deficits in some frequencies in their audiogram. Hearing impairments were of the low-frequency sensorineural type in 18.2xa0% of patients and were limited to the high frequencies in 77.9xa0% of patients. Tinnitus was unilateral in 51xa0% of patients and had a tonal nature in 45xa0% of patients. In total, 45.8xa0% of patients with high-frequency sensorineural hearing loss had high-pitched tinnitus. There were significant correlations between tinnitus severity, loudness and annoyance. Correlations with THI (Tinnitus Handicap Inventory) and Beck depression index scores were also found. Sensorineural tinnitus was related with hearing loss in some frequencies nevertheless of patients’ own awareness of hearing loss. Loudness and annoyance of tinnitus seems to be two important factors reflecting psychological problems of patients’ stress and depression.

Pulsatile Tinnitus as the Sole Manifestation of an Internal Carotid Artery Aneurysm Successfully Treated by Coil Embolization

Pulsatile tinnitus is tinnitus that coincides with the patients heartbeat. It constitutes a small portion of all tinnitus, but it is often the first or sole manifestation of a serious disease in the nervous system. Aneurysm of the internal carotid artery is known as a rare cause of pulsatile tinnitus and, in the main, aneurysms of the petrous portion have been reported as a cause of pulsatile tinnitus. We present an interesting case of pulsatile tinnitus that was caused by a paraclinoid aneurysm in this report and discuss clinical features and treatment of paraclinoid aneurysm.

Palatal Myoclonus Associated with Orofacial Buccal Dystonia.

Palatal myoclonus is a rare condition in which there are rhythmic jerky movements of the soft palate and sometimes of the other muscles innervated by the brainstem A particularly annoying symptom is a rhythmic clicking sound in the ear due to the opening and closing of the Eustachian tube. Orofacial buccal dystonia is a focal dystonia with sustained spasms of the masticatory, facial or lingual muscles. The frequent symptoms of this disease have mainly been reported to be involuntary and possibly painful jaw opening, closing, deflecting and retruding, or a combination of the above. However, the subtle and unnoticeable involuntary movement of multiple facial muscles, which might be an infrequent symptom of orofacial buccal dystonia, makes this disease hard to diagnose. Understanding the functional orofacial anatomy that is responsible for the clinical signs and symptoms is necessary for making a proper diagnosis. Here we report on a rare case of palatal myoclonus that was associated with orofacial buccal dystonia, and such a case has not been previously reported. We describe the diagnostic approach and excellent treatment results after Botulinum toxin A (Dysport) injection and proper counseling.

Cavernous sinus thrombophlebitis secondary to petrous apicitis: A case report

Septic inflammation and thrombosis of the cavernous sinus were fatal during the preantibiotic era, but after the introduction of antibiotics, the incidence of septic cavernous thrombophlebitis diminished significantly.1 However, septic cavernous thrombophlebitis remains a serious disease and is accompanied by high morbidity and mortality rates. A high index of suspicion and the aggressive initiation of treatment are of utmost importance in the prognosis. We present a case of cavernous sinus thrombophlebitis secondary to petrous apicitis that was diagnosed with magnetic resonance imaging (MRI). Septic thrombus resolution and complete recovery of sixth nerve palsy were achieved after treatment with antibiotics and steroids accompanied by tympanotomy tube placement.

Characterization of tinnitus in different age groups: A retrospective review.

Objectives: The aim of this study was to characterize tinnitus in affected patients. Methods: A retrospective review of medical records from 470 consecutive patients who visited a tertiary care hospital for evaluation of chronic subjective tinnitus between January 2009 and June 2010 was performed. Patients were divided into three subgroups based on age. Clinical, audiological, and psychological characteristics of each subgroup were analyzed. Results: Of the 470 patients evaluated, 85 were less than 40, 217 between 40 and 60, and 168 above 60 years of age. Most patients were men and complained of unilateral, acute high-pitched tinnitus. Most patients above the age of 40 years complained of loud and annoying tinnitus and had worse stress and severity scores. Conclusions: Chronic tinnitus in older adults is subjectively louder, more annoying, and more distressing than that found in younger patients. We recommend considering age in the patient management plan.

Cochlear function tests in estimation of speech dynamic range.

Abstract Objectives: The loss of active cochlear mechanics causes elevated thresholds, loudness recruitment, and reduced frequency selectivity. The problems faced by hearing-impaired listeners are largely related with reduced dynamic range (DR). The aim of this study was to determine which index of the cochlear function tests correlates best with the DR to speech stimuli. Methods: Audiological data on 516 ears with pure tone average (PTA) of ≤55u2009dB and word recognition score of ≥70% were analyzed. PTA, speech recognition threshold (SRT), uncomfortable loudness (UCL), and distortion product otoacoustic emission (DPOAE) were explored as the indices of cochlear function. Audiometric configurations were classified. Correlation between each index and the DR was assessed and multiple regression analysis was done. Results: PTA and SRT demonstrated strong negative correlations with the DR (ru2009=u2009−0.788 andu2009−0.860, respectively), while DPOAE sum was moderately correlated (ru2009=u20090.587). UCLs remained quite constant for the total range of the DR. The regression equation was Y (DR)u2009=u200975.238u2009−u20090.719u2009×u2009SRT (R2u2009=u20090.721, pu2009<u20090.001). The other variables such as audiometric configurations and DPOAE sum were excluded from the final model. Conclusion: SRT was the most predictive of the DR among the indices of the cochlear function tests. A reduced DR in cochlear hearing loss was the product of an elevated audiometric threshold and a relatively constant UCL level. The results enable prediction of the DR from SRT and possibly PTA using the suggested regression equation.