Vestibular Histopathology in Temporal Bone / 대한평형의학회지

There are a number of reports on the pathologies of vestibular disorders. However, these studies included only a few examples, which were not quantitative but merely anecdotal or descriptive. However, a single tissue section may be relevant to a specific disease in multiple ways. The histopathological characteristics of common peripheral vestibulopathies, including benign paroxysmal positional vertigo, Ménière's syndrome, labyrinthitis, vestibular neuritis, and ototoxicity, have been described. A recent study validated a new quantitative method for determining vestibular otopathology. Detailed quantitative analyses of vestibular pathology are required to obtain a deeper understanding of the vestibular system. Such studies will likely reveal the pathophysiological causes of specific diseases by elucidating the correlations between structural and functional features. Therefore, histopathological studies of vestibular disorders should be performed.

Bacterial Meningitis Initially Presenting as Labyrinthitis / 대한평형의학회지

Labyrinthitis causes damage to inner ear structure, and in turn hearing loss and vertigo. Labyrinthitis is classified as otogenic labyrinthitis and meningogenic labyrinthitis. Otogenic labyrinthitis can be diagnosed early through otoscopic examination. However, when there are no characteristic neurologic symptoms in patients with meningogenic labyrinthitis, clinicians can overlook the underlying meningitis and this may lead to the peripheral vertigo. We encountered an unusual case of meningogenic labyrinthitis that is misdiagnosed as peripheral dizziness.

Recent Research Trend for Ménière's Disease / 대한평형의학회지

Ménière's disease is a poorly understood disorder of the inner ear characterized by intermittent episodic vertigo, fluctuating hearing loss, ear fullness and tinnitus. In this paper, we present a review of the histopathology, cytochemistry, gene, blood-labyrinthine barrier and imaging of Ménière's disease. Histopathology is significant for neuroepithelial damage with hair cell loss, basement membrane thickening, perivascular damage and microvascular damage. Cytochemical alterations are significant for altered AQP4 and AQP6 expression in the supporting cell, and altered cochlin and mitochondrial protein expression. Since the discovery of aquaporin water channels (AQP1, AQP2, AQP3, AQP4, AQP5, AQP6, AQP7 and AQP9), it has become clear that these channels play a crucial role in inner ear fluid homeostasis. Several gene studies related to Ménière's disease have been published, but there is no clear evidence that Ménière's disease is associated with a special gene. Currently, imaging techniques to determine the extent and presence of endolymphatic hydrops are being studied, and further studies are needed to correlate the visualization of the endolymphatic hydrops with clinical symptoms.

Foreign Body of External Auditory Canal: Review of 170 Cases / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Foreign bodies in the external auditory canal (EAC) are frequently encountered by otolaryngologists, emergency care physicians and pediatricians. The purpose of this study was to assess clinical characteristics, complications, as well as to investigate the proper management of foreign bodies in the EAC. SUBJECTS AND METHOD: We retrospectively reviewed and analyzed clinical records of patients who presented with foreign bodies in the EAC at the otolaryngologic department of Keimyung University Dongsan Hospital from January, 2011 to October, 2016. RESULTS: One-hundred seventy patients with aural foreign bodies were identified. The age of patients ranged from 12 months to 83 years, with 34.1% of the patients being under 10 years of age. Thirteen different types of foreign bodies were found, where insects, cottons and beads were the most common. Approximately 98% of the foreign bodies were removed without general anesthesia by using proper instruments under direct vision. Complications were observed in 5.8% of the patients: these included laceration and bleeding from the EAC (80%) and traumatic perforation of the tympanic membrane (20%). CONCLUSION: Various methods are available for foreign body removal from the EAC. In order to remove foreign bodies successfully and reduce complications, patients should be given precautions, such as, regarding adequate immobilization, prior to removing foreign bodies using proper instruments with a surgical microscope under appropriate anesthesia.

Vestibular Paroxysmia Mimicking Benign Parxysmal Positional Vertigo / 대한평형의학회지

Vestibular paroxysmia is the name given to the syndrome caused by vascular compression of the vestibulocochlear nerve. The main symptoms of vestibular paroxysmia are recurrent, spontaneous, brief attacks of spinning, non-spinning vertigo or positional vertigo that generally last less than one minute, with or without ear symptoms (tinnitus and hypoacusis). Prior to attributing a patient's symptoms to vestibular paroxysmia, however, clinicians must exclude common conditions like benign paroxysmal positional vertigo, Menière's disease, vestibular neuritis and vestibular migraine. This is usually possible with a thorough history and bedside vestibular/ocular motor examination. Herein, we describe a patient with vestibular paroxysmia that mimicked resolved BPPV with a literature review.

Medications as Risk Factor for Falls / 대한평형의학회지

Falls are the most common cause of accidents among the older population, leading to both fatal and non-fatal injuries. Falls is a syndrome resulting from the cumulative effect of various extrinsic and intrinsic factors. It is considered to be a multifactorial disorder. Medication use is considered a risk factor for falls. We reviewed medications associated with falls in older individuals. In geriatrics populations, polypharmacy is associated with falls. Medical doctors should be aware of the possibility that starting a new medication, such as antihypertensive agents, benzodiazepine, antidepressants, opioid agents and antihistamines, may act as a trigger for the onset of a fall.

The Value of PROPELLER Diffusion-Weighted Image in the Detection of Cholesteatoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: This study was to done to determine the value of PROPELLER diffusion-weighted imaging in detecting cholesteatoma. SUBJECTS AND METHOD: Sixty-five patients were evaluated by preoperative magnetic resonance imaging (MRI) with PROPELLER diffusion-weighted imaging. Of 65 patients, 16 patients had chronic otitis media without cholesteatoma and 49 patients with cholesteatoma. Surgical and pathologic findings were compared with the preoperative findings by PROPELLER diffusion-weighted imaging to assess the sensitivity, specificity, positive and negative predictive values. RESULTS: In 49 patients with cholesteatoma, high signal intensity compatible with cholesteatoma was found in 46 patients, whereas in 16 patients without cholesteatoma, high signal intensity was not detected in any of them. The sensitivity, specificity, positive and negative predictive values for PROPELLER diffusion-weighted imaging were 94.1%, 100%, 100%, and 84.2%, respectively. CONCLUSION: PROPELLER diffusion-weighted imaging can be a useful tool in detecting cholesteatoma.

A Case of Two Isolated Congenital Cholesteatomas Presented in Middle Ear Cavity / 대한이비인후과학회지

Middle ear cholesteatoma is considered to be congenital in origin when there is an intact tympanic membrane with no prior history of otorrhea, tympanic perforation or otologic procedure. However, congenital cholesteatoma is a relatively rare disease entity for which a variety of theories regarding its pathogenesis have been suggested as follows: epidermoid formation, migration of squamous epithelium, implantation, metaplasia, and acquired inclusion theory. However, the pathogenesis of congenital cholesteatoma remains unclear. There are two pathologic types of congenital cholesteatoma, "closed" and "open". We present a rare case of congenital cholesteatoma arising from middle ear cavity in a condition of two completely isolated closed congenital cholesteatomas, which were successfully removed via transcanal approach. Also we review the literature and discuss the theories on the development of two separate congenital cholesteatomas.

Objective Tinnitus Concomitant with Eye Blinking: A Case Report

Tinnitus is a common auditory phenomenon associated with many otological diseases, and is usually subjective. Objective tinnitus can be generated by para-auditory structures, usually derived from vascular or myogenic sources, or the eustachian tube. We present a rare case of intermittent unilateral tinnitus associated with eye blinking. Otoendoscopic examination showed that the external auditory canals and tympanic membranes were normal; however, rhythmic movements of both tympanic membranes, concomitant with the tinnitus, were evident whenever the patient blinked. The tympanometry and stapedial reflexes measured via impedance audiometry exhibited saw-tooth patterns; movement of the tympanic membrane was associated with eyelid blinking. The patient was managed conservatively, with reassurance and medication, and the condition became well-controlled. Here, we present this educational case and review the literature.

Dicer Is Down-regulated and Correlated with Drosha in Idiopathic Sudden Sensorineural Hearing Loss

Previously, we reported the expression levels of specific microRNA machinery components, DGCR8 and AGO2, and their clinical association in patients with idiopathic sudden hearing loss (SSNHL). In the present study, we investigated the other important components of microRNA machinery and their association with clinical parameters in SSNHL patients. Fifty-seven patients diagnosed with SSNHL and fifty healthy volunteers were included in this study. We evaluated mRNA expression levels of Dicer and Drosha in whole blood of patients with SSNHL and the control group, using RT & real-time PCR analysis. The Dicer mRNA expression level was down-regulated in patients with SSNHL. However, the Drosha mRNA expression level was not significantly altered in patients with SSNHL. Neither the Dicer nor Drosha mRNA expression level was not associated with any clinical parameters, including age, sex, duration of initial treatment from onset (days), initial Pure tone average, Siegel's criteria, WBC, and Erythrocyte sedimentation rate. However, mRNA expression levels of Dicer and Drosha were positively correlated to each other in patients with SSNHL. In this study, we demonstrated for the first time that the Dicer mRNA expression level was down-regulated in patients with SSNHL, suggesting its important role in pathobiology of SSNHL development.

Dexamethasone Inhibits Interleukin-1beta-Induced Matrix Metalloproteinase-9 Expression in Cochlear Cells

OBJECTIVES: To investigate the effect of interleukin (IL)-1beta on matrix metalloproteinase (MMP)-9 expression in cochlea and regulation of IL-1beta-mediated MMP-9 expression by dexamethasone and the molecular and signaling mechanisms involved. METHODS: House ear institute-organ of Corti 1 (HEI-OC1) cells were used and exposed to IL-1beta with/without dexamethasone. Glucocorticoid receptor antagonist, RU486, was used to see the role of dexamethasone. PD98059 (an extracellular signal-regulated kinases [ERKs] inhibitor), SB203580 (a p38 mitogen-activated protein kinases [MAPK] inhibitor), SP600125 (a c-Jun N-terminal kinase [JNK] inhibitor) were also used to see the role of MAPKs signaling pathway(s) in IL-1beta-induced MMP-9 expression in HEI-OC1 cells. Reverse transcription-polymerase chain reaction and gelatin zymography were used to measure mRNA expression level of MMP-9 and activity of MMP-9, respectively. RESULTS: Treatment with IL-1beta-induced the expression of MMP-9 in a dose- and time-dependent manner. IL-1beta (1 ng/mL)-induced MMP-9 expression was inhibited by dexamethasone. Interestingly, p38 MAPK inhibitor, SB203580, significantly inhibited IL-1beta-induced MMP-9 mRNA and MMP-9 activity. However, inhibition of JNKs and ERKs had no effect on the IL-1beta-induced MMP-9 expression. CONCLUSION: These results suggest that the pro-inflammatory cytokine IL-1beta strongly induces MMP-9 expression via activation of p38 MAPK signaling pathway in HEI-OC1 cells and the induction was inhibited by dexamethasone.

The Expression of AGO2 and DGCR8 in Idiopathic Sudden Sensorineural Hearing Loss

OBJECTIVES: The microRNAs have been implicated in the development and function of the inner ear, especially in contribution to hearing. However, the impact of idiopathic sudden sensorineural hearing loss (SSNHL) on expression of miRNA biogenesis-related components has not been established. To investigate the regulations of microRNA (miRNA) biogenesis-related components, argonaute 2 (AGO2) and DiGeorge syndrome critical region gene 8 (DGCR8) mRNA expression in SSNHL and to evaluate the value of clinical parameters on their expression. METHODS: Thirty-seven patients diagnosed with SSNHL and fifty-one healthy volunteers were included in this study. We measured mRNA expression levels of AGO2 and DGCR8 in whole blood cells but erythrocytes of patients with SSNHL and controls, using reverse transcription and real-time polymerase chain reaction analysis. RESULTS: The mRNA expression level of AGO2 is upregulated in SSNHL. The expression level of AGO2 was significantly correlated with that of DGCR8 in both patients with SSNHL and controls. Expression level of AGO2 in SSNHL was correlated with white blood cell counts. CONCLUSION: This study demonstrated for the first time that the AGO2 mRNA expression level was upregulated in SSNHL, suggesting its important role in pathobiology of SSNHL development.

Benign Paroxysmal Positional Vertigo After Cochlear Implantation / 대한평형의학회지

Cochlear implantation (CI) has enabled hearing rehabilitation of patients with severe hearing impairment for more than 20 years now. There have been reported that one possible complication of CI is the impairment of balance function with resulting vertigo symptoms. CI still implies trauma on the labyrinthine structures to allow the electrode system to be inserted into the cochlear turns. Benign paroxysmal positional vertigo is an uncommon development after CI. We experienced an 80-year-old woman who had immediate onset of vertigo after CI, which diagnosed in postoperative one day after CI. In postoperative videonystagmography, no spontaneous nystagmus was observed, but in right Dix-Hallpike, torsional nystagmus, where the top of the eye rotates towards the right ear in beating fashion. Vertigo improved after modified Epley maneuver. However there was one recurrence after 12 days later. The case is described along with a review of the literature.

Multicenter Study on the Clinician's Diagnostic and Therapeutic Approaches for Benign Paroxysmal Positional Vertigo in Korea / 대한평형의학회지

BACKGROUND AND OBJECTIVES: It is necessary to establish the most efficient diagnostic and therapeutic method for benign paroxysmal positional vertigo (BPPV), which is appropriate for Korean healthcare system. We aimed to evaluate current state of Korean clinician's diagnostic and therapeutic approaches for BPPV. MATERIALS AND METHODS: A 16-item survey was emailed to the members of dizziness department of Otology Research Interest Group in the Korean Otologic Society (n=68). 43 were returned and analyzed. RESULTS: All respondents (100%) used Dix-Hallpike test as a diagnostic tool for vertical canal-BPPV. Supine roll test was used for diagnosing lateral canal BPPV in nearly all the respondents (97.7%). Epley maneuver was chosen as otolith repositioning maneuver (ORM) for posterior canal BPPV in all respondents and barbecue rotation (BBQ) was used for treating lateral canal BPPV with geotropic nystagmus in 95.3% of respondents. Extreme variation was noted for therapeutic approach of lateral canal BPPV with ageotropic nystagmus BBQ, with 4 kinds of ORM and adjunctive measures to liberate otolith from cupula, while BBQ was again the most commonly used ORM (76.7%). CONCLUSION: The development of practical and efficient ORM for lateral canal BPPV with ageotropic nystagmus is necessary.

The Role of Vestibular Function Tests in Patients with Sudden Sensorineural Hearing Loss Who Have Subclinical Vestibular Dysfunction / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The evaluation of vestibular function is very important for patients with sudden sensorineural hearing loss (SNHL) as it is a well-known prognostic factor. The purpose of this study was to evaluate subclinical vestibular dysfunction (SVD) and its association with prognosis in sudden SNHL patients with and without dizziness using the vestibular function tests. SUBJECTS AND METHOD: Seventy eight patients who had been diagnosed with unilateral sudden SNHL were examined by dividing them into three groups according to their clinical findings such as vestibular function and subjective symptoms: 1) normal, 2) SVD and 3) dizziness. Vestibular dysfunction and hearing recovery rates were also assessed. RESULTS: Patients with SVD accounted for 62.5% of patients even though they did not complain subjective dizziness. The extent of vestibular dysfunction in the dizziness group was greater than that in the SVD group (p=0.05). The hearing recovery rates for normal, SVD and dizziness group were 72% (13/18), 57% (17/30) and 48% (12/25), respectively. The incidence and extent of vestibular dysfunction was greater in patients with severe hearing loss than in those with moderate to severe loss. A significant correlation was noted between hearing recovery rate and vestibular evoked myogenic potential (VEMP) testing. Normal and abnormal VEMP data were associated with good and poor recovery (p=0.001). CONCLUSION: The evaluation of vestibular function is important in sudden SNHL patients with dizziness; however, SVD also explains a significant proportion of sudden SNHL in the absence of dizziness. Notably, VEMP is useful tools for evaluating prognosis of sudden SNHL.

Endolymphatic Hydrops: Pathophysiology and Etiology / 대한이비인후과학회지

Endolymphatic hydrops (EH) represents a histopathologic finding in which the structures bounding the endolymphatic space are distended by an enlargement of endolymphatic volume. EH primarily involves the cochlear duct and saccule but can involve the utricle and ampullae of the semicircular canals. EH is a consistent finding in patients with Meniere's disease, however, the reverse is not true. EH may occur as a consequence of a variety of disorders, including DFNA 9, Alport syndrome, serous labyrinthitis, suppurative labyrinthitis, otosyphilis, temporal bone fracture, surgical trauma, neoplasm, immune disorders, otosclerosis, or Paget's disease. The mechanism of development of hydrops is also unclear. This review provides information to understand the recent pathophysiologic mechanism and causal disoders in EH.

Characterization of Gentamicin-Induced Apoptosis in a Cochlear Cell Model / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Aminoglycoside antibiotics are ototoxic. Understanding of the molecular mechanisms underlying the drug-induced ototoxicity, however, has been hampered by limited cell availability. Recently, HEI-OC1 cells, which are of an immortalized cochlear cell line sensitive to ototoxic drugs, have been derived from the auditory sensory organ. This study was performed to confirm whether cultured HEI-OC1 cells can be used to evaluate aminoglycoside-induced ototoxicity and the effect of antioxidants against aminoglycoside-induced colchlear cell damage. MATERIALS AND METHOD: Gentamicin was administered for 3 days in the media containing HEI-OC1 cells. RESULTS: Cell viability was decreased by gentamicin in a dose-dependent manner. The cell number was decreased by 50% 3 days after the exposure to 2 mM gentamicin. Penicillin did not have any significant effect. Flow cytometric analysis revealed that sub G1 arrest representing cellular apoptosis was accelerated by gentamicin treatment but not by penicillin. Expression of p27Kip1, the cyclin-dependent kinase inhibitor, was exclusively increased by gentamicin. Reactive oxygen species were also increased by gentamicin when compared with those of the control or when penicillin was used. Caspase-3 activity became increased according to the elevation of gentamicin concentrations. N-acetyl cysteine, but not vitamin E or vitamin C, ameliorated cell survival dose-dependently against gentamicin. CONCLUSION:The present study reveals that the HEI-OC1 cell line is a good model to evaluate gentamicin-induced ototoxicity. The results suggest that gentamicin-induced apoptosis may be, at least partially, linked to the overproduction of a reactive oxygen species called. Nacetyl cysteine, a free radical scavenger, that decreases the gentamicin ototoxicity.

Staging in Vestibular Schwannoma Surgery: A Modified Technique

The authors herein propose the staged excision as a novel strategy to preserve facial nerve and minimize complication during microsurgery of large vestibular schwannoma (VS). At the first stage, for reducing mass effect on the brain stem and cerebellum, subtotal tumor resection was performed via a retrosigmoid craniotomy without intervention of meatal portion of tumor. With total resection of the remaining tumor, the facial nerve was decompressed and delineated during the second stage translabyrinthine approach at a later date. A 38-year-old female who underwent the staging operation for resection of her huge VS is illustrated.

New Technique for Surgery of Petrous Apex Cholesterol Granuloma

The authors present a new technique for surgery of cholesterol granuloma (CG) at the petrous apex. An epidural middle fossa approach is used to expose and remove the cyst, with silicon tube drainage into the sphenoid sinus via the anterolateral cavernous sinus triangle between the first and second divisions of the trigeminal nerve. This novel method is less invasive skull base approach to the petrous apex and very effective for minimizing recurrence of CGs within the petrous apex.

Single Nucleotide Polymorphism of Tumor Necrosis Factor-Alpha Gene with Sudden Deafness in Korean Population / 항공우주의학회지

BACKGROUND: Infections and vascular disorders are the two most widely accepted probable causes of sudden hearing loss. Tumor necrosis factor alpha (TNF-alpha) is major pro-inflammatory cytokine that is thought to be important in the pathogenesis of sudden deafness. However, the functions of genetic polymorphism in this cytokine have not been throughly examined in the context of sudden deafness pathology. In an effort to discover polymorphism in genes whose variants have been implicated in sudden deafness phenotypes, we examined the genetic effects of TNF-alpha polymorphisms in Koreans with sudden deafness. METHODS: Two common single nucleotide polymorphism (SNP) in TNF-alpha gene were genotyped in a Korean sudden deafness. Ninety nine patients with sudden deafness (45 males and 54 females) were selected from Keimyung University Dongsan Medical Center. The control subjects consisted of healthy 285 males and 319 females. RESULTS: Human genomic DNA was extracted from peripheral blood sample. The SNP at position -863 C/A and -857 C/T of TNF-alpha promoter were analyzed by PCR and pyrosequencing. Genotype distribution and allele frquencies in subjects were in Hardy-Weinberg equilibrium (p>0.05). No significant association was found between TNF-alpha -863 C/A and -857 C/T polymorphism and sudden deafness. We examined whether the relation between TNF-alpha polymorphism and sudden deafness varied according to tinnitus. Statistical analysis of TNF-alpha polymorphism at -857 C/T showed that there was a significant difference between SD without tinnitus and the control in both genotype distribution (p<0.05) and allele frequency [OR (95% CI)=2.63 (1.29-5.34)], but not between SD with tinnitus. CONCLUSION: These findings suggest TNF-alpha polymorphisms at -863C/A, -857 C/T are likely to play a role in SD.