National representative analysis of unilateral hearing loss and hearing aid usage in South Korea.

A definitive study on the prevalence of adult unilateral hearing loss and hearing aid rehabilitation is lacking in Korea. The purpose of our study was to investigate the prevalence of adult unilateral hearing loss and the factors associated with hearing aid use in patients with unilateral hearing loss in South Korea. We obtained data from 2009 to 2012 from the Korea National Health and Nutrition Examination Surveys (KNHANES), a cross-sectional, nationwide and population-based survey in the Republic of Korea. We analyzed the prevalence and associated factors of unilateral hearing loss and hearing aid adoption by univariable and multivariable analysis. Unilateral hearing loss was defined as pure tone average ≥ 41 dB in the worse hearing ear, and < 41 dB in the other ear assessed at 0.5, 1.0, 2.0, and 3.0 kHz. From 2009 to 2012, 33,252 individuals participated in the KNHANES. Among them, the number of patients with unilateral hearing loss was 1632 (5.55%) and the prevalence of hearing aid adoption in unilateral hearing loss was 1.56%. We also compared the factors between hearing aid users and non-users. Occupational status (OR 3.759, 95% CI 1.443-9.804), the hearing threshold in the better ear (OR 1.088, 95% CI 1.029-1.151), and hearing threshold in the worse ear (OR 1.031, 1.005-1.058) were found to affect the adoption of hearing aids. The prevalence of noise exposure at work in hearing aid users was significantly lower than the prevalence of noise exposure at work in those with no hearing aid. The prevalence of hearing aid use in patients with unilateral hearing loss in Korea is very low compared to other countries. Public health education is needed to increase public awareness of unilateral hearing loss, hearing aid adoption and its continued usage. Auditory rehabilitation should be actively recommended to patients with unilateral hearing loss.

Microscopic versus Endoscopic Inlay Butterfly Cartilage Tympanoplasty.

BACKGROUND AND OBJECTIVES: Inlay butterfly cartilage tympanoplasty makes the graft easy, and reduces operating time. The present study aimed to investigate the outcomes of microscopic versus endoscopic inlay butterfly cartilage tympanoplasty. SUBJECTS AND METHODS: In this retrospective study, the outcomes of 63 patients who underwent inlay butterfly cartilage tympanoplasty with small to medium chronic tympanic membrane perforation were evaluated. Twenty-four patients underwent conventional microscopic tympanoplasty and 39 underwent endoscopic tympanoplasty. The outcomes were analyzed in terms of the hearing gain and graft success rate. RESULTS: The surgical success rate was 95.8% in the patients who underwent conventional microscopic tympanoplasty and 92.3% in those who underwent endoscopic tympanoplasty. In both groups of patients, the postoperative air-bone gap (ABG) was significantly lower than the preoperative ABG. There were no significant differences between the preoperative and postoperative ABG values in either group. CONCLUSIONS: Endoscopic inlay tympanoplasty using the butterfly cartilage technique appears to be an effective alternative to microscopic tympanoplasty and results in excellent hearing.

Acute vestibular asymmetry disorder: a new disease entity in acute vestibular syndrome?

BACKGROUND: Acute vestibular syndrome (AVS) is characterized by the rapid onset of vertigo, nausea, vomiting and gait unsteadiness, which lasts for days. AIMS/OBJECTIVES: We report cases as acute vestibular asymmetry disorder (AVAD), with presentations that mimic vestibular neuritis (VN) but without central lesions. MATERIALS AND METHODS: We retrospectively reviewed records of patients presenting with acute spontaneous vertigo lasting more than 24 h from January 2011 to June 2016. Among 341 patients, five showed different findings that did not indicate either VN or stroke. We analyzed the clinical features and vestibular assessments of these patients. RESULTS: All five patients showed spontaneous nystagmus continuing for several days. However, head impulse tests (HITs) did not reveal a corrective saccade. Brain magnetic resonance imaging showed no abnormal lesions. The bithermal caloric test revealed directional preponderance without canal paresis. Finally, the slow harmonic test of the rotatory chair revealed unilateral high gain and phase within the normal range, but a significantly asymmetric response was observed. No patients showed recurrence during follow-up. CONCLUSIONS AND SIGNIFICANCE: Our study suggests that a normal HIT in AVS is not always a dangerous sign indicating an acute stroke. From our observations, we propose that AVAD would be a new disease entity within AVS.

Outcomes of Modified Canal Wall Down Mastoidectomy and Mastoid Obliteration Using Autologous Materials.

OBJECTIVES: The traditional canal wall down mastoidectomy (CWDM) procedure commonly has potential problems of altering the anatomy and physiology of the middle ear and mastoid. This study evaluated outcomes in patients who underwent modified canal wall down mastoidectomy (mCWDM) and mastoid obliteration using autologous materials. METHODS: Our study included 76 patients with chronic otitis media, cholesteatoma, and adhesive otitis who underwent mCWDM and mastoid obliteration using autologous materials between 2010 and 2015. Postoperative hearing airbone gap and complications were evaluated. RESULTS: During the average follow-up of 64 months (range, 20 to 89 months), there was no recurrent or residual cholesteatoma or chronic otitis media. No patient had a cavity problem and anatomic integrity of the posterior canal wall was obtained. There was a significant improvement in hearing with respect to the postoperative air-bone gap (P<0.05). A retroauricular skin depression was a common complication of this technique. CONCLUSION: The present study suggests that our technique can prevent various complications of the classical CWDM technique using autologous tissues for mastoid cavity obliteration. It is also an appropriate method to obtain adequate volume for safe obliteration.

The extent of vestibular impairment is important in recovery of canal paresis of patients with vestibular neuritis.

OBJECTIVES: We questioned whether the extent of vestibular impairment affected the recovery of vestibular function in acute vestibular neuritis (VN). The objective of this study was to identify how the extent of vestibular impairment influenced the recovery from canal paresis (CP) in patients with VN. METHODS: We retrospectively reviewed the medical records of 46 patients diagnosed with acute vestibulopathy between January 2012 and December 2015. Pure-tone audiometry, a caloric test, and cervical vestibular evoked myogenic potential (cVEMP) testing were performed in all patients. Patients were divided into two groups, superior VN and total VN, according to the results of the cervical vestibular evoked myogenic potential (cVEMP) testing. The caloric test was rechecked 6-12months after diagnosis and the CP values were compared at 6 and 12months. The degree of recovery was evaluated by comparing the CP values. We defined good recovery as CP<25% at follow-up. RESULTS: We found no significant difference in age, sex ratio, lesional site, or follow-up period between patients with superior VN and total VN. The follow-up CP in patients with superior VN was significantly lower than that in those with total VN. Twenty patients (65%) in the superior VN group exhibited good recovery as did three (20%) in the total VN group; the between-group difference was significant. CONCLUSIONS: We found that CP values recovered well in patients with superior VN. We suggest that the extent of vestibular impairment is important in the recovery of CP in acute vestibulopathy.

Acute vertigo and sensorineural hearing loss from infarction of the vestibulocochlear nerve: A case report.

RATIONALE: Acute unilateral audiovestibulopathy is a common neurotological syndrome. Differential diagnoses of acute unilateral audiovestibulopathy include viral infection, vascular insults, and tumors. Regarding vascular causes, ischemic stroke in the anterior inferior cerebellar artery (AICA) territory is known to be the leading cause of acute audiovestibular loss. Previous reports of AICA infarction with audiovestibulopathy failed to demonstrate magnetic resonance imaging (MRI)-positive vestibulocochlear infarctions. Only 1 report demonstrated acute infarction involving the vestibulocochlear nerve on diffusion weighted imaging (DWI)-MRI. PATIENT CONCERNS: A 67 year old man complained of sudden left hearing loss and vertigo. The patient showed left horizontal gaze-evoked nystagmus (GEN) and the head impulse test (HIT) was positive on the left side. Videonystagmography revealed spontaneous rebound nystagmus toward the right side; head-shaking nystagmus toward the right side. The patient presented with left caloric paresis (20.1%). Pure tone audiometry (PTA) revealed severe sensorineural hearing loss on the left side. DIAGNOSIS: MRI of temporal bone showed multifocal acute infarctions in the left inferior cerebellum. Moreover, images revealed tiny infarctions along the left vestibulocochlear nerve and the cochlea, implying acute vestibulocochlear nerve and labyrinthine infarction. There was no evidence of steno-occlusion of major cerebral vessels on MR angiography. INTERVENTIONS: Immediate stroke management was done. OUTCOMES: Neurological symptoms gradually improved after 3 to 5 days. LESSONS: We present a case illustrating a rare but significant finding of vestibulocochlear nerve infarction revealed by DWI-MRI. Prompt imaging protocol enabled the detection of significant findings in this patient with acute unilateral audiovestibulopathy. Clinicians should be aware of the vestibulocochlear nerve and labyrinth on MRI in patients with cerebellar stroke.

Effect of sleep deprivation on hearing levels in rats.

OBJECTIVES: To our knowledge, the influence of sleep deprivation on hearing levels has yet to be assessed in animals. Therefore, we evaluated whether auditory function was affected by sleep deprivation in rats. METHODS: Male Wistar rats (aged 9 weeks, weighing 300-400 g) were used for the study and were randomly assigned to a control (n = 15) or sleep deprivation group (n = 12). Hearing levels were evaluated at baseline and 9 days after sleep deprivation using auditory evoked brainstem responses (ABRs) and distortion product otoacoustic emission (DPOAE) measurements. Blood was collected for the measurement of interleukin-1ß and corticosterone levels. RESULTS: The ABR thresholds (at 8, 16, and 32 kHz) at 9 days were significantly elevated in the sleep deprivation group compared to the control group (p < 0.05, respectively). The sleep deprivation group showed a defect in the function of outer hair cells, as evidenced by decreased levels of distortion product otoacoustic emission. IL-1ß was significantly increased in the sleep deprivation group. Sleep-deprived rats exhibited rupture of Reissner's membrane and morphological damage to stereocilia. CONCLUSION: These results suggest that sleep deprivation induces damage to the cochlea and results in hearing loss in Wistar rats.

Feasibility of magnetic resonance imaging in the differential diagnosis of isolated acute audiovestibular loss.

BACKGROUND: Isolated acute audiovestibular loss is characterized by the sudden onset of unilateral hearing loss and prolonged vertigo. OBJECTIVE: The purpose of this study is aimed to identify the value of magnetic resonance imaging (MRI) for the evaluation of isolated acute audiovestibular loss. METHODS: We retrospectively enrolled 31 patients with isolated acute audiovestibular loss from March 2007 to December 2017. Specific medical records including initial and final pure tone audiometry (PTA), and canal paresis value were reviewed. Abbreviated MRI was performed in all patients. RESULTS: Fifteen patients showed increased signal of labyrinth on FLAIR images and eleven revealed negative findings on MRI. Two patients showed an infarction in the anterior inferior cerebellar artery (AICA) territory and three exhibited vestibular schwannoma in the internal auditory canal. There were no significant differences in initial, final PTA, and hearing recovery between negative and labyrinthine abnormality groups on MRI. CONCLUSIONS: Our results show that isolated acute audiovestibular loss due to labyrinthitis is more common than other secondary causes including vestibular schwannoma or AICA infarction. However, MRI with a tailored, abbreviated protocol is strongly recommended in patients with isolated acute audiovestibular loss to identify the exact etiologies.

ß1- and ß2-adrenergic stimulation-induced electrogenic transport by human endolymphatic sac epithelium and its clinical implications.

The endolymphatic sac (ES) is a cystic structure of the inner ear connected to the cochlea and vestibule, which plays a role in regulating ion homeostasis in inner ear fluid. Disruption of ion homeostasis can cause inner ear disorders with hearing loss and dizziness, such as Meniere's disease. Herein, we found, for the first time, functional evidence for the involvement of ß1- and ß2-adrenergic receptors in apical electrogenic ion transport by human ES epithelium by using electrophysiological/pharmacological and molecular biological methods, which were dependent on K+ and Cl- ion transport. The apical electrogenic transport was absent or very weak in ES epithelia of patients with Meniere's disease. These results suggested that adrenergic stimulation via ß1- and ß2-adrenergic receptors in the human ES was involved in regulation of inner ear fluid ion homeostasis and impairment of this response could be a pathological mechanism of Meniere's disease.

Analysis of Prognostic Factors in Malignant External Otitis.

OBJECTIVES: Malignant external otitis (MEO) is a potentially fatal infection of the external auditory canal, temporal bone, and skull base. Despite treatment with modern antibiotics, MEO can lead to skull base osteomyelitis. Until now, there have been few studies on the prognostic factors of MEO. METHODS: We performed a retrospective study to identify prognostic factors of MEO, and a meta-analysis of other articles investigating MEO. On the basis of disease progression the 28 patients in our study were divided into 'controlled' and 'uncontrolled' groups, consisting of 12 and 16 patients, respectively. We identified three categories of prognostic factors: those related to patient, disease, and treatment. We compared these prognostic factors between the controlled and uncontrolled groups. RESULTS: In our study, the duration of diabetes mellitus (DM), presence of inflammatory markers (C-reactive protein and erythrocyte sedimentation rate), and computed tomography or magnetic resonance imaging findings influenced the prognosis of MEO. In contrast, prognosis was unrelated to age, gender, mean glucose level, hemoglobin A1c level, pathogen, comorbidity, or cranial nerve involvement. No factor related to treatment modality was correlated with prognosis, such as surgery, steroid therapy, or interval to the first appropriate treatment. Cranial nerve involvement has been proven to be associated with disease progression, but the relationship between cranial nerve involvement and the prognosis of MEO remains controversial. As a part of this study, we conducted a meta-analysis of cranial nerve involvement as a prognostic factor of MEO. We found that cranial nerve involvement has a statistically significant influence on the prognosis of MEO. CONCLUSION: We found that glycemic control in diabetes mellitus, cranial nerve involvement, and the extent of disease determined from various imaging modalities influence the prognosis of MEO. We suggest that significant prognostic factors should be monitored to determine the prognosis of patients with MEO.

Sulforaphane, a natural component of broccoli, inhibits vestibular schwannoma growth in vitro and in vivo.

Vestibular schwannoma (VS) is an intracranial tumor that causes significant morbidity, including hearing loss, tinnitus, dizziness, and possibly even death from brainstem compression. However, FDA-approved pharmacologic treatments for VS do not exist. Sulforaphane (SFN) is a naturally occurring isothiocyanate found in cruciferous vegetables, such as broccoli, with potent chemoprotective effects in several cell types. Our objective was to determine whether SFN is effective against VS in vitro and in vivo. Human primary VS cells, HEI-193 schwannoma cells, and SC4 Nf2-/- Schwann cells were used to investigate the inhibitory effects of SFN in vitro. Cell proliferation was assessed by bromodeoxyuridine (BrdU) incorporation, and cell viability and metabolic activity was calculated by MTT assay. Apoptosis was measured by flow cytometry, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and Western blot for cleaved caspases. A mouse model with a murine schwannoma allograft was also used to examine the antitumor activity of SFN. SFN exhibited significant antiproliferative activity in schwannoma cells in vitro, via the inhibition of HDAC activity and the activation of ERK. SFN treatment induced apoptosis and cell cycle arrest at the G2/M phase. SFN also significantly inhibited schwannoma growth in vivo. Our preclinical studies motivate a future prospective clinical study of SFN for the treatment of VS.

Is dehydration test using isosorbide useful in Meniere's disease?

CONCLUSION: The dehydration test using isosorbide is well tolerated when used to detect endolymphatic hydrops and may also be used to improve the sensitivity of ECoG performed on patients with MD, especially in poor hearing at low-frequency. OBJECTIVE: This prospective study was to explore the diagnostic utility of a dehydration test, administering oral isosorbide, which has been used to treat Meniere's disease (MD). METHOD: Electrocochleography (ECoG) and the dehydration test with isosorbide were performed on 32 patients diagnosed with definite diagnosed MD. Isosorbide (120 mL) was orally administered after baseline audiometric testing, and the testing was repeated 3 h later. The dehydration test was considered positive when improvements in hearing thresholds of 10 dB or more were evident at two or more frequencies, or the speech discrimination score increased by 12% or more. An abnormal ECoG finding was defined as an SP/AP (summating potential/action potential) ratio ≥0.4. RESULTS: The dehydration test using isosorbide was positive in 10 of 32 patients (31.3%). The test was not associated with development of any serious side-effect. Abnormal ECoG findings were noted in 14 of 32 patients (43.8%). When endolymphatic hydrops was defined as an abnormal ECoG or a positive dehydration test, the condition was detected in 21 of 32 patients (65.6%). The positive result in dehydration test was significantly higher in patients with above moderate hearing loss at low-frequency.

Early deterioration of residual hearing in patients with SLC26A4 mutations.

OBJECTIVES/HYPOTHESIS: To compare changes in hearing in patients with SLC26A4 during early and late childhood. STUDY DESIGN: Retrospective chart review. METHODS: A total of 102 patients with biallelic SLC26A4 mutations visited the tertiary referral otolaryngology department between March 2005 and February 2015. Newborn hearing screening tests had been performed on 22 of these patients. We analyzed 26 patients who underwent hearing tests more than twice using the same method (auditory brainstem response/auditory steady state response/play audiometry) before and after 3 years of age. We analyzed changes in hearing levels according to age. RESULTS: Among 22 patients with SLC26A4 mutations who underwent newborn hearing screening tests, seven (31.8%) passed the newborn hearing screening test in both ears, and six (27.3%) passed in one ear. Among 16 patients with SLC26A4 mutations who underwent hearing tests more than twice before age 3 years, the hearing levels of 14 (87.5%) deteriorated rapidly during this time. Among 16 patients with SLC26A4 mutations who underwent hearing tests more than twice after the age of 3 years, two (12.5%) patients' hearing levels deteriorated; the hearing levels of most of the patients were relatively stable. CONCLUSIONS: These data suggest that many patients with SLC26A4 mutations have significant residual hearing at birth, and that the hearing deterioration in these patients occurs before 3 years of age. After age 3 years, the residual hearing was relatively stable and did not tend to deteriorate. Therefore, in patients with a pendrin mutation, early intervention to preserve residual hearing should be a clinical focus. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:E286-E291, 2016.

Electrogenic transport and K(+) ion channel expression by the human endolymphatic sac epithelium.

The endolymphatic sac (ES) is a cystic organ that is a part of the inner ear and is connected to the cochlea and vestibule. The ES is thought to be involved in inner ear ion homeostasis and fluid volume regulation for the maintenance of hearing and balance function. Many ion channels, transporters, and exchangers have been identified in the ES luminal epithelium, mainly in animal studies, but there has been no functional study investigating ion transport using human ES tissue. We designed the first functional experiments on electrogenic transport in human ES and investigated the contribution of K(+) channels in the electrogenic transport, which has been rarely identified, even in animal studies, using electrophysiological/pharmacological and molecular biological methods. As a result, we identified functional and molecular evidence for the essential participation of K(+) channels in the electrogenic transport of human ES epithelium. The identified K(+) channels involved in the electrogenic transport were KCNN2, KCNJ14, KCNK2, and KCNK6, and the K(+) transports via those channels are thought to play an important role in the maintenance of the unique ionic milieu of the inner ear fluid.

Adverse events and discomfort during magnetic resonance imaging in cochlear implant recipients.

IMPORTANCE: Patients with cochlear implants (CIs) should be fully informed before undergoing magnetic resonance imaging (MRI) about the possibility of discomfort or pain. Prior to an MRI scan, patients need to fully understand not only the potential complications but also the potential discomfort that they may experience during the scan. OBJECTIVE: To assess the adverse events during MRI in patients with CIs and to investigate the safety and diagnostic efficiency of MRI in patients with CIs with internal magnets. DESIGN, SETTING, AND PARTICIPANTS: Retrospective review of the medical records of 18 patients with CIs undergoing MRI between September 2003 and February 2014 at a single tertiary referral center. INTERVENTIONS: Sixteen patients underwent MRI in a 1.5-T scanner, and 2 patients underwent MRI in a 3.0-T scanner. Twelve brain MRI scans were performed, and 18 MRI scans were performed in areas outside the brain. MAIN OUTCOMES AND MEASURES: Discomfort or pain, adverse events, and auditory performance after MRI were evaluated using medical records or interviews. RESULTS: Thirteen of 18 patients completed their MRI scans (25 of 30 scans). Five patients with head bandages were unable to complete their MRI scans owing to pain; one of these patients experienced magnet displacement, and another underwent surgery for magnet removal and reinsertion. Finally, 1 patient experienced polarity reversal of the magnet. Artifacts induced by the CI internal magnet compromised the diagnosis of ipsilateral brain lesions under 1.5-T MRI. Auditory performance in the CI recipients who had major events was unaffected. CONCLUSIONS AND RELEVANCE: Even with protective head bandages, 1.5-T MRI in patients with CIs led to a variety of adverse events, including discomfort or pain and displacement of the internal magnet. Therefore, sedation and careful head positioning may be appropriate for some patients with CIs who undergo MRI, and these patients should be carefully monitored to decrease the likelihood of such adverse effects.

Autoimmunity as a candidate for the etiopathogenesis of Meniere's disease: detection of autoimmune reactions and diagnostic biomarker candidate.

Meniere's disease is an inner ear disorder that can manifest as fluctuating vertigo, sensorineural hearing loss, tinnitus, and aural fullness. However, the pathologic mechanism of Meniere's disease is still unclear. In this study, we evaluated autoimmunity as a potential cause of Meniere's disease. In addition we tried to find useful biomarker candidates for diagnosis. We investigated the protein composition of human inner ear fluid using liquid column mass spectrometry, the autoimmune reaction between circulating autoantibodies in patient serum and multiple antigens using the Protoarray system, the immune reaction between patient serum and mouse inner ear tissues using western blot analysis. Nine proteins, including immunoglobulin and its variants and interferon regulatory factor 7, were found only in the inner ear fluid of patients with Meniere's disease. Enhanced immune reactions with 18 candidate antigens were detected in patients with Meniere's disease in Protoarray analysis; levels of 8 of these antigens were more than 10-fold higher in patients than in controls. Antigen-antibody reactions between mouse inner ear proteins with molecular weights of 23-48 kDa and 63-75 kDa and patient sera were detected in 8 patients. These findings suggest that autoimmunity could be one of the pathologic mechanisms behind Meniere's disease. Multiple autoantibodies and antigens may be involved in the autoimmune reaction. Specific antigens that caused immune reactions with patient's serum in Protoarray analysis can be candidates for the diagnostic biomarkers of Meniere's disease.

Developmental changes of ENaC expression and function in the inner ear of pendrin knock-out mice as a perspective on the development of endolymphatic hydrops.

Pendrin mutations cause enlarged vestibular aqueducts and various degrees of sensorineural hearing loss. The selective abolition of pendrin causes dilation of the membranous labyrinth known as endolymphatic hydrops, loss of the endocochlear potential, and consequently loss of hearing function. Because Na+ transport is one of the most important driving forces for fluid transport, the epithelial Na+ channel (ENaC) is believed to play an important role in fluid volume regulation in the inner ear. Therefore, the dysfunction of Na+ transport through ENaC by the acidification of endolymph in Pendred syndrome is one of the potential causes of endolymphatic hydrops. We investigated the changes of ENaC expression and function during the development of the pendrin knock-out mouse. In the cochlea, the expression of ß and γENaC was significantly increased at P56 in Pds-/- mice compared with Pds+/+ mice. In the vestibule, the expression of ßENaC was significantly increased at P56, and γENaC expression significantly increased from P6 to P56 in Pds-/- mice. The ENaC-dependent trans-epithelial current was not significantly different between Pds+/+ and Pds-/- mice in Reissner's membrane or the saccular extramacular roof epithelium at P0, but the current was significantly increased in Pds-/- mice at P56 compared with Pds+/+ mice. These findings indicate that the expression and function of ENaC were enhanced in Pds-/- mice after the development of endolymphatic hydrops as a compensatory mechanism. This result provides insight into the role of Na+ transport in the development and regulation of endolymphatic hydrops due to pendrin mutations.

Prevalence and clinical significance of spontaneous low-frequency air-bone gaps in Ménière's disease.

OBJECTIVES: The prevalence and clinical significance of spontaneous low-frequency air-bone gaps (LFABGs) in Ménière's disease were investigated. STUDY DESIGN: A retrospective study. SETTINGS: Tertiary referral center. PATIENTS: Three hundred thirty-seven patients with definite Ménière's disease. MAIN OUTCOME MEASURES: The prevalence of LFABG in this population was calculated, and the following parameters were analyzed: 1) changes in hearing thresholds after the resolution of LFABG; 2) correlation between LFABG and electrocochleography (ECoG) results; 3) changes in the number of vertigo spells after the resolution of LFABG; 4) correlation between LFABG and canal paresis (CP) values in caloric testing; and 5) the difference in the prognoses of patients with and without LFABG. RESULTS: The prevalence of LFABG was 13.9%. Patients' hearing thresholds were significantly decreased after the resolution of LFABG (from 49.4 ± 16.8 to 38.3 ± 19.3, p = 0.044), whereas the summating potential and action potential ratio in ECoG tended to increase as LFABG increased (R = 0.09, p = 0.03). The mean number of vertigo spells was significantly reduced after the resolution of LFABG (from 2.9 to 0.5, p < 0.0001), but CP did not correlate with LFABG. The prognosis was not different for patients with and without LFABG. CONCLUSION: The number of vertigo spells and hearing thresholds were significantly higher during the period of LFABG development. Although the prognostic importance of LFABG was not significant, it likely reflects the aggravation of the endolymphatic hydrops in the cochlear and vestibular compartments and may be useful for evaluating and treating patients with Ménière's disease.

Comparison of the outcomes of repetitive transcranial magnetic stimulation to the ipsilateral and contralateral auditory cortex in unilateral tinnitus.

Transcranial magnetic stimulation (TMS) is a noninvasive method of activating or deactivating focal areas of the human brain. Repetitive TMS (rTMS) applied over the temporoparietal cortex has been reported to show therapeutic effects on tinnitus. We compared the effects of 1 Hz rTMS delivered either contralaterally or ipsilaterally to the symptomatic ear in patients with unilateral tinnitus. Forty patients with asymmetric hearing loss and non-pulsatile tinnitus localized to poorer ear of 6 months in duration or greater who were refractory to medication were enrolled in this study. Patients were assigned randomly to one of two treatment groups: with 1 Hz stimulation applied the temporoparietal junction either ipsilaterally (n = 21) or contralaterally (n = 19) to the symptomatic ear. The patients were given 600 pulses per session daily for 5 d. Changes in the tinnitus handicap inventory (THI) and self-rating visual analog scores (VAS) for loudness, awareness and annoyance were analyzed before, immediately after and 1 month after treatment. There was no significant difference in the rate of patients with marked improvement between ipsilateral and contralateral stimulation groups. In addition, there were no significant differences in the amount of decreases in THI scores and VAS between the two groups immediately or 1 month after rTMS. Finally, significant decreases in THI scores and most VAS were observed 1 month after rTMS in both groups compared to pretreatment. Daily treatment with 1 Hz rTMS ipsilaterally and contralaterally to the side of tinnitus both had significant beneficial effects. The laterality of stimulation with 1 Hz rTMS is not the decisive factor in relieving symptoms.

Association between vestibular schwannomas and mobile phone use.

Vestibular schwannomas (VSs) grow in the region where the energy from mobile phone use is absorbed. We examined the associations of VSs with mobile phone use. This study included 119 patients who had undergone surgical tumor removal. We used two approaches in this investigation. First, a case-control study for the association of mobile phone use and incidence of VSs was conducted. Both cases and controls were investigated with questions based on INTERPHONE guidelines. Amount of mobile phone use according to duration, daily amount, and cumulative hours were compared between two groups. We also conducted a case-case study. The location and volume of the tumors were investigated by MRI. Associations between the estimated amount of mobile phone use and tumor volume and between the laterality of phone use and tumor location were analyzed. In a case-control study, the odds ratio (OR) of tumor incidence according to mobile phone use was 0.956. In the case-case study, tumor volume and estimated cumulative hours showed a strong correlation (r(2) = 0.144, p = 0.002), and regular mobile phone users showed tumors of a markedly larger volume than those of non-regular users (p < 0.001). When the analysis was limited to regular users who had serviceable hearing, laterality showed a strong correlation with tumor side (OR = 4.5). We found that tumors may coincide with the more frequently used ear of mobile phones and tumor volume that showed strong correlation with amount of mobile phone use, thus there is a possibility that mobile phone use may affect tumor growth.