Tinnitus and treatment-resistant depression.

Tinnitus, a frequent disorder, is the conscious perception of a sound in the absence of a corresponding external acoustic sound source in the sense of a phantom sound. Although the majority of people who perceive a tinnitus sound can cope with it and are only minimaly impaired in their quality of lfe, 2-3% of the population perceive tinnitus as a major problem. Recently it has been proposed that the two groups should be differentiated by distict terms: "Tinnitus" describes the auditory or sensory component, whereas "Tinnitus Disorder" reflects the auditory component and the associated suffering. There is overwhelming evidence that a high tinnitus burden is associated with the increased occurrence of comorbidities, including depression. Since no causal therapeutic options are available for patients with tinnitus at the present time, the identification and adequate treatment of relevant comorbidities is of great importance for the reduction of tinnitus distress. This chapter deals with the relationship between tinnitus and depression. The neuronal mechanisms underlying tinnitus will first be discussed. There will also be an overview about depression and treatment resistant depression (TRD). A comprehensive review about the state-of-the-art evidences of the relationship between tinnitus and TRD will then be provided.

Clinical standardization for the detection of hemispheric dominance for steady-state auditory evoked fields in normal hearing.

BACKGROUND: Steady-state auditory evoked responses (SSAERs) are promising indicators of major auditory function. The improvement in accessibility in the clinical setting depends on the standardization and definition of the characteristics of SSAERs. There have been some insights into the changes in the interhemispheric dominance of SSAERs in some clinical entities. However, the hemispheric asymmetry of SSAERs in healthy controls remains inconclusive. METHODS: Twelve right-handed healthy volunteers with normal hearing were recruited. Steady-state auditory evoked fields (SSAEFs) were measured binaurally using magnetoencephalography (MEG) under pure-tone auditory stimuli at 1000 Hz with an amplitude modulation frequency of 43 Hz. The laterality index, based on the ratio of SSAEF strength over the right hemisphere to that over the left hemisphere, was also analyzed. RESULTS: The SSAEFs source was localized bilaterally on the superior temporal plane, with an orientation centripetal to the auditory cortex. The laterality index ranged from 1.1 to 2.3, and there were no sex differences. In all subjects, the strength of the SSAEFs was significantly weaker in the left hemisphere than in the right hemisphere ( p = 0.014). CONCLUSION: Right-sided dominance of the SSAEFs was verified in subjects with normal hearing. Acoustic sources clinically available in audiometric tests were used as stimuli. Such a simplification of parameters would be helpful for the standardization of precise production and the definition of the characteristics of SSAERs. Because MEG is still not easily accessible clinically, further studies using electroencephalography with larger sample sizes are necessary to address these issues.

Revisiting the relationship of three-dimensional fluid attenuation inversion recovery imaging and hearing outcomes in adults with idiopathic unilateral sudden sensorineural hearing loss.

BACKGROUND AND PURPOSE: Three-dimensional fluid attenuation inversion recovery (3D FLAIR) may demonstrate high signal in the inner ears of patients with idiopathic sudden sensorineural hearing loss (ISSNHL), but the correlations of this finding with outcomes are still controversial. Here we compared 4 3D MRI sequences with the outcomes of patients with ISSNHL. MATERIALS AND METHODS: 77 adult patients with ISSNHL underwent MRI with pre contrast FLAIR, fast imaging employing steady-state acquisition images (FIESTA-C), post contrast T1WI and post contrast FLAIR. The extent and degree of high signal in both cochleas were evaluated in all patients, and asymmetry ratios between the affected ears and the normal ones were calculated. The relationships among MRI findings, including extent and asymmetry of abnormal cochlear high signals, degree of FLAIR enhancement, and clinical information, including age, vestibular symptoms, baseline hearing loss, and final hearing outcomes were analyzed. RESULTS: 54 patients (28 men; age, 52.1±15.5years) were included in our study. Asymmetric cochlear signal intensities were more frequently observed in pre contrast and post contrast FLAIR (79.6% and 68.5%) than in FIESTA-C (61.1%) and T1WI (51.9%) (p<0.001). Age, baseline hearing loss, extent of high signal and asymmetry ratios of pre contrast and post contrast FLAIR were all correlated with final hearing outcomes. In multivariate analysis, age and the extent of high signals were the most significant predictors of final hearing outcomes. CONCLUSION: 3D FLAIR provides a higher sensitivity in detecting the asymmetric cochlear signal abnormality. The more asymmetric FLAIR signals and presence of high signals beyond cochlea indicated a poorer prognosis.

Effects of diagnosis-related group payment on health-care provider behaviors: A consecutive three-period study.

BACKGROUND: This study aimed to evaluate the impact of diagnosis-related group (DRG) payments on health-care providers' behavior and the potential best course of action to make a profit under a DRG payment mechanism. METHODS: This is a natural experiment study with a tertiary hospital-based dataset. Under a consecutive three-period (3 years) or 12-period (12 seasons) design, length of stay, medical cost with detailed items, the percentage of general anesthesia (GA), and the percentage of receiving additional operations were compared. Furthermore, the differences between negative- and positive-profit groups were also examined. RESULTS: There was no difference in the length of stay and total medical cost after the launch of the DRG payment scheme. However, the percentage of additional operations increased significantly. In addition, there were reduced costs of radiological images and medication, a reduced percentage of GA, fewer patients undergoing additional operations, and a higher rate of complications or comorbidities in the "positive-profit group." CONCLUSION: The introduction of DRG payment resulted in significantly reduced examination fee, slightly decreased medical costs without significant difference in several detailed items, a reduced number of GA cases without statistical significance, and more patients receiving additional operations. The possible solution to make a profit under the DRG payment scheme is to curtail the costs of radiological images and medication, lower GA percentage, perform fewer additional operations, and correct recording of complications or comorbidities.

Extractions of steady-state auditory evoked fields in normal subjects and tinnitus patients using complementary ensemble empirical mode decomposition.

BACKGROUND: Auditory steady-state response (ASSR) induced by repetitive auditory stimulus is commonly used for audiometric testing. ASSR can be measured using electro-encephalography (EEG) and magnetoencephalography (MEG), referred to as steady-state auditory evoked potential (SSAEP) and steady-state auditory evoked field (SSAEF), respectively. However, the signal level of SSAEP and SSAEF are weak so that signal processing technique is required to increase its signal-to-noise ratio. In this study, a complementary ensemble empirical mode decomposition (CEEMD)-based approach is proposed in MEG study and the extraction of SSAEF has been demonstrated in normal subjects and tinnitus patients. METHODS: The CEEMD utilizes noise assisted data analysis (NADA) approach by adding positive and negative noise to decompose MEG signals into complementary intrinsic mode functions (IMF). Ten subjects (five normal and five tinnitus patients) were studied. The auditory stimulus was designed as 1 kHz carrier frequency with 37 Hz modulation frequency. Two channels in the vicinities of right and left temporal areas were chosen as channel-of-interests (COI) and decomposed into IMFs. The spatial distribution of each IMF was correlated with a pair of left- and right-hemisphere spatial templates, designed from each subject's N100m responses in pure-tone auditory stimulation. IMFs with spatial distributions highly correlated with spatial templates were identified using K-means and those SSAEF-related IMFs were used to reconstruct noise-suppressed SSAEFs. RESULTS: The current strengths estimated from CEEMD processed SSAEF showed neural activities greater or comparable to those processed by conventional filtering method. Both the normal and tinnitus groups showed the phenomenon of right-hemisphere dominance. The mean current strengths of auditory-induced neural activities in tinnitus group were larger than the normal group. CONCLUSIONS: The present study proposes an effective method for SSAEF extraction. The enhanced SSAEF in tinnitus group echoes the decreased inhibition in tinnitus's central auditory structures as reported in previous studies.

High-dose amoxicillin with clavulanate for the treatment of acute otitis media in children.

OBJECTIVE: This study uses the acute otitis media clinical practice guideline proposed in 2004 as a reference to evaluate whether antibiotics doses that are in line with the recommendations lead to better prognosis. The study also attempts to clarify possible factors that influence the outcome. STUDY DESIGN: Retrospective cohort study. SUBJECTS AND METHODS: A total of 400 children with acute otitis media were enrolled. The dosage of amoxicillin was considered to be appropriate when in accord with clinical practice guidelines, that is, 80-90 mg/kg/day. The outcome was defined according to the description of tympanic membrane on medical records. Multivariate logistic regression was used to analyze the relationship between antibiotic dosage and prognosis after adjusting for baseline factors. RESULTS: The majority of prescriptions were under dosage (89.1%) but it was not noticeably associated with outcome (P = 0.41). The correlation between under dosage and poor prognosis was significant in children below 20 kg with bilateral acute otitis media (odds ratio 1.63; 95% CI 1.02-2.59, P = 0.04). CONCLUSION: Treating acute otitis media in children, high-dose amoxicillin with clavulanate as recommended in the clinical practice guideline was superior to conventional doses only in children under 20 kg with bilateral diseases.

Neuromagnetic index of hemispheric asymmetry prognosticating the outcome of sudden hearing loss.

The longitudinal relationship between central plastic changes and clinical presentations of peripheral hearing impairment remains unknown. Previously, we reported a unique plastic pattern of "healthy-side dominance" in acute unilateral idiopathic sudden sensorineural hearing loss (ISSNHL). This study aimed to explore whether such hemispheric asymmetry bears any prognostic relevance to ISSNHL along the disease course. Using magnetoencephalography (MEG), inter-hemispheric differences in peak dipole amplitude and latency of N100m to monaural tones were evaluated in 21 controls and 21 ISSNHL patients at two stages: initial and fixed stage (1 month later). Dynamics/Prognostication of hemispheric asymmetry were assessed by the interplay between hearing level/hearing gain and ipsilateral/contralateral ratio (I/C) of N100m latency and amplitude. Healthy-side dominance of N100m amplitude was observed in ISSNHL initially. The pattern changed with disease process. There is a strong correlation between the hearing level at the fixed stage and initial I/C(amplitude) on affected-ear stimulation in ISSNHL. The optimal cut-off value with the best prognostication effect for the hearing improvement at the fixed stage was an initial I/C(latency) on affected-ear stimulation of 1.34 (between subgroups of complete and partial recovery) and an initial I/C(latency) on healthy-ear stimulation of 0.76 (between subgroups of partial and no recovery), respectively. This study suggested that a dynamic process of central auditory plasticity can be induced by peripheral lesions. The hemispheric asymmetry at the initial stage bears an excellent prognostic potential for the treatment outcomes and hearing level at the fixed stage in ISSNHL. Our study demonstrated that such brain signature of central auditory plasticity in terms of both N100m latency and amplitude at defined time can serve as a prognostication predictor for ISSNHL. Further studies are needed to explore the long-term temporal scenario of auditory hemispheric asymmetry and to get better psychoacoustic correlates of pathological hemispheric asymmetry in ISSNHL.

Comparison of short tone burst-evoked and click-evoked vestibular myogenic potentials in healthy individuals.

BACKGROUND: Vestibular evoked myogenic potential (VEMP) is one of the clinical tools to evaluate vestibular function. The VEMP can be recorded from sternocleidomastoid muscle by auditory stimulation with various sound stimuli. The aim of this study was to compare the VEMP responses evoked by short tone burst (STB) with those evoked by click stimuli in healthy young individuals. METHODS: Twenty-two healthy volunteers (11 males, 11 females; 44 ears), with ages ranging from 17 to 30 years were enrolled in this study. Subjects were instructed to lie in supine position and elevate their heads unsupported. The VEMP was recorded using 500Hz STB and then click sound stimuli to each ear. The latency p13, n23, peak-to-peak p13-n23 amplitude and VEMP asymmetry ratio (VAR) were obtained for further analysis. RESULTS: The VEMP responses were present in all subjects. The latencies p13 and n23 of STB-VEMP were significantly longer, and the p13-n23 amplitudes were significantly greater for STB-VEMP (p<0.05, paired t test), as well. The VAR, however, showed no significant difference between the 2 stimuli. The latency n23 of click VEMP in our study was significantly different from that of 1 of the other studies (p<0.05). CONCLUSION: The VEMP responses were significantly different between the stimuli of STB and click, and the norms of different stimuli should be established for clinical interpretations. For clinical diagnosis using VEMP, we recommend STB stimuli because the latencies and amplitudes of click were significantly different among several labs, including ours.

CO2 laser myringotomy in children with otitis media with effusion.

BACKGROUND: The study aimed to evaluate the clinical application of CO2 laser myringotomy in children with otitis media with effusion (OME) under topical anaesthesia in an office setting. METHODS: Laser myringotomy was performed with the CO2 laser Otoscan (OtoLAM) in 54 children (73 ears) with OME. The procedure on the tympanic membrane was performed under topical anaesthesia using Bonain's solution or 10 per cent Xylocaine (lidocaine) solution for 30 minutes before surgery. A circular perforation was created with a power of 15 W, single pulse duration of 200 msec and a scanned area of 1.9 mm in diameter. RESULTS: The mean healing time was 2.51 weeks (range 1-5 weeks). Effusion content was not a predictive prognostic factor for perforation healing time. Perforation location over anterior inferior or posterior inferior quadrants was not a predictive factor for perforation healing time. Xylocaine was the more effective anaesthestic. The OME resolution rate was 73 per cent. CONCLUSION: Laser myringotomy provides intermediate duration middle-ear ventilation. It could be beneficial in selected children with OME.