Consensus Statements on the Definition, Classification, and Diagnostic Tests for Tinnitus: A Delphi Study Conducted by the Korean Tinnitus Study Group.

BACKGROUND: Tinnitus is a bothersome condition associated with various symptoms. However, the mechanisms of tinnitus are still uncertain, and a standardized assessment of the diagnostic criteria for tinnitus is required. We aimed to reach a consensus on diagnosing tinnitus with professional experts by conducting a Delphi study with systematic review of the literature. METHODS: Twenty-six experts in managing tinnitus in Korea were recruited, and a two-round modified Delphi study was performed online. The experts evaluated the level of agreement of potential criteria for tinnitus using a scale of 1-9. After the survey, a consensus meeting was held to establish agreement on the results obtained from the Delphi process. Consensus was defined when over 70% of the participants scored 7-9 (agreement) and fewer than 15% scored 1-3 (disagreement). To analyze the responses of the Delphi survey, the content validity ratio and Kendall's coefficient of concordance were evaluated. RESULTS: Consensus was reached for 22 of the 38 statements. For the definition of tinnitus, 10 out of 17 statements reached consensus, with three statements achieving complete agreement including; 1) Tinnitus is a conscious perception of an auditory sensation in the absence of a corresponding external stimulus, 2) Tinnitus can affect one's quality of life, and 3) Tinnitus can be associated with hearing disorders including sensorineural hearing loss, vestibular schwannoma, Meniere's disease, otosclerosis, and others. For the classification of tinnitus, 11 out of 18 statements reached consensus. The participants highly agreed with statements such as; 1) Vascular origin is expected in pulse-synchronous tinnitus, and 2) Tinnitus can be divided into acute or chronic tinnitus. Among three statements on the diagnostic tests for tinnitus only Statement 3, "There are no reliable biomarkers for sensory or emotional factors of tinnitus." reached consensus. All participants agreed to perform pure-tone audiometry and tinnitus questionnaires, including the Tinnitus Handicap Inventory and Tinnitus Questionnaire. CONCLUSION: We used a modified Delphi method to establish a consensus-based definition, a classification, and diagnostic tests for tinnitus. The expert panel reached agreement for several statements, with a high level of consensus. This may provide practical information for clinicians in managing tinnitus.

Management of frontal sinus trauma: a retrospective study of surgical interventions and complications.

BACKGROUND: Frontal sinus injuries are relatively rare among facial bone traumas. Without proper treatment, they can lead to fatal intracranial complications, including meningitis or brain abscesses, as well as aesthetic and functional sequelae. The management of frontal sinus injuries remains controversial, with various treatment methods and outcomes being reported. This article describes the clinical characteristics, surgical methods, and outcomes among 17 patients who underwent surgery for frontal sinus injury and related complications. CASE PRESENTATION: We retrospectively included 17 patients who underwent surgery for frontal sinus injury and its related complications at the Kangwon National University Hospital between July 2010 and September 2021. Among them, six underwent simple open reduction and fixation of the anterior wall, eight underwent sinus obliteration, and three underwent cranialization. Two patients who underwent sinus obliteration died due to infection-related complications. The patient who underwent cranialization reported experiencing chronic headache and expressed dissatisfaction regarding the esthetic outcomes of the forehead. Except for these three patients, the other patients achieved satisfactory esthetic and functional recovery. CONCLUSION: Active surgical management of frontal sinus injuries is often required owing to the various complications caused by these injuries; however, several factors, including the fracture type, clinical presentation, related craniomaxillofacial injury, and medical history, should be considered while formulating the treatment plan. Surgical treatment through the opening of the frontal sinus should be actively considered in patients with severely damaged posterior wall fractures and those at risk of developing infection.

The 24-Hour Cardiac Autonomic Activity in Patients With Allergic Rhinitis.

BACKGROUND: Definitive knowledge of the 24-hour cardiac autonomic activity in patients with allergic rhinitis (AR) is lacking. Thus, we aimed to evaluate heart rate variability (HRV), which is used to measure cardiac autonomic activity by 24-hour Holter monitoring in patients with AR. METHODS: We enrolled 32 patients who visited our clinic and were diagnosed with AR. The control group was selected four-fold (n = 128) by matching (age, sex, hypertension, and diabetes) in the AR group from a Holter registry in the cardiology department. The HRV results, which were measured using 24-hour Holter monitoring, were compared between the AR and control groups. RESULTS: All time-domain parameters of HRV revealed no differences between the groups. However, among the frequency domain parameters of HRV, the low-frequency to high-frequency ratio and low-frequency power in normalized units were significantly lower in the AR group. Conversely, high-frequency power in normalized units was significantly higher in the AR group. In the multiple regression analysis, AR was independently associated with sympathetic withdrawal (adjusted odds ratio = 3.393, P = 0.020) after adjusting for age, sex, hypertension, diabetes mellitus, and hyperlipidemia. CONCLUSIONS: The present findings suggest differences in cardiac autonomic activity which are related with sympathetic withdrawal in patients with AR compared with that in the normal population over 24 hours.

Does Listening to Tinnitus Frequency-Filtered Music Relieve Tinnitus?

BACKGROUND AND OBJECTIVES: Tinnitus frequency-filtered music therapy aims to restore lateral inhibition to reverse tonotopic reorganization in the auditory cortex. Although the tinnitus-relieving effect of this therapy has been investigated, the results remain controversial. We performed a prospective, randomized, controlled double-blind study to determine the tinnitus-suppressing effect of tinnitus frequency-filtered music therapy. SUBJECTS AND METHODS: The study included 90 participants who were randomly categorized into an experimental group that listened to tinnitus frequency-filtered music and a control group that listened to music from which a random frequency was removed. The Tinnitus Handicap Inventory (THI) score and measures of tinnitus loudness, daily awareness, and tinnitus-induced annoyance were evaluated at the initial visit and at 3 and 6 months (final follow-up). The rates of improvement in THI scores in the two groups were also recorded. RESULTS: All measured variables showed significant improvement in both groups, except the matched tinnitus loudness and minimal masking level. However, no significant intergroup differences were observed in the amount of improvement in THI scores and any other variable. The rates of improvement in THI scores were higher in the control group at 3 and 6 months. CONCLUSIONS: Listening to tinnitus frequency-filtered music reduced tinnitus-induced handicaps; however, this approach was not significantly better than listening to music from which a random frequency was removed.

The differences between daytime and nighttime heart rate variability may usefully predict the apnea-hypopnea index in patients with obstructive sleep apnea.

STUDY OBJECTIVES: The association between daytime/nighttime heart rate variability (HRV) and the apnea-hypopnea index (AHI) remains unclear. We sought a relationship between AHI and the daytime-to-nighttime HRV ratio as measured by 24-hour Holter monitoring in patients with obstructive sleep apnea. METHODS: We prospectively enrolled 66 patients who visited our sleep clinic complaining of habitual snoring or sleep apnea. All underwent 24-hour Holter monitoring (to measure HRV) combined with full-night polysomnography. Sixty-two met our enrollment criteria. We evaluated the associations between HRV frequency domains and the polysomnography indices. We also considered medical histories and anthropometric data. RESULTS: The nighttime very-low-frequency (VLF), low-frequency (LF), and high-frequency HRVs were significantly higher than the daytime values. On correlation analysis, the day/night VLF (r = .550, P < .001), LF (r = .556, P < .001), and high-frequency (r = .303, P = .017) HRVs were significantly related to the AHI. Of the day/night HRV ratios, the VLF (P for trend = .003) and LF (P for trend = .013) ratios decreased significantly by obstructive sleep apnea severity. Multivariable analysis showed that the day/night VLF (ß = 16.387, P < .001) and day/night LF (ß = 25.248, P < .001) were independently (and significantly) associated with the AHI. CONCLUSIONS: Twenty-four-hour Holter monitoring may usefully predict AHI. The day/night VLF and day/night LF ratios tended to decrease by obstructive sleep apnea severity and were independently associated with the AHI. CITATION: Nam E-C, Chun KJ, Won JY, Kim J-W, Lee WH. The differences between daytime and nighttime heart rate variability may usefully predict the apnea-hypopnea index in patients with obstructive sleep apnea. J Clin Sleep Med. 2022;18(6):1557-1563.

Effect of sinus opacification on the severity of obstructive sleep apnea.

PURPOSE: The association between rhinosinusitis and obstructive sleep apnea (OSA) remains unclear. Here, we aimed to elucidate the association between sinus opacification and OSA severity. METHODS: Patients with snoring problems who visited our clinic from April 2018 to December 2020 were retrospectively enrolled. Among these patients, we included those who underwent a physical examination, overnight polysomnography, and osteomeatal-unit computed tomography. We evaluated the association between apnea-hypopnea index (AHI) and Lund-Mackay score (LMS). LMS ≥ 5 was considered indicative of sinus opacification. RESULTS: Among the 122 patients included in the study, LMS exhibited an increasing trend based on OSA severity. The LMS in the moderate OSA group was significantly higher than that in the no OSA group (P = 0.002), and the LMS in the severe OSA group was significantly higher than that in the no OSA (P < 0.001) and mild OSA (P = 0.006) groups. A correlation analysis revealed that AHI was significantly associated with body mass index (BMI) (r = 0.367, P < 0.001) and LMS (r = 0.255, P = 0.005). A multivariate analysis revealed that sinus opacification was associated with moderate and severe OSA [Adjusted odds ratio = 11.986 (P = 0.005) and 3.756 (P = 0.044), respectively] after adjusting for age, sex, BMI, smoking, hypertension, atopy, tonsil size, and palatal position. The effect of sinus opacification on OSA severity was comparable to that of overweight. CONCLUSION: Sinus opacification may increase OSA severity since moderate and severe OSA is independently associated with it.

Direct and Transcutaneous Vagus Nerve Stimulation for Treatment of Tinnitus: A Scoping Review.

Recent animal research has shown that vagus nerve stimulation (VNS) paired with sound stimuli can induce neural plasticity in the auditory cortex in a controlled manner. VNS paired with tones excluding the tinnitus frequency eliminated physiological and behavioral characteristics of tinnitus in noise-exposed rats. Several clinical trials followed and explored the effectiveness of VNS paired with sound stimuli for alleviating tinnitus in human subjects. Transcutaneous VNS (tVNS) has received increasing attention as a non-invasive alternative approach to tinnitus treatment. Several studies have also explored tVNS alone (not paired with sound stimuli) as a potential therapy for tinnitus. In this review, we discuss existing knowledge about direct and tVNS in terms of applicability, safety, and effectiveness in diminishing tinnitus symptoms in human subjects. This review includes all existing clinical and neuroimaging studies of tVNS alone or paired with acoustic stimulation in tinnitus patients and outlines the present limitations that must be overcome to maximize the potential of (t)VNS as a therapy for tinnitus.

A double-blind, randomized controlled trial exploring the efficacy of frequency lowering hearing aids in patients with high-frequency hearing loss.

OBJECTIVE: Whether linear frequency transposition (LFT) assists individuals with hearing difficulties has been studied for years, but no reliable comparison between LFT hearing aids (HAs) and conventional compression-type HAs has been conducted. Herein, we report on the first, relevant, double-blind, randomized controlled trial on this topic using a large sample size. We compared the efficacies of LFT HAs to those of compression-type HAs in patients with high-frequency hearing loss (HFHL); we also reviewed the literature. METHODS: A total of 103 patients were randomized into three groups: conventional HAs featuring wide dynamic range compression (control group); HAs featuring LFT (LFT group); and HAs employing both LFT and wide dynamic range compression of high frequencies (combined group). Pure tone averages (PTAs), speech recognition thresholds (SRTs), word recognition scores (WRSs), and Abbreviated Profile of Hearing Aid Benefit (APHAB) inventories were assessed at the initial visit and after 3 months of HA use. Subject preferences in terms of continued use of their HAs were also evaluated. RESULTS: The PTA, SRT, and WRS scores significantly improved in all three groups. No significant among-group differences were evident. The APHAB score significantly improved only in the control group; HA future-use preference was also highest in this group. CONCLUSION: LFT did not provide an additional benefit for subjects with HFHL over conventional amplification and users preferred conventional HAs featuring wide dynamic range compression.

Does the tinnitus pitch correlate with the frequency of hearing loss?

BACKGROUND: The tonotopic model of tinnitus claims that the tinnitus pitch corresponds to the audiometric edge; the homeostatic model suggests that it falls within the hearing loss (HL) area. The existing evidence mostly supports the homeostatic model, but the relationship between the tinnitus pitch and the HL frequencies has been insufficiently explored. AIMS/OBJECTIVE: To investigate the association between the tinnitus pitch and the audiometric profile in the largest study population to date. MATERIALS AND METHODS: Three hundred and ninety-three patients with tonal or narrow-band tinnitus participated. HL frequencies included 30, 40, 50 (F50), 60 dB, and maximum HL. We defined edge frequencies in four different ways according to the existing studies. We assessed the association between all estimated frequencies and the tinnitus pitch using t-tests, Spearman's correlation, and multiple regression. RESULTS: All calculated frequencies differed significantly from the tinnitus pitch except for F50. None were correlated with the tinnitus pitch. F50 was the only significant predictor among the estimated frequencies in multiple regression. CONCLUSIONS: The tinnitus pitch fell within the HL area, and was mildly associated with F50. SIGNIFICANCE: Our results support the homeostatic tinnitus model, and provide reliable evidence that tinnitus pitch does not correspond to the audiometric edge.

What Makes Tinnitus Loud?

INTRODUCTION: Tinnitus loudness is a subjective measure, and it does not directly reflect either tinnitus severity or the impact on daily life. Nevertheless, loud tinnitus may be the most frequent clinical complaint of tinnitus patients. Factors contributing to the loudness of the phantom sound have rarely been studied. We evaluated both matched and self-rated loudness in a large sample of patients with tinnitus and analyzed the influencing factors among demographic, hearing, and tinnitus characteristics. METHODS: Two hundred ninety-nine patients with chronic tinnitus were enrolled. We evaluated the matched loudness, minimal masking level (MML), and visual analog scale (VAS) loudness. Stepwise multiple regression analyses were performed for each loudness measure using independent variables of age, sex, time since tinnitus onset, tinnitus laterality, pure-tone average, tinnitus pitch, tinnitus handicap inventory (THI) score, VAS annoyance, disturbance and daily tinnitus duration, and depression score. We calculated bivariate correlations between each loudness measure and all independent variables. RESULTS: The psychoacoustic loudness measures (matched loudness and MML) were highly correlated and were affected by the hearing deficit and tinnitus pitch (Pearson r > 0.5 for pure tone averages, and r > 0.3 for tinnitus pitch for both variables, p < 0.05), whereas the subjective measurement (VAS loudness) exhibited little to no correlation with the other two measures and was related to psycho-emotional factors such as the THI score, VAS variables, and depression (Pearson r > 0.6 for VAS annoyance, r > 0.4 for VAS daily duration and disturbance and THI score, r > 0.3 for the depression score, p < 0.05). CONCLUSION: The matched tinnitus loudness and MML values were influenced principally by the extent of hearing loss and related factors, suggesting that rehabilitation using hearing aids could help reduce perception of tinnitus loudness. A psycho-emotional approach might more effectively lessen self-perceived loudness.

Clinical Manifestations of Allergic Rhinitis by Age and Gender: A 12-Year Single-Center Study.

OBJECTIVES: Currently, epidemiological data on allergic rhinitis collected through the skin prick test are scarce. Moreover, the relationship of age and sex to allergic rhinitis is not comprehensively understood. This study aimed to characterize allergic rhinitis and the associated clinical manifestations by age and sex. METHODS: We retrospectively investigated data from 2883 patients who visited a single university hospital for rhinitis symptoms between January 2003 and December 2014. Of these 2883 patients, 1964 who underwent a skin prick test with 11 standardized allergen extracts and completed a nasal symptom questionnaire were enrolled. The clinical characteristics of allergen sensitization and nasal symptoms were analyzed by sex and age distribution. RESULTS: The prevalence of allergen sensitization progressively decreased with age after peaking at between 20 and 29 years. The sensitization rate was higher in males than in females (P = .046). The sensitization rate to house dust mites decreased with age, while sensitization to mugwort and ragweed increased. Six allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, mugwort, trees, ragweed, and cats) were sufficient to identify >96% of patients with allergen sensitization. Nasal obstruction tended to decrease with age and was more prevalent in males (P = .002) than in females, while rhinorrhea (P = .007) and itching (P = .013) were more prevalent in females. Total nasal symptom scores did not differ by sex. CONCLUSIONS: The clinical characteristics of allergic rhinitis, including allergen-sensitization patterns and related symptoms, varied by age and sex. Six common allergens could be sufficient to generate a cost-effective tool to identify allergic rhinitis.

Tinnitus Suppression Effect of Hearing Aids in Patients With High-frequency Hearing Loss: A Randomized Double-blind Controlled Trial.

INTRODUCTION: Hearing aids (HAs) with frequency lowering have been used for high-frequency hearing loss (HFHL), but their effects on tinnitus relief have not been studied extensively. This randomized double-blind trial was performed to investigate and compare tinnitus suppression effects of conventional type HAs and frequency-lowering HAs in patients with HFHL. METHODS: A total of 114 patients were randomized into three groups: conventional HA using wide dynamic range compression, HA with frequency translation, and HA with linear frequency transposition. Participants wore HAs for 3 months and then discontinued their use. The final evaluation was performed at 3 months after cessation of wearing HA (6 mo after the initial visit). The Tinnitus Handicap Inventory (THI) score and additional variables, such as matched tinnitus loudness and visual analog scale scores of subjectively perceived tinnitus loudness, daily awareness, and annoyance, were measured at the initial visit and at 3- and 6-month follow-ups. RESULTS: THI score and most of the additional outcomes were significantly improved at 3 and 6 months (3 mo after HA removal) compared with their initial values in all three groups. The incidence rates of patients with improvements in the THI score by 20% or more were 71.0, 72.7, and 74.3% at 3 months, and 54.8, 51.6, and 59.4% at 6 months for the three groups, respectively. There were no significant differences in primary or additional variables between hearing aid types at either 3 or 6 months. CONCLUSION: This is a consolidated standards of reporting trials-guided study providing direct evidence for tinnitus suppression effects of HA alone, without accompanying counseling or any other treatments, which lasted for at least 3 months after patients stopped using HAs. HAs effectively suppressed tinnitus in patients with HFHL regardless of the amplification strategy type.

Functional MRI evidence of the cortico-olivary efferent pathway during active auditory target processing in humans.

Auditory target detection has been explored by a number of studies, but none have demonstrated activity in the auditory subcortical centers evoked by the top-down attentional mechanism related to target detection in humans. We applied functional magnetic resonance imaging (fMRI) with sparse sampling to explore activity in the auditory centers, particularly in the subcortex, during an active auditory target detection task. Fourteen healthy subjects with normal hearing tapped the left index finger in response to target tonal stimuli presented among other (non-target) stimuli during continuous white noise stimulation. General linear model, region-of-interest, and connectivity analyses were performed. In the cortex, bilateral auditory cortices as well as the cingulate gyrus, thalamus, and supramarginal gyrus were activated to target stimuli and functionally connected to each other. In the subcortex, the superior olivary complex (SOC) and locus coeruleus were activated to the target but not to the non-target or background noise stimuli. The SOC was the only auditory subcortical center that displayed connectivity to the auditory cortical areas as well as the cingulate and supramarginal gyri during target presentation but not during other conditions. SOC activation appears to be the first fMRI evidence of direct cortico-olivary projections in the human brain as well as SOC participation in auditory target detection. Our results may be an initial step towards developing a noninvasive methodology to evaluate the functional integrity of the auditory efferent system in humans.

Sequential versus Combination Treatment Using Steroids and Diuretics for Acute Low-Frequency Sensorineural Hearing Loss: A Noninferiority Trial.

OBJECTIVE: Acute low-frequency hearing loss (ALHL) is typically treated with combination therapy, including steroids and diuretics. To avoid unnecessary use of steroids we proposed a method of sequential administration using these two drugs, and compared the efficacy of our protocol with that of existing combination treatments. METHODS: A prospective, randomized, open-label, single-blind, noninferiority clinical trial was conducted to investigate whether the effectiveness of sequential treatment is noninferior to that of combination treatment for ALHL. Ninety-two patients with ALHL received either steroids and diuretics simultaneously for 2 weeks (combination group), or diuretics for 2 weeks followed by steroids for another 2 weeks if they did not respond to diuretic treatment (sequential group). The primary outcome measure was a change in mean hearing threshold at three frequencies (125, 250, and 500 Hz) at 4 weeks after treatment. RESULTS: The mean hearing threshold of the low frequencies improved 20.0 and 17.2 dB in the combination and the sequential group, respectively. The 95% lower confidence interval was -8.0 dB and noninferiority was established at p < 0.05. At 4 weeks after treatment, the complete recovery rate was 80.5 and 82.9% in the combination and sequential groups, respectively. CONCLUSION: This is the first study on ALHL treatment following the establishment of Consolidated Standards of Reporting Trials (CONSORT). The sequential treatment is not inferior to combination treatment for ALHL, and therefore may be a better treatment guideline for ALHL considering that patients receive less steroid exposure and smaller restrictions in diuretic use compared with steroids.

BOLD fMRI effects of transcutaneous vagus nerve stimulation in patients with chronic tinnitus.

OBJECTIVE: Vagus nerve stimulation (VNS) is a neuromodulation method used for treatment of epilepsy and depression. Transcutaneous VNS (tVNS) has been gaining popularity as a noninvasive alternative to VNS. Previous tVNS neuroimaging studies revealed brain (de)activation patterns that involved multiple areas implicated in tinnitus generation and perception. In this study, functional magnetic resonance imaging (fMRI) was used to explore the effects of tVNS on brain activity in patients with tinnitus. METHODS: Thirty-six patients with chronic tinnitus received tVNS to the inner tragus, cymba conchae, and earlobe (sham stimulation). RESULTS: The locus coeruleus and nucleus of the solitary tract in the brainstem were activated in response to stimulation of both locations compared with the sham stimulation. The cochlear nuclei were also activated, which was not observed in healthy subjects with normal hearing. Multiple auditory and limbic structures, as well as other brain areas associated with generation and perception of tinnitus, were deactivated by tVNS, particularly the parahippocampal gyrus, which was recently speculated to cause tinnitus in hearing-impaired patients. CONCLUSIONS: tVNS via the inner tragus or cymba conchae suppressed neural activity in the auditory, limbic, and other tinnitus-related non-auditory areas through auditory and vagal ascending pathways in tinnitus patients. The results from this study are discussed in the context of several existing models of tinnitus. They indicate that the mechanism of action of tVNS might be involved in multiple brain areas responsible for the generation of tinnitus, tinnitus-related emotional annoyance, and their mutual reinforcement.

Changes in the regional shape and volume of subcortical nuclei in patients with tinnitus comorbid with mild hearing loss.

PURPOSE: Tinnitus, the perception of sound without an external source, is a prevalent disease, but its underlying mechanism has not been fully elucidated. Recent studies have suggested the involvement of subcortical nuclei in tinnitus generation. We investigated changes in the local shape and volume of subcortical nuclei in relation to tinnitus. METHODS: The participants included 53 patients with tinnitus and 52 age- and gender-matched normal controls. Individual 3D T1-weighted structural images were obtained using 3-T magnetic resonance imaging. Surface-based vertex analysis (SVA) was performed with automated segmentation of the bilateral caudate nuclei, putamina, nucleus accumbens, thalami, pallidum, hippocampi, amygdalae, and brainstem. The scalar distances from the mean surface and volumes of 15 nuclei were compared between the tinnitus and control groups and correlated with tinnitus handicap score (THI) and tinnitus duration. RESULTS: SVA revealed regional contractions in the accessory basal and lateral nuclei of the right amygdala and expansions in the left medial and right ventral posterior nuclei and lateral dorsal nucleus of both thalami. The surface distances of the right nucleus accumbens were positively correlated with tinnitus duration, while those of the left nucleus accumbens and left hippocampus were negatively correlated with THI. CONCLUSION: Regional atrophy of the amygdala may indicate self-modulation of emotional response regulation to diminish tinnitus-related emotional distress. Thalamic regional expansion may signify dysfunctional auditory gating in the thalamus, where inhibition of the tinnitus signal at the thalamus level is disrupted due to abnormal changes in the limbic system, ultimately leading to the tinnitus percept.

Diagnostic Criteria for Somatosensory Tinnitus: A Delphi Process and Face-to-Face Meeting to Establish Consensus.

Since somatic or somatosensory tinnitus (ST) was first described as a subtype of subjective tinnitus, where altered somatosensory afference from the cervical spine or temporomandibular area causes or changes a patient's tinnitus perception, several studies in humans and animals have provided a neurophysiological explanation for this type of tinnitus. Due to a lack of unambiguous clinical tests, many authors and clinicians use their own criteria for diagnosing ST. This resulted in large differences in prevalence figures in different studies and limits the comparison of clinical trials on ST treatment. This study aimed to reach an international consensus on diagnostic criteria for ST among experts, scientists and clinicians using a Delphi survey and face-to-face consensus meeting strategy. Following recommended procedures to gain expert consensus, a two-round Delphi survey was delivered online, followed by an in-person consensus meeting. Experts agreed upon a set of criteria that strongly suggest ST. These criteria comprise items on somatosensory modulation, specific tinnitus characteristics, and symptoms that can accompany the tinnitus. None of these criteria have to be present in every single patient with ST, but in case they are present, they strongly suggest the presence of ST. Because of the international nature of the survey, we expect these criteria to gain wide acceptance in the research field and to serve as a guideline for clinicians across all disciplines. Criteria developed in this consensus paper should now allow further investigation of the extent of somatosensory influence in individual tinnitus patients and tinnitus populations.

Epidemiology of Clinically Significant Tinnitus: A 10-Year Trend From Nationwide Health Claims Data in South Korea.

OBJECTIVES: Prevalence of tinnitus has been reported to vary according to the target population and definition of tinnitus. To improve the understanding of tinnitus, authors used the nation-wide health claim data to study the tinnitus in the entire population of South Korea. STUDY DESIGN: Retrospective big data review. SETTING: Analysis of big data from the National Health Information Database. PATIENTS: Patients diagnosed with tinnitus according to International Classification of Diseases code 10th edition (ICD-10) and requested to receive National Health Insurance claim at least once from January 2006 to December 2015. INTERVENTION: None. MAIN OUTCOME MEASURE: Epidemiologic data, association of tinnitus with the otologic and systemic diseases. RESULTS: The number of patients who received medical care because of tinnitus was 1.44% (0.78 million per 51 million) in 2015. There was a higher prevalence of tinnitus in women, and the overall prevalence increased with increasing age of patients and peaked at patients in their 70s (4.43%). The prevalence of tinnitus among patients aged 10 to 30 years, showed a tendency to increase during study period. In the regional analysis, highest prevalence was observed in Gwangju (2.02%). In comparison with the control group, the patients with tinnitus showed a higher frequency in otologic and systemic disease. Especially, noise induced hearing loss (adjusted odds ratio [AOR] = 82.1, 95% confidence interval [95% CI] = 74.8-90.2) and sudden sensorineueal hearing loss (AOR = 49.7, 95% CI = 48.4-51.0) showed high frequency in tinnitus patient group. CONCLUSIONS: The prevalence and incidence of tinnitus in this study for entire nation were lower than previously reported studies. These results have limitation because the study only covered patient using the medical service for tinnitus and missed tinnitus sufferers not seeking medical service. However, this study is meaningful in that it was targeting entire nation, reflected the characteristics of clinically significant tinnitus patient enough to visit medical service.

The Effect of Primary Levels and Frequencies on the Contralateral Suppression of Distortion Product Otoacoustic Emission.

BACKGROUND AND OBJECTIVES: Changes in distortion product otoacoustic emission (DPOAE) caused by contralateral suppression (CS) allow the function of the auditory efferent system to be evaluated. Parameters affording maximum CS are preferred in terms of clinical application. Our objective was to evaluate the effects of primary levels and frequencies on DPOAE-mediated CS. SUBJECTS AND METHODS: Sixteen subjects with normal hearing participated. DPOAEs were recorded with and without contralateral acoustic stimulation; we delivered broadband noise of 65 dB SPL at f2 frequencies between 1,000 Hz and 6,727 Hz, at 8 pt/octave. The L2 was varied between 40 dB SPL and 80 dB SPL in 10-dB steps. RESULTS: L2 did not significantly affect DPOAE-mediated CS. Higher L2 levels significantly reduced the fine structure depth of both the baseline and suppressed DPOAE datasets. The amount of CS was greatly affected by the f2 frequency; lower and higher frequency ranges afforded significantly stronger suppression than did mid-frequencies within the studied range. CONCLUSIONS: Our findings suggest that DPOAE CS should be measured over a wide range of frequencies as the amount of CS seems to be highly dependent on f2. The use of a higher L2 level may be optimal when it is sought to evoke strong DPOAE-mediated suppression while simultaneously minimizing DPOAE fine structure. Our findings may assist in optimization of clinical procedures evaluating the integrity of the auditory efferent system.

Clinical effect of intratympanic dexamethasone injection in acute unilateral tinnitus: A prospective, placebo-controlled, multicenter study.

OBJECTIVE: The purpose of this study was to investigate the effectiveness of intratympanic dexamethasone injection (ITDI) in acute tinnitus of presumed cochlear origin. STUDY DESIGN: A prospective, randomized, placebo-controlled, double-blinded, multicenter study. METHODS: Between August 2013 and December 2015, 54 patients with unilateral tinnitus were enrolled at four different centers. Patients were assigned either to an ITDI (n = 27) or an intratympanic normal saline injection (ITNI; n = 27) group through block randomization. Intratympanic injections were administered four times over 2 weeks. At 4 weeks after initial injection, we analyzed the improvement rates of tinnitus using the tinnitus handicap Inventory (THI) and visual analogue scale (VAS) for loudness, awareness, and annoyance. We defined improvement as the reduction of more than 7 points or of more than 20% in the final THI score compared to the initial THI score. RESULTS: The initial mean hearing thresholds and VAS and THI scores of the two groups did not differ significantly. At 4 weeks after initial injection, the mean VAS and THI scores of both groups had significantly reduced. However, the improvement rate did not differ significantly between the groups (ITDI, 51.9%; ITNI, 59.3%). CONCLUSION: The results indicate that ITDI might not be more effective than ITNI for the treatment of acute unilateral tinnitus. Therefore, ITDI should not be considered as the main treatment for patients presenting with acute tinnitus as the primary symptom. LEVEL OF EVIDENCE: 1b. Laryngoscope, 128:184-188, 2018.