Foreign Body Complications in Ears due to Mishandled Hearing Aid Fitting and Proposed Clinical Guidelines to Address the Complications.

BACKGROUND: South Korea has one of the world's fastest aging populations and is witnessing increased age-related hearing impairment cases as well as an increase in the number of hearing aid users. The aim of this study was to analyze complications caused by hearing aid mold materials. In addition, we hope to raise awareness of the harm and danger that inexperienced hearing aid providers can cause to patients. METHODS: We retrospectively reviewed the medical records of 11 patients who were diagnosed with hearing aid mold material as a foreign body in the ear at a tertiary center between 2016 and 2020. The following data were analyzed: symptoms, endoscopic findings, audiometry, temporal bone CT images, treatment methods, and complications after removal. The currently available literature was also reviewed to develop clinical guidelines, to identify the systematic weaknesses in the South Korean hearing aid market, and to identify policies that warrant better quality control. RESULTS: Among the 11 cases, 9 were restricted to the external auditory canal, all of which were successfully removed under endoscopy with minor complications. Two cases with middle ear involvement resulted in infection and thus required surgical removal with mastoidectomy. The average age of these patients was 76.4, and all patients received their molding procedure at private hearing aid shops without an otolaryngologist's examination. CONCLUSION: Thorough patient history-taking and otologic examination must be performed to identify patients at higher risk of complications. Such patients should be referred to an otolaryngologist. If a patient exhibits alarming symptoms, early referral is critical since prompt surgery can minimize complications. A CT scan is highly recommended to determine an optimal approach for foreign body removal. Systematic and regulatory changes in hearing aid dispensers, such as requiring apprenticeship, raising the required level of education, and legally mandating referrals, can help reduce these complications.

Acute Alcohol Intake Deteriorates Hearing Thresholds and Speech Perception in Noise.

OBJECTIVES: The hearing process involves complex peripheral and central auditory pathways and could be influenced by various situations or medications. To date, there is very little known about the effects of alcohol on the auditory performances. The purpose of the present study was to evaluate how acute alcohol administration affects various aspects of hearing performance in human subjects, from the auditory perceptive threshold to the speech-in-noise task, which is cognitively demanding. METHODS: A total of 43 healthy volunteers were recruited, and each of the participants received calculated amounts of alcohol according to their body weight and sex with a targeted blood alcohol content level of 0.05% using the Widmark formula. Hearing was tested in alcohol-free conditions (no alcohol intake within the previous 24 h) and acute alcohol conditions. A test battery composed of pure-tone audiometry, speech reception threshold (SRT), word recognition score (WRS), distortion product otoacoustic emission (DPOAE), gaps-in-noise (GIN) test, and Korean matrix sentence test (testing speech perception in noise) was performed in the 2 conditions. RESULTS: Acute alcohol intake elevated pure-tone hearing thresholds and SRT but did not affect WRS. Both otoacoustic emissions recorded with DPOAE and the temporal resolution measured with the GIN test were not influenced by alcohol intake. The hearing performance in a noisy environment in both easy (-2 dB signal-to-noise ratio [SNR]) and difficult (-8 dB SNR) conditions was decreased by alcohol. CONCLUSIONS: Acute alcohol elevated auditory perceptive thresholds and affected performance in complex and difficult auditory tasks rather than simple tasks.

Quantitative analysis of cochlear signal intensity on three-dimensional and contrast-enhanced fluid-attenuated inversion recovery images in patients with Meniere's disease: Correlation with the pure tone audiometry test.

PURPOSE: The purpose of this study was to correlate the quantitative analysis of cochlear signal intensity (SI) on 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and contrast-enhanced (CE) 3D-FLAIR images with results of the pure tone audiometry (PTA) test in patients with Meniere's disease (MD). MATERIALS AND METHODS: Over a 3-year period, 123 patients with MD underwent 3-Tesla (3 T) temporal magnetic resonance imaging (MRI), including 3D-FLAIR and CE-FLAIR sequences. The SI of membranous labyrinth of the cochlea in both ears of each patient was measured by drawing a region of interest (ROI) with a seed growing technique. The correlation between measured cochlear SIs on 3D-FLAIR and CE-FLAIR images, contrast enhancement index (CEI), and contrast enhancement ratio (CER) and clinical findings and pre- and post-treatment PTA results were assessed. RESULTS: Cochlear signal ratios of symptomatic ears on 3D-FLAIR and CE-FLAIR images were significantly higher than those of asymptomatic ears (P < 0.001). The area under the curve, from the receiver operating characteristic curve of cochlear SIs on 3D-FLAIR and CE-FLAIR images for discrimination between symptomatic and asymptomatic ears, was 0.729 and 0.728, respectively. Cochlear SIs on 3D-FLAIR and CE-FLAIR images were significantly correlated with patients' sex (P < 0.05 and P < 0.01, respectively), symptomatic ear (both P < 0.0001), and pre-treatment PTA (P < 0.0001 and P < 0.005, respectively), but were not significantly correlated with patients' age, post-treatment PTA or hearing threshold level at 0.5, 1.0, 2.0, or 4.0 kHz. CONCLUSION: Quantitative analysis of cochlear SI on 3D-FLAIR and CE-FLAIR images may be a helpful diagnostic adjunct for MD, but may be of little value in predicting the prognosis of MD.

Isolated horizontal positional nystagmus from a posterior fossa lesion.

Isolated vertigo with horizontal positional nystagmus as an impending sign of a central lesion has rarely been reported. Here we present neuro-otologic findings of patients with these clinical signs. Lesion overlays from 6 patients with ageotropic positional nystagmus revealed that the nodulus and vermis are common areas of injury. In contrast, 2 patients with geotropic positional nystagmus had cerebellar peduncle and lateral medullary lesions. These clinical findings suggest that vertigo with horizontal positional nystagmus, even in the absence of other initial neurological signs, may indicate a posterior fossa lesion, including that in the nodulus, vermis, and deep cerebellar structures.

Analysis of Predisposing Factors for Hearing Loss in Adults.

We aimed to estimate the effects of various risk factors on hearing level in Korean adults, using data from the Korea National Health and Nutrition Examination Survey. We examined data from 13,369 participants collected between 2009 and 2011. Average hearing thresholds at low (0.5, 1, and 2 kHz) and high frequencies (3, 4, and 6 kHz), were investigated in accordance with various known risk factors via multiple regression analysis featuring complex sampling. We additionally evaluated data from 4,810 participants who completed a questionnaire concerned with different types of noise exposure. Low body mass index, absence of hyperlipidemia, history of diabetes mellitus, low incomes, low educational status, and smoking were associated with elevated low frequency hearing thresholds. In addition, male sex, low body mass index, absence of hyperlipidemia, low income, low educational status, smoking, and heavy alcohol consumption were associated with elevated high frequency hearing thresholds. Participants with a history of earphone use in noisy circumstances demonstrated hearing thresholds which were 1.024 dB (95% CI: 0.176 to 1.871; P = 0.018) higher, at low-frequencies, compared to participants without a history of earphone use. Our study suggests that low BMI, absence of hyperlipidemia, low household income, and low educational status are related with hearing loss in Korean adults. Male sex, smoking, and heavy alcohol use are related with high frequency hearing loss. A history of earphone use in noisy circumstances is also related with hearing loss.

Clinical efficacy of the Romberg test using a foam pad to identify balance problems: a comparative study with the sensory organization test.

The modified Romberg test using a foam pad ("MRuFP") as a bedside examination has been used to assess the function of the complex sensory input needed for upright stance. The objective of this study was to assess its clinical value detecting vestibular falls in comparison with the sensory organization test (SOT), the gold standard. In total, 80 patients who had undergone the MRuFP, SOT, and bithermal caloric tests were included in this study. The MRuFPs were performed on two (height 12 cm, MRu2FP) or three (18 cm, MRu3FP) layers of foam pads. The odds ratios of falling on SOT were calculated. Iterative algorithms were used for linear curve fitting between the balance time on the MRuFP and SOT equilibrium score (ES). The diagnostic performance of MRuFP under different conditions was poor, with low sensitivity (0.07-0.63), when the results of SOT were used as the gold standard. However, the odds ratios of failing SOT condition 5 were 6.78 (95% CI = 1.26-36.50) for patients with abnormal findings on eyes closed (EC)-MRu2FP and 10.91 (95% CI = 2.58-46.11) for those on the EC-MRu3FP in patients without caloric weakness. In patients with caloric weakness, the odds ratio of failing SOT condition 5 for patients with abnormal findings on EC-MRu2FP was 7.0 (95% CI = 0.69-70.74, p > 0.05), and 32.0 for those on EC-MRu3FP (95% CI = 2.81-364.7). A linear equation was presented as the model fit (adjusted R(2) = 0.355) predicting the SOT condition 5 ES according to the balance time on EC-MRu3FP. In conclusion, the EC-MRu3FP, as a bedside examination, correlated well with SOT condition 5 as an objective measure.

A multicenter randomized double-blind study: comparison of the Epley, Semont, and sham maneuvers for the treatment of posterior canal benign paroxysmal positional vertigo.

We evaluated the short-term efficacy of Epley, Semont, and sham maneuvers for resolving posterior canal benign paroxysmal positional vertigo (BPPV) in a prospective multicenter randomized double-blind controlled study. Subjects were randomly divided into three groups: Epley (36 patients), Semont (32 patients), and sham (Epley maneuver for the unaffected side, 31 patients). Out of 14 institutes which participated in this study, 5 institutes had previous experience of the Epley but not the Semont maneuver and the other 9 had previous experience of both maneuvers. Each maneuver was repeated twice if there was still positional vertigo or nystagmus on day 0, and the presence of nystagmus and vertigo on positional testing were evaluated immediately, 1 day, and 1 week after treatment. After the first maneuver, the Epley group showed a significantly higher resolution rate of positional nystagmus than the Semont or sham groups (63.9, 37.5, and 38.7%, respectively). After the second maneuver, the resolution rate (83.3%) of the Epley group was significantly higher than that (51.6%) of the sham group. At 1 day and 1 week after treatment, the resolution rate of the Epley group was significantly higher than those of the other groups. Similar results were seen for the resolution of positional vertigo. The Epley maneuver showed persistent resolution rates of positional vertigo and nystagmus without a fatigue phenomenon. The Epley maneuver was significantly more effective per maneuver than Semont or sham maneuvers for the short-term treatment of posterior canal BPPV. The Semont maneuver showed a higher success rate than the sham maneuver, but it was not significantly different.

Feasibility of video-based real-time nystagmus tracking: a lightweight deep learning model approach using ocular object segmentation.

Background: Eye movement tests remain significantly underutilized in emergency departments and primary healthcare units, despite their superior diagnostic sensitivity compared to neuroimaging modalities for the differential diagnosis of acute vertigo. This underutilization may be attributed to a potential lack of awareness regarding these tests and the absence of appropriate tools for detecting nystagmus. This study aimed to develop a nystagmus measurement algorithm using a lightweight deep-learning model that recognizes the ocular regions. Method: The deep learning model was used to segment the eye regions, detect blinking, and determine the pupil center. The model was trained using images extracted from video clips of a clinical battery of eye movement tests and synthesized images reproducing real eye movement scenarios using virtual reality. Each eye image was annotated with segmentation masks of the sclera, iris, and pupil, with gaze vectors of the pupil center for eye tracking. We conducted a comprehensive evaluation of model performance and its execution speeds in comparison to various alternative models using metrics that are suitable for the tasks. Results: The mean Intersection over Union values of the segmentation model ranged from 0.90 to 0.97 for different classes (sclera, iris, and pupil) across types of images (synthetic vs. real-world images). Additionally, the mean absolute error for eye tracking was 0.595 for real-world data and the F1 score for blink detection was ≥ 0.95, which indicates our model is performing at a very high level of accuracy. Execution speed was also the most rapid for ocular object segmentation under the same hardware condition as compared to alternative models. The prediction for horizontal and vertical nystagmus in real eye movement video revealed high accuracy with a strong correlation between the observed and predicted values (r = 0.9949 for horizontal and r = 0.9950 for vertical; both p < 0.05). Conclusion: The potential of our model, which can automatically segment ocular regions and track nystagmus in real time from eye movement videos, holds significant promise for emergency settings or remote intervention within the field of neurotology.

Association between Chronic Kidney Disease and Chronic Rhinosinusitis: A Longitudinal Follow-Up Study Using a National Health Screening Cohort.

Chronic kidney disease (CKD) is a leading cause of global mortality. While recent reports suggest potential connections between CKD and chronic rhinosinusitis (CRS), further research is needed to elucidate the direct association between CKD and CRS. This study investigated the association between CKD and CRS using data from the Korean National Health Insurance Service Health Screening Cohort. Participants were recruited according to medical claim codes, and individuals with CKD were matched in a 1:4 ratio with the control group. Covariates, such as demographics, health-related data, and medical history were used. The incidence rates and hazard ratio of CRS were analyzed. A further analysis was performed based on the presence of nasal polyps. Among the 514,866 participants, 16,644 patients with CKD and 66,576 matched controls were included in the analysis. The CKD group demonstrated a higher incidence of CRS than the controls: 18.30 versus 13.10 per 10,000 person-years. The CKD group demonstrated a higher risk of CRS than the control group (1.28 adjusted hazard ratio). In additional analyses, the CKD group did not exhibit a statistically significant correlation for the development of CRS with nasal polyps. This study suggests that CKD is associated with an increased risk for CRS.

Nationwide Prevalence of Video Head Impulse Test Abnormality and its Risk Factors in South Korea.

OBJECTIVE: To identify the prevalence of and relevant information for video head impulse test (vHIT) abnormality in a large population. STUDY DESIGN: A cross-sectional design. SETTING: Korean National Health and Nutrition Examination Survey, 2021. METHODS: The sample was representative of the Korean population, with 2237 participants aged ≥40 years. A vHIT was performed to evaluate vestibular function. The vestibulo-ocular reflex (VOR) gain and the presence of reproducible catch-up saccades was assessed in a vHIT. Participants also completed questionnaires for demographics, socioeconomic status, and basic information regarding systemic diseases and dizziness and underwent hearing tests with automated pure-tone audiometry. RESULTS: The prevalence of vHIT abnormality was 22.5%, with unilateral (14.3%) being more common than bilateral (8.2%). The prevalence of vHIT abnormality increased significantly with age, with the highest rate observed in individuals aged >70 years (42.5%). Both hearing and VOR gain deteriorated with age, but the patterns of age-related progression were different. While hearing loss (HL) deteriorated gradually and progressively throughout adulthood, VOR gain deterioration was markedly evident after 70 years of age. CONCLUSION: Considering the high prevalence of vHIT abnormality, appropriate social and medical policies are needed to prevent associated injuries and improve patients' quality of life. The distinct age-related changes in HL and objective findings of vestibular dysfunction indicate the need for different approaches to address these social problems in aging countries.

Clinical characteristics of persistent postural-perceptual dizziness and its visual subtype in Korean patients: A multicenter cross-sectional study.

OBJECTIVES: Persistent postural-perceptual dizziness (PPPD) is a chronic functional vestibular disorder for which the Bárány Society has established diagnostic criteria. This nationwide multicenter study aims to investigate the clinical features of individuals with definite PPPD and clinical variant PPPD who do not fully meet the diagnostic criteria, with a particular focus on visual exaggeration. METHODS: Between September 2020 and September 2021, a total of 76 individuals with definite PPPD and 109 individuals with clinical variant PPPD who did not meet all three exacerbating factors outlined in Criterion B were recruited from 18 medical centers in South Korea. The study gathered information on demographic factors, clinical manifestations, balance scales, and personality assessments. RESULTS: Comparative analysis between groups with definite PPPD and clinical variant with visual exacerbation revealed no significant differences in sociodemographic characteristics, clinical course, dizziness impact, and specific precipitants. Only disease duration was significantly longer in definite PPPD compared with variant with visual exacerbation. However, the variant without visual exacerbation displayed significantly reduced rates of panic disorder, diminished space-motion discomfort, lesser impact of dizziness, and decreased prevalence of depression when compared with the definitive PPPD. CONCLUSION: This is the first comprehensive nationwide study examining clinical features of both definite PPPD patients and its clinical variants, considering visual exacerbating factors. Differences in dizziness and personality traits emerged between definite PPPD and its potential variant without visual issues. Our results highlight the possibility of a distinct clinical variant of PPPD influenced by visual dependency.

Clinical observation on acute low-frequency hearing loss without vertigo: the role of cochlear hydrops analysis masking procedure as initial prognostic parameter.

OBJECTIVES: Even though it is currently not possible to prove a pathological diagnosis for inner ear disease, acute low-frequency hearing loss (ALFHL) without vertigo could be caused by inner ear hydrops because progression into the clinical spectrum of endolymphatic hydrops (EH) frequently occur among patients with the initial clinical presentation. Therefore, audiological measures representative of inner ear hydrops, such as the cochlear hydrops analysis masking procedure (CHAMP) test, may be used to predict the prognosis of ALFHL without vertigo. To test this hypothesis, we prospectively investigated patients with ALFHL unaccompanied by vertigo and examined whether the CHAMP test generated more useful information for prediction of progression into clinical spectrum of EH compared with other neurotologic parameters. DESIGN: A prospective clinical study of 28 patients who initially presented with ALFHL without vertigo was conducted. Detailed neurotologic findings from pure-tone audiometry, electrocochleography, CHAMP, spontaneous nystagmus, head-shaking nystagmus, vibration-induced nystagmus, the bithermal caloric test, and the rotatory chair test were recorded at the time of initial presentation. A regular audiological and clinical examination was conducted until either the last follow-up at our clinic or on the day on which secondary audiovestibular symptoms occurred. The rates of progression to Ménière's disease (MD) or clinical presentation compatible with isolated cochlear hydrops during the study period were calculated by the log-rank test and relative risk. A receiver operating characteristics curve was plotted to determine the prognostic value of CHAMP. RESULTS: Of 28 patients, 15 (53%) showed improvement in hearing on pure-tone audiometry. Seven patients (25%) showed hearing fluctuation and nine (32%) developed a vertigo attack during the observation period. Of these, three patients experienced both vertigo and a hearing fluctuation. Abnormal results of electrocochleography and neurotologic tests reflecting vestibular ocular reflex on yaw plane were common at the time of diagnosis of ALFHL in many patients, but these parameters were not associated with an increased risk of progression of clinical spectrum of EH. In contrast, patients with an abnormal complex amplitude ratio (CAR) on CHAMP had a 2.6-fold increased risk of progression to a clinical spectrum of EH (either hearing fluctuation or MD). The hazard ratio of developing MD for patients with normal CAR as compared with those with an abnormal CAR was 0.137 (95% confidence interval 0.03-0.57; p < 0.001), which indicates an 84.3% reduced risk of developing MD in those with normal CAR. A CAR value of 0.975 or less indicated the possibility of developing either a hearing fluctuation or vertiginous episode with a sensitivity of 82% and a specificity of 73% by receiver operating characteristics curve analysis. CONCLUSIONS: The results of the study suggest that CHAMP measurement may be useful for determining the prognosis of patients with ALFHL without vertigo. A CAR value of 0.975 or less indicates the possibility of developing fluctuating hearing loss or vertigo in patients with ALFHL unaccompanied by vertigo.

Deep learning-based electroencephalic diagnosis of tinnitus symptom.

Tinnitus is a neuropathological phenomenon caused by the recognition of external sound that does not actually exist. Existing diagnostic methods for tinnitus are rather subjective and complicated medical examination procedures. The present study aimed to diagnose tinnitus using deep learning analysis of electroencephalographic (EEG) signals while patients performed auditory cognitive tasks. We found that, during an active oddball task, patients with tinnitus could be identified with an area under the curve of 0.886 through a deep learning model (EEGNet) using EEG signals. Furthermore, using broadband (0.5 to 50 Hz) EEG signals, an analysis of the EEGNet convolutional kernel feature maps revealed that alpha activity might play a crucial role in identifying patients with tinnitus. A subsequent time-frequency analysis of the EEG signals indicated that the tinnitus group had significantly reduced pre-stimulus alpha activity compared with the healthy group. These differences were observed in both the active and passive oddball tasks. Only the target stimuli during the active oddball task yielded significantly higher evoked theta activity in the healthy group compared with the tinnitus group. Our findings suggest that task-relevant EEG features can be considered as a neural signature of tinnitus symptoms and support the feasibility of EEG-based deep-learning approach for the diagnosis of tinnitus.

Feasibility of Virtual Reality-Based Auditory Localization Training With Binaurally Recorded Auditory Stimuli for Patients With Single-Sided Deafness.

OBJECTIVES: To train participants to localize sound using virtual reality (VR) technology, appropriate auditory stimuli that contain accurate spatial cues are essential. The generic head-related transfer function that grounds the programmed spatial audio in VR does not reflect individual variation in monaural spatial cues, which is critical for auditory spatial perception in patients with single-sided deafness (SSD). As binaural difference cues are unavailable, auditory spatial perception is a typical problem in the SSD population and warrants intervention. This study assessed the applicability of binaurally recorded auditory stimuli in VR-based training for sound localization in SSD patients. METHODS: Sixteen subjects with SSD and 38 normal-hearing (NH) controls underwent VR-based training for sound localization and were assessed 3 weeks after completing training. The VR program incorporated prerecorded auditory stimuli created individually in the SSD group and over an anthropometric model in the NH group. RESULTS: Sound localization performance revealed significant improvements in both groups after training, with retained benefits lasting for an additional 3 weeks. Subjective improvements in spatial hearing were confirmed in the SSD group. CONCLUSION: By examining individuals with SSD and NH, VR-based training for sound localization that used binaurally recorded stimuli, measured individually, was found to be effective and beneficial. Furthermore, VR-based training does not require sophisticated instruments or setups. These. RESULTS: suggest that this technique represents a new therapeutic treatment for impaired sound localization.

Risk for Esophageal Cancer Based on Lifestyle Factors-Smoking, Alcohol Consumption, and Body Mass Index: Insight from a South Korean Population Study in a Low-Incidence Area.

Esophageal cancer constitutes a global public health challenge. However, South Korean population-specific information on the association of lifestyle (smoking, alcohol consumption, and obesity status) with esophageal cancer risk is sparse. This nested case-control study analyzed the Korean national health screening cohort data (2002-2019) of 1114 patients with esophageal cancer and 4456 controls (1:4 propensity-score matched for sex, age, income, and residential region). Conditional and unconditional logistic regression analyses, after adjustment for multiple covariates, determined the effects of lifestyle factors on esophageal cancer risk. Smoking and alcohol consumption increased the esophageal cancer risk (adjusted odds ratio [95% confidence interval]: 1.37 [1.15-1.63] and 1.89 [1.60-2.23], respectively). Overweight (body mass index [BMI] ≥ 23 to <25 kg/m2), obese I (BMI ≥ 25 to <30 kg/m2), or obese II (BMI ≥ 30 kg/m2) categories had reduced odds of esophageal cancer (0.76 [0.62-0.92], 0.59 [0.48-0.72], and 0.47 [0.26-0.85], respectively). In the subgroup analyses, the association of incident esophageal cancer with smoking and alcohol consumption persisted, particularly in men or those aged ≥55 years, whereas higher BMI scores remained consistently associated with a reduced esophageal cancer likelihood across all age groups, in both sexes, and alcohol users or current smokers. Underweight current smokers exhibited a higher propensity for esophageal cancer. In conclusion, smoking and alcohol drinking may potentially increase the risk, whereas weight maintenance, with BMI ≥ 23 kg/m2, may potentially decrease the risk, for esophageal cancer in the South Korean population. Lifestyle modification in the specific subgroups may be a potential strategy for preventing esophageal cancer.

Analysis of psychological distress after management of dizziness in old patients: multicenter study.

Dizziness is a common problem in older people, with a reported prevalence of 13-38%. A large percentage of patients with dizziness develop secondary psychiatric disorders over the course of their disease. In particular, clinical depression and anxiety are significant health problems for older adults. We investigated the relationship between dizziness and psychological distress (depression and anxiety) in elderly patients with dizziness, and the relationship with psychological symptoms after managing the dizziness. This study enrolled 126 patients with dizziness, who were 65 years or older. Dizziness and the psychological symptoms of all patients were measured using the Korean Version of the Vestibular Disorders Activities of Daily Living Scale (K-VADL), the Beck Depression Inventory (BDI), and the Spielberger State-Trait Anxiety Inventory (STAI) before and after management. We found a significant decrease in the BDI and STAI state scores after treatment with a reduction in the K-VADL score. For the STAI, the decrease in the score was relatively small after management. Nevertheless, there were significant correlations between the K-VADL score and both the BDI and STAI scores before and after management. Therefore, in the management of elderly patients with dizziness, a psychiatric approach should be considered and psychological support may be needed after managing the dizziness.

Acute Alcohol Intake Impairs the Velocity Storage Mechanism and Affects Both High-Frequency Vestibular-Ocular Reflex and Postural Control.

BACKGROUND: Acute alcohol intake is known to cause gait instability, dizziness, and lack of psychomotor coordination. Previous studies demonstrated the positive effects of alcohol on the oculomotor system and the low-frequency vestibulo-ocular reflex (VOR). However, the low-frequency VORs is a rather un-physiologic stimulation, and the reported explanations regarding the relations between the alcohol-induced VOR changes and posture control are inconsistent. OBJECTIVE: The present study evaluates how acute alcohol intake affects more physiologic mid- to high-frequency VORs, postural control, and elucidates the connection between the VOR and posture control after alcohol intake. METHODS: A total of 31 healthy volunteers participated. Each participant received calculated amounts of alcohol drinks according to their body weight and genders with the targeted blood alcohol content (BAC) level of 0.05% using the Widmark formula. A vestibular test battery composed of posturography, video head impulse test, rotatory chair test (slow harmonic acceleration (SHA) and step velocity), and subjective visual vertical/horizontal tests (SVV/SVH) were conducted twice in alcohol-free condition (no alcohol intake within 24 h) and acute alcohol condition. RESULTS: Acute alcohol intake decreased stability scores in all NS/EO (normal stability-eyes open), NS/EC (normal stability- eyes closed), PS/EO (perturbed stability-eyes open), and PS/EC (perturbed stability-eyes closed) conditions. High-frequency VOR gains decreased, but mid-frequency VOR gains were not significantly affected by alcohol intake. In addition, time constants were reduced significantly after alcohol ingestion in both clockwise and counter-clockwise rotation. Phase lead in SHA test and SVV/SVH was not affected by alcohol intake. CONCLUSION: Acute alcohol intake affected postural stability, high-acceleration head impulses, and the velocity storage mechanism.

Neurobiological Signatures of Auditory False Perception and Phantom Perception as a Consequence of Sensory Prediction Errors.

In this study, we hypothesized that top-down sensory prediction error due to peripheral hearing loss might influence sensorimotor integration using the efference copy (EC) signals as functional connections between auditory and motor brain areas. Using neurophysiological methods, we demonstrated that the auditory responses to self-generated sound were not suppressed in a group of patients with tinnitus accompanied by significant hearing impairment and in a schizophrenia group. However, the response was attenuated in a group with tinnitus accompanied by mild hearing impairment, similar to a healthy control group. The bias of attentional networks to self-generated sound was also observed in the subjects with tinnitus with significant hearing impairment compared to those with mild hearing impairment and healthy subjects, but it did not reach the notable disintegration found in those in the schizophrenia group. Even though the present study had significant constraints in that we did not include hearing loss subjects without tinnitus, these results might suggest that auditory deafferentation (hearing loss) may influence sensorimotor integration process using EC signals. However, the impaired sensorimotor integration in subjects with tinnitus with significant hearing impairment may have resulted from aberrant auditory signals due to sensory loss, not fundamental deficits in the reafference system, as the auditory attention network to self-generated sound is relatively well preserved in these subjects.

Thyroid Diseases and Chronic Rhinosinusitis: A Nested Case-Control Study Using a National Health Screening Cohort.

This study aimed to investigate the association between thyroid diseases and chronic sinusitis (CRS) in a matched cohort in a study conducted within the Korean National Health Insurance Service-Health Screening Cohort (2002−2015). A total of 6024 patients with CRS were 1:4-matched for age, sex, household income, and region of residence with 24,096 control participants. Effects of a previous history of thyroid disease, including hypothyroidism, hyperthyroidism, thyroiditis, autoimmune thyroiditis, and Graves' disease, were investigated using conditional logistic regression. Subgroup analyses were performed in regard to the presence of nasal polyposis. A history of hypothyroidism (2.8% vs. 1.8%), hyperthyroidism (2.0% vs. 1.5%), thyroiditis (1.1% vs. 0.8%), autoimmune thyroiditis (0.4% vs. 0.3%), and Graves' disease (0.3% vs. 0.2%) was not more prevalent in the CRS group than in the control group according to univariate analysis (all p > 0.05). Hypothyroidism was associated with CRS in the multivariate-adjusted model (odds ratio [OR] 1.25, 95% confidence interval [CI] 1.00−1.57). In the subgroup analyses, thyroid diseases were not statistically significantly associated with CRS after being classified according to the presence or absence of nasal polyps. Additional studies are required to elucidate the relationship between thyroid diseases and CRS, as this may aid in screening and clinical decision making.