Brain Morphological Changes in Acquired Auditory Deprivation: A Surface-Based Morphometry Study

Objective: Prolonged auditory deprivation induces neuroplastic changes throughout the brain, including the auditory system. This study aimed to investigate brain morphological changes caused by peripheral hearing loss, focusing primarily on alterations in cortical thickness (CT) and cortical volume (CV), assessed using surface-based morphometry (SBM) with FreeSurfer. Additionally, we aimed to determine whether the degree of cortical changes is correlated with the duration of deafness (DoD) or hearing aid use (DoHA). Methods: We conducted a retrospective analysis of magnetic resonance imaging (MRI) data from 47 adults with bilateral severe to profound sensorineural hearing loss for over 10 years (bilateral deaf, BD) and 73 normal hearing (NH) controls. High-resolution 3D T1-weighted MRI volumes were reviewed, and CT and CV were measured using FreeSurfer’s automated pipeline. Vertex-wise comparisons between the BD and NH groups, controlling for age as a confounding factor, were conducted using a General Linear Model. Subcortical gray matter volumes were also analyzed in FreeSurfer, and a complementary voxel-based morphometry (VBM) analysis for CV comparison was conducted using the FMRIB Software Library (FSL). Correlations between significant brain morphometric changes and DoD/DoHA in the BD group were assessed. Results: We observed thinner CT in the bilateral superior temporal gyri and lateral occipital cortices, along with significant reductions in CV in the bilateral superior temporal gyri, superior parietal cortices, and lateral occipital cortices in the BD group compared to NH controls. The VBM findings partially aligned with the structural CV alterations identified through SBM. Additionally, subcortical volumes of the thalamus, hippocampus, and amygdala were significantly reduced in the BD group. Loger duration of hearing rehabilitation using hearing aids (DoHA) showed a positive correlation with the CT of the right superior temporal gyrus, as well as the bilateral hippocampal volumes in the BD group. Conclusion: Our findings reveal significant structural changes in the brains of BD individuals, affecting key areas involved in auditory processing and the integration of somatosensory and visual information. Furthermore, a longer duration of hearing rehabilitation using hearing aids was found to suppress the decrease in CT of the right superior temporal gyrus as well as the bilateral hippocampal volumes in the BD group, suggesting that timely auditory rehabilitation could help preserve cortical and subcortical structures, potentially mitigating cognitive risks associated with hearing loss.Docto

Two Cases of Autoimmune Disease-Associated Laryngotracheal Stenosis

Autoimmune disease-associated laryngotracheal stenosis (AD-LTS) is very rare but can pose a life-threatening risk. Pathogenesis of AD-LTS is still uncertain and standard treatment protocol has not been proposed. In this study, we reported two rare cases of AD-LTS in patients with relapsing polychondritis and rheumatoid arthritis, respectively. Two middle-aged female patients visited our clinic due to progressive dyspnea, and stenosis of subglottis and upper trachea was identified. Under general anesthesia, stenotic area was dilated with balloon gradually following steroid injection. As both patients had developed dyspnea after several months postoperatively, they underwent revision surgery. After two times of surgery, dyspnea was relieved and patients are maintaining systemic immunosuppressive therapy with regular rheumatology clinic follow up. AD-LTS should be carefully diagnosed and proper intervention with multidisciplinary team approach is required

와우내 신경초종 환자에서 시행한 인공와우 이식술 1예

Intralabyrinthine schwannomas are rare benign tumors, which arise from neural portions within the labyrinth. These are subclassified into seven groups according to the affected inner ear structures. Intracochlear schwannomas (ICS) are tumors confined to the cochlea, and these can cause progressive unilateral sensorineural hearing loss, tinnitus, vertigo and aural fullness. Here, we report a 49-year-old female patient with left sudden sensorineural hearing loss. There was no improvement of hearing despite steroid and hyperbaric oxygen therapy. Space occupying lesion in the basal turn of the left cochlea was identified in MRI with enhancement. She underwent tumor removal through an extended round window approach, and cochlear implantation was performed successfully. This is the first case report of cochlear implantation after tumor removal in a patient with ICS in Korea, and we discuss management options with a review of the literature

Diagnostic Accuracies of Laryngeal Diseases Using a Convolutional Neural Network-Based Image Classification System

Objectives/Hypothesis: There may be an interobserver variation in the diagnosis of laryngeal disease based on laryngoscopic images according to clinical experience. Therefore, this study is aimed to perform computer-assisted diagnosis for common laryngeal diseases using deep learning-based disease classification models. Study Design: Experimental study with retrospective data Methods: A total of 4106 images (cysts, nodules, polyps, leukoplakia, papillomas, Reinke's edema, granulomas, palsies, and normal cases) were analyzed. After equal distribution of diseases into ninefolds, stratified eightfold cross-validation was performed for training, validation process and remaining onefold was used as a test dataset. A trained model was applied to test sets, and model performance was assessed for precision (positive predictive value), recall (sensitivity), accuracy, F1 score, precision-recall (PR) curve, and PR-area under the receiver operating characteristic curve (PR-AUC). Outcomes were compared to those of visual assessments by four trainees. Results: The trained deep neural networks (DNNs) outperformed trainees' visual assessments in discriminating cysts, granulomas, nodules, normal cases, palsies, papillomas, and polyps according to the PR-AUC and F1 score. The lowest F1 score and PR-AUC of DNNs were estimated for Reinke's edema (0.720, 0.800) and nodules (0.730, 0.780) but were comparable to the mean of the two trainees' F1 score with the best performances (0.765 and 0.675, respectively). In discriminating papillomas, the F1 score was much higher for DNNs (0.870) than for trainees (0.685). Overall, DNNs outperformed all trainees (micro-average PR-AUC = 0.95; macro-average PR-AUC = 0.91). Conclusions: DNN technology could be applied to laryngoscopy to supplement clinical assessment of examiners by providing additional diagnostic clues and having a role as a reference of diagnosis