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Reducing electrode impedance is an important factor in improving the functional benefits of cochlear implants (CIs). The immediate effect of early switch-on within 24 h of surgery on impedance among CI recipients with various types of electrodes has been reported previously; however, the immediate change and the evolution of electrode impedances of slim modiolar electrodes after early switch-on within 24 h of implantation has not. Therefore, the focus of this retrospective cohort study of CI patients was to compare the effect of early switch-on (n = 36) and conventional switch-on (n = 72) 2–4 weeks post-operation on impedance. Compared with impedance measured intraoperatively, our results demonstrate a significant decrease in impedance from 11.5 to 8.9 kΩ (p p = 0.001). Notably, a comparatively lower impedance than the conventional switch-on protocol was observed for up to 2 months post-operation. Most importantly, a much earlier stabilization of impedance can be achieved with the early switch-on protocol coupled with the slim modiolar electrode array compared to the conventional switch-on protocol, offering the advantage of reducing the number of required mapping sessions in the early stages of rehabilitation.

BackgroundDown-sloping sensorineural hearing loss (SNHL) in people in their teens and 20s hampers efficient learning and communication and in-depth social interactions. Nonetheless, its aetiology remains largely unclear, with the exception of some potential causative genes, none of which stands out especially in people in their teens and 20s. Here, we examined the role and genotype–phenotype correlation of lipoxygenase homology domain 1 (LOXHD1) in down-sloping SNHL through a cohort study.MethodsBased on the Seoul National University Bundang Hospital (SNUBH) genetic deafness cohort, in which the patients show varying degrees of deafness and different onset ages (n=1055), we have established the ‘SNUBH Teenager–Young Adult Down-sloping SNHL’ cohort (10–35 years old) (n=47), all of whom underwent exome sequencing. Three-dimensional molecular modelling, minigene splicing assay and short tandem repeat marker genotyping were performed, and medical records were reviewed.ResultsLOXHD1 accounted for 33.3% of all genetically diagnosed cases of down-sloping SNHL (n=18) and 12.8% of cases in the whole down-sloping SNHL cohort (n=47) of young adults. We identified a potential common founder allele, as well as an interesting genotype–phenotype correlation. We also showed that transcript 6 is necessary and probably sufficient for normal hearing.ConclusionsLOXHD1 exceeds other genes in its contribution to down-sloping SNHL in young adults, rising as a signature causative gene, and shows a potential but interesting genotype–phenotype correlation.

Objective In patients with pulsatile tinnitus (PT), physical examination such as auscultation with head position change or digital compression over the ipsilateral jugular vein provides physicians with important information. However, objective diagnosis of PT is sometimes limited because 1) audible bruit is absent on auscultation in some patients, 2) abnormal vascular structures found in radiologic evaluation is not always pathognomonic because they can be found in asymptomatic subjects as well, and 3) although an objective diagnostic tool using transcanal sound recording has recently been introduced, special equipment is needed. In this regard, recent studies that have reported ipsilateral low-frequency hearing loss (LFHL) on pure-tone audiometry (PTA) in some patients with PT, and its recovery after successful management, prompted us to conduct a retrospective observational study on the characteristics of the audiometric profile, the association between the audiometric profile and radiologic findings, and pre- and posttreatment changes in low-frequency hearing thresholds in PT patients. We tested two hypotheses: PT patients with marked vascular pathologies located close to the cochlea may show ipsilateral pseudo-LFHL (PLFHL) because of the masking effects of the PT itself, and their PLFHL may disappear if their vascular pathology is successfully managed by surgical or endovascular intervention. Study design Retrospective case review. Setting Tertiary referral center. Patients A total of 85 PT subjects who underwent both audiologic and radiologic examinations. Main outcome measure All patients' pre- and posttreatment PTA thresholds and radiologic findings were analyzed. By comparing the LFHL (an ipsilateral hearing threshold greater than 10 dB HL at both 250 and 500 Hz or greater than 20 dB HL at either 250 or 500 Hz compared with the contralateral side) group and a non-LFHL group with regard to the incidence of vascular structural abnormalities, we evaluated the incidence of abnormal vascular structures in the head and neck between the LFHL and non-LFHL groups. In addition, by comparing pre- and posttreatment PTA thresholds of seven PT patients with ipsilateral LFHL, we further evaluated the changes in low-frequency hearing thresholds and their role as an objective sign for diagnosis and outcome evaluation. Results Of 85 patients, 22 (25.9%) presented with ipsilateral LFHL. Compared with patients without this condition, patients with ipsilateral LFHL showed a significantly higher rate of abnormal vascular structure. In addition, most of the radiologic abnormalities found in the LFHL group were highly suspicious causative lesions that are responsible for the perception of PT according to the previous literature. In eight PT patients with ipsilateral LFHL who underwent both pre- and posttreatment audiograms, the average posttreatment pure-tone threshold at 250 Hz showed significant improvement compared with the pretreatment threshold. Conclusion PT patients presenting with ipsilateral LFHL have higher possibility of having a discrete vascular pathology near the cochlea on radiologic evaluation. As ipsilateral LFHL improves in most patients after treatment, LFHL in patients with PT may be PLFHL because of the masking effects of the pulsatile sound, and the changes in the low-frequency thresholds may be applicable for objective diagnosis and evaluation of the effects of the treatment.

Objective To describe a method of hyoid cartilage division during Sistrunk operation for management of thyroglossal duct cyst (TGDC) and compare postoperative outcomes with those of conventional hyoid bone cutting. Methods Fifty-nine patients who received operative treatment for TGDC from January 2005 to July 2013 were enrolled. The degree of fusion in the cartilaginous portion of the hyoid was evaluated by preoperative neck computed tomography and classified into (1) non-fusion, (2) partial fusion, and (3) complete fusion. Techniques of hyoid management, division of the cartilaginous portion of the hyoid or conventional hyoid bone cutting, during Sistrunk operation were analyzed according to the fusion classification. Results Of the 59 patients, 27 were pediatric patients and 32 were adults. In 32 adults undergoing TGDC, there were 13 cases (41%) of complete hyoid fusion and 7 (22%) of non-fusion. A total of 20 adult patients (63%) were treated with the cartilage division. Among the pediatric patients, 96% of cases were classified as non-fusion of the hyoid, and all of these were treated with the cartilage division. Patients who were treated with the cartilage division showed better postoperative results. However, there were no statistical differences. Conclusions Our cartilage division technique at Sistrunk operation for TGDC is feasible and comparable to conventional hyoid cutting with regard to postoperative results.

Although continuous positive airway pressure (CPAP) is a highly efficacious treatment for obstructive sleep apnea (OSA), there is a need for alternative treatment options, such as sleep surgeries and mandibular advancement devices (MADs), to overcome the limitations of CPAP. This study aimed to analyze the therapeutic outcomes of OSA subjects who were treated with a MAD, and to estimate the clinical impact of MAD as a first-line treatment for OSA. Forty-seven patients diagnosed with OSA received an adjustable MAD as an initial treatment. Drug-induced sleep endoscopic findings and sleep parameters (both pre-MAD and post-MAD treatment), such as apnea index, oxygen saturation, and degree of daytime sleepiness, were assessed retrospectively. The MAD treatment resulted in a significant reduction in apnea–hypopnea index, and also a significant elevation in lowest oxygen saturation. Satisfactory results of MAD treatment as a first treatment modality were observed in 27 patients, and a successful outcome was reached in approximately 72% of patients. The OSA patients who had lower body mass index and upper airway narrowing at the level of palate and tongue base showed relatively higher rates of a satisfactory outcome even in cases of moderate or severe OSA. These results suggest that the use of a MAD may be an alternative treatment option in OSA patients with retropalatal and retroglossal area narrowing regardless of disease severity. Additionally, MADs can be recommended as an initial treatment modality, and the effectiveness of MADs in achieving success may not be inferior to CPAP.