HRAS-related epidermal nevus syndromes: Expansion of the spectrum with first branchial arch defects.

Epidermal nevus syndrome (ENS) comprises a heterogeneous group of neurocutaneous syndromes associated with the presence of epidermal nevi and variable extracutaneous manifestations. Postzygotic activating HRAS pathogenic variants were previously identified in nevus sebaceous (NS), keratinocytic epidermal nevus (KEN), and different ENS, including Schimmelpenning-Feuerstein-Mims and cutaneous-skeletal-hypophosphatasia syndrome (CSHS). Skeletal involvement in HRAS-related ENS ranges from localized bone dysplasia in association with KEN to fractures and limb deformities in CSHS. We describe the first association of HRAS-related ENS and auricular atresia, thereby expanding the disease spectrum with first branchial arch defects if affected by the mosaic variant. In addition, this report illustrates the first concurrent presence of verrucous EN, NS, and nevus comedonicus (NC), indicating the possibility of mosaic HRAS variation as an underlying cause of NC. Overall, this report extends the pleiotropy of conditions associated with mosaic pathogenic variants in HRAS affecting ectodermal and mesodermal progenitor cells.

Cochlear implant electrode array tip-foldover detection by electrode voltage telemetry.

OBJECTIVES: With the introduction of more flexible and thinner electrodes, such as Cochlear's Slim Modiolar Electrode, there is a higher risk of electrode insertion problems, in particular the tip foldover. Timely intraoperative detection of the problem would allow for direct intraoperative correction. This paper describes a non-radiological method for intraoperative tip foldover detection that is applicable in all surgical centers and can quickly deliver accurate results. METHODS: Postoperative radiographs of 118 CI-recipients implanted with Nucleus devices were retrospectively analyzed on the presence of a tip foldover. Electrode Voltage Telemetry (EVT), also called Electric Field Imaging, was performed by means of Cochlear's EVT software tool, which is now integrated into Custom Sound-EP as the Trans-Impedance-Matrix measurement option. Tip foldover detection was automated by using the linear Hough transform for extracting straight-line patterns in the Trans-Impedance Matrix's heatmap. RESULTS: The six cases of electrode tip foldover were accurately identified by the EVT measurements, including two cases with folding location very close to the electrode tip (contact 20). CONCLUSION: Electrode Voltage Telemetry measures the Trans-Impedance Matrix, which can accurately detect tip foldovers of the cochlear implant electrodes within 1 min. This method can be reliably applied in all patients with normal cochlear anatomy and is able to intraoperatively detect foldovers localized even very close to the electrode tip. Application of the linear Hough transform allows for automatic detection of electrode tip foldovers that shows excellent agreement with visual evaluation of the radiological images and the transimpedance matrix's heatmap.

Novel Impedance Measures as Biomarker for Intracochlear Fibrosis.

Measurement of the complex electrical impedance of the electrode contacts can provide new insights into the factors playing a role in the preservation of residual hearing with cochlear implants (CIs). However, unraveling the contributions related to the different phenomena from impedance data necessitates more advanced measurement and analysis techniques. The present study explores a new impedance measurement option recently included into the cochlear-implant programming software and aims to contribute to a more solid basis for the clinical use of impedance measures as a biomarker for fibrous tissue formation. Twenty adult CI-recipients were followed from surgery until 1 year after implantation by means of Electrode Voltage Telemetry (EVT), also called Electric Field Imaging or TransImpedance-Matrix measurement, and a 4-point technique for probing the voltage between adjacent electrode contacts. The data were compared to the electrode location derived from computed tomography, and to the device usage log. Using our impedance model for electrical stimulation of the cochlea, the polarization impedance related the electrode-tissue interface was determined, and the bulk impedance (access resistance) was split into a near-field and a far-field component. On average, the polarization impedance increased abruptly after surgery, indicating a strong passivation of the electrode contacts before cochlear-implant initiation. Its initial rise resolved almost completely soon after device switchon (2-4 weeks). The gradual increase of the access resistance mainly happened during the first 40 days on a time scale very similar to that observed in a guinea-pig study correlating impedance changes to fibrous tissue growth. The higher increase towards the round window is consistent with the higher amount of tissue observed in histological animal studies close to the electrode entry point. While the initial changes were due to the near-field resistance, the far-field resistance began to rise only after one month for half of the study group, once the near-field component had reached its critical value. This suggests indeed fibrosis initiating near the electrode contacts and spreading thereafter farther away. The near-field resistance positively correlated to device usage. EVT data allow for a further decomposition of the impedance at a cochlear-implant electrode, yielding a more detailed description of the postoperative intracochlear phenomena, such as fibrosis.

Long-term results of a modified expansion sphincter pharyngoplasty for sleep-disordered breathing.

Our aim was to evaluate the long-term objective and subjective results of a modified expansion sphincter pharyngoplasty (ESP) technique in patients with sleep-disordered breathing. Single center prospective study of 35 patients underwent an ESP as a primary surgical treatment between June 2012 and September 2015 at the hospital AZ Sint-Jan Bruges-Ostend. Patients were divided into non-OSAS and OSAS (AHI >5). Primary outcome parameters were the Epworth Sleeping Scale (ESS, reduction and score less then 10) and the Visual Analogue Score of snoring (VAS, assessed by partner) evaluated at 3 months and 1 year. In addition, the OSAS group underwent a polysomnography after 6 months to calculate the Apneu-Hypopneu Index (AHI) change. Secondary outcome parameters were possible complications and morbidity rate. The overall Epworth Sleepiness Scale showed a steady total reduction of, respectively, 42 and 48% at the two timepoints. All patients had a post-operative score of less than ten points. The Visual Analogue Score improved in 92% of the patients; of these, the snoring was reduced in 86% and disappeared in 6%. In the OSAS group, we noticed a reduction in AHI of more than 50 in 53% of the patients. A considerable reduction was found in the severe OSAS group, where we found a mean pre-operative average AHI of 41.3/h that was reduced 6 months after the operation to 17.4/h. There were no severe complications or increased morbidity rate observed. This first long-term study shows that the modified ESP seems to be a safe and promising technique in palatal surgery for patients with sleep-disordered breathing. Surgical effectiveness is sustained after 1 year, both in OSAS as in snoring pathology. The technique seems as approachable for the basic ENT surgeon as the uvulopalatopharynoplasty.

Functional correlations of tympanic membrane perforation size.

OBJECTIVE: The correlation between tympanic membrane perforations and hearing loss was studied. STUDY DESIGN: Prospective data from 220 patients, who underwent primary surgery for simple chronic otitis media with a perforated eardrum, were analyzed. SETTING: Tertiary referral center. PATIENTS: One hundred fifty-one patients with 155 eardrum perforations, which were checked for correct diagnosis, normal middle-ear status, and integrity of the ossicular chain, were included. INTERVENTIONS: All patients underwent primary myringoplasty. MAIN OUTCOME MEASURES: Preoperative conductive hearing loss due to eardrum perforations. RESULTS: Hearing loss shows a linear relationship with increasing eardrum perforation size. Umbo involvement shows a worsening of the hearing by 5 to 6 dB (p < 0.0001). The least impact of a perforation is seen at the resonance frequency of 2 kHz. Above and below 2 kHz, an 'inverted V shape' of the air-bone gap is a consistent finding. If the air-bone gap exceeds the 'inverted V-shape' pattern, additional pathology behind the eardrum must be assumed and addressed. CONCLUSION: We propose using standardized photographs or drawings to document preoperative perforation sizes. A linear relationship between the size of a perforation and the conductive hearing loss does exist. Umbo involvement at the perforation margin may worsen the hearing by 5 to 6 dB, whereas the position of the perforation itself does not play a role. The least impact of a perforation is seen at the resonance frequency of 2 kHz. An "inverted V-shape" pattern, above and below 2 kHz, of the air-bone gap is a consistent finding. If the air-bone gap exceeds this pattern, additional pathology behind the eardrum perforation must be assumed and addressed.