[Etiological factors of sensorineural hearing loss in children after cochlear implantation]. / Halláscsökkenést okozó etiológiai tényezok cochlearis implantáción átesett gyermekekben.

Introduction: Congenital sensorineural hearing loss is one of the most common sensory defects affecting 1-3 children per 1000 newborns. There are a lot of causes which result in congenital hearing loss, the most common is the genetic origin, but infection, cochlear malformation or other acquired causes can be reasons as well. Aim: The aim of this study was to establish the etiological factors of congenital profound sensorineural hearing loss in children who underwent cochlear implantation. Results: Our results show that the origin of the hearing loss was discovered in 62.9% of our patients. The most common etiological factor was the c.35delG mutation of the gap junction protein ß-2 gene, the allele frequency was 38.7% in our cohort. Infection constituted to 10.1%, and meningitis and cytomegalovirus infection were the second most common cause. 79.9% of our patients received sufficient hearing rehabilitation before the end of the speech development's period (6 years old), but 11.2% of our cases were still diagnosed late. Conclusions: Based on our data we can state that genetic evaluation is crucial in the diagnostic process of congenital profound sensorineural hearing loss. Sufficient hearing rehabilitation affects the whole life of the child, and by late cochlear implantation the speech development falls behind. We can decrease the ratio of the late implantation with the new protocol of newborn hearing screening, and with sufficient information provided to the colleagues, so the children may be referred to the proper center for rehabilitation without delay. Orv Hetil. 2019; 160(21): 822-828.

Cochlear implantation under local anesthesia: a possible alternative for elderly patients.

INTRODUCTION: As average life-expectancy increases, a sufficient hearing rehabilitation for elderly patients with severe-to-profound sensorineural hearing loss becomes more important. Cochlear implantation is a relatively safe surgical procedure also for elderly patients, the higher risk is caused by general anesthesia. We report on four patients who underwent cochlear implantation under local anesthesia. METHODS: After detailed preoperative examinations (audiological tests, imaging, genetic tests, evaluation of motivation and compliance of the patient), four patient with severe-to-profound hearing loss were selected for cochlear implantation under local anesthesia. For the electrode insertion, we used the posterior suprameatal approach technique. Pre- and postoperative pure tone audiometry and speech-perception tests were conducted to prove the success of the procedure. RESULTS: The mentioned technique was applied; the average length of the operation was 52 min. The intraoperative measurements showed normal impedance and normal neuronal response telemetry, all the patients had sound experience during the intraoperative examination of the engineer. No complications were observed. The postoperative audiological tests showed a significant increase in the hearing perception. CONCLUSION: Cochlear implantation under local anesthesia is a safe and fast procedure for elderly patients. The intraoperative sound experience can give an extra motivation in the postoperative rehabilitation. Our results prove that by carefully selected elderly patients cochlear implantation can assure a significant increase in speech perception. We can establish that the new posterior suprameatal approach technique combined with local anesthesia presents a viable future option for those patients who were inoperable beforehand because of high risks of general anesthesia.

Analysis of GJB2 mutations and the clinical manifestation in a large Hungarian cohort.

PURPOSE: Pathogenic variants of the gap junction beta 2 (GJB2) gene are responsible for about 50% of hereditary non-syndromic sensorineural hearing loss (NSHL). In this study, we report mutation frequency and phenotype comparison of different GJB2 gene alterations in Hungarian NSHL patients. METHODS: The total coding region of the GJB2 gene was analyzed with Sanger or NGS sequencing for 239 patients with NSHL and 160 controls. RESULTS: Homozygous and compound heterozygous GJB2 mutations were associated with early onset serious clinical phenotype in 28 patients. In 24 patients, two deletion or nonsense mutations were detected in individuals with mainly prelingual NSHL. In compound heterozygous cases, a combination of deletion and missense mutations associated with milder postlingual NSHL. A further 25 cases harbored single heterozygous GJB2 mutations mainly associated with later onset, milder clinical phenotype. The most common mutation was the c.35delG deletion, with 12.6% allele frequency. The hearing loss was more severe in the prelingual groups. CONCLUSION: The mutation frequency of GJB2 in the investigated cohort is lower than in other European cohorts. The most serious cases were associated with homozygous and compound heterozygous mutations. In our cohort the hearing impairment and age of onset was not altered between in cases with only one heterozygous GJB2 mutation and wild type genotype, which may exclude the possibility of autosomal dominant inheritance. In early onset, severe to profound hearing loss cases, if the GJB2 analysis results in only one heterozygous alteration further next generation sequencing is highly recommended.

Cochlear implantation using posterior suprameatal approach.

When cochlear implantation was first introduced, the mastoidectomy and posterior tympanotomy approach was the most frequently used technique to gain access to the middle ear and the cochlea. Since 2000, several authors have routinely used a non-mastoidectomy nonposterior tympanotomy technique, which has undergone several modifications. Alternative surgical techniques for cochlear implantation have recently been introduced, such as endomeatal-alone or suprameatal-alone and combined posterior tympanotomy/endomeatal approaches. The goal of this study was to describe another modification of this less invasive technique to perform cochlear implantation. Cochlear implantations were performed between January 1, 2002, and December 31, 2012, in 220 patients through the posterior suprameatal approach. In reviewing our experiences, we have concluded that this approach, which eliminates the need for mastoidectomy, is considered safe, time-efficient, and minimally invasive. The possible pitfalls and the microsurgical relevance of anatomic structures of this technique are discussed in detail. Using this technique, not all classical anatomic orientation points are identified. However, certain landmarks predict the depth and the three-dimensional location of invisible anatomic structures.