Long term effects of cochlear implant surgery on vestibular system in pediatric population

OBJECTIVE

The aim was to evaluate the vestibular system of children who had undergone cochlear implant surgery and to compare them with the healthy population by vestibulo-ocular reflex (VOR) gains in unilateral and bilateral implant users, with the implants both on and off.

METHODS

Patients older than 5 years who had undergone cochlear implant surgery between 2012 and 2020 and who were cochlear implant users for at least one year were included. After consent was obtained, a video head impulse test (VHIT) was performed to evaluate the three semicircular canals, with devices on and off, and VOR gains were evaluated. VHIT was also used to assess VOR gains in the control group. The VOR gains of the study and control groups, VOR gains of unilateral and bilateral implant users, and VOR gains with implants on and off were compared.

RESULTS

When the VOR gains of 24 unilateral and 13 bilateral cochlear implant users and the control group (n = 30) were compared, a significant difference was found only in the anterior semicircular canal, although the VOR gains were found to be low in all three semicircular canals in the implant users (p < 0.05). There was no significant difference between the VOR gains of unilateral and bilateral implant users. There was no significant difference between the VOR gains when either on or off. There was no correlation between cochlear implant usage time, implant insertion age, patient age and VOR gain.

CONCLUSION

The effects of cochlear implant surgery on the vestibular system continue in the late period, but no correlation was observed between implant usage time and VOR gain after the first year. It was observed that having the cochlear implant on or off had no effect on VOR gain. Furthermore, bilateral implant surgery did not lead to additional vestibular dysfunction compared to unilateral implant surgery.

Genome sequencing identifies coding and non-coding variants for non-syndromic hearing loss

Hearing loss (HL) is a common heterogeneous trait that involves variants in more than 200 genes. In this study, we utilized exome (ES) and genome sequencing (GS) to effectively identify the genetic cause of presumably non-syndromic HL in 322 families from South and West Asia and Latin America. Biallelic GJB2 variants were identified in 58 probands at the time of enrollment these probands were excluded. In addition, upon review of phenotypic findings, 38/322 probands were excluded based on syndromic findings at the time of ascertainment and no further evaluation was performed on those samples. We performed ES as a primary diagnostic tool on one or two affected individuals from 212/226 families. Via ES we detected a total of 78 variants in 30 genes and showed their co-segregation with HL in 71 affected families. Most of the variants were frameshift or missense and affected individuals were either homozygous or compound heterozygous in their respective families. We employed GS as a primary test on a subset of 14 families and a secondary tool on 22 families which were unsolved by ES. Although the cumulative detection rate of causal variants by ES and GS is 40% (89/226), GS alone has led to a molecular diagnosis in 7 of 14 families as the primary tool and 5 of 22 families as the secondary test. GS successfully identified variants present in deep intronic or complex regions not detectable by ES.

Congenital Cytomegalovirus Infection Screening in Newborns From Saliva Samples by Real-Time Polymerase Chain Reaction Analysis

OBJECTIVE

Congenital cytomegalovirus infection is the most common congenital infection. Although screening of congenital cytomegalovirus infection with polymerase chain reaction studies in blood, urine, and saliva samples has been developed in recent years, it is not yet in routine use in any country.

MATERIALS AND METHODS

In our study, cytomegalovirus deoxyribonucleic acid analysis was per- formed by real-time polymerase chain reaction method in saliva samples taken before the first feeding during the first day following birth in neonates born in a university hospital between January 2021 and January 2022. To support the diagnosis, additionally, cytomegalovirus deoxy- ribonucleic acid positivity in urine and blood samples was investigated in newborns with cyto- megalovirus deoxyribonucleic acid positivity in saliva.

RESULTS

Cytomegalovirus deoxyribonucleic acid was investigated in saliva samples of 545 neonates by real-time polymerase chain reaction method in 1-year period and positiv- ity was found in 6 neonates. Since cytomegalovirus deoxyribonucleic acid was found nega- tive by the real-time polymerase chain reaction method in the urine and blood samples of 5 of these neonates, the positivity in the saliva sample was interpreted as false positivity. In 1 case, cytomegalovirus deoxyribonucleic acid positivity was detected in urine and blood samples 5 weeks later. As a result, definite congenital cytomegalovirus infection could not be diagnosed in 545 cases, while possible congenital cytomegalovirus infection was diag- nosed in 1 case.

CONCLUSION

It has been concluded that the frequency of congenital cytomegalovirus infection is low in our study group and studying saliva samples showed high false-positive rates. It is seen that saliva is not a suitable sample for detecting cytomegalovirus deoxyribonucleic acid by real-time polymerase chain reaction method.

Comparison of two different bone anchored hearing instruments: Baha-5 vs Ponto-plus

BACKGROUND

To our knowledge, there is no study comparing Ponto Plus^® (Oticon Medical AB, Askim, Sweden) and Baha^® 5 (Cochlear Bone Anchored Solutions AG, Mölnlycke, Sweden) available in the literature.

AIMS/OBJECTIVES

The primary aim was to compare the performance of the Baha 5 with the Ponto Plus device in terms of speech understanding in quiet and in noise. In addition, to determine statistically whether or not the difference between the abutment systems created any variation in terms of skin reaction.

MATERIALS AND METHODS

Twenty bone-anchored hearing instrument users, ten in each group, were evaluated for speech understanding in quiet and several signal-to-noise ratios using the Turkish Matrix Test in a two-speaker setup. The Holger classifications were also reviewed to determine adverse skin reactions.

RESULTS

It was revealed that the hearing results of both devices were similar and, when the skin reactions were compared, there was no statistically significant difference between the two-implant systems.

CONCLUSIONS AND SIGNIFICANCE

Because of the similar results of the groups, it can be interpreted as the key different device features such as the size, weight, colour alternatives, and the ease of use of the devices might be important in terms of device preference.