Cochlear Implants and Children with Vestibular Impairments

Vestibular Preservation in Pediatric Cochlear Implantation

OBJECTIVES

Evaluate the rate of preserved vestibular function in pediatric cochlear implant surgery.

STUDY DESIGN

Retrospective case review.

METHODS

Pre- and post-operative vestibular tests were compared in children who underwent cochlear implantation at a tertiary level pediatric hospital over a 4-year period.

RESULTS

Data from 59 implanted ears in 44 children was included. Median age was 2.8 years at initial testing (range 7 months - 21 years) with 1:1 male/female ratio. Implant surgeries were 26 unilateral, 13 bilateral simultaneous, and 5 bilateral sequential. The majority were implanted with slim, non-styletted electrodes (86.4%) via a round window approach (91.5%). Normal pre-operative results were preserved post-operatively on rotary chair testing in 75% (21/28) of patients, cervical vestibular evoked myogenic potential testing in (75%) 30/40 of ears tested, ocular vestibular evoked myogenic potential testing in 85.7% (6/7) of ears tested, video head impulse testing in 100% (9/9) of ears tested, and computerized dynamic posturography in 100% (5/5) of patients tested. Overall, 62.5% of patients had no new deficits on any vestibular test performed post-operatively.

CONCLUSIONS

Preservation rates of vestibular function following cochlear implant surgery were higher in this cohort than what has been reported in many earlier studies. Contemporary, less traumatic electrodes and insertion techniques may be a significant factor. The risk of causing a new, severe bilateral vestibular loss with long-term functional impacts appears to be low. Further study is warranted on the impacts of different cochlear implant electrode designs and insertion approaches on post-operative vestibular preservation.

LEVEL OF EVIDENCE

4, Case Series Laryngoscope, 134:1913-1918, 2024.

Characteristics of vestibular-evoked myogenic potentials in children with vestibular malformation and severe sensorineural hearing loss

BACKGROUND

With the increasing clinical focus on the safety of bilateral cochlear implantation (CI) and the potential risk of bilateral vestibular dysfunction, evaluating vestibular end-organ function in patients with vestibular malformations with accompanying abnormalities has been strongly recommended.

OBJECTIVES

To identify the vestibular-evoked myogenic potential (VEMP) values among children with sensorineural hearing loss (SNHL) with vestibular malformation and assess the effectiveness of VEMP testing for inner ear malformations (IEM) diagnosis.

METHODS

This study included 96 children (192 ears), including those with vestibular malformations (48 ears), large vestibular aqueduct syndrome (LVAS) (50 ears), and SNHL without IEM (94 ears; control group). All groups underwent ocular and cervical VEMP (oVEMP and cVEMP, respectively) testing. The response rates, VEMP parameters, and wave characteristics were compared.

RESULTS

The cVEMP response rates were 37.5 %, 64 %, and 58.51 % and the oVEMP response rates were 42.86 %, 78.95 %, and 77.27 % in the vestibular malformation, LVAS, and control groups, respectively, and significantly differed between groups (cVEMP: X2 = 18.228, P<0.001) (oVEMP: X2 = 7.528, P = 0.023). Significant inter-group differences were observed for the cVEMP and oVEMP latency and amplitude (P < 0.05). The LVAS group's waveform exhibited a prolonged latency and increased amplitude compared with that of the other groups.

CONCLUSION

Patients with SNHL were highly susceptible to otolith dysfunction, regardless of comorbid vestibular malformation presence. Measuring VEMPs is an effective and rapid evaluation technique for vestibular function and could provide a basis for vestibular rehabilitation training.

Vestibular function, subjective complaints, perceived disability in daily life, and sports activities in patients with cochlear implants performed during childhood: a prospective cross-section study

BACKGROUND

Vestibular function (VF) in patients with cochlear implantation (CI) performed during childhood is underinvestigated.

OBJECTIVE

To study VF in patients receiving CI during childhood.

MATERIAL & METHODS

Sixty patients (22 females) from 7-34 years old, unilaterally (n = 21) and bilaterally (n = 39) implanted, were included. Deafness was congenital (n = 45), consequential to meningitis (n = 3), skull fracture (n = 1), perinatal CMV infection (n = 1), ototoxic drugs (n = 1), unknown etiology (n = 9). VF was measured between 1 to 22 years after implantation, including calorics, v-HIT, c-VEMPS. Dizziness handicap inventory (DHI), age at independent walking(IW), sport activities were also investigated.

RESULTS

Nine CI-patients (15%) reported dizziness/vertigo either prior or months to years after surgery. Comparison between symptomatic (15%), asymptomatic (85%), uni-bilaterally CI-patients showed no significant difference on VF's impairment for calorics (p = .603) and v-HIT (p = 1). Symptoms were not related to vestibular impairment. Age at implantation (p = 0.956), uni- bilateral (p = .32), simultaneous versus sequential (p = .134) did not influence IW age. DHI showed a tendency for being symptomatic at higher implantation age. Interval between CI, IWage, current age between surgery and vestibular evaluation did not have a significant effect on symptomatology.

CONCLUSION & SIGNIFICANCE

This first middle to long-term evaluation of the VF in CI-patients, implanted in childhood, pointed out that 85% of patients were asymptomatic, with a mean time of >10 years after surgery. Vestibular impairment and symptoms seem to be mainly due to the underlying inner ear's disease rather than surgery.

Paediatric vestibular assessment in French cochlear implant centres: Challenges and improvement areas

OBJECTIVE

Survey of paediatric vestibular activity in all 30 French paediatric cochlear implant (CI) centres to identify challenges and areas of improvement.

METHOD

All 30 French CI centres answered a 29-question questionnaire about their paediatric vestibular activity, equipment, and management in different clinical situations (e.g. vestibular assessment before a cochlear implantation or in cases of vertigo) at different ages.

RESULTS

Eighteen CI centres had dedicated paediatric vestibular clinics and 12 did not. Minimum age required for vestibular testing was 3 years in eight centres. Four vestibular tests stood out: caloric tests, video Head Impulse Test (vHIT), rotating chair, vestibular evoked myogenic potentials (VEMP). Depending on the centre's experience, the use of vestibular tests in clinical routine was very heterogeneous. Expert centres mostly used vHIT and cervical VEMP (in bone conduction) for assessments before the first cochlear implantation in 1-year-old children. Dizziness assessment in 4-year children was based on the use of vHIT, cervical VEMP on bone conduction, rotatory test, and caloric test. Ocular VEMP was rarely used.

CONCLUSIONS

Paediatric vestibular assessment requires specific expertise compared to adults. Due to a lack of specialised human resources, some centres may be unable to follow French paediatric CI guidelines. International recommendations could help standardise paediatric vestibular management and public health policies should be discussed to improve training and access for children.

Vestibular Infant Screening-Flanders: What is the Most Appropriate Vestibular Screening Tool in Hearing-Impaired Children?

OBJECTIVES

As children with sensorineural hearing loss have an increased risk for vestibular impairment, the Vestibular Infant Screening-Flanders project implemented a vestibular screening by means of cervical vestibular evoked myogenic potentials (cVEMP) at the age of 6 months for each child with hearing loss in Flanders (Belgium). Given that vestibular deficits can affect the child's development, this vestibular screening should allow early detection and intervention. However, less is currently known about which screening tool would be the most ideal and how vestibular impairment can evolve. Therefore, this study aimed to determine the most appropriate tool to screen for vestibular deficits, to assess the necessity of vestibular follow-up, and to set clinical guidelines for vestibular screening in children with hearing loss.

DESIGN

In total, 71 children with congenital or early-onset sensorineural hearing loss were enrolled (mean age at first appointment = 6.7 months). Follow-up was provided at 6 months, 1, 2, and 3 years of age. Below three years of age, the video Head Impulse Test (vHIT) of the horizontal semicircular canals (SCC), the cVEMP, and the rotatory test at 0.16, 0.04, and 0.01 Hz were applied. At 3 years of age, the vHIT of the vertical SCC and ocular vestibular evoked myogenic potentials (oVEMP) were added. To evaluate early motor development, the Alberta Infant Motor Scale (AIMS) results at 6 months and 1-year old were included.

RESULTS

At 6 months of age, the highest success rate was obtained with the cVEMP (90.0%) compared to the vHIT (70.0%) and the rotatory test (34.3-72.9%). Overall, vestibular deficits were found in 20.0% of the children, consisting of 13.9% with both SCC and otolith deficits (bilateral: 9.3%, unilateral: 4.6%), and 6.1% with unilateral isolated SCC (4.6%) or otolith (1.5%) deficits. Thus, vestibular deficits would not have been detected in 4.6% of the children by only using the cVEMP, whereas 1.5% would have been missed when only using the vHIT. Although vestibular deficits were more frequently found in severe to profound hearing loss (28.6%), characteristics of vestibular function were highly dependent on the underlying etiology. The AIMS results showed significantly weaker early motor development in children with bilateral vestibular deficits ( p = 0.001), but could not differentiate children with bilateral normal vestibular function from those with unilateral vestibular deficits ( p > 0.05). Progressive or delayed-onset vestibular dysfunction was only found in a few cases (age range: 12-36 months), in which the hearing loss was mainly caused by congenital cytomegalovirus (cCMV).

CONCLUSIONS

The cVEMP is the most feasible screening tool to assess vestibular function in 6-months-old children with hearing loss. Although the majority of children with vestibular deficits are detected with the cVEMP, the vHIT seems even more sensitive as isolated SCC deficits are associated with specific etiologies of hearing loss. As a result, the cVEMP is an appropriate vestibular screening tool, which is advised at least in severe to profound hearing loss, but certain etiologies require the addition of the vHIT (i.e., cCMV, meningitis, cochleovestibular anomalies with or without syndromic hearing loss).

Development of a new clinical tool to evaluate the balance abilities of children with bilateral vestibular loss: The Geneva Balance Test

Introduction

Vestibular deficits are considered rare in children, but the lack of systematic screening leads to underdiagnosis. It has been demonstrated that chronic vestibular dysfunction impacts the normal psychomotor development of children. Early identification is needed to allow for clinical management, ensuring better global development. For this purpose, our research group has developed the Geneva Balance Test (GBT), aiming to objectively quantify the balance capacity of children over a broad age range, to screen for bilateral vestibulopathy (BV), and to quantify the improvement of balance abilities in children.

Methods

To determine the capacity of the GBT to quantify the balance capacity of children with BV, we conducted an observational prospective study with three populations: 11 children with BV, and two age-matched control groups composed of (1) 15 healthy subjects without the vestibular or auditory disorder (HS) and (2) 11 pediatric cochlear implant recipients (CIs) without vestibular disorders. Results of the three populations have been compared in three different age sub- groups (3-5, 6-9, and ≥10 years), and with results of a short, modified version of the Bruininks-Oseretsky test of Motor proficiency Ed. 2 (mBOT-2).

Results

Statistical analyses demonstrated significant differences in the scores of the GBT between children aged 3-5, 6-9, and ≥10 years with BV and in both control populations (HS and CI). BV scores reflected poorer balance capacities at all ages. Children in the youngest CI sub-group (3-5 years) showed intermediate GBT scores but reached HS scores at 6-9 years, reflecting an improvement in their balance capacities. All the results of the GBT were significantly correlated with mBOT-2 results, although only a few BV completed the entire mBOT-2.

Discussion

In this study, the GBT allowed quantifying balance deficits in children with BV. The BOT-2 test is not validated for children <4.5 years of age, and the GBT seems to be better tolerated in all populations than the mBOT-2. Furthermore, mBOT-2 results saturated, reaching maximum values by 6-9 years whereas the GBT did not, suggesting that the GBT could be a useful tool for monitoring the development of balance capacities with age and could be used in the follow-up of children with severe vestibular disorders.

Altering gene expression using antisense oligonucleotide therapy for hearing loss

Hearing loss affects more than 430 million people, worldwide, and is the third most common chronic physical condition in the United States and Europe (GBD Hearing Loss Collaborators, 2021; NIOSH, 2021; WHO, 2021). The loss of hearing significantly impacts motor and cognitive development, communication, education, employment, and overall quality of life. The inner ear houses the sensory organs for both hearing and balance and provides an accessible target for therapeutic delivery. Antisense oligonucleotides (ASOs) use various mechanisms to manipulate gene expression and can be tailor-made to treat disorders with defined genetic targets. In this review, we discuss the preclinical advancements within the field of the highly promising ASO-based therapies for hereditary hearing loss disorders. Particular focus is on ASO mechanisms of action, preclinical studies on ASO treatments of hearing loss, timing of therapeutic intervention, and delivery routes to the inner ear.

Indicators of pediatric peripheral vestibular disorder: A retrospective study in a tertiary referral center

OBJECTIVES

This study aims to present characteristics of pediatric patients with peripheral vertigo and dizziness and their clinical workup results in the tertiary otorhinolaryngology center. We wanted to investigate whether the detailed history could replace the extensive vestibular testing and whether the clinical presentation could guide the first contact physician to appropriately directed specialist referral.

METHODS

Retrospective case review of consecutive pediatric vertigo and dizziness patients referred to the tertiary otorhinolaryngology center from 2015 to 2020. The data about the signs and symptoms of vertigo and dizziness and the results of audiological and vestibular tests were collected.

RESULTS

Of 257 children aged 10.9±4.3 years (R: 1-17 years), 32 (12.5%) had peripheral, and 49 (19%) had central vertigo and dizziness. Acute vestibulopathy was diagnosed in 22/257 (8.5%) children, sudden sensorineural hearing loss and benign paroxysmal positional vertigo in 5/257 (2%) children each. 60% of children with peripheral vertigo and dizziness had emesis, and 55.6% had nausea. 8% of children had spontaneous horizontal-rotatory nystagmus that followed Alexander's law. Goodman and Kruskal's л for determining whether the type of nystagmus could predict the type of vertigo and dizziness (central or peripheral) was 0.481 (p = 0.001). 12/26 (60%) of children with peripheral vertigo and dizziness had emesis compared to 14 (30.04%) children without emesis, a difference in proportions of 0.296 (p = 0.024, chi-square test of homogeneity). Binomial logistic regression to ascertain the effects of duration, nausea and emesis on the likelihood of the presence of peripheral vertigo was statistically significant (χ2(3) = 10.626, p = 0.014).

CONCLUSION

Unlike adults, peripheral vestibular causes of vertigo and dizziness in children may be rare but have the same typical signs and symptoms. The detailed history and careful clinical examination are crucial in differentiating between peripheral and central causes. This guides the first contact physician for further referral to appropriate specialists included in a multidisciplinary workup. Namely, nausea, emesis, horizontal nystagmus and a longer duration of symptoms in a child with vertigo and dizziness indicate a peripheral etiology. Therefore, a referral to an otorhinolaryngologist is reasonable.

Correlation of SVINT and Sensory Organization Test in Children with Hearing Loss

Objective: The skull vibration-induced-nystagmus test (SVINT) is a noninvasive and effective screening tool for the function of the otolith and canal structures in children. It can instantaneously assess vestibular asymmetry. This study aimed to analyze the SVINT results of healthy children vs. children with hearing loss (HL) and to correlate it with sensory organization test (SOT) results as a functional balance evaluation tool. Design: This case-controlled study compared the results of SVINT to the results of the SOT of the computerized dynamic posturography (CDP) in a control group of 120 healthy normal-hearing children (i.e., NH group) vs. hearing loss (HL) group of 60 children, including 30 children with hearing aids (HAs) and 30 children with a unilateral cochlear implant (CI). The SVINT results were compared to the caloric test (CaT) and video head impulse test (vHIT) and associated with SOT scores. Results: Thirty-one children in the HL group had normal SVINT and normal SOT results. A total of 21 children in the HL group had SVINT-negative and abnormal results in the SOT (possibly due to bilateral vestibular loss (BVL)). Eight children in the HL group had positive SVINT and abnormal SOT results. However, none of the children had only positive SVINT with normal SOT findings. Moreover, 52% of children had a normal result on both the SOT and CaT, whereas 27% had abnormal results on both tests (17% bilateral weakness and 10% unilateral), and 22% had the only result of the SOT suggesting a functional abnormality. Similarly, when associating the result to vHIT, 51% had normal results on both tests, and 25% had abnormal results (13% bilateral and 12% unilateral weakness). Conclusion: SVINT findings can be correlated with SOT findings in the case of the unilateral vestibular lesion (UVL), which adds a diagnostic value in these pediatric cases but may differ in the case of the bilateral vestibular lesion (BVL). However, SVINT findings need to be cautiously interpreted in light of other test findings such as the SOT, CaT, and vHIT.

[Effects of cochlear implantation on vestibular function]

The literature review is devoted to the effects arising from the effect of a cochlear implant on the vestibular system. Due to the pronounced anatomical proximity and physiological interaction of vestibular receptors with the cochlea, the installation of a cochlear implant and its electrical activity are associated with an effect on the vestibular system. The analysis of the works of foreign and domestic researchers who carried out monitoring of vestibular function in patients after cochlear implantation using modern objective methods was carried out.

Peripheral Vestibular Dysfunction Is a Common Occurrence in Children With Non-syndromic and Syndromic Genetic Hearing Loss

Hearing loss (HL) is the most common sensory deficit in humans and is frequently accompanied by peripheral vestibular loss (PVL). While often overlooked, PVL is an important sensory dysfunction that may impair development of motor milestones in children and can have a significant negative impact on quality of life. In addition, many animal and in vitro models of deafness use vestibular hair cells as a proxy to study cochlear hair cells. The extent of vestibular end organ dysfunction associated with genetic pediatric hearing loss is not well-understood. We studied children with a known genetic cause of hearing loss who underwent routine preoperative vestibular testing prior to cochlear implantation between June 2014 and July 2020. Vestibular testing included videonystagmography, rotary chair, video head impulse testing, and/or vestibular evoked myogenic potentials. Etiology of HL was determined through history, physical examination, imaging, laboratory testing, and/or genetic testing. Forty-four children (21 female/23 male) met inclusion criteria; 24 had genetic non-syndromic and 20 had genetic syndromic forms of HL. Mean age at the time of testing was 2.8 ± 3.8 years (range 7 months-17 years). The most common cause of non-syndromic HL was due to mutations in GJB2 (n = 13) followed by MYO15A (3), MYO6 (2), POU3F4 (2), TMPRSS3 (1), CDH23 (1), TMC1 (1), and ESRRB (1). The most common forms of syndromic HL were Usher syndrome (4) and Waardenburg (4), followed by SCID/reticular dysgenesis (3), CHARGE (2), CAPOS (1), Coffin-Siris (1), Jervell and Lange-Nielsen (1), Noonan (1), peroxisome biogenesis disorder (1), Perrault (1), and Trisomy 21 (1). Overall, 23 patients (52%) had PVL. A larger proportion of children with syndromic forms of HL had PVL (12/20, 60%) compared with children with genetic non-syndromic HL (11/24, 46%), though without statistical significant (p = 0.3). The occurrence of PVL varied by affected gene. In conclusion, PVL is a common finding in children with syndromic and non-syndromic genetic HL undergoing vestibular evaluation prior to cochlear implantation. Improved understanding of the molecular physiology of vestibular hair cell dysfunction is important for clinical care as well as research involving vestibular hair cells in model organisms and in vitro models.

Changes in Vestibular Function Following Pediatric Cochlear Implantation: a Prospective Study

OBJECTIVES

Given the close interconnection between the auditory and vestibular end organs, the increasingly broad application of (bilateral) cochlear implantation (CI) in children raises concern about its impact on the vestibular function. Unfortunately, literature on this matter is inconclusive and subject to several limitations. Therefore, this study aimed to elucidate the impact of pediatric CI on the vestibular function in a large sample of children, representative for the current CI population.

DESIGN

Fifty hearing-impaired children followed in the Ghent University Hospital were included in this prospective study. Twenty-seven patients underwent unilateral CI, and 23 were bilaterally implanted (9 sequentially, 14 simultaneously), adding up to 73 implanted ears. Children's median age at first implantation was 29 (range 8 to 194) months. Vestibular assessment was scheduled on average 2.8 months (SD: 3.6) before and 4.6 (SD: 4.0) months after implantation and consisted of video Head Impulse Testing of the lateral semicircular canals, rotatory testing (0.16, 0.04, and 0.01 Hz) and cervical vestibular evoked myogenic potential (cVEMP) testing with bone conduction stimulation. Caloric testing was added in children older than 3 years of age.

RESULTS

Overall, group analysis in our sample of 73 CI-ears did not reveal any significant impact on the vestibular function, except for a significantly shortened ipsilateral N1 latency of the cVEMP responses (p = 0.027) after CI. Complete ipsilateral loss of function after implantation was seen in 5% (3/54) of all CI-ears on the video head impulse testing, in 0% (0/10) on the caloric test and in 2% (1/52) on the cVEMP, notably all patients deafened by a congenital cytomegalovirus infection.

CONCLUSIONS

The impact of CI on the vestibular function in our dataset was limited. Therefore, the many advantages of simultaneous bilateral implantation may outweigh the risk for vestibular damage postoperatively. However, the impact on the vestibular function may be dependent on various factors (e.g., etiology of the hearing loss), and the clinical outcome is still difficult to predict. Vestibular assessment remains thus an important aspect in the pediatric CI population; first because the vestibular function should be considered in the decision-making process on (simultaneous or sequential bilateral) CI and second because it is essential to reveal a possible additional sensory deficit, allowing an opportunity for rehabilitation to improve the overall outcome of these children.

Vestibular Infant Screening (VIS)-Flanders: results after 1.5 years of vestibular screening in hearing-impaired children

Due to the close anatomical relationship between the auditory and vestibular end organs, hearing-impaired children have a higher risk for vestibular dysfunction, which can affect their (motor) development. Unfortunately, vestibular dysfunction often goes unnoticed, as vestibular assessment in these children is not standard of care nowadays. To timely detect vestibular dysfunction, the Vestibular Infant Screening–Flanders (VIS–Flanders) project has implemented a basic vestibular screening test for hearing-impaired infants in Flanders (Belgium) with a participation rate of 86.7% during the first year and a half. The cervical Vestibular Evoked Myogenic Potentials (cVEMP) test was applied as vestibular screening tool to map the occurrence of vestibular (mainly saccular) dysfunction in this population. At the age of 6 months, 184 infants were screened. No refers on vestibular screening were observed in infants with permanent conductive hearing loss. In infants with permanent sensorineural hearing loss, a cVEMP refer rate of 9.5% was observed. Failure was significantly more common in infants with severe-profound compared to those with mild-moderate sensorineural hearing loss (risk ratio = 9.8). Since this is the first regional study with a large sample size and successful participation rate, the VIS–Flanders project aims to set an example for other regions worldwide.

Hearing Loss in Children: A Review

IMPORTANCE

Hearing loss in children is common and by age 18 years, affects nearly 1 of every 5 children. Without hearing rehabilitation, hearing loss can cause detrimental effects on speech, language, developmental, educational, and cognitive outcomes in children.

OBSERVATIONS

Consequences of hearing loss in children include worse outcomes in speech, language, education, social functioning, cognitive abilities, and quality of life. Hearing loss can be congenital, delayed onset, or acquired with possible etiologies including congenital infections, genetic causes including syndromic and nonsyndromic etiologies, and trauma, among others. Evaluation of hearing loss must be based on suspected diagnosis, type, laterality and degree of hearing loss, age of onset, and additional variables such as exposure to cranial irradiation. Hearing rehabilitation for children with hearing loss may include use of hearing aids, cochlear implants, bone anchored devices, or use of assistive devices such as frequency modulating systems.

CONCLUSIONS AND RELEVANCE

Hearing loss in children is common, and there has been substantial progress in diagnosis and management of these cases. Early identification of hearing loss and understanding its etiology can assist with prognosis and counseling of families. In addition, awareness of treatment strategies including the many hearing device options, cochlear implant, and assistive devices can help direct management of the patient to optimize outcomes.

Postural control characterization according to age and auditory input in cochlear implant users

Aims/Objectives: Understand the relationship between auditory input and balance motor control. Material and Methods: Twelve prelingual adolescent cochlear implant users (CIU) and 12 adult postlingual CIU were tested by posturography on a force platform with eyes open in two conditions, with the cochlear implant (CI) on and off. Energy consumption (EC) of the body center of pressure sway signal was measured, calculating total EC and divided into three bands of frequencies; low (B1) 0-0.1 Hz, medium (B2) 0.1-1 Hz, and high (B3)1-2 Hz. Wilcoxon and Mann-Whitney tests were used for statistical analysis and the significance level was P ≤ 0.05. Results: Prelingual CIU decrease the EC in low and high frequencies throughout the adolescence (P < 0.05) assessed with the CI turned on, while it did not show any modification with the CI off. Postlingual CIU showed a deterioration of PR related to aging when evaluated with the CIU turned off, P < 0.05 in band 1. However, with the CI turned on they had no significant increase in this age range. Conclusions and Significance: The acoustic input improved EC of postural responses in higher and lower frequencies in adolescence and with aging which suggests a relationship with gross and fine movements involved in postural control.

Analysis of cochlear implant revision surgeries

PURPOSE

This study aimed to evaluate the reasons for cochlear implant (CI) revision surgeries in pediatric and adult groups.

METHODS

A total of 490 CIs were used for 423 patients between August 2005 and August 2019. Among these, patients who underwent a CI revision surgery were identified retrospectively. The reasons for CI revision surgeries were classified mainly as medical problems and device failure. These were also determined according to implant brands.

RESULTS

Of 423 patients with a CI surgery, 27 (6.3%) underwent a CI revision surgery. The revision implant rate was 4.9% for the pediatric group and 1.4% for the adult group. Five patients underwent a CI revision surgery due to medical problems (23.8%) and 16 due to device failure (76.2%) in the pediatric group, while 3 patients (50.0%) underwent a CI revision surgery due to medical problems and 3 (50.0%) due to device failure in adults.

CONCLUSIONS

A CI surgery is safe for patients with severe-to-profound sensorineural hearing loss, although a CI revision surgery has some potential. Device failure is the most common cause in children. It may be due to early implantation, frequent fall when children learn walking, or impaired vestibular function.

Evolution of Cochlear implant mapping and vestibular function in a pediatric case of Labyrinthitis

Background

Vestibular symptoms such as vertigo and imbalance are known to occur in some cochlear implant patients during the immediate postoperative period; however, acute vertigo in implanted children occurring remotely from the postoperative period has not been previously well-described.

Case presentation

A three-year-old girl with a history of bilateral sequential cochlear implantation presented with acute labyrinthitis associated with sudden onset of vertigo, balance impairment, and decline in right cochlear implant function 2 years after her most recent implant surgery. We describe her audiological and vestibular testing results during both the acute phase and following medical management and recovery.

Conclusion

Acute labyrinthitis should be considered when sudden onset vertigo and/or imbalance presents in children with cochlear implants outside of the perioperative period. Such symptoms should prompt early assessment of cochlear implant function, so that the device can be reprogrammed accordingly.

Early general development and central auditory system maturation in children with cochlear implants - A case series

OBJECTIVES

A cochlear implant (CI) has the potential to improve the functioning of a deaf child in many aspects. Nevertheless, the dynamics of the general development, beyond the typically measured language abilities, directly after CI, is still unknown, especially if a child is implanted early. In this study we present a methodological framework for assessment of different domains of development, as well as the central auditory nervous system (CANS) maturation in infants and toddlers with a CI.

METHODS

Three children with bilateral congenital hearing loss and a unilateral CI, aged below 2.5 years, participated in a longitudinal study. Children were tested at three time points after cochlear implantation using the Polish Children Development Scale (CDS) consisting of a comprehensive battery of tests, as well as recordings of Cortical Auditory Evoked Potentials (CAEP).

RESULTS

All three children revealed gradual improvement in the overall CDS result as well as most of the CDS subscales. After 9 months of CI experience two younger children showed age-appropriate performance. In CAEP measurements a decrease of latency of the P1 component (an established biomarker of cortical auditory maturation) was observed in the same two children, with one achieving normal ranges of P1 latency after 9 months of CI use.

CONCLUSIONS

Our novel methodological framework can be successfully applied in small children with cochlear implants. It contributes to better understanding of the general development in early implanted children. The preliminary results indicate variability in children's performance in various developmental domains and thus the need to monitor the development of each child individually and holistically.

Vestibular Infant Screening - Flanders: The implementation of a standard vestibular screening protocol for hearing-impaired children in Flanders

OBJECTIVES

The Vestibular Infant Screening - Flanders (VIS-Flanders) project aims to implement and refine a vestibular screening protocol for all children with neonatal hearing loss in Flanders (Belgium) to limit the impact of a vestibular dysfunction on the motor, cognitive and psychosocial development of hearing-impaired children.

METHODS

Each child with a confirmed neonatal hearing loss in Flanders will undergo a vestibular screening at the age of 6 months in the reference centers involved in the neonatal hearing screening program. The cervical Vestibular Evoked Myogenic Potential (cVEMP) test will be used as a screening tool. The test is short, child-friendly, feasible at a young age and highly correlated with motor and balance performance. The results of an extensive follow-up protocol at the Ghent University Hospital will enable further refinement of the screening protocol.

RESULTS

Data collection in all reference centers has started since June 2018. This paper outlines the rationale for the screening and the set-up of this four-year project.

CONCLUSIONS

Current available literature strongly favors vestibular assessment in congenitally hearing-impaired children. A standard vestibular screening for these children should lead to early identification of vestibular deficits and subsequent prompt referral for further motor assessment and rehabilitation, in order to limit the impact of a vestibular dysfunction in developing children and improve their quality of life.