Static balance function in children with cochlear implants

Postural Sway Velocity of Deaf Children with and without Vestibular Dysfunction

BACKGROUND

Sensory information obtained from the visual, somatosensory, and vestibular systems is responsible for regulating postural control, and if damage occurs in one or more of these sensory systems, postural control may be altered.

OBJECTIVE

To evaluate and compare the postural sway velocity between children with normal hearing and with sensorineural hearing loss (SNHL), matched by sex and age group, and to compare the postural sway velocity between children with normal hearing and with SNHL, with and without vestibular dysfunction.

METHODS

Cross-sectional study that evaluated 130 children (65 with normal hearing and 65 with SNHL), of both sexes and aged between 7 and 11 years, from public schools of the city of Caruaru, Pernambuco state, Brazil. The postural sway velocity of the center of pressure (COP) was assessed by a force platform, in two directions, anteroposterior (AP) and mediolateral (ML)), in three positions, namely bipedal support with feet together and parallel (parallel feet (PF)), bipedal support with one foot in front of the other (tandem foot (TF)), and single-leg support (one foot (OF)), evaluated with the eyes open and closed.

RESULTS

Children with SNHL demonstrated greater postural sway velocity compared to children with normal hearing in all the positions evaluated, with significant differences in the AP direction, with the eyes open (PF: p = 0.001; TF: p = 0.000; OF: p = 0.003) and closed (PF: p = 0.050; TF: p = 0.005). The same occurred in the ML direction, with the eyes open (PF: p = 0.001; TF: p = 0.000; OF: p = 0.001) and closed (PF: p = 0.002; TF: p = 0.000). The same occurred in relation to vestibular function, where the children with SNHL with an associated vestibular dysfunction demonstrated greater postural sway velocity compared to children with normal hearing in all the positions evaluated, demonstrating significant differences in the AP direction, with the eyes open (TF: p = 0.001; OF: p = 0.029) and eyes closed (PF: p = 0.036; TF: p = 0.033). The same occurred in the ML direction, with the eyes open (TF: p = 0.000) and with the eyes closed (PF: p = 0.008; TF: p = 0.009).

CONCLUSIONS

Children with SNHL demonstrated greater instability of postural control than children with normal hearing in all the directions assessed. Children with SNHL and an associated vestibular dysfunction demonstrated the greatest instability of postural control in this study.

Impact of hearing impairment on the mental status of the adults and older adults in Jordanian society

BACKGROUND

Hearing loss is a common disorder, affecting both children and adults worldwide. Individuals with hearing loss suffer from mental health problems that affect their quality of life.

OBJECTIVE

This study aimed to investigate the social and emotional consequences of hearing loss in a Jordanian population using Arabic versions of the Hearing Handicap Inventory for Adults (HHIA) and the Hearing Handicap Inventory for the Elderly (HHIE).

METHODS

This study included 300 Jordanian participants aged 18-90 years with hearing loss. Each participant underwent a complete audiological evaluation before answering the questionnaires.

RESULTS

The median overall scores of the HHIA and HHIE groups were 39 and 65, respectively. Both HHIA (Cronbach's alpha = 0.79, p < 0.001) and HHIE (Cronbach's alpha = 0.78, p < 0.001) were significantly associated with the social, emotional, and overall scores. Compared to the adult group, the median emotional and social scores of the older adults group were significantly higher than the adults group (Z = -4.721, p = 0.001), using the Mann-Whitney test.

CONCLUSION

The present research revealed that psychological disabilities associated with hearing loss in the adult Jordanian population are more frequent and severe than in other nations. This may be attributed to the lack of awareness of the mental consequences of hearing loss among Jordanian healthcare providers and the public.

Effects of the BalanCI on Working Memory and Balance in Children and Young Adults With Cochleovestibular Dysfunction

OBJECTIVES

This study aimed to: (1) determine the interaction between cognitive load and balance in children and young adults with bilateral cochleovestibular dysfunction who use bilateral cochlear implants (CIs) and (2) determine the effect of an auditory balance prosthesis (the BalanCI) on this interaction. Many (20 to 70%) children with sensorineural hearing loss experience some degree of vestibular loss, leading to poorer balance. Poor balance could have effects on cognitive resource allocation which might be alleviated by the BalanCI as it translates head-referenced cues into electrical pulses delivered through the CI. It is hypothesized that children and young adults with cochleovestibular dysfunction will demonstrate greater dual-task costs than typically-developing children during dual balance-cognition tasks, and that BalanCI use will improve performance on these tasks.

DESIGN

Study participants were 15 typically-developing children (control group: mean age ± SD = 13.6 ± 2.75 years, 6 females) and 10 children and young adults who use bilateral CIs and have vestibular dysfunction (CI-V group: mean age ± SD=20.6 ± 5.36 years, 7 females). Participants completed two working memory tasks (backward auditory verbal digit span task and backward visuospatial dot matrix task) during three balance conditions: seated, standing in tandem stance with the BalanCI off, and standing in tandem stance with the BalanCI on. Working memory performance was quantified as total number of correct trials achieved. Postural stability was quantified as translational and rotational path length of motion capture markers worn on the head, upper body, pelvis, and feet, normalized by trial time.

RESULTS

Relative to the control group, children and young adults in the CI-V group exhibited poorer overall working memory across all balance conditions ( p = 0.03), poorer translational postural stability (larger translational path length) during both verbal and visuospatial working memory tasks ( p < 0.001), and poorer rotational stability (larger rotational path length) during the verbal working memory task ( p = 0.026). The CI-V group also exhibited poorer translational ( p = 0.004) and rotational ( p < 0.001) postural stability during the backward verbal digit span task than backward visuospatial dot matrix task; BalanCI use reduced this stability difference between verbal and visuospatial working memory tasks for translational stability overall ( p > 0.9), as well as for rotational stability during the maximum working memory span (highest load) participants achieved in each task ( p = 0.91).

CONCLUSIONS

Balance and working memory were impaired in the CI-V group compared with the control group. The BalanCI offered subtle improvements in stability in the CI-V group during a backward verbal working memory task, without producing a negative effect on working memory outcomes. This study supports the feasibility of the BalanCI as a balance prosthesis for individuals with cochleovestibular impairments.

Use of Virtual Reality-Based Games to Improve Balance and Gait of Children and Adolescents with Sensorineural Hearing Loss: A Systematic Review and Meta-Analysis

BACKGROUND

Children and adolescents with sensorineural hearing loss (SNHL) often experience motor skill disturbances, particularly in balance and gait, due to potential vestibular dysfunctions resulting from inner ear damage. Consequently, several studies have proposed the use of virtual reality-based games as a technological resource for therapeutic purposes, aiming to improve the balance and gait of this population.

OBJECTIVE

The objective of this systematic review is to evaluate the quality of evidence derived from randomized or quasi-randomized controlled trials that employed virtual reality-based games to enhance the balance and/or gait of children and adolescents with SNHL.

METHODS

A comprehensive search was conducted across nine databases, encompassing articles published in any language until 1 July 2023. The following inclusion criteria were applied: randomized or quasi-randomized controlled trials involving volunteers from both groups with a clinical diagnosis of bilateral SNHL, aged 6-19 years, devoid of physical, cognitive, or neurological deficits other than vestibular dysfunction, and utilizing virtual reality-based games as an intervention to improve balance and/or gait outcomes.

RESULTS

Initially, a total of 5984 articles were identified through the searches. Following the removal of duplicates and screening of titles and abstracts, eight studies remained for full reading, out of which three trials met the eligibility criteria for this systematic review. The included trials exhibited a very low quality of evidence concerning the balance outcome, and none of the trials evaluated gait. The meta-analysis did not reveal significant differences in balance improvement between the use of traditional balance exercises and virtual reality-based games for adolescents with SNHL (effect size: -0.48; [CI: -1.54 to 0.57]; p = 0.37; I² = 0%).

CONCLUSION

Virtual reality-based games show promise as a potential technology to be included among the therapeutic options for rehabilitating the balance of children and adolescents with SNHL. However, given the methodological limitations of the trials and the overall low quality of evidence currently available on this topic, caution should be exercised when interpreting the results of the trials analyzed in this systematic review.

Interaction of Hearing and Balance

There is increasingly assumed that, in addition to visual, vestibular and somatosensory afferents, hearing also plays a role in the regulation of balance. It seems that, especially in old age, progressive hearing loss is associated with a decrease in postural control. Several studies investigated this relationship in normal-hearing people, in patients with conventional hearing aids and with implantable hearing systems, as well as in patients with vestibular disorders. Despite the inhomogeneous study situation and lack of evidence, hearing seems to interact with the balance regulation system with potentially stabilizing effect. Furthermore, insights into audiovestibular interaction mechanisms could be achieved, which could possibly be integrated into therapeutic concepts of patients with vestibular disorders. However, further prospective controlled studies are necessary to bring this issue to an evidence-based level.

Vestibular status: A missing factor in our understanding of brain reorganization in deaf individuals

The brain of deaf people is definitely not just deaf, and we have to reconsider what we know about the impact of hearing loss on brain development in light of comorbid vestibular impairments.

Long-Term Lateral Semicircular Canal Function in Children with Cochlear Implants: Results of Video Head Impulse Test

In children with profound deafness, bilateral cochlear implant (CI) is an effective, established procedure. However, its safety on vestibular function has recently been debated. The goal of this study is to evaluate the long-term lateral semicircular canal high-frequency vestibulo-oculomotor reflex (LSC HF VOR) in children with CI by video head impulse testing (vHIT). This is a cross-sectional study assessing a cohort of children who received either a unilateral (12) or a bilateral (12) cochlear implant (CI), compared with a control group of 12 normal-hearing children. No significant LSC HF VOR gain difference was found between CI users and controls. In the unilaterally implanted group, the LSC HF VOR gain measured in the “CI-ON” condition was significantly higher than in the “CI-OFF” condition, both in the implanted and in the non-implanted ear. In the bilaterally implanted group, the difference between the two conditions was not significant. Our results do not show any impairment of LSC HF VOR function in children with CI compared to normal-hearing children in the long-term period. This suggests that both unilateral and simultaneous/sequential bilateral CI are procedures that do not impair HF LSC long-term function when analyzed by vHIT.

The Influence of Hearing Aids on Balance Control: A Systematic Review

AIM

To assess the current opinion on the effects of hearing loss treatment by hearing aids (HAs) and the benefits of HA use on imbalance.

METHODS

PRISMA-compliant systematic review was done, including observational studies in patients affected by mild to severe sensorineural hearing loss with HAs, investigating the benefits of HAs on balance. Electronic searches were performed through Medline, Cochrane, Embase, Web of Science, and Scopus.

RESULTS

A total of 200 patients in 8 studies were included in this systematic review. Four studies were cross-sectional, 3 cross-sectional controlled and 1 prospective nonrandomized study. Static and dynamic balance in the aided condition improved in patients assessed using clinical investigations including Romberg test and Functional Ambulation Performance/mini-BESTest, respectively. Variable outcomes were found measuring static and dynamic balance during the aided condition with objective tests (computerized posturography, Mobility Lab device). Improved quality of life outcomes and self-confidence were noted, while subjective measurements of balance had conflicting results.

CONCLUSION

Although an improvement in balance in patients with HAs has been shown in certain conditions, the overall benefit is still unclear and it is only possible to speculate that HAs may also improve static, dynamic, or subjective perception of balance function in adults affected by hearing loss.

The effects of age at cochlear implantation on balance in children: A pilot study

AIM

The evaluation of the effects of age at cochlear implantation on balance in children.

RESEARCH DESIGN

Cross-sectional study.

STUDY SAMPLE

Twenty children who received their cochlear implants (CI) before the chronologic age of 48 months (Early CI Group), and 20 children who received their CI at 48 months chronologic age or later (Late CI Group).

INTERVENTION

All children underwent Tandem Romberg (TR) test, Single-Leg stance (SLS) test, Pediatric Clinical Test of Sensory Interaction for Balance (P-CTSIB), Pediatric Balance scale (PBS) and Timed Up and Go (TUG) test.

DATA COLLECTION AND ANALYSIS

The scores of TR, SLS and P-CTSIB and TUG tests and PBS were recorded. Mann Whitney U test and Independent-samples t-test were used to compare data between groups.

RESULTS

TR (eyes opened-EO), SLS (EO), PBS, and TUG scores and incidence in dizziness symptoms did not show significant differences between the groups (p > 0.05). Duration of TR and SLS tests (eyes closed-EC), P-CTSIB-positions 5, and 6 were significantly longer in the Early CI Group than the Late implanted group(p < 0.05).

CONCLUSION

Although the age of cochlear implantation did not affect functional balance for children, it has been found to cause impaired balance performance in difficult static conditions and increased frequency of dizziness.

Does the practice of sports or recreational activities improve the balance and gait of children and adolescents with sensorineural hearing loss? A systematic review

BACKGROUND

Balance and gait disorders have been observed in children and adolescents with sensorineural hearing loss (SNHL), justified by vestibular dysfunctions that these children may present, due to the injury to the inner ear. Therefore, some investigations have suggested that the practice of sports or recreational activities can improve the balance and gait of this population.

OBJECTIVE

Assess the evidence quality from randomized or quasi-randomized controlled trials that used sports or recreational activities as an intervention to improve the balance and /or gait of children and/or adolescents with SNHL.

METHODS

Systematic review that surveyed articles in nine databases, published up to January 10, 2019, in any language, using the following inclusion criteria: (1) Randomized or quasi-randomized controlled trials. (2) Participants from both groups with the clinical diagnosis of SNHL, aged 6-19 years old, without physical problems, cognitive or neurological deficits, except the vestibular dysfunction. (3) Using the practice of sports or recreational activities as an intervention, to improve the balance and/or gait outcomes.

RESULTS

4732 articles were identified in the searches, after the removal of the duplicates articles and the reading of the titles and their abstracts, remained 16 articles for reading in full, being 5 trials eligible for this systematic review. Of the five eligible trials, three used sports activities and two recreational activities as intervention and presented very low-quality evidence for balance and gait outcomes.

SIGNIFICANCE

Sports and recreational practices seem to represent promising modalities to improve the balance and gait of children and adolescents with SNHL. However, due to the methodological limitations of the trials and the low quality of the current evidence on the topic, the results of the trials should be interpreted with caution. Due to the low quality of evidence observed, we suggest that new trials be proposed on this topic, with greater methodological rigor, to provide high-quality evidence on the effectiveness of sports and recreational practices to improve the balance and gait of children and adolescents with SNHL.

Vestibular rehabilitation exercises programs to improve the postural control, balance and gait of children with sensorineural hearing loss: A systematic review

BACKGROUND

Several studies have demonstrated that children with sensorineural hearing loss (SNHL) exhibit postural instabilities, as well as balance and gait disorders, due to the vestibular dysfunction that they are prone to display as a consequence of inner ear injury. Thus, some experiments have proposed vestibular rehabilitation exercises programs as a treatment to improve these motor skills in children with SNHL.

OBJECTIVE

Assess the evidence quality of the trials that used vestibular rehabilitation exercises programs to improve the postural control, balance and gait of children with SNHL.

METHODS

This is a systematic review that surveyed articles in nine databases, published up to July 4, 2019, in any language, using the following inclusion criteria: (1) Randomized or quasi-randomized controlled trials. (2) Participants of both groups with clinical diagnosis of SNHL, aged up to 12 years old, with no physical problems, cognitive or neurological impairments, except the vestibular dysfunction. (3) Using vestibular rehabilitation exercises programs to improve the following outcomes: postural control, balance and/or gait.

RESULTS

Six experiments, including 153 children, met the inclusion criteria of this systematic review. Two randomized controlled trials (45 children) on the postural control exhibited low evidence quality and four others; three randomized and controlled trials (90 children) on the balance and one quasi-randomized (18 children) on the gait demonstrated very low evidence quality, respectively.

CONCLUSION

There is promising evidence that vestibular rehabilitation exercises programs improve the postural control, balance and gait of children with SNHL. However, due to the methodological limitations of the trials and low quality of current evidence on this topic, the trials results analyzed by this systematic review should be interpreted with caution. Due to the low quality of evidence observed in this review, we suggest that new trials be proposed on this topic, with better methodological quality, to prove the effectiveness of vestibular rehabilitation exercises programs to improve the postural control, balance and gait of children with SNHL.

Balance performance of children and adolescents with sensorineural hearing loss: Repercussions of hearing loss degrees and etiological factors

INTRODUCTION

Some studies have demonstrated a parallelism between the extent of hearing loss and the frequency of vestibular dysfunction in children with sensorineural hearing loss (SNHL). Despite this, little is known about the repercussion of degrees of hearing loss and etiological factors on the balance performance in this children.

OBJECTIVE

Compare the balance performance between normal hearing (NH) children and those with SNHL, considering the sex and age range of the sample, and analyze balance performance according to the degrees of hearing loss and etiological factors in the latter group.

METHODS

Cross-sectional study that assessed 96 children (48 NH and 48 with SNHL), aged between 7 and 18 years old. The balance performance was assessed by the Brazilian version of the Pediatric Balance Scale, validated for Brazilian child population and the Mann-Whitney test used for statistical analysis.

RESULTS

The group with SNHL showed lower average balance performance compared to NH (p = 0.000). This was also observed when the children were grouped by sex: female and male (p = 0.001). The same difference occurred when the children were stratified by age group: 7-14 years old (p = 0.000). There were no differences between the balance performance of the groups according to the degrees of hearing loss (p = 0.236) and the children with prematurity or post-natal meningitis as an etiological factor demonstrated the worst balance performance.

CONCLUSION

The children with SNHL showed worse balance performance compared to NH of the same sex and age range between seven to fourteen years. There were no differences between balance performance and hearing loss degrees, and those children with prematurity or post-natal meningitis as an etiological factor demonstrated the worst balance performances.

Vestibular dysfunction and postural balance in cochlear implant users: a narrative literature review

ABSTRACT Cochlear implants directly stimulate nerve fibers and ganglion cells of the auditory nerve, which transform sound energy into low levels of electrical current, stimulating the remaining fibers of the auditory nerve in patients with severe to profound hearing loss, in order to provide the significant range of auditory sensation and speech comprehension. Due to the close relationship between cochlea and vestibular receptors, some patients may present vestibular and postural balance changes concomitantly after surgery. This study aimed to perform a narrative review of the main studies that relate vestibular symptoms in patients implanted in the last six years. The research was performed through the databases: SciELO, LILACS and PubMed, using associated descriptors for "cochlear implant", "vestibular dysfunction", "vertigo" and "balance", totalizing 21 studies that fitted the inclusion criteria. The results were described in a chronological order of publication, showing the main conclusions. Of the total studies analyzed, 18 related vestibular function to cochlear implant and only 3 studies did not find such a relationship. The literature characterize the effects of the cochlear implant on the vestibular system, however, the results are contradictory.

Sudden onset of static equilibrium dysfunction in patients receiving a cochlear implant

BACKGROUND

We investigated the sudden onset of static equilibrium dysfunction caused by cochlear implantation (CI) in congenital hearing loss patients.

METHOD

Twenty-five patients were selected from a cohort of unilateral CI recipients to form the CI group. Static posturography was performed 1 to 3 days before and 3 to 5 days after CI. Each patient underwent the test with eyes open (EO) and eyes closed (EC) for 30 seconds, separately. Another group of age- and sex-matched patients with no history of hearing impairment undergoing unrelated surgeries formed the control group, and were examined with the same tests pre- and post-surgery. A third group of patients undergoing middle ear surgery formed the otitis media (OM) group. Postural sway parameters including sway velocity (SV) in the X-axis, SV in the Y-axis, length of sway locus length (LNG), and environmental area (ENV) were measured and recorded.

RESULTS

Comparison of pre-surgery posturographical parameters between the CI and control groups revealed no significant differences. Significant differences were found in most parameters in pre- and post-surgery comparisons in the CI group. Mean SV values in the X-axis pre- and post-surgery were 8.48 and 11.52 mm/s, respectively, in the EO condition (P < .05), and 14.94 and 20.16 mm/s, respectively, in the EC condition (P < .05). In the Y-axis, mean SV values were 15.36 and 20.24 mm/s pre- and post-surgery, respectively, in the EC condition (P < .05). The LNG values in the CI group pre- and post-surgery were 319.60 and 469.88 mm in the EO condition (P < .05), and 571.40 and 764.12 mm in the EC condition (P < .05). No significant functional equilibrium change was observed in the control group between pre- and post-surgery (P > .05) except SV in the X-axis and LNG in the EO condition (P < .05). No significant pre- and post-surgery differences were found in the OM group.

CONCLUSION

CI appeared to influence static equilibrium function within 1 week post-surgery. This influence was greater when eyes were closed.

Effect of hearing aids on static balance function in elderly with hearing loss

While a few studies have investigated the relationship between hearing acuity and postural control, little is known about the effect of hearing aids on postural stability in elderly with hearing loss. The aim was to compare static balance function between elderly with hearing loss who used hearing aids and those who did not use. The subjects asked to stand with (A) open eyes on rigid surface (force platform), (B) closed eyes on rigid surface, (C) open eyes on a foam pad, and (D) closed eyes on a foam pad. Subjects in the aided group (n=22) were tested with their hearing aids turned on and hearing aids turned off in each experimental condition. Subjects in the unaided group (n=25) were tested under the same experimental conditions as the aided group. Indicators for postural stability were center of pressure (COP) parameters including; mean velocity, standard deviation (SD) velocity in anteroposterior (AP) and mediolateral (ML) directions, and sway area (95% confidence ellipse). The results showed that within open eyes-foam surface condition, there was greater SD velocity in the off-aided than the on-aided and the unaided than the on-aided (p<0.0001 for SD velocity in AP and ML). Also, no significant differences were found between the off-aided and unaided group (p=0.56 and p=0.77 for SD velocity in AP and ML, respectively). Hearing aids improve static balance function by reducing the SD velocity. Clinical implications may include improving hearing inputs in order to increase postural stability in older adults with hearing loss.

Study of the effects of hearing on static and dynamic postural function in children using cochlear implants

OBJECTIVE

The present study aimed to evaluate the postural control perturbations by the center of pressure parameters in two main approaches, cochlear implant turned "on" and "off".

METHODS

We included 25 children aged 8-10 years with unilateral cochlear implants and bilateral vestibular hypofunction deficit. To evaluate the postural function, each children was asked to stand on the force plate under 3 different conditions and cochlear implant turned "on" and "off": Condition (A) double stance from open eyes to closed eyes, Condition (B) double stance with open eyes engaging in the dual task and Condition (C) From double leg stance to one leg stance with open eyes for assessment of dynamic postural control. Also to calculate the center of pressure parameters, we designed new software for the force plate RESULTS: In condition A: although the results demonstrated an overall reduction in the mean of center of pressure parameters when the cochlear implant was "on", only the significant differences were seen in mean and standard deviations for anterior-posterior displacement, mediolateral displacement, area and mean velocity (P =0.00, P=0.04, P=0.02 and P=0.00, respectively) in open eyes In condition B: no significant difference was found between "on" and "off" cochlear implant in single or dual-task situations. In condition C: mean velocity variable demonstrated a significant difference (P=0.00) in the cochlear implant "on" condition in double leg stance only. Also, anterior-posterior displacement demonestrated a significant difference (P=0.00) when the cochlear implant was turned "on" in one leg stance situation.

CONCLUSION

The results of our study show that auditory information can improve postural stability and reduce body sways in different situations as an underlying system for reinforcement of the postural control in children without complete normal balance subsystems.

The Contribution of Hearing and Hearing Loss to Balance Control

This study investigated the hypothesis that a hearing ‘map' of our surroundings is used to maintain balance control. We investigated the effects of sound on postural sway using centre of pressure analysis in 50 subjects with normal hearing, 28 with hearing loss and 19 with vestibular dysfunction. The acoustic environments utilized sound cues that were either present or absent. It was found that auditory cues are utilized by subjects with normal hearing to improve postural sway. The ability to utilize sound for postural control is diminished when there is a hearing loss, but this appears to be overcome by the use of a hearing aid. Patients with additional vestibular deficits exploit auditory cues to a greater degree, suggesting that sensory weighting to enhance the use of auditory cues may be applied when there is diminished sensory redundancy.

Body Perception and Action Following Deafness

The effect of deafness on sensory abilities has been the topic of extensive investigation over the past decades. These investigations have mostly focused on visual capacities. We are only now starting to investigate how the deaf experience their own bodies and body-related abilities. Indeed, a growing corpus of research suggests that auditory input could play an important role in body-related processing. Deafness could therefore disturb such processes. It has also been suggested that many unexplained daily difficulties experienced by the deaf could be related to deficits in this underexplored field. In the present review, we propose an overview of the current state of knowledge on the effects of deafness on body-related processing.

Effects of Unilateral Cochlear Implantation on Balance Control and Sensory Organization in Adult Patients with Profound Hearing Loss

Many studies were interested in the consequence of vestibular dysfunction related to cochlear implantation on balance control. This pilot study aimed to assess the effects of unilateral cochlear implantation on the modalities of balance control and sensorimotor strategies. Posturographic and vestibular evaluations were performed in 10 patients (55 ± 20 years) with profound hearing loss who were candidates to undergo unilateral multichannel cochlear implantation. The evaluation was carried out shortly before and one year after surgery. Posturographic tests were also performed in 10 age-matched healthy participants (63 ± 16 years). Vestibular compensation was observed within one year. In addition, postural performances of the patients increased within one year after cochlear implantation, especially in the more complex situations, in which sensory information is either unavailable or conflicting. Before surgery, postural performances were higher in the control group compared to the patients' group. One year after cochlear implantation, postural control was close to normalize. The improvement of postural performance could be explained by a mechanism of vestibular compensation. In addition, the recovery of auditory information which is the consequence of cochlear implantation could lead to an extended exploration of the environment possibly favoring the development of new balance strategies.

Cochlear implantation and vestibular function in children

OBJECTIVES

To analyze vestibular function Q2 (VF) after cochlear implantation (CI) in children.

METHODS

Retrospective cohort study at a tertiary pediatric referral center. 43 children that had vestibular testing (VT) after unilateral cochlear implantation, from 2001 to 2010, were included. CT scan of the temporal bone was done systematically before surgery. VT included three tests: head-impulse test, caloric tests, vestibular evoked myogenic potentials. VF was graded in: normal (type 1), partial dysfunction (type 2), severe dysfunction and areflexia (type 3). In 12 cases, VT was done before and after CI. Vestibular function was analyzed looking to side, etiology and preoperative status.

RESULTS

Mean age at CI was 2.9 years. Bilateral inner ear malformation were retrieved in 16%. Before surgery, 50% of children had normal vestibular responses, 4/12 had bilateral type 2, two had asymmetrical VF. In this group, after surgery, 2 children had VF worsening, none on the CI side only. Considering all 43 patients, post operative VT showed normal response in 48.8% and type 2&3 in 16.2%. Children had asymmetrical poorer vestibular function on the side of CI in 19%. Among them, 75% had normal contralateral VF. Sensorineural hearing loss etiologies known to be associated with vestibulopathy (Usher/Meningitis/Inner Ear Malformations/CMV) were associated to abnormal vestibular function more frequently than in other causes (p=0.01).

CONCLUSION

Half of the children had initial vestibular dysfunction. In our study, 20% of cochlear implantation could have worsened vestibular function. As vestibular function should be part of the choice in cochlear implantation, side of implantation and survey; and vestibular tests are uneasy to achieve in pediatric population, we propose a three-steps evaluation and gradation which allow easier comparison.

Evaluation of Vestibular and Dynamic Visual Acuity in Adults with Congenital Deafness

This study compared vestibular and dynamic visual acuity in 19 adult athletes with deafness participating in Deaflympics to those of 25 young adults with normal hearing. Balance capability was evaluated using a one-leg standing test with eyes open and stabilometry. Caloric tests and vestibular evoked myogenic potential tests were conducted to test vestibular function. Visual function was evaluated using a dynamic visual acuity test. No significant difference was found between results of the one-leg standing test with eyes open and stabilometry with eyes open. Athletes with deafness performed better than normal hearing young adults with eyes closed. The caloric test indicated hypofunction of the lateral semicircular canal function in 5 of the 19 athletes with deafness. Balance-function tests showed normal results for both groups. The results for athletes with deafness on visual acuity were better than those of controls. Young Deaflympics athletes with deafness can adjust their balance function as well as or better than normal hearing young adults using dynamic visual acuity.