Working Memory, Attention Skills, and Language Proficiency in Children with Unilateral and Bilateral Cochlear Implants

BACKGROUND

 Previous studies observed that children with cochlear implants (CIs) have poor language, working memory, and attention skills. The ability to perform cognitive tasks, such as attention and memory, plays a crucial role in the academic achievement and everyday life of children with hearing impairment.

PURPOSE

 This study aimed to evaluate and compare the effects of age at the time of implantation and bilateral hearing on cognitive skills, such as language development, working memory, and selective attention, among children with CIs.

RESEARCH DESIGN

 Language skills were assessed using the Test of Language Development-Primary: Fourth Edition (TOLD-P:4), working memory using the Visual-Aural Digit Span Test-Revised Form (VADS-R), and selective attention skills using the Stroop Test TBAG Form.

STUDY SAMPLE

 A total of 58 participants, comprised of 21 children with early unilateral CIs (before 2 years), 18 children with late unilateral CIs (after 2 years), and 19 children with bilateral CIs, between the ages of 6 and 9 years, were included in the study.

DATA COLLECTION AND ANALYSIS

 According to the age at the time of implantation and whether or not the participant was unilaterally or bilaterally implanted, the mean scores, percentage values, and resultant scores of the participants were calculated using the Mann-Whitney U test. The number of repeated backward digit spans for the VADS-R test, completion times, number of errors and corrections for the Stroop test, raw scores, scaled scores corresponding to raw scores at the relevant age, descriptive terms for the TOLD-P:4 test, and within-group comparisons for all tests were examined.

RESULTS

 There were significant differences in language, working memory, and attention skills between individuals with early and late unilateral cochlear implantation, whereas there were no significant differences in many subtests between individuals with early unilateral and bilateral cochlear implantation.

CONCLUSION

 These findings demonstrate the importance of early cochlear implantation and bilateral hearing on the development of cognitive processes, such as language development, selective attention, and memory skills, which are important factors that may contribute to children's academic performance and overall success.

Early cochlear implantation supports narrative skills of children with prelingual single-sided deafness

Prelingual single-sided deafness (SSD) not only affects children's hearing skills, but can also lead to speech-language delays and academic underachievement. Early cochlear implantation leads to improved spatial hearing, but the impact on language development is less studied. In our longitudinal study, we assessed the language skills of young children with SSD and a cochlear implant (CI). In particular, we investigated their narrative skills in comparison to two control groups: children with SSD without a CI, and children with bilateral normal hearing. We found that children with SSD and a CI performed in line with their normal-hearing peers with regard to narrative and verbal short-term memory skills. Children with SSD without a CI had worse narrative (group difference = - 0.67, p = 0.02) and verbal short-term memory (group difference = - 0.68, p = 0.03) scores than the implanted group. Verbal short-term memory scores and grammar scores each correlated positively with narrative scores across all groups. Early grammar scores (at 2-3 years of age) could partially predict later narrative scores (at 4-6 years of age). These results show that young children with prelingual SSD can benefit from early cochlear implantation to achieve age-appropriate language skills. They support the provision of a CI to children with prelingual SSD.

Intra- and Interrater Reliability of CT- versus MRI-Based Cochlear Duct Length Measurement in Pediatric Cochlear Implant Candidates and Its Impact on Personalized Electrode Array Selection

Background: Radiological high-resolution computed tomography-based evaluation of cochlear implant candidates’ cochlear duct length (CDL) has become the method of choice for electrode array selection. The aim of the present study was to evaluate if MRI-based data match CT-based data and if this impacts on electrode array choice. Methods: Participants were 39 children. CDL, length at two turns, diameters, and height of the cochlea were determined via CT and MRI by three raters using tablet-based otosurgical planning software. Personalized electrode array length, angular insertion depth (AID), intra- and interrater differences, and reliability were calculated. Results: Mean intrarater difference of CT- versus MRI-based CDL was 0.528 ± 0.483 mm without significant differences. Individual length at two turns differed between 28.0 mm and 36.6 mm. Intrarater reliability between CT versus MRI measurements was high (intra-class correlation coefficient (ICC): 0.929–0.938). Selection of the optimal electrode array based on CT and MRI matched in 90.1% of cases. Mean AID was 629.5° based on the CT and 634.6° based on the MRI; this is not a significant difference. ICC of the mean interrater reliability was 0.887 for the CT-based evaluation and 0.82 for the MRI-based evaluation. Conclusion: MRI-based CDL measurement shows a low intrarater difference and a high interrater reliability and is therefore suitable for personalized electrode array selection.

Psychoacoustic abilities in pediatric cochlear implant recipients: The relation with short-term memory and working memory capacity

OBJECTIVE

The aim was to investigate school-age children with cochlear implants (CIs) and their typically developing peers in terms of auditory short-term memory (ASTM), auditory working memory (AWM), visuospatial short-term memory (VSTM), visuospatial working memory (VWM), spectral resolution and monosyllabic word recognition in noise.

METHODS

Twenty-three prelingually deaf CI users and twenty-three typically developing (TD) peers aged 7-10 years participated. Twelve children with CI were earlier-implanted (i.e., age at implantation ≤24 months). Children with CIs were compared to typically developing peers and correlations between cognitive and psychoacoustic abilities were computed separately for the groups. Besides, regression analyses were conducted to develop models that could predict SMRT (spectral-temporally modulated ripple test) and speech recognition scores.

RESULTS

The AWM scores of the later-implanted group were significantly lower than both earlier-implanted and TD groups. ASTM scores of TD children were significantly higher than both earlier-implanted and later-implanted participants. There was no statistically significant difference between groups in terms of VSTM and VWM. AWM performance was positively correlated with ASTM, SMRT scores, and speech recognition under noisy conditions for pediatric CI recipients. The AWM was a statistically significant predictor of the SMRT score and the SMRT score was an indicator of speech recognition score under 0 dB SNR condition.

CONCLUSION

Most of children using CI are at risk for clinically remarkable deficits across cognitive abilities such as AWM and ASTM. While evaluating cognitive and psychoacoustic abilities in the clinic routine, it should be kept in mind that they can be influenced by each other.

Long-term follow-up of auditory performance and speech perception and effects of age on cochlear implantation in children with pre-lingual deafness

Background:

The development of auditory and speech perception ability of children with hearing loss is affected by many factors after they undergo cochlear implantation (CI). Age at CI (CI age) appears to play an important role among these factors. This study aimed to evaluate the development of auditory and speech perception ability and explore the impact of CI age on children with pre-lingual deafness present before 3 years of age.

Methods:

Two hundred and seventy-eight children with pre-lingual deafness (176 boys and 102 girls) were included in this study, and the CI age ranged from 6 to 36 months (mean age, 19 months). Categorical auditory performance (CAP) was assessed to evaluate auditory ability, and the speech intelligibility rating was used to evaluate speech intelligibility. The evaluations were performed before CI and 1, 3, 6, 12, 18, 24, 36, 48, and 60 months after CI.

Results:

The auditory ability of the pre-lingually hearing-impaired children showed the fastest development within 6 months after CI (k = 0.524, t = 30.992, P < 0.05); then, the progress started to decelerate (k = 0.14, t = 3.704, P < 0.05) and entered a plateau at the 24th month (k = 0.03, t = 1.908, P < 0.05). Speech intelligibility showed the fastest improvement between the 12th and 24th months after CI (k = 0.138, t = 5.365, P < 0.05); then, the progress started to decelerate (k = 0.026, t = 1.465, P < 0.05) and entered a plateau at the 48th month (k = 0.012, t = 1.542, P < 0.05). The CI age had no statistical significant effect on the auditory and speech abilities starting at 2 years after CI (P > 0.05). The optimal cutoff age for CI was 15 months.

Conclusions:

Within 5 years after CI, the auditory and speech ability of young hearing-impaired children continuously improved, although speech development lagged behind that of hearing. An earlier CI age is recommended; the optimal cutoff age for CI is at 15 months.

Effects of Age at Cochlear Implantation on Learning and Cognition: A Critical Assessment

Purpose Age at cochlear implantation frequently is assumed to be a key predictor of pediatric implantation benefits, but outcomes related to learning and cognition appear inconsistent. This critical assessment examines relevant literature in an effort to evaluate the impact of age at implantation in those domains for individuals who received their devices as children. Method We examined 44 peer-reviewed articles from 2003 to 2018 considering age at implantation and conducted statistical analyses regarding its impact on several domains, including literacy, academic achievement, memory, and theory of mind. Results Across 167 assessments in various experiments and conditions, only 21% of the analyses related to age at implantation yielded evidence in favor of earlier implantation, providing greater benefits to academic achievement, learning, or cognition compared to implantation later in childhood. Among studies that considered cognitive processing (e.g., executive function, memory, visual-spatial functioning), over twice as many analyses indicated significant benefits of earlier implantation when it was considered as a discrete rather than a continuous variable. Conclusion Findings raise methodological, practical, and theoretical questions concerning how "early" is defined in studies concerning early cochlear implantation, the impact of confounding factors, and the use of nonstandard outcome measures. The present results and convergent findings from other studies are discussed in terms of the larger range of variables that need to be considered in evaluating the benefits of cochlear implantation and question the utility of considering age at implantation as a "gold standard" with regard to evaluating long-term outcomes of the procedure as a medical treatment/intervention for hearing loss. Supplemental Material https://doi.org/10.23641/asha.8323625.

Assessment of outcomes of hearing and speech rehabilitation in children with cochlear implantation

Objectives

This study aimed to assess the effect of hearing and speech rehabilitation in patients with Nurotron^® cochlear implants.

Design

Ninety-eight paediatric patients with bilateral severe-to-profound sensorineural deafness who received cochlear implantation were divided into three groups according to age: group A (≤3 years), group B (4–7 years), and group C (8–16 years). All patients were followed up for one year for hearing and speech performance after the surgery. The comprehensive Auditory Perception Assessment, MAIS, CAP and SIR hearing and speech assessments and rating materials were used for assessment before the surgery and at 3, 6, and 12 months after implant activation.

Results

The scores of patients in the open-set speech assessment, Chinese Auditory Perception Assessment, MAIS, CAP and SIR significantly improved after cochlear implantation in all age groups. The younger the age at implantation, the better the results. Moreover, the hearing and speech performance of cochlear implant recipients gradually improved with the extension of rehabilitation time.

Conclusions

Nurotron^® Venus™ cochlear implantation can improve the hearing and speech performance of patients with bilateral severe-to-profound sensorineural deafness.

Medical and bioethical considerations in elective cochlear implant array removal

OBJECTIVE

Cochlear explantation for purely elective (e.g. psychological and emotional) reasons is not well studied. Herein, we aim to provide data and expert commentary about elective cochlear implant (CI) removal that may help to guide clinical decision-making and formulate guidelines related to CI explantation.

DATA SOURCES

We address these objectives via three approaches: case report of a patient who desired elective CI removal; review of literature and expert discussion by surgeon, audiologist, bioethicist, CI user and member of Deaf community.

REVIEW METHODS

A systematic review using three scientific online databases was performed. Included articles addressed the benefits and/or complications of cochlear implantation in young children, CI explantation with or without revision surgery and the ethical debate between the medical and Deaf communities on cochlear implantation and explantation.

CONCLUSIONS

The medical and audiological perspectives identify a host of risks related to implant removal without reimplantation, including risk from surgery, general anaesthesia, cochlear ossification and poor audiometric outcomes. The member of the deaf community and bioethicist argue that physicians need to guide the principles of beneficence, non-maleficence and patient autonomy. Taken together, patient desires should be seen as paramount, if the patient is otherwise fit for surgery and well informed.

IMPLICATIONS FOR PRACTICE

Similar to the case of device implantation, device explantation should be a multidisciplinary and collaborative decision with the patient and the family's desires at the centre. While every case is different, we offer a CI explantation discussion to assist in clinical decision-making, patient counselling and education.