Comprehensive Etiologic Analyses in Pediatric Cochlear Implantees and the Clinical Implications

Cochlear implantation is the treatment of choice for children with profound sensorineural hearing impairment (SNHI), yet the outcomes of cochlear implants (CI) vary significantly across individuals. To investigate the CI outcomes in pediatric patients with SNHI due to various etiologies, we prospectively recruited children who underwent CI surgery at two tertiary referral CI centers from 2010 to 2021. All patients underwent comprehensive history taking, next generation sequencing (NGS)-based genetic examinations, and imaging studies. The CI outcomes were evaluated using Categories of Auditory Performance (CAP) and Speech Intelligibility Rating (SIR) scores. Of the 160 pediatric cochlear implantees (76 females and 84 males) included in this study, comprehensive etiological work-up helped achieve clinical diagnoses in 83.1% (133/160) of the patients, with genetic factors being the leading cause (61.3%). Imaging studies identified certain findings in 31 additional patients (19.3%). Four patients (2.5%) were identified with congenital cytomegalovirus infection (cCMV), and 27 patients (16.9%) remained with unknown etiologies. Pathogenic variants in the four predominant non-syndromic SNHI genes (i.e., SLC26A4, GJB2, MYO15A, and OTOF) were associated with favorable CI outcomes (Chi-square test, p = 0.023), whereas cochlear nerve deficiency (CND) on imaging studies was associated with unfavorable CI outcomes (Chi-square test, p < 0.001). Our results demonstrated a clear correlation between the etiologies and CI outcomes, underscoring the importance of thorough etiological work-up preoperatively in pediatric CI candidates.

Outcome for bilateral cochlear implantation in patients with congenital Cytomegalovirus infection

OBJECTIVES

To analyze the impact of bilateral cochlear implantation (CI) on perceptual and linguistic development in hearing-impaired children with congenital Cytomegalovirus (CMV) infection.

PATIENTS AND METHOD

A retrospective study was performed for the period 1991-2016 in a pediatric CI reference center. Closed Set Word (CSW) recognition scores, Categories of Auditory Performance (CAP) and linguistic level on the MT Lenormand scale (MTL) were compared between bilateral (Bi) and unilateral (Uni) groups 12, 24 and 36 months after first CI (CI-1).

RESULTS

84 patients with congenital CMV infection who underwent CI were included, in 2 groups: sequential or simultaneous bilateral CI (Bi) (N=20), and unilateral CI (Uni) (N=64). Twelve, 24 and 36 months after CI-1, CSW scores were 35.56%, 64.52% and 82.93% in Uni and 60.3%, 85% (P=0.0084*), and 100% (P=0.00085*) in Bi. CAP scores 12, 24 and 36 months after CI-1 were 2.57, 3.85 and 4.3 in Uni and 3.91 (P=0.0068*), 5.00 (p=0.029*) and 5.50 (P=0.051*) in Bi. MTL linguistic level scores at 12, 24 and 36 months were 0.72, 1.25 and 1.65 in Uni, and 1.72, 3 (P=0.033) and 3.11 (P=0.045) in Bi. These significantly better scores in Bi at 24 and 36 months after CI-1 were also found on analysis of subgroups with no associated neurologic disorder (P=0.046* and P=0.032*), no associated psychiatric pathology (P=0.0055* and P=0.0073*), and no other associated disorder (P=0.0018* and P=0.035*), and for all subgroups together (P=0.0036 and P=0.037).

CONCLUSION

Bilateral CI is a faster way than unilateral CI for patients with congenital CMV infection to achieve structured fluent oral language. 50% of the series showed cerebral abnormalities on MRI, without difference between groups. This was not in itself predictive of poor progression of oral communication, unless associated with major neurologic disorder. Some children made little or no use of their CI in the medium term.

Congenital human cytomegalovirus infection and neurologic diseases in newborns

Objective:

This review aimed to summarize research progress regarding congenital cytomegalovirus (cCMV) infection-related nervous system diseases and their mechanisms.

Data sources:

All literature quoted in this review was retrieved from PubMed and Web of Science using the keywords “Cytomegalovirus” and “Neurologic disease” in English. To identify more important information, we did not set time limits.

Study selection:

Relevant articles were selected by carefully reading the titles and abstracts. Then, different diagnosis and clinical treatment methods for human CMV infection-related neurologic diseases were compared, and the main mechanism and pathogenesis of neurologic damage caused by CMV were summarized from the selected published articles.

Results:

cCMV infection is a major cause of neonatal malformation. cCMV can infect the fetal encephalon during early gestation and compromise neurodevelopment, resulting in varying degrees of neurologic damage, mainly including hearing impairment, central nervous system (CNS) infection, neurodevelopmental disorders, ophthalmic complications, cerebral neoplasms, infantile autism, epilepsy, and other neurologic abnormalities.

Conclusions:

cCMV infection-induced neurodevelopmental abnormalities, which were directly caused by fetal encephalon infection, thus inducing neuroimmune responses to damage nerve cells. Such abnormalities were also caused by suppression of the proliferation and differentiation of neural progenitor cells by CMV's gene products. cCMV infection in the fetal encephalon can also inhibit neuronal migration and synapse formation and indirectly trigger placental inflammation and thus disrupt the oxygen supply to the fetus.

Prediction of the Outcome of Cochlear Implantation in the Patients with Congenital Cytomegalovirus Infection based on Magnetic Resonance Imaging Characteristics

The goal of this study was to elucidate radiologic biomarker that can predict the outcome of cochlear implantation (CI) in congenital cytomegalovirus (cCMV) related deafness. A retrospective survey of speech perception after CI and an evaluation of brain magnetic resonance imaging (MRI) findings were performed in 10 cochlear implantees with cCMV-related prelingual deafness. Specifically, a special attention was paid to the degree of white matter (WM) abnormality shown in brain MRI, which was used to divide our cohort into two groups: The mild and severe pathology groups. Age-matched prelingual deaf patients with idiopathic sensorineural hearing loss were selected as controls. Subjects in mild pathology groups showed higher a Category of Auditory Performance (CAP) score (5.2 ± 0.8) than those with severe pathologies (3.4 ± 1.5) (P = 0.041). Importantly, speech performance from subjects with mild pathology was comparable to that of the control group (mean CAP score of 5.2 ± 0.8 vs. 5.1 ± 1.2) (P = 0.898). Mild pathologies related to the limited WM lesion in MRI not accompanied by severe MRI pathologies, such as diffuse WM abnormality, myelination delay, ventriculomegaly, migration abnormality, and cerebellar hypoplasia, can be tolerated and do not adversely affect the CI outcome in cCMV deafness.

Long-term Outcomes of Cochlear Implantation in Children With Congenital Cytomegalovirus Infection

OBJECTIVE

To investigate the role of the developmental delay often observed in children with congenital cytomegalovirus (CMV) infection on the improvement of language understanding after cochlear implantation (CI).

STUDY DESIGN

Retrospective chart review.

PATIENTS

Sixteen children with severe and/or profound hearing loss due to congenital CMV infection (CMV group) and 107 congenitally deaf children (168 ears) without CMV infection as the cause of deafness (non-CMV group). Mean age at which patients underwent CI was 2.9 years in both groups. The mean follow-up period was 7.8 versus 8.2 years, respectively.

INTERVENTIONS/MAIN OUTCOME MEASURES

The Enjoji Scale of Infant Analytical Development was used to evaluate/compare pre- and postoperative hearing level, word recognition score, speech discrimination score, and language production and perception skills. The Picture Vocabulary Test-Revised was used to assess vocabulary understanding skill. Correlation between the final vocabulary understanding skill assessment and several factors was also examined.

RESULTS

Improvement in hearing thresholds (mean: 106.0 dB) was greater after the first CI, (27-45 dB; mean: 33.8 dB) compared with hearing aid (48-74 dB; mean: 63.1 dB). Similarly, language perception and production were better in the CMV group. However, in the long term, differences between good and poor cases became prominent, especially in children with motor or cognitive delay and brain abnormalities who performed poorly in the CMV group.

CONCLUSION

Long-term language perception and production after CI were overall satisfactory in congenital CMV-deafened children. CI was effective, particularly in the absence of CMV-induced disorders. However, this effectiveness was limited in those with motor or cognitive delay.

Evaluation and management of cytomegalovirus-associated congenital hearing loss

PURPOSE OF REVIEW

The current article reviews the current literature related to congenital cytomegalovirus (CMV)-related hearing loss. The discussion will focus on the epidemiology, pathogenesis, and clinical presentation of human CMV infection as it pertains to hearing loss. Current methods of CMV diagnosis with a focus on the evolving trend toward broader neonatal screening protocols will also be explored. Discussion of medical, surgical, and audiologic management of the condition will also be addressed.

RECENT FINDINGS

Much of the current research on this topic is focused on improving detection of CMV through screening programs. Some advances in understanding cochlear pathogenesis have also been made.

SUMMARY

Congenital CMV infection remains an important cause of hearing loss in infants and children. Early detection of CMV infection can broaden treatment options and allow for improved hearing and language outcome for patients with CMV-associated sensorineural hearing loss.

Long-term outcomes of children with symptomatic congenital cytomegalovirus disease

OBJECTIVE

To assess long-term outcomes of children with symptomatic congenital cytomegalovirus (CMV) disease detected at birth.

STUDY DESIGN

We used Cox regression to assess risk factors for intellectual disability (intelligence quotient <70), sensorineural hearing loss (SNHL; hearing level ⩾25 dB in any audiometric frequency) and vision impairment (best corrected visual acuity >20 or based on ophthalmologist report).

RESULTS

Among 76 case-patients followed through median age of 13 (range: 0-27) years, 56 (74%) had SNHL, 31 (43%, n=72) had intellectual disability and 18 (27%, n=66) had vision impairment; 28 (43%, n=65) had intellectual disability and SNHL with/without vision impairment. Microcephaly was significantly associated with each of the three outcomes. Tissue destruction and dysplastic growth on head computed tomography scan at birth was significantly associated with intellectual disability and SNHL.

CONCLUSION

Infants with symptomatic congenital CMV disease may develop moderate to severe impairments that were associated with presence of microcephaly and brain abnormalities.

Cochlear implantation in children with single-sided deafness: does aetiology and duration of deafness matter?

For adult patients with single-sided deafness (SSD), treatment with a cochlear implant (CI) is well established as an acceptable and beneficial hearing rehabilitation method administered routinely in clinical practice. In contrast, for children with SSD, CI has been applied less often to date, with the rationale to decide either on a case-by-case basis or under the realm of clinical research. The aim of our clinical study was to evaluate the longitudinal benefits of CI for a group of children diagnosed with SSD and to compare their outcomes with respect to patient characteristics. Evaluating a pool of paediatric SSD patients presenting for possible CI surgery revealed that the primary aetiology of deafness was congenital cochlear nerve deficiency. A subgroup of children meeting the CI candidacy criteria for the affected ear (the majority with acquired hearing loss) were enrolled in the study. Preliminary group results suggest substantial improvements in speech comprehension in noise and in the ability to localise sound, which was demonstrated through objective and subjective assessments after CI treatment for the group, with results varying from patient to patient. Our study shows a trend towards superior outcomes for children with acquired hearing loss and a shorter duration of hearing loss compared to congenitally deafened children who had a longer duration of SSD. This indicates an interactive influence of the age at onset, aetiology and duration of deafness upon the restoration of binaural integration and the overall benefits of sound stimulation to two ears after CI treatment. Continued longitudinal investigation of these children and further studies in larger groups may provide more guidance on the optimal timing of treatment for paediatric patients with acquired and congenital SSD.

Cochlear implants in children deafened by congenital cytomegalovirus and matched Connexin 26 peers

OBJECTIVE

To compare the long-term speech perception and production outcomes after cochlear implantation (CI) in children deafened by congenital cytomegalovirus (cCMV) with a matched group of Cx26-CI children by controlling for chronological age and magnetic resonance imaging (MRI) findings.

METHODS

Retrospective review of 12 cCMV-CI children and matched Cx26-CI children for speech perception and speech production outcomes.

RESULTS

Two trends were seen in our data. First, cCMV-CI children with normal MRI scans perform equally or even slightly better on speech perception tests compared to their Cx26-CI peers during the first three years. The majority of cCMV-CI children with normal MRI scans (5 out of 7), suffered from a delayed-onset SNHL. Their mean age at first implantation (2y9m, range 15-82m) was higher compared to their matched Cx26 peers (9m, range 7-12m). Before being implanted, the majority of these delayed-onset hearing impaired children had benefited from a certain period of normal hearing (with or without amplification of a hearing aid). Possibly, this input might have led to an advantage the first three years after CI. Second, results between cCMV-CI children with and cCMV-CI children without MRI abnormalities and their matched Cx26-CI counterparts tentatively suggest that, over a 5-yr follow-up period, cCMV-CI children with abnormalities on MRI scans catch up for speech perception, but lag behind for speech production.

CONCLUSION

cCMV-CI children with normal MRI scans perform equally or even slightly better on speech perception tests compared to their Cx26-CI peers during the first three years, whereas results between cCMV-CI children with and cCMV-CI children without MRI abnormalities and their matched Cx26-CI counterparts tentatively suggest that, over a 5-yr follow-up period, cCMV-CI children with abnormal MRI scans catch up for speech perception, but lag behind for speech production. In future, the inclusion of MRI results may assist in improved counseling of parents with cCMV deafened children seeking CI.

Evaluation of cortical processing of language by use of positron emission tomography in hearing loss children with congenital cytomegalovirus infection

OBJECTIVE

To predict cochlear implant efficacy and investigate the cortical processing of the visual component of language in profoundly deafened patients with asymptomatic congenital cytomegalovirus (CMV) infection.

METHODS AND CASES

The cortical activity of two children with CMV-related hearing loss was evaluated with fluorodeoxyglucose-positron emission tomography (FDG-PET) with a visual language task before cochlear implantation. Total development and auditory perception ability were assessed one year after implantation.

RESULTS

The two children with CMV-related hearing loss showed activation in the auditory association area where no activation was found in the controls, and exhibited nearly identical cortical activation patterns to those seen in patients with profound congenital hearing loss. In contrast, differences in total development in verbal ability and discrimination of sentences between the two cases were revealed one year after implantation.

CONCLUSION

These results might indicate that the differences of cortical activities according to hearing abilities could have been influenced by CMV infection that involves higher function of the brain directly and/or affects the cochlea peripherally. Additionally, if CMV infection might have affected only the cochlea, these cortical activation patterns were influenced secondary by the time course of hearing loss characterized by CMV infection, which had varied manifestations. Accurate diagnosis and cochlear implantation at the appropriate time are important for successful speech development, and each patient needs a personalized habilitation program based on their etiology and brain function.