Importance of age at 2nd implantation and interimplant interval to the outcome of bilateral prelingually deafened pediatric cochlear implantation

BACKGROUND

In Taiwan, the number of cases of sequential bilateral pediatric cochlear implantation (CI) is increasing but data regarding its effectiveness and impact of the reimbursement policy are lacking. We examined the speech perception and quality of life (QOL) of bilateral prelingually deaf children who underwent sequential CI, considering the effects of age at the time of second implantation and interimplant interval.

METHODS

We enrolled 124 Mandarin-speaking participants who underwent initial cochlear implant (CI1) in 2001-2019 and a second CI (CI2) in 2015-2020. Patients were followed up for ≥2 years and were categorized into groups based on age at the time of CI2 implantation (<3.5, 3.6-7, 7.1-10, 10.1-13, and 13.1-18 years) and interimplant interval (0.5-3, 3.1-5, 5.1-7, 7.1-10, and >10 years). We evaluated speech perception, device usage rates, and QOL using subjective questionnaires (Speech, Spatial, and Qualities of Hearing and Comprehension Cochlear Implant Questionnaire).

RESULTS

Speech perception scores of CI2 were negatively correlated with ages at the time of CI1 and CI2 implantation and interimplant interval. Older age and a longer interimplant interval were associated with higher nonuse rates for CI2 and worse auditory performance and QOL. Among individuals aged >13 years with interimplant intervals >10 years, up to 44% did not use their second ear. Patients aged 7.1 to 10 years had better speech perception and higher questionnaire scores than those aged 10.1 to 13 and 13.1 to 18 years. Furthermore, patients aged 10.1 to 13 years had a lower rate of continuous CI2 usage compared to those aged 7.1 to 10 years.

CONCLUSION

Timely implantation of CI2 is essential to achieve optimal outcomes, particularly among sequentially implanted patients with long-term deafness in the second ear and no improvement with hearing aids following CI1 implantation. For CI2 implantation, an upper limit of age of 10 years and interimplant interval of 7 years are essential to prevent suboptimal outcomes. These data can provide useful information to implant recipients, their families, and medical and audiological professionals, enabling a comprehensive understanding of the benefits and potential impacts of the timing of CI2 implantation.

Listening evaluation of cochlear implant users: comparison of subjective and objective evaluation by visual analogue scale

OBJECTIVE

This study aimed to use short-form visual analogue scale cochlear implantation questionnaires to evaluate subjective aspects at each out-patient visit. The correlation between subjective hearing tests using the short-form visual analogue scale and objective hearing outcomes was evaluated.

METHOD

This study was conducted in a single centre. Cochlear implant users (n = 199) evaluated their hearing on a scale of 0 to 100 for the right, left and both ears. The Japanese speech perception test (CI-2004) Japanese monosyllable speech perception test (67-S) and cochlear implantation threshold were used for the objective cochlear implantation evaluation.

RESULTS

A significant correlation was found between the short-form visual analogue scale questionnaire and objective hearing outcome, for words (r = 0.64) and sentences (r = 0.62) in CI-2004 and 67-S (r = 0.56) tests. No significant correlation was found between the short-form visual analogue scale score and cochlear implantation threshold (r = -0.18).

CONCLUSION

Short-form visual analogue scale cochlear implantation questionnaires mean cochlear implant users spend less time answering subjective visual analogue scale questionnaires, and clinicians estimate a patient's cochlear implantation hearing and abnormality by chronological evaluation.

A Novel Bone Conduction Hearing System May Improve Memory Function in Children with Single Side Hearing loss: A Case-Control Study

OBJECTIVES

To evaluate the effects of an adhesive adapter prosthesis (AAP) on memory function in pediatric subjects with single side hearing loss (SSHL).

MATERIALS AND METHODS

Case-control study. 19 pediatric subjects with mild to moderate SSHL treated with AAP and 15 subjects with normal hearing (control group) were included in this study. Working and short-term memory functions were tested in all subjects, in silence and noise conditions. In SSHL subjects, tests were performed before the AAP was applied (T0) and at 1-month (T1) follow-up. The control group was tested once.

RESULTS

AAP significantly improved working memory function in noise as measured at T1 (p<0.01) compared with T0, but T1 scores in children with SSHL remained significantly different from the ones of the control group (p<0.01). AAP also significantly improved short- term memory function test scores at T1 compared with T0 (p<0.01), but despite being in the normal range for the subjects' age, the scores remained significantly different from those of the control group (p<0.01).

CONCLUSION

In pediatric subjects with mild, moderate, and moderate-severe SSHL, restoration of bilateral hearing through AAP improved short-term memory function and working memory function in noise, as measured at 1 month follow-up; however, AAP did not seem to lead to a full restoration of such functions as measured by a comparison with healthy controls. Further studies with longer follow-ups might help elucidate whether AAP can elicit further improvements in memory functions.

Impact of Underlying Diagnosis on Speech and Quality of Life Outcomes After Cochlear Implantation for Single-Sided Deafness

OBJECTIVE

Our objective was to compare outcomes in speech and quality of life in those undergoing cochlear implantation for single-sided deafness (SSD), with the aim to characterize the clinical impact of underlying diagnosis in the affected ear and pre-operative hearing status.

STUDY DESIGN

Prospective case series.

SETTING

Academic Cochlear Implant Center.

PATIENTS

42 adult patients implanted with the diagnosis of SSD.

INTERVENTIONS

Patients were evaluated at 3-, 6-, and 12-months post-operatively using AZBio sentence and speech, and consonant-nucleus-consonant (CNC) depending on appropriate testing level. Our previously validated Comprehensive Cochlear Implant Quality of Life (CCIQ) questionnaire was administered.

MAIN OUTCOME MEASURES

Speech perception, quality of life.

RESULTS

Subjects were stratified by the underlying diagnosis: Meniere's Disease (MD; n = 10), sudden sensorineural hearing loss (SSNHL; n = 13), and Other (eg TBI, acoustic neuroma, progressive, noise-induced; n = 19). Mean preoperative PTA of the implanted ear was 82dB ± 17; that of the nonimplanted ear was 32dB ± 17. SSNHL and MD demonstrated the highest speech perception score at 3 months (93 and 95%), and "Other" demonstrated the lowest scores at 88%. All 3 groups demonstrated nadir in speech scores at 6 months before improving at 12 months, but the "Other" diagnoses maintained the lowest speech testing across all time points. All 3 groups reported improved quality of life on CCIQ.

CONCLUSIONS

Subjects with SSNHL and MD demonstrate excellent speech perception and quality of life outcomes after cochlear implantation for SSD. Subjects with "Other" diagnoses underlying their SSD demonstrated lower scores on speech testing but nonetheless reported improved quality of life.

Area-dependent change of response in the rat's inferior colliculus to intracochlear electrical stimulation following neonatal cochlear damage

To understand brain changes caused by auditory sensory deprivation, we recorded local-field potentials in the inferior colliculus of young adult rats with neonatal cochlear damage produced by systemic injections of amikacin. The responses were elicited by electrical stimulation of the entire cochlea and recorded at various locations along a dorsolateral-ventromedial axis of the inferior colliculus. We found that hair cells were completely destroyed and spiral ganglion neurons were severely damaged in the basal cochleae of amikacin-treated animals. Hair cells as well as spiral ganglion neurons were damaged also in the middle and apical areas of the cochlea, with the damage being greater in the middle than the apical area. Amplitudes of local-field potentials were reduced in the ventromedial inferior colliculus, but enhanced in the dorsolateral inferior colliculus. Latencies of responses were increased over the entire structure. The enhancement of responses in the dorsolateral inferior colliculus was in contrast with the damage of hair cells and spiral ganglion cells in the apical part of the cochlea. This contrast along with the overall increase of latencies suggests that early cochlear damage can alter neural mechanisms within the inferior colliculus and/or the inputs to this midbrain structure.