Bony cochlear nerve canal stenosis and speech discrimination in pediatric unilateral hearing loss

Hsu

JAMA Otolaryngol Head Neck Surg

et al. 2017

Section: Discussionsupporting

confidence: 92%

Etiologic and Audiologic Characteristics of Patients With Pediatric-Onset Unilateral and Asymmetric Sensorineural Hearing Loss

Hsu

JAMA Otolaryngol Head Neck Surg

et al. 2017

Otology &Amp; Neurotology

“…Based on our previous analysis 15 , we defined cochlear nerve canal stenosis as a diameter of ≤1.4 mm in the axial plane, near the lower limit of the thresholds presented in other investigations. In this study, 17% (22 of 128) of children with unilateral SNHL were found to have BCNC stenosis; this percentage is smaller than other reports 13 , likely due to our tighter diagnostic criteria.…”

Section: Discussionmentioning

confidence: 99%

“…In which case, children may be at risk of progression in ipsilateral, or even contralateral, ears. Therefore, providers may face difficulties when attempting to counsel families of children with BCNC stenosis who have residual, aidable hearing 15 .…”

Section: Introductionmentioning

confidence: 99%

Progression of Unilateral Hearing Loss in Children With and Without Ipsilateral Cochlear Nerve Canal Stenosis: A Hazard Analysis

Purcell¹,

Shinn²,

Coggeshall³

et al. 2017

Self Cite

Objective To investigate the risk of hearing loss progression in each ear among children with unilateral hearing loss associated with ipsilateral bony cochlear nerve canal (BCNC) stenosis. Setting Tertiary pediatric referral center Patients Children diagnosed with unilateral hearing loss who had undergone temporal bone computed tomography imaging and had at least six months of follow-up audiometric testing were identified from a prospective audiological database. Interventions Two pediatric radiologists blinded to affected ear evaluated imaging for temporal bone anomalies and measured bony cochlear canal width independently. All available audiograms were reviewed, and air conduction thresholds were documented. Main outcome measure Progression of hearing loss was defined by a 10 dB increase in air conduction pure-tone average. Results 128 children met inclusion criteria. Of these, 54 (42%) had a temporal bone anomaly, and 22 (17%) had ipsilateral BCNC stenosis. At 12 months, rates of progression in the ipsilateral ear were as follows: 12% among those without a temporal bone anomaly, 13% among those with a temporal bone anomaly, and 17% among those with BCNC stenosis. Children with BCNC stenosis had a significantly greater risk of progression in their ipsilateral ear compared to children with no stenosis: hazard ratio 2.17, 95% CI (1.01, 4.66), p-value 0.046. When we compared children with BCNC stenosis to those with normal temporal bone imaging, we found that the children with stenosis had nearly 2 times greater risk estimate for progression, but this difference did not reach significance, HR 1.9, CI (0.8, 4.3), p = 0.1. No children with BCNC stenosis developed hearing loss in their contralateral year by 12 months of follow-up. Conclusion Children with bony cochlear nerve canal stenosis may be at increased risk for progression in their ipsilateral ear. Audiometric and medical follow-up for these children should be considered.

“…The internal auditory canal (IAC) was diagnosed to be narrow if its diameter was 3 mm or less (Sennaroǧlu & Saatci, 2002). Bony cochlear nerve canal (BCNC) stenosis was diagnosed if the diameter was less than 1.4 mm (Purcell et al, 2015).…”

Section: Subjectsmentioning

confidence: 99%

The Effect of Interphase Gap on Neural Response of the Electrically Stimulated Cochlear Nerve in Children With Cochlear Nerve Deficiency and Children With Normal-Sized Cochlear Nerves

Skidmore

et al. 2019

Ear &Amp; Hearing

Objective: This study aimed to compare effects of increasing the interphase gap (IPG) on the neural response of the electrically-stimulated cochlear nerve (CN) between children with cochlear nerve deficiency (CND) and children with normal-sized CNs. Design: Study participants included 30 children with CND and 30 children with normal-sized CNs. All subjects were implanted with a Cochlear™ Nucleus® device with the internal electrode array 24RE[CA] in the test ear. The stimulus was a charge-balanced, cathodic leading, biphasic pulse with a pulse-phase duration of 50 μs. For each subject, the eCAP input/output (I/O) function was measured for six IPGs (i.e., 7, 14, 21, 28, 35 and 42 μs) at three electrode locations across the electrode array. For each subject and each testing electrode, the highest stimulation used to measure the eCAP I/O function was the maximum comfortable level measured with an IPG of 42 μs. Dependent variables (DVs) were the maximum eCAP amplitude, the eCAP threshold and the slope of the eCAP I/O function estimated using both linear and sigmoidal regression functions. For each DV, the size of the IPG effect was defined as the proportional change relative to the result measured for the 7 μs IPG at the basal electrode location. Generalized Linear Mixed effect Models with subject group, electrode location and IPG duration as the fixed effects and subject as the random effect were used to compare these DVs and the size of the IPG effect on these DVs.