PP1016 - Incidence of Cochlear Nerve Deficiency in Children with Unilateral Auditory Dyssynchrony

Abstract:
Patients with Cochlear Nerve Deficiency (CND) can present with audiologic findings similar to Auditory Neuropathy Spectrum Disorder (ANSD). However, given that the pathophysiologic bases of these two conditions are independent from one another, the management and course of treatment for each condition is different. The literature reports CND can be present anywhere from 25%-50% with unilateral hearing loss, but there is a gap in existing literature specifically looking at the rate of CND when an ANSD-like audiologic profile is present unilaterally. This study seeks to report on the incidence of CND in pediatric patients with a unilateral, ANSD-like audiologic profile.

Summary:
Rationale/Purpose
Auditory neuropathy spectrum disorder (ANSD) is a characterization referring to a range of hearing impairments and decreased speech perception. The incidence rate of ANSD has been defined as approximately 5% among pediatric patients previously diagnosed with sensory neural hearing loss (SNHL). Meanwhile, cochlear nerve deficiency (CND) is a more specific diagnosis characterized by an imaging-confirmed deficient or absent cochlear nerve. Its incidence has been reported as 26% among patients diagnosed with unilateral SNHL. Patients with CND can often present with audiologic findings similar to an ANSD profile. However, given that the pathophysiologic bases of these two conditions are independent from one another, the management and course of treatment for each condition is different. Therefore, failure to diagnose CND in the setting of ANSD-like audiologic signs can potentially lead to ineffective treatment and inefficiency of care.

This study seeks to establish that imaging should be performed on all patients who present with an ANSD-like audiologic profile in order to rule out CND, especially in the setting of unilateral findings, as the literature reports CND can be present anywhere from 25%-50% with unilateral hearing loss. There is a gap in existing literature specifically looking at the rate of CND when an ANSD-like audiologic profile is present unilaterally. This study aims to report on the incidence of CND in the presence of unilateral, ANSD-like audiologic profiles. Findings from this study can help to establish best practice guidelines, which in turn will allow audiologists to recommend an effective and efficient treatment plan in this unique population of patients.

Study Aims
This study seeks to investigate the prevalence of imaging-positive cochlear nerve deficiency (CND) in patients previously diagnosed with audiologic profiles consistent with or suggestive of auditory neuropathy spectrum disorder (ANSD) in one ear.

Methods
Patient information will be obtained from the electronic medical record. Included will be 10 patients previously diagnosed with ANSD in one ear and who have MRI imaging available. This imaging will be reviewed by a neuroradiologist to confirm the presence or absence of CND.

Basic descriptive statistics will be applied, and analysis will be performed using t-test for quantitative variables and chi-square for qualitative data.

Data Variables
Data collection will be completed through patient charts using our electronic medical records system. Data variables categorically include demographic information: age, sex, race; and medical history: presence/absence of ANSD diagnosis, results of auditory brainstem response (ABR) test, presence/absence of MRI brain, and neuroradiologist’s analysis of MRI (presence/absence of imaging-confirmed CND).

Results & Conclusions
Data collection and analysis for this retroactive study is ongoing; results and conclusions will be reported at the time of the presentation.