PP501 - Diagnosis and Management of ANSD/Neurological ABR in Pediatrics: A Case Series

POSTERS

Location: Halls A1-A2

Instructional Level: Intermediate

Lead Presenter(s)

Sophie L. Werk, AuD (she/her/hers)

Pediatric Audiologist
NYEEI of Mount Sinai
New York, New York

Disclosure(s): No financial or nonfinancial relationships to disclose.

PDF Handouts Slides

Presenter(s)

Evangeline Wong, AuD

Pediatric Audiologist
NYEE of Mount Sinai
Brooklyn, New York

Disclosure(s): No financial or nonfinancial relationships to disclose.

Contributor(s)

RT

Randi Tepper, AuD

Associate Director, Pediatric Audiology
New York Eye and Ear of Mount Sinai

Disclosure(s): No financial or nonfinancial relationships to disclose.
MC

Maura Cosetti

NYEE/Mount Sinai
Icahn school of medicine at Mount Sinai, New York

Disclosure(s): Acclarent: Consultant (Ongoing); Cochlear Americas: Consultant/Advisory Board (Ongoing); MedEL: Research Grant (includes principal investigator, collaborator or consultant and pending grants as well as grants already received) (Ongoing)

Abstract: Auditory Neuropathy Spectrum Disorder (ANSD) describes a hearing disorder that arises from neural or synaptic abnormality/asynchrony. Clinical presentation of ANSD typically includes present otoacoustic emissions (OAEs) and absent waveforms during high intensity auditory brainstem response (ABR) click testing with present cochlear microphonic response that grows with increasing intensity. The current project outlines five case studies of pediatric ABRs with click testing consistent with ANSD, varying OAE results, and possible neurological considerations to compare typical ANSD from neurologically involved cases. Studies include birth history, audiological diagnosis (based on ABR, tympanometry, OAE testing), imaging/genetic results, audiological follow-up/ management, and amplification.

Summary:
Auditory Neuropathy Spectrum Disorder (ANSD; also termed auditory desynchrony) is a clinical diagnosis which is caused by the dysfunction of the inner ear, synapses, and/or auditory nerve. “Typical” ANSD describes a hearing disorder in which the auditory nerve does not fire appropriately resulting in disrupted signals from the inner ear to the auditory cortex, however, the physical structure of the nerve is intact, and no visible abnormalities may be seen from radiographic imaging (MRI). Diagnosis of ANSD requires an audiological evaluation including Auditory Brainstem Response (ABR) and otoacoustic emissions (OAE) testing. ANSD usually presents with normal outer hair cell function as measured by present cochlear microphonic that increases in amplitude with increased intensity and present OAEs. “Atypical” ANSD presents similar ABR findings, absent waveforms with present cochlear microphonic, but with absent OAEs. Neurologically involved patients may also demonstrate similar test patterns to typical or atypical ANSD presentation. Once diagnosed, individuals are recommended to follow-up with ENT/otology for subsequent genetic testing, imaging, and medical management/monitoring.

The current project outlines five case studies of pediatric ABRs with click testing consistent with ANSD, varying OAE results, and possible neurological considerations. These cases will describe different variations of typical and atypical ANSD that could be encountered along with the neurological and other comorbidities that add to the complexity of this ANSD diagnosis. Functionally, those with ANSD have varied and often fluctuating hearing thresholds (ranging from normal to profound) but impaired speech understanding. Therefore, the management of ANSD differs from individuals with typical sensorineural hearing loss. Once ANSD is diagnosed during the ABR, threshold testing is discontinued as ABR thresholds are not reliable in ANSD populations. As a result, audiological management typically involves monitoring hearing sensitivity through behavioral testing once a child can sit up independently. Depending on thresholds of hearing, unilateral versus bilateral diagnosis, and results of speech testing, a hearing aid and/or cochlear implant will be recommended. Should a patient undergo a hearing aid trial, the benefit will be closely monitored through speech testing. Limitations in audiological management may include the difficulty obtaining hearing thresholds through behavioral testing due to developmental level or comorbidities as well as difficulty distinguishing true ANSD from other neurological conditions that result in similar ABR findings. Therefore, it is crucial that these patients are monitored closely to provide appropriate audiological management.

Neurologically involved patients demonstrating ABR findings consistent with ANSD, can pose an interesting dilemma in determining appropriate audiological management. The clinical decision-making process used for this patient population may be informed by common ANSD recommendations, but also must take into account the individual needs of the patient and family. In these cases of ANSD, patients with comorbid conditions or disorders, an interdisciplinary approach will provide the most comprehensive care. This requires communication and cooperation between the child's medical providers and family. Future directions of this case series may include further investigation into neurologically involved cases for which, we may have to adjust our protocols and expectations in management.

Learning Objectives:

Upon completion, participants will be able to describe the clinical presentation of ANSD based on audiological test findings.
Upon completion, participants will be able to apply ANSD/neurological concepts to inform audiological management and make appropriate recommendations for intervention based on individual patient needs.
Upon completion, participants will be able to compare audiologic and medical evaluation results among typical ANSD and atypical ANSD patients (i.e., comorbities such as syndromes and other neurological considerations).