Auditory nerve disease and auditory neuropathy spectrum disorders

Area of Science:

• Audiology
• Neuroscience
• Genetics

Background:

• Auditory neuropathy (AN) is a bilateral hearing disorder characterized by poor speech discrimination despite normal cochlear outer hair cell function.
• Initially termed 'auditory nerve disease' or 'auditory neuropathy', AN presents with absent auditory brainstem response (ABR) but present otoacoustic emissions (DPOAEs).
• Genetic factors, including OTOF and OPA1 gene mutations, are implicated in AN pathophysiology.

Purpose of the Study:

• To present the auditory profiles of 17 additional adult cases with auditory neuropathy.
• To differentiate Auditory Neuropathy Spectrum Disorders (ANSD) from AN in adults.
• To highlight the effectiveness of cochlear implants for hearing restoration in adult AN.

Main Methods:

• Clinical assessment of 17 adult patients diagnosed with auditory neuropathy.
• Analysis of auditory profiles, including pure-tone hearing loss, speech discrimination, auditory brainstem response (ABR), and otoacoustic emissions (DPOAEs).
• Review of diagnostic criteria and classification of Auditory Neuropathy Spectrum Disorders (ANSD) over time.

Main Results:

• Adult AN is characterized by mild-to-moderate hearing loss, poor speech discrimination, and absent ABR with normal DPOAEs.
• Cochlear implants are effective for hearing rehabilitation in adult AN patients.
• Auditory Neuropathy Spectrum Disorders (ANSD) in adults are distinct from true auditory neuropathy (AN), with specific classifications based on ABR and DPOAE changes over time.

Conclusions:

• Auditory neuropathy in adults requires specific management strategies, with cochlear implantation being a viable option.
• Distinguishing between AN and ANSD in adults is crucial for accurate diagnosis and treatment.
• Further research into the diverse etiologies and auditory profiles of AN and ANSD is warranted.