An EABR paradigm for assessing inner ear malformations in cochlear implantation

Area of Science:

• Otolaryngology
• Neuroscience
• Biomedical Engineering

Background:

• Children with prelingual profound sensorineural hearing loss and inner ear malformations present complex cochlear implantation challenges.
• Intraoperative electric auditory brainstem response (eABR) is vital for assessing auditory pathway integrity during surgery.

Purpose of the Study:

• To evaluate a novel intraoperative eABR paradigm in children with inner ear malformations (IEM).
• To compare these findings with children having normal inner ear anatomy.

Main Methods:

• Nineteen pediatric cochlear implant candidates (11 with IEM, 8 with normal anatomy) were studied.
• Intraoperative eABR was recorded using external promontory (ePEABR), internal promontory (iPEABR), and intracochlear (iEABR) stimulation under general anesthesia.
• Analysis focused on the presence, latency, amplitude, and threshold of Waves III and V.

Main Results:

• ePEABR showed limited utility in IEM cases due to artifacts and elevated thresholds.
• Internal promontory eABR (iPEABR) provided consistent latency patterns in all patients.
• Intracochlear eABR (iEABR) yielded robust responses, with latency shortening and amplitude increasing closer to the cochlear nerve.

Conclusions:

• Intraoperative iPEABR is a feasible and valuable objective assessment tool for auditory pathway function in pediatric cochlear implantation with IEM.
• This technique supports surgical decision-making in complex cases.