Bilateral Auditory Brainstem Implants in Patients With Neurofibromatosis 2.

Area of Science:

• Neurosurgery
• Audiology
• Medical device technology

Background:

• Neurofibromatosis 2 (NF2) often necessitates auditory brainstem implants (ABIs) for hearing restoration.
• Sequential placement of bilateral ABIs is a complex consideration for managing hearing loss in NF2 patients.

Purpose of the Study:

• To evaluate the indications for bilateral auditory brainstem implants (ABIs).
• To compare audiometric outcomes between unilateral and bilateral ABI use.
• To determine if adding a second ABI improves patient outcomes.

Main Methods:

• Retrospective review of 24 NF2 patients who received sequential ABIs between 1989 and 2019.
• Analysis of patient charts for reasons for second-side surgery, implant use, and audiometric results.
• Comparison of speech perception scores (NU-CHIPS/CUNY) in unilateral versus bilateral ABI conditions.

Main Results:

• Indications for a second ABI included severe nonauditory symptoms, marginal audiometric results, outdated technology, or first-side deterioration.
• 75% of patients showed improved audiometric outcomes after receiving a second ABI; 20% had stable results.
• One patient discontinued bilateral use due to lack of significant improvement over unilateral use.

Conclusions:

• Bilateral ABIs are a viable option for patients with suboptimal performance from a first-side implant.
• The majority of patients experience subjective hearing improvements with bilateral ABI use.
• Further research is needed to develop better objective measures for assessing bilateral ABI benefits.