Objective To demonstrate magnetic resonance imaging’s (MRI’s) utility in investigating auditory brainstem implant (ABI) performance degradation.

Design Case study.

Setting Academic medical center.

Participant This report presents a patient with neurofibromatosis type 2 and an ABI with durable, limited open-set speech who developed nonauditory side effects and a complete lack of auditory perception. ABI paddle placement was assessed with 1.5 Tesla (T) Siemens MRI, and device function was assessed utilizing integrity tests.

Main Outcome Measure The etiology of ABI performance degradation utilizing 1.5 T Siemens MRI.

Results On initial postoperative 1.5 T Siemens MRI, the ABI paddle approximated the cochlear nucleus. Approximately 1 year later, the patient experienced ABI performance degradation and dizziness. Although ABI device integrity testing was normal, follow-up 1.5 T Siemens MRI revealed lateral ABI paddle migration from the foramen of Luschka toward the flocculus, likely due to observed fat atrophy from the prior craniotomy reconstruction, suggesting a possible etiology for the observed ABI degradation.

Conclusion This report presents MRI’s ability to successfully delineate postoperative fat atrophy, ABI paddle migration in relation to the brainstem, and residual tumor in a patient with ABI degradation.

Received: 16 October 2025

Accepted after revision: 21 April 2026

Article published online:
13 May 2026

© 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).

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