Impact of Vestibular Schwannoma Management on Cochlear Implant Programming and Outcomes.

Objectives: To compare electrical stimulation and speech perception in vestibular schwannoma (VS) patients across treatment modalities and standard cochlear implant (CI) patients.

Study design: Retrospective review.

Setting: Tertiary academic center.

Patients: Sixty-seven CI ears consisting of 23 standard CI controls and 44 VS patients with ipsilateral CI. VS patients were separated by treatment modality: 24 microsurgical resection, 15 radiation therapy, and 5 observation. Eleven VS patients with CI did not receive auditory sensation from electrical stimulation.

Interventions: VS microsurgical resection, radiation therapy, and observation.

Main outcome measures: Threshold (T-levels), comfort (C-levels), consonant-nucleus-consonant (CNC) word score, and AzBio sentence recognition scores.

Results: Patients who underwent microsurgical resection required significantly higher (p < 0.001) T-levels and C-levels compared with the standard CI group. Stimulation levels in the VS radiation therapy and observation groups were higher but not significantly different compared with standard CI controls. Overall rate of CI nonstimulation across all VS patients was 25%: 38% for microsurgery and 13% for radiation. Average CNC score for microsurgery group was 18% compared with 44% for radiation, 55% for observation, and 68.5% for standard CI controls. CNC word and AzBio scores were significantly lower (p < 0.001) for the microsurgery group compared with standard CI group.

Conclusions: Resection may negatively affect auditory nerve function, leading to higher stimulation levels, increased risk of nonstimulation, and poorer postoperative CI speech outcomes compared with observation or radiosurgery. When medically appropriate, nonsurgical VS management may be used to allow for optimization of CI programming and postoperative hearing outcomes.