Simultaneous cochlear implantation and removal of acoustic neuroma: implications for hearing

Simultaneous cochlear implantation during resection of a cerebellopontine angle meningioma: case report

Cerebellopontine angle (CPA) meningiomas commonly involve the internal auditory canal (IAC). We report a case of a 68-year-old lady with idiopathic profound bilateral deafness with a meningioma which was discovered on workup for cochlear implantation. We performed simultaneous excision of her CPA and IAC meningioma with insertion of a cochlear implant (CI). She regained functional hearing with marked improvement in quality of life. Intraoperative electrophysiological testing can be used to confirm preservation of the cochlear nerve enabling simultaneous implantation which is preferable for clinical and logistical reasons. This creates an option for hearing rehabilitation at the time of IAC/CPA tumour surgery in appropriate patients.

Cochlear Implant Outcomes between Patients with Sporadic and Neurofibromatosis Type 2-Associated Vestibular Schwannoma

OBJECTIVE

Compare cochlear implant (CI) performance between patients with ipsilateral sporadic vestibular schwannoma (VS) and NF2-related schwannomatosis (NF2). Compare CI performance according to VS management modality.

STUDY DESIGN

Historical cohort.

SETTING

Tertiary academic center.

PATIENTS

Forty-nine patients (52 ears) undergoing cochlear implantation in the setting of ipsilateral sporadic (n = 21) or NF2-associated VS (n = 28).

INTERVENTIONS

CI ipsilateral to VS.

MAIN OUTCOME MEASURES

Auditory thresholds, consonant-nucleus-consonant (CNC) word scores, and AzBio sentences in quiet scores.

RESULTS

Among all patients, median post-CI pure tone average was 28 dB HL (interquartile range [IQR], 21-38), CNC word score was 39% (IQR, 6-62), and AzBio sentences in quiet score was 60% (IQR, 11-83) at a median of 12.5 months postimplantation. Despite the NF2 cohort having larger tumors, when comparing patients with sporadic versus NF2-associated VS, there were no statistically significant differences in CNC word (49% [30-70] vs. 31% [0-52]) or AzBio sentences in quiet (66% [28-80] vs. 57% [5-83]) scores. Regardless of NF2 status, all patients managed with observation, and radiosurgery achieved open-set speech. In patients who underwent microsurgery, 6 (46%) of 13 with NF2 achieved open-set speech recognition compared with 4 (67%) of 6 with sporadic disease.

CONCLUSION

Select patients with VS achieve successful hearing rehabilitation with a CI. In this cohort, tumor management strategy significantly influenced CI performance, whereas differences in NF2 status exhibited less effect. Specifically, all patients managed with observation or radiosurgery achieved open-set speech perception, whereas approximately half of people with NF2-related VS and two-thirds of people with sporadic VS achieved this outcome after tumor microsurgery. When disease permits, observation and radiosurgery should be considered in patients who may later pursue a CI.

Is the intra-operative morphology of the cochlear nerve a good predictor of the results of simultaneous ipsilateral cochlear implantation in vestibular schwannoma surgery?

OBJECTIVE

There are currently no guidelines for simultaneous vestibular schwannoma surgery and cochlear implantation. This paper therefore provides our experience and our results regarding predictive parameters of good hearing.

METHODS

Morphological appearance of the cochlear nerve after tumour resection was used as the main criterion for implantation in the case series. Patients were then divided into responders and non-responders to cochlear implantation, and potential outcome predicting factors were evaluated in the two groups.

RESULTS

Nine of the 16 patients showed a response to cochlear implantation. Pre-surgery serviceable hearing was significantly more common in the responder group, while no difference was found in the two groups for other variables.

CONCLUSION

This study highlights how the morphological appearance of the cochlear nerve can be useful to predict the hearing outcome and indicates that satisfactory hearing results are closely related to pre-surgery serviceable hearing.