Operative technique andworkflow of deep brain stimulation surgery with pre-existing cochlear implants

BACKGROUND: Deep brain stimulation (DBS) surgery in patients with pre-existing cochlear implants (CIs) poses various challenges. We previously reported successful magnetic resonance imaging (MRI)-based, microelectrode recording (MER)-guided subthalamic DBS surgery in a patient with a pre-existing CI. Other case reports have described various DBS procedures in patients with pre-existing CIs using different techniques, leading to varying issues to address. A standardized operative technique and workflow for DBS surgery in the setting of pre-existing CIs is much needed. OBJECTIVE: To provide a standardized operative technique and workflow for DBS lead placement in the setting of pre-existing CIs. METHODS: Our operative technique is MRI-based and MER-guided, following a workflow involving coordination with a neurotology team to remove and re-implant the internal magnets of the CIs in order to safely perform DBS lead placement, altogether within a 24-h time frame. Intraoperative nonverbal communication with the patient is easily possible using a computer monitor. RESULTS: A 65-yr old woman with a 10-yr history of craniocervical dystonia and preexisting bilateral CIs underwent successful bilateral pallidal DBS surgery at our institution. No merging errors or difficulties in targeting globus pallidus internus were experienced. Also, inactivated CIs do not interfere with MER nor with stimulation, and intraoperative communication with the patient using a computer monitor proved feasible and satisfactory. CONCLUSION: DBS procedures are safe and feasible in patients with pre-existing CIs if precautions are taken following our workflow.