Implantation of bilateral deep brain stimulators in patients with Parkinson disease and preexisting cardiac pacemakers. Report of two cases.

Deep brain stimulation (DBS) has become an important modality in the treatment of refractory Parkinson disease (PD). In patients with comorbid arrhythmias requiring cardiac pacemakers, DBS therapy is complicated by concerns over a possible electrical interaction between the devices (or with device programming) and the inability to use magnetic resonance imaging guidance for implantation. The authors report two cases of PD in which patients with preexisting cardiac pacemakers underwent successful implantation of bilateral DBS electrodes in the subthalamic nucleus (STN). Each patient underwent computerized tomography-guided stereotactic frame-based placement of DBS electrodes with microelectrode recording. Both extension wires were passed from the right side of the head and neck (contralateral to the pacemaker) to place the cranial pulse generators subcutaneously in the left and right abdomen. The cranial pulse generators were placed farther than 6 in from the cardiac pacemaker and from each other to decrease the chance of interference between the devices during telemetry reprogramming. Postoperative management involved brain stimulator programming sessions with simultaneous cardiological monitoring of pacemaker function and cardiac rhythm. No interference was noted at any time, and proper pacemaker function was maintained throughout the follow-up period. With bilateral STN stimulation, both patients experienced a dramatic improvement in their PD symptoms, including elimination of dyskinesias, reduction of "off" severity, and increase of "on" duration. With some modifications of implantation strategy, two patients with cardiac pacemakers were successfully treated with bilateral DBS STN therapy for refractory PD. To our knowledge, this is the first report on patients with cardiac pacemakers undergoing brain stimulator implantation.