Implantation of Deep Brain Stimulation Electrodes Under General Anesthesia for Parkinson Disease and Essential Tremor

For more than three decades, the implantation of deep brain stimulation (DBS) electrodes has typically been performed using indirect targeting and microelectrode-guided (MER) physsiogoical confimration of targets in the subthalamic nucleus (STN) and globus pallidus internus (GPI) for medically-intractable Parkinson’s Disease patients, and ventralis intermedius (VIM) for those with Essential Tremor. Improvements in high-field MRI now allow visualization of subcortical structures commonly targeted during DBS surgery. Further, the feasibility of intraoperative MR and CT imaging allows for the precise, near real-time imaging of electrode location during DBS implantation. These advanced imaging techniques allow direct targeting of DBS leads without MER, or intraoperative stimulation testing. Asleep DBS (aDBS) appears to be safe and effective, and allows fewer brain penetrations, thus reducing the risk of intraparenchymal hemorrhage and damage to target structures. Stereotactic error using intraoperative imaging appears to be at least as infrequent as when using traditional, frame-based techniques and MER for DBS electrode placement. The literature reflects outcomes for aDBS cases that are indistinguishable from those obtained during MER-guided techniques. Importantly, DBS implantation under general anesthesia is more comfortable for patients and reduces the anxiety surrounding awake surgery. This chapter reviews the evidence supporting aDBS, and suggests that this technique will eventually supplant MER-guided DBS procedures.