The Modern Utility of Awake DBS Surgery with Microelectrode Recording

Introduction: Awake deep brain stimulation (DBS) surgery with microelectrode recording (MER) and test stimulation offers real-time physiologic feedback to refine lead placement, but its relevance is increasingly debated in an era of advanced imaging and streamlined asleep workflows. We describe a contemporary framework for awake DBS with MER and evaluate whether, in our hands, this approach results in a final lead position different from what we would have achieved with asleep DBS.

Methods: We outline a standardized workflow combining high-resolution imaging, confirmatory MER, and intraoperative stimulation mapping for an example context of thalamic targeting for essential tremor. To quantify the impact of the awake approach on surgical decision making,
we retrospectively reviewed the first 137 consecutively implanted VIM DBS leads placed by a single surgeon working with a single intraoperative neurologist. In each case, we recorded whether the final lead was implanted along the planned target, whether it was adjusted in depth along the planned trajectory, or whether it was moved to a parallel track. For the parallel track moves, we compared the final lead position to the initially planned target using co-registered pre- and postoperative imaging.

Results: Among 137 consecutive leads implanted, 116 were implanted in the planned trajectory, with 49 at the planned depth and 67 at an adjusted depth. Twenty-one of the 137 leads were placed along a parallel trajectory based on intraoperative findings. Post-operative analysis showed that only 2 of the 21 were moved toward the intended target, indicating compensation for a stereotactic placement error. The remaining 19 were moved away (17) or equidistant (2) from the intended target.

Conclusion: Feedback from MER and test stimulation in awake DBS cases frequently informs surgical adjustments that deviate from the planned trajectory, often in response to patient-specific physiology not captured by imaging. In the vast majority of cases, these adjustments would not have been made using an asleep DBS approach, since moves were not made toward the planned target. This indicates that, in our practice, awake surgery results in adjustment of lead position in response to discovered functional anatomy rather than to stereotactic inaccuracy. Our findings underscore the continued utility in our practice of awake DBS with MER in tailoring therapy to individual anatomy and functional organization.