How to avoid pneumocephalus in deep brain stimulation surgery? Analysis of potential risk factors in a series of 100 consecutive patients.

BACKGROUND: Accuracy of lead placement is the key to success in deep brain stimulation (DBS). Precise anatomic stereotactic planning usually is based on stable perioperative anatomy. Pneumocephalus due to intraoperative CSF loss is a common procedure-related phenomenon which could lead to brain shift and targeting inaccuracy. The aim of this study was to evaluate potential risk factors of pneumocephalus in DBS surgery. METHODS: We performed a retrospective single-center analysis in patients undergoing bilateral DBS. We quantified the amount of pneumocephalus by postoperative CT scans and corrected the data for accompanying brain atrophy by an MRI-based score. Automated computerized segmentation algorithms from a dedicated software were used. As potential risk factors, we evaluated the impact of trephination size, the number of electrode tracks, length of surgery, intraoperative blood pressure, and brain atrophy. RESULTS: We included 100 consecutive patients that underwent awake DBS with intraoperative neurophysiological testing. Systolic and mean arterial blood pressure showed a substantial impact with an inverse correlation, indicating that lower blood pressure is associated with higher volume of pneumocephalus. Furthermore, the length of surgery was clearly correlated to pneumocephalus. CONCLUSION: Our analysis identifies intraoperative systolic and mean arterial blood pressure as important risk factors for pneumocephalus in awake stereotactic surgery.