Lead-Shift Error and Pneumocephalus in Awake, Robotic Deep Brain Stimulation Patients

The mechanisms of lead placement error and brain shift in deep brain stimulation (DBS) remain poorly understood. Further understanding is critical as lead displacement >2 mm can lead to poor treatment efficacy. Differences between anesthesia and surgical techniques often vary significantly, making the cause of error challenging to ascertain. The objective of this study was to demonstrate the relationship between pneumocephalus and lead shift error in patients undergoing awake, robotic-assisted surgery.

Seventy-six patients undergoing DBS with target ventral intermediate nucleus of the thalamus (VIM) or subthalamic nucleus (STN) were included. All patients underwent bilateral lead placement under robotic guidance in an awake procedure, with left-sided leads placed first, followed by right-sided leads. Preoperative plan target points were compared with the final lead placement based on stereotactic computed tomography performed immediately postoperatively. The radial error between the postoperative computed tomography observation of the lead placement and the planned target was compared with the volume of pneumocephalus in the left vs right leads.

All patients had some degree of pneumocephalus, with an average amount of 18.9 ± 15.8 cm 3 for both STN and VIM targets combined. The right-sided leads were placed medially to the planned target for both STN and VIM. There was a significant increase in the error magnitude for right-sided leads compared with left-sided leads for both STN and VIM targets ( P < .01). Pneumocephalus was similar when comparing STN and VIM placement. No significant correlation existed between the total volume of pneumocephalus measured and lead misplacement.

This study contributes valuable insights into lead placement errors and pneumocephalus variability in bilateral DBS procedures in awake patients. Addressing these issues, correcting for possible systematic errors during preoperative planning, and further exploring the relationship between pneumocephalus and lead placement accuracy can optimize the therapeutic benefits of DBS.