Investigators note that postoperative confusion frequently occurs in patients after DBS surgery is performed under local anesthesia. However, contrary to their expectations, the incidence of cognitive, mood, and behavioral adverse effects was no higher after DBS during “awake” surgery.
As expected, performing the surgery under general anesthesia was faster, less burdensome, and more patient friendly, report P. Rick Schuurman, MD, PhD, Department of Neurosurgery, Amsterdam University Medical Centers, Amsterdam, the Netherlands, and colleagues.
The study was published online September 7 in JAMA Neurology.
Asleep vs Awake
The study compared bilateral subthalamic nucleus DBS performed either asleep (general anesthesia) or awake (local anesthesia) in 110 patients with advanced PD.
Stereotactic frame-based MRI and microelectrode recordings for target determination were employed in both groups and clinical tests were performed in the awake group. There were 56 patients in the asleep group and 54 in the awake group.
Six months after surgery there was no significant difference in the primary outcome — a composite score of 1 or more representing cognitive, mood, or behavioral adverse effects — between the awake and asleep groups: 15 of 52 (29%) patients in the awake group met the primary outcome as did 11 of 51 (22%) after asleep DBS (odds ratio, 0.7; 95% CI, 0.3 – 1.7; P = .40).
There was also no significant difference in the secondary outcome of improvement in motor symptoms — reflected by change from baseline to 6 months in the Movement Disorders Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) Motor Examination score during the off-medication phase.
On this secondary outcome measure, there was a 52% improvement (−27.3 points) in the awake group and a 50% improvement (−25.3 points) in the asleep group (mean difference between groups, −2.0; 95% CI: −8.1 to 4.2).
This level of motor improvement — as well as the 28%-33% improvement in quality of life seen on the PD Questionnaire-39 — are in line with what has been reported previously, the study team notes.
DBS surgery under general anesthesia was viewed as more patient friendly and was 26 minutes shorter than doing the surgery under local anesthesia.
The authors note that the study was limited to frame-based microelectrode-guided procedures used in both awake and asleep procedures.
“Therefore, it remains uncertain if these results also apply to some of the newer, asleep-based implantation procedures without guidance of microrecordings or to frameless DBS procedures,” they note.
In addition, the study was not designed or powered to determine whether abandoning intraoperative clinical testing has a meaningful influence on final electrode placement, but abandoning awake clinical testing does not lead to less motor improvement, the investigators add.
Patient Preference “No Surprise”
Reached for comment, Michele Tagliati, MD, neurologist and director of the movement disorders program at Cedars-Sinai Medical Center, Los Angeles, California, said “this randomized trial confirms that doing DBS surgery awake or asleep makes no difference in terms of outcomes.”
“The reason why DBS surgery has been developed as an awake procedure has been that general anesthesia might affect the neuronal recordings that the surgeon uses to localize the perfect lead placement,” Tagliati told Medscape Medical News.
“Based on the fact that the DBS outcomes were the same, it can be assumed that the precision of the implant was not affected by being asleep or awake,” said Tagliati, who was not involved with the study.
He said it’s no surprise that patient satisfaction was higher with general anesthesia.
“Most patients prefer to be asleep during DBS surgery. They don’t like the idea of being awake when someone drills a hole in their skull,” he said.
He noted that a limitation of the most promising asleep-based implantation procedure — MRI-guided surgery — is capital expense, “because you basically have to either reserve an MRI for a number of hours or purchase a dedicated MRI just to do DBS, which not every hospital may want to do.”
The trial was supported the Dutch Brain Foundation. Schuurman reported personal fees from Medtronic and Boston Scientific during the conduct of the study. Tagliati has served as a consultant for major DBS manufacturers, including Abbott, Boston Scientific, and Medtronic.
JAMA Neurology. Published online September 7, 2021. Abstract