AWAKE brain mapping can reveal information that changes deep brain stimulation (DBS) lead placement beyond what imaging alone would suggest, according to research in patients with essential tremor.
A retrospective Mayo Clinic analysis examined how recordings of brain activity and stimulation testing influenced surgical decisions. The findings support the potential value of physiological feedback when tailoring electrode placement to an individual patient.
DBS uses implanted electrodes to deliver electrical stimulation to selected brain regions. Imaging helps surgeons plan the target and the route used to reach it, while awake testing allows the team to assess responses during implantation.
The researchers reviewed 137 consecutive leads implanted by one surgeon working with one intraoperative neurologist. They recorded whether each lead followed the planned trajectory and depth, required a depth adjustment, or moved to a parallel trajectory.
Of the 137 leads, 116 remained on the planned trajectory. Within this group, 49 were implanted at the original depth and 67 at an adjusted depth. The remaining 21 leads were placed along a parallel trajectory following intraoperative assessment.
Seventeen of the leads moved to parallel trajectories had imaging available for comparison. Only two had moved closer to the intended imaging target; 13 were farther away and two remained the same distance from it.
This pattern suggests that the changes often reflected functional information obtained during surgery, rather than simply correction towards the original anatomical target.
In its report accompanying the research, Mayo Clinic described more favourable intraoperative responses after repositioning, including improved tremor suppression, fewer side effects and wider therapeutic windows. A wider window separates the stimulation level needed for symptom control from the level at which adverse effects appear, potentially offering more flexibility during subsequent programming.
The results provide a practical reason to retain awake assessment as an option as imaging technology advances. They illustrate how an apparently accurate anatomical plan may still be refined by observing a patient’s response to stimulation.
However, the analysis was retrospective and reflected the practice of a single surgical team. It did not directly compare long-term outcomes between patients undergoing awake and asleep surgery, so it cannot establish that one approach is superior overall.
Mayo Clinic reports that future work will explore more efficient ways to collect physiological information during surgery. The aim is to preserve the patient-specific feedback that informs lead placement while reducing the time required to obtain it.
Reference
Klassen BT et al. The modern utility of awake deep brain stimulation surgery. medRxiv [preprint]. 2025. doi:10.1101/2025.09.25.25336654.
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