In awake subthalamic (STN) deep brain stimulation for Parkinson's disease, testing the patient during electrode placement shows, in real time, where stimulation improves bradykinesia, rigidity and tremor, and where it starts to cause side effects such as speech disturbance or muscle contractions. That live response, alongside imaging, helps confirm the best position for the lead.
- Every millimetre counts in and around the subthalamic nucleus.
- The neurologist tests finger tapping, rigidity and tremor at each depth.
- The team watches for side effects: speech disturbance and capsular contractions.
- Patients usually come off medication beforehand so their true symptoms, and the response, can be seen.
- It only works as a team: neurology, DBS nursing, anaesthesia and neurosurgery.
In awake deep brain stimulation for Parkinson’s disease, every millimetre counts. The subthalamic nucleus is small, and the structures around it are responsible for most of the side effects we see when stimulation reaches beyond it.
What happens in theatre
As the electrode is advanced through the subthalamic nucleus, the neurologist assesses the patient at each depth. Finger tapping, “as fast as you can, as big as you can”, gives a direct read-out of bradykinesia, alongside changes in rigidity and tremor.
At the same time, the team monitors for side effects, such as speech disturbance or muscle contractions from current spreading into the internal capsule.
That live feedback is how we find the optimal stimulation depth: not only on a scan, but in the patient in front of us.
Why the patient comes off medication
Patients usually stop their Parkinson’s medication before surgery, so that the true severity of their symptoms, and the real response to stimulation, can be seen clearly. Seeing them on the morning of surgery, rigid and slow, is a powerful reminder of what they give on that day.
It only works as a team
- Neurologists with expertise in Parkinson’s phenotyping, who examine and interpret the response.
- DBS nurses who know the patient’s baseline.
- Anaesthetists who keep the patient awake yet comfortable.
- Neurosurgeons focused on precise targeting and lead placement.
But the most important person in that theatre is the patient.
Awake or asleep?
Many centres now also offer DBS under general anaesthesia, relying on high-quality imaging and intraoperative imaging to confirm lead position. Comparisons of awake and asleep approaches have reported broadly similar motor outcomes, and the choice depends on the patient, the target and the centre’s experience. Where awake testing is used, it gives information no scan can: how this patient responds, at this depth, today.
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Key references
- Limousin P, Krack P, Pollak P, et al. Electrical stimulation of the subthalamic nucleus in advanced Parkinson's disease. N Engl J Med. 1998;339(16):1105-11. doi:10.1056/NEJM199810153391603
- Deuschl G, Schade-Brittinger C, Krack P, et al. A randomized trial of deep-brain stimulation for Parkinson's disease. N Engl J Med. 2006;355(9):896-908. doi:10.1056/NEJMoa060281
- Ho AL, Ali R, Connolly ID, et al. Awake versus asleep deep brain stimulation for Parkinson's disease: a critical comparison and meta-analysis. J Neurol Neurosurg Psychiatry. 2018;89(7):687-691. doi:10.1136/jnnp-2016-314500
Original sources
- Originally shared on LinkedIn, 20 February 2026 · Read the original post
- You do not need more stimulation. You need better aim. · YouTube
Educational content for clinicians and trainees, reflecting the author's understanding at the date of review. It is not medical advice: if you are a patient, please discuss your care with your own clinical team.