Deep brain stimulation is a surgical treatment in which thin electrodes are placed in precisely defined deep brain structures and connected to a small pulse generator implanted under the skin below the collarbone. Continuous electrical stimulation changes the activity of circuits that are malfunctioning, reducing tremor, rigidity, slowness or abnormal postures. It does not destroy tissue, it is adjustable, and it can be switched off or removed.
At a glance
- What is implanted
- One or two electrodes in the brain, connecting leads under the skin, and a pulse generator below the collarbone
- Common targets
- Subthalamic nucleus (STN); globus pallidus internus (GPi); ventral intermediate nucleus (VIM); posterior subthalamic area (PSA/cZi)
- Main indications
- Parkinson's disease, essential tremor, head tremor, dystonia, Holmes tremor; selected psychiatric indications
- Anaesthesia
- Electrode placement may be awake or asleep; generator implantation under general anaesthesia
- Hospital stay
- Typically 3–5 days
- First programming
- Usually days to a few weeks after surgery, then refined over months
- Reversible
- Yes — stimulation can be adjusted, switched off, or the system explanted
- Battery
- Non-rechargeable generators typically need replacement after several years; rechargeable systems last considerably longer
What DBS actually does
In Parkinson's disease, tremor and dystonia, the brain's motor circuits are anatomically intact but are firing in abnormal, over-synchronised patterns. High-frequency stimulation interrupts those patterns. The clinically important consequence is that the effect appears within seconds of switching stimulation on, and disappears within minutes to hours of switching it off — which is exactly why the treatment can be titrated to each patient.
The operation, step by step
- Imaging and planning. High-resolution MRI, usually fused with CT, is used to define the target on the individual patient's anatomy and to plan a trajectory that avoids blood vessels and the ventricles.
- Frame or frameless fixation. A stereotactic frame is fitted under local anaesthesia, or a frameless system is used, to allow sub-millimetre accuracy.
- Electrode placement. Small openings are made in the skull and electrodes are advanced to the target. Microelectrode recording can be used to listen to the characteristic firing of the target structure; test stimulation checks that symptoms improve and that side effects do not appear at usable settings. This part may be performed with the patient awake.
- Imaging confirmation. Position is confirmed intraoperatively or immediately afterwards.
- Pulse generator. Under general anaesthesia, the generator is implanted below the collarbone and connected to the electrodes by leads tunnelled under the skin.
- Programming. Stimulation is started and refined over weeks to months, with medication adjusted in parallel.
Brain shift, and why the second side is harder
One detail is worth knowing because it explains much of the technical care that goes into this operation. The target is planned on images taken before surgery. The moment the first opening is made in the skull, cerebrospinal fluid can escape and the brain settles a little — so by the time the second electrode is placed, the anatomy has moved slightly away from the plan. Surgeons manage this with head positioning, by limiting fluid loss, by sealing the opening, and by confirming position with recording and test stimulation rather than trusting the coordinates alone. Prof. YILMAZ is a co-inventor of a registered device for sealing the burr hole against fluid leakage for exactly this reason (see the research page).
Awake or asleep?
Both approaches are used. Awake surgery allows direct testing — tremor stopping under the surgeon's hand is the most reliable confirmation available that the electrode is in the right place, and side effects such as speech disturbance or visual phenomena can be provoked and avoided. Asleep, image-guided surgery is more comfortable and is appropriate for patients who cannot tolerate being awake, for severe dystonia, and for some children. The choice is made per patient, not as a fixed policy of the centre.
Risks
| Risk | Approximate frequency in published large series | Notes |
|---|---|---|
| Intracranial haemorrhage | About 1–2% | The most serious risk; may cause permanent deficit or, rarely, be fatal |
| Infection of the implanted system | A few per cent | May require removal of part or all of the hardware |
| Lead misplacement requiring revision | Uncommon | Detected on post-operative imaging or through poor response |
| Hardware fracture, migration or erosion | Uncommon, accumulates over years | Usually correctable surgically |
| Stimulation side effects (speech change, paraesthesia, mood or impulse-control change, weight gain) | Common but usually adjustable | Managed by reprogramming; some require medication review |
| Seizure around the time of surgery | Uncommon | Usually self-limiting |
These figures are drawn from published multicentre DBS literature to give an honest order of magnitude. Individual risk depends on age, comorbidity, anticoagulation, target and the number of trajectories, and is discussed personally before consent.
Recovery and follow-up
Most patients are mobile the day after surgery and go home within three to five days. Scalp and chest wounds heal over about two weeks. A temporary improvement in symptoms before stimulation is switched on — the microlesion effect — is common and fades; patients should know this in advance so that its disappearance is not alarming.
Programming begins days to a few weeks after surgery and is refined repeatedly during the first six months. For international patients, this continues by video call in coordination with the referring neurologist, with in-person review when travel is possible.
Living with the system
- MRI: modern systems are MRI-conditional, meaning scans are possible under specified conditions. The exact conditions depend on the device; patients are given documentation to show any radiology department.
- Airports and security: patients carry an implant identification card. Walking through security gates is generally acceptable; hand-held wands should not be held over the generator.
- Battery: non-rechargeable generators are replaced in a short procedure after several years; rechargeable systems last considerably longer but require regular charging.
- Dental and other surgery: the implanted system should be declared; diathermy precautions apply.
Request a DBS candidacy review
Complication frequencies are quoted from published multicentre DBS series to indicate order of magnitude, not from this centre's own data. Individual risk is discussed personally.
Frequently asked questions
How does deep brain stimulation work?
Electrodes deliver continuous high-frequency electrical pulses to a precisely defined deep brain structure, interrupting the abnormal, over-synchronised firing patterns that produce tremor, rigidity, slowness or abnormal postures. The effect starts within seconds of switching stimulation on and reverses when it is switched off.
Is DBS brain surgery, and how dangerous is it?
Yes, it is brain surgery. The most serious risk is bleeding inside the brain, reported at roughly 1–2% in large published series, which can cause permanent deficit. Infection of the implanted hardware occurs in a few per cent. Most stimulation-related side effects are adjustable by reprogramming.
Is DBS permanent? Can it be removed?
No tissue is destroyed, so the treatment is reversible in principle: stimulation can be reduced or switched off, and the system can be explanted if necessary. This is the main difference between DBS and lesioning procedures such as thalamotomy.
How long does a DBS battery last?
Non-rechargeable pulse generators typically last several years, depending on stimulation settings — dystonia, which needs higher energy, drains them faster. Rechargeable generators last considerably longer but must be charged regularly by the patient.
Can I have an MRI scan after DBS?
Usually yes. Modern DBS systems are MRI-conditional: scanning is permitted under specified conditions that depend on the device model. Patients are given documentation setting out those conditions to present to any radiology department.
How soon after DBS surgery will I feel better?
Many patients notice a temporary improvement immediately after electrode placement (the microlesion effect) which then fades. Real benefit begins when stimulation is programmed, typically days to a few weeks after surgery, and is refined over the following months.