Deep Brain Stimulation

Deep Brain Stimulation (DBS) is a neurosurgical procedure in which a surgeon implants tiny electrodes deep inside specific areas of the brain to deliver continuous, precisely controlled electrical pulses that change abnormal brain signals.

Certain brain conditions cause specific regions of the brain to fire signals in a disordered or overactive way, producing symptoms such as uncontrollable tremors (shaking), stiffness, or abnormal movements. DBS works by sending mild electrical pulses through the implanted electrodes to interrupt or modulate (adjust) those faulty signals — much like a pacemaker regulates the heart. The electrical pulses come from a small battery-powered device called a neurostimulator (sometimes called an implantable pulse generator, or IPG), which a surgeon places under the skin of the chest or abdomen. Thin insulated wires called leads connect the neurostimulator to the electrodes in the brain.

DBS is used when a patient's movement or neurological disorder has not responded adequately to medication, or when side effects from medication have become difficult to tolerate. It is not a cure, but it can significantly reduce symptoms and improve daily life for carefully selected patients. A specialist team — usually including a neurologist (a doctor specialising in brain and nerve conditions) and a neurosurgeon — will evaluate whether DBS is appropriate for each individual.

• Parkinson's disease — particularly when tremor, stiffness, or fluctuating responses to medication (known as 'on-off' episodes) are hard to control
• Essential tremor — persistent, involuntary shaking of the hands, head, or voice that is severe enough to interfere with daily activities
• Dystonia — a condition where muscles contract involuntarily, causing repetitive or twisted postures
• Obsessive-Compulsive Disorder (OCD) — severe, treatment-resistant cases where repeated unwanted thoughts and compulsive behaviours greatly impair daily functioning
• Epilepsy (seizure disorder) — specific drug-resistant forms where seizures cannot be controlled by medication alone

DBS is generally not considered suitable in certain situations. The specialist team will usually advise against it if:

• The diagnosis is uncertain or has not been confirmed by a specialist neurologist
• Significant cognitive decline (noticeable memory or thinking problems) is already present, as DBS does not treat this and may worsen it
• There are active psychiatric conditions — such as untreated severe depression or psychosis — that have not been stabilised first
• The patient has a medical condition that makes brain surgery too risky, such as uncontrolled bleeding disorders or serious heart or lung disease
• A pacemaker or other implanted electronic device is present that may interfere with the neurostimulator — your medical team will assess this carefully

Like any brain surgery, DBS carries real risks that every patient should understand and discuss with their surgical team before deciding to proceed.

• Bleeding in the brain (intracranial haemorrhage) — a small amount of bleeding can occur when the electrode is inserted; in rare cases this can cause a stroke or lasting neurological change
• Infection — the implanted hardware (electrodes, leads, and neurostimulator) can become infected, sometimes requiring removal of the device
• Seizures (fits) — can occur around the time of surgery
• Misplaced electrode — if the electrode does not land in exactly the right spot, symptoms may not improve or new side effects may appear
• Stimulation-related side effects — depending on which brain area is targeted, these can include tingling sensations, muscle pulling on one side of the body, changes in speech or vision, balance problems, or mood changes; most can be reduced by adjusting the stimulation settings
• Hardware problems — the leads can fracture (break), the connection between parts can loosen, or the neurostimulator battery can run down over time and require replacement surgery
• Swelling of brain tissue around the electrode site, which usually settles on its own
• Anaesthesia-related risks — reactions to the general or local anaesthetic (the medication used to prevent pain during surgery)
• Cognitive or mood changes — some patients notice temporary or, less commonly, longer-lasting changes in memory, concentration, or emotions after surgery

Preparation for DBS is thorough and takes place over several weeks or months. A specialist team will carry out a detailed evaluation to confirm that DBS is the right choice and to plan the surgery precisely.

Before the procedure, your medical team will usually give the following instructions — though the exact requirements may vary between hospitals and individual patients:

• Fasting: You will usually be asked to stop eating solid food for a number of hours before surgery. Your team will give you exact timings.
• Medications: Blood thinners and certain other medications are typically paused before surgery to reduce the risk of bleeding. Do not stop or change any medication without your doctor's specific guidance.
• Parkinson's medication: Patients with Parkinson's disease are sometimes asked to withhold their medication the night before or morning of surgery so that their natural symptoms are visible during the procedure — this helps the surgical team verify electrode placement.
• Alcohol and smoking: Smoking and alcohol should be avoided in the period leading up to surgery, as both can affect healing and anaesthetic response.
• Skin care: The surgical site — usually the scalp and chest — should be kept clean. You may be asked to wash with a special antiseptic (germ-killing) solution.

Tests that are typically carried out before DBS include:

• MRI (Magnetic Resonance Imaging) and/or CT scan of the brain — to create detailed maps used for precise electrode targeting
• Neuropsychological testing — a series of memory, language, and cognitive (thinking) tasks to record a baseline and check suitability
• Psychiatric evaluation — to assess mood and mental health
• Blood tests — including clotting function, blood count, and general health markers
• Heart tracing (EKG/ECG) and chest X-ray — to assess general fitness for surgery
• Video recording of your current symptoms — so the team can compare before and after stimulation

The DBS procedure itself is usually carried out in stages, and the exact steps can vary between surgical centres and individual cases. A typical sequence is as follows:

• 1. A rigid frame (called a stereotactic frame) is attached to the patient's head under local anaesthetic (numbing injection), or a frameless navigation system is fitted — this keeps the head completely still and allows millimetre-precise targeting.
• 2. A brain MRI or CT scan is done with the frame in place to map the exact target inside the brain.
• 3. Small holes (burr holes) are drilled in the skull under local or general anaesthetic.
• 4. In many centres, the patient is kept awake during electrode insertion so they can respond to questions or perform simple tasks — this real-time feedback helps confirm correct placement. Not all centres use this approach; your team will explain their method.
• 5. The electrode is guided slowly to the target area. Microelectrode recording (listening to the electrical activity of individual brain cells) and test stimulation may be used to fine-tune placement.
• 6. Once placement is confirmed, the electrode is fixed to the skull.
• 7. In a separate stage — often a few days later, or during the same session — the neurostimulator (pulse generator) is implanted under the skin of the chest or abdomen, and the connecting leads are tunnelled under the skin of the neck.
• 8. The neurostimulator is switched on and initial settings are programmed. Fine-tuning of settings usually continues over the following weeks and months.

Recovery after DBS varies from person to person. Most patients spend at least a few days in hospital after the electrode surgery. The neurostimulator implant stage, if done separately, usually involves a shorter hospital stay. After discharge, a period of close follow-up is essential — not just for wound healing, but because fine-tuning the stimulation settings is a gradual process that can take weeks or months and has a direct effect on how much benefit the patient experiences.

• Monitoring: You will be observed closely by nurses and doctors in the ward after surgery. Neurological checks — including tests of movement, speech, and alertness — are done regularly in the early days.
• Wound care: The scalp incision (cut) and chest wound will need to be kept dry and clean. Your team will explain how to care for them and when stitches or staples are removed.
• Activity restrictions: Strenuous physical activity, heavy lifting, and contact sports are usually restricted for several weeks. Your surgical team will advise on when it is safe to gradually return to normal activities.
• Driving: Most patients are advised not to drive for a period after surgery; rules vary by country, so check with your doctor and local transport authority.
• MRI scans: Having MRI scans after DBS requires special precautions. Always tell any doctor or technician that you have a DBS device before any scan or medical procedure.
• Strong magnetic and electrical fields: Certain environments — such as near industrial equipment, theft-detection gates at some stores, or some physiotherapy machines — can interact with the neurostimulator. Your team will give you a list of things to be aware of.
• Device care: You will be given a patient controller — a small handheld device — that allows you to check whether the stimulator is on, and sometimes to make limited adjustments. You will receive training on how to use it.
• Battery replacement: The neurostimulator battery lasts for a variable number of years depending on the device type and settings used. When the battery runs low, a minor surgical procedure to replace the unit is needed.
• Follow-up appointments: Regular clinic visits are scheduled to adjust stimulation settings, monitor your progress, and manage any side effects. These visits are a critical part of getting the most benefit from DBS.
• Medications: Many patients continue taking some of their pre-surgery medications after DBS, though the dose may be reduced over time under medical supervision. Your neurologist will guide this process.
• Lifestyle: A healthy lifestyle — including regular gentle exercise, good sleep, and mental activity — is encouraged alongside DBS to support overall brain and body health.