DBS surgery can be performed while you are awake (with local anaesthesia and mild sedation) or asleep (local anaesthesia). Some people may remain awake for a part of surgery and asleep during the other part.
If the surgery is performed while the patient is awake, a local anaesthesia is used to numb the scalp and no anaesthesia is required for the brain as it does not have any pain receptors.
The doctors may ask the patient to stop taking the medicines that control Parkinson’s symptoms. During the procedure, the patient is asked to perform certain tasks to help guide the surgeon while placing electrode in the accurate part of the brain.
However, remaining awake during a brain surgery or not taking medicine can be unsettling for some people. So using a general anaesthesia is an alternative option as the patient will be unconscious during the surgery.
Following are the steps involved in a Deep Brain Stimulation Surgery in India:
1. Attaching the stereotactic frame
The surgeon first attaches a stereotactic frame to the head of the patient. A local anaesthesia is applied on the scalp where the four pin sites will be inserted to minimize discomfort. The might patient might feel some pressure as the pins are tightened.
2. Imaging scans – MRI or CT scan
The doctor will take imaging scan such as computerized tomography (CT) or magnetic resonance imaging (MRI). These images and special computer software are used to map the brain and identify the area for placement of the electrodes.
3. Incision on skin and skull
After the imaging scans, the patient will be taken to the operating room. The stereotactic head frame remains secured and it prevents any movement of the head while placing the electrodes. The patient may remain awake during this part of the surgery. The doctor may give a mild sedative to make it more comfortable during the skin incision. Later, the sedation is stopped so that the doctors can talk to patient and perform the tasks.
The hair is shaved and an incision is made on the skin on the top of the head to expose the skull. The surgeon will then make two burr holes using a drill on the left and right sides of the skull. Through these holes, electrodes are passed into the brain.
4. Insertion of electrode in the brain
The electrodes are inserted through the small burr holes in the skull and placed in the brain. Using the images from the MRI / CT scans and the planning software, the electrode are inserted into the brain at a precise depth and angle. There will be no discomfort as the brain itself does not feel any pain.
The surgeon may implant one lead wire into each side of the brain. The wire will run under the skin, reaching to a pulse generator (neurostimulator) that is implanted near the collarbone.
5. Stimulation of the brain cells
Once the permanent DBS electrode/lead are placed on the correct nerve, test stimulation will be performed. The surgery team will ask if the patient feels any of their symptoms have lessened or completely gone away.
6. Closure of incision
The surgeon will place a plastic cap over the small hole on the head to hold the lead in place. The incision of the scalp is closed with sutures or staples. Later a bandage is placed on the surgical wounds.
After a week later, an outpatient surgery is performed to implant the stimulator in the chest. This is performed under a general anesthesia and the patient will remain unconscious during the procedure.
Implanting the stimulator
In the operation theatre, the surgeon will reopen a portion of incision on the scalp to access the leads. Then a small incision is made near the collarbone where the neurostimulator will be implanted under the skin. The electrode/lead is attached to the extension wire that is passed under the skin down the neck to connect to the stimulator/battery in the chest.
The stimulator might be visible as a small bulge under the skin, but it usually remains hidden under the clothes.
It is advisable to avoid movement of arm over the shoulder or an excessive stretching of the neck as the incision heals.
Programming the stimulator
About a few days after the surgery, the patient will have their stimulator programmed in a follow-up visit. The doctor programs the pulse generator in his clinic using a special remote control. It may take some time to find 3 to 4 programming sessions to find the optimal setting. The amount of stimulation required is customized depending on the person’s condition. Once the stimulator is programmed, the medication dosage will be adjusted.