Deep Brain stimulation is a technique in which deep part of brain is stimulated with the surgically placed electrodes. This technique is now a well established procedure in cases of Parkinsonism. Electrical stimulation of the subthalamic nucleus (STN) is an accepted treatment for advanced Parkinson disease (PD). To place electrode in the the deeper part of brain , a surgical procedure needs to be very precise.
So a preoperative imaging is required to localize the lesion.
Step 1.Stereotactic frame is fixed over the head of the patient.
So, the DBS procedure begins with placing a stereotactic frame fixed over the head.
For example
(Source)
A stereotactic frame applied over the head. The application of this frame is very easy and it does not require general anesthesia. Local anesthetic agent may be used and patient remains conscious after the application of the frame.
Step 2. Patient is shifted to the MRI room to calculate the distance of the subthalamic nucleus from the arc of the stereotactic frame. So the length of the electrode can be measured. Now the neurosurgeon knows the distance , direction and depth of the target on X-axis, Y - axis and Z-axis, and actually is the aim of stereotaxy.
Magnified area of interest in the sagittal (A), coronal (B), and axial (C) planes. R, red nucleus; SN, substantia nigra; ZI, zona incerta; CI, capsula interna; T, thalamus; LV, lateral ventricle; STN, subthalamic nucleus.
(Source AJNR )
Step 3. Two Burr holes are made under local anesthesia , usually 3 cm lateral to midline and just anterior to the coronal suture on either side ( In Frontal bone).
Step 4. After initial burr holes, dura is coagulated a very thin micro electrode is introduced in the brain towards the subthalamic nucleus.
Step 5. Deep brain stimulation of the target site to see the pattern of dischrges from the subthalamic nucleus. When an expected pattern or discharges or wave pattern is seen or heard , neurosurgeon or neurologist becomes sure that the electrode is in the subthalamic nucleus. Then the scalp is closed in layers and electrodes remain in place. Till this procedure patient usually remains awake and alert and may respond the the electrode stimulation .
Sample intraoperative microelectrode recording from a single neuron at the center of the STN calculated with preoperative 3T MR imaging. A, Real-time electrophysiologic recording. B, Single-cell spike registration screen
(Source AJNR )
Step 6. Then a small sized neurostimulator is connected to the electrodes. For Placing the neurostimulator a subcutaneous tunnel is made and a subcutaneous pouch is made just below the collar bone. This procedure requires General anesthesia. The neurostimulator of Medtronic company is shown below ( White in color).
Step 7. Programming of the stimulation.
(Source : Medtronic Product information online)
I have written only about the use of DBS in Parkinson disease to give a very simple overview of the procedure. Now, there are many indications for DBS. This is very easy procedure and any neurosurgical center can adopt this procedure. This technique has great potential. This procedure requires a stereotactic frame and MRI. There are only a few neurosurgical complications which are almost same as burr hole evacuation of chronic SDH.
So a preoperative imaging is required to localize the lesion.
Step 1.Stereotactic frame is fixed over the head of the patient.
So, the DBS procedure begins with placing a stereotactic frame fixed over the head.
For example
(Source)
A stereotactic frame applied over the head. The application of this frame is very easy and it does not require general anesthesia. Local anesthetic agent may be used and patient remains conscious after the application of the frame.
Step 2. Patient is shifted to the MRI room to calculate the distance of the subthalamic nucleus from the arc of the stereotactic frame. So the length of the electrode can be measured. Now the neurosurgeon knows the distance , direction and depth of the target on X-axis, Y - axis and Z-axis, and actually is the aim of stereotaxy.
Magnified area of interest in the sagittal (A), coronal (B), and axial (C) planes. R, red nucleus; SN, substantia nigra; ZI, zona incerta; CI, capsula interna; T, thalamus; LV, lateral ventricle; STN, subthalamic nucleus.
(Source AJNR )
Step 3. Two Burr holes are made under local anesthesia , usually 3 cm lateral to midline and just anterior to the coronal suture on either side ( In Frontal bone).
Step 4. After initial burr holes, dura is coagulated a very thin micro electrode is introduced in the brain towards the subthalamic nucleus.
Step 5. Deep brain stimulation of the target site to see the pattern of dischrges from the subthalamic nucleus. When an expected pattern or discharges or wave pattern is seen or heard , neurosurgeon or neurologist becomes sure that the electrode is in the subthalamic nucleus. Then the scalp is closed in layers and electrodes remain in place. Till this procedure patient usually remains awake and alert and may respond the the electrode stimulation .
Sample intraoperative microelectrode recording from a single neuron at the center of the STN calculated with preoperative 3T MR imaging. A, Real-time electrophysiologic recording. B, Single-cell spike registration screen
(Source AJNR )
Step 6. Then a small sized neurostimulator is connected to the electrodes. For Placing the neurostimulator a subcutaneous tunnel is made and a subcutaneous pouch is made just below the collar bone. This procedure requires General anesthesia. The neurostimulator of Medtronic company is shown below ( White in color).
Step 7. Programming of the stimulation.
(Source : Medtronic Product information online)
I have written only about the use of DBS in Parkinson disease to give a very simple overview of the procedure. Now, there are many indications for DBS. This is very easy procedure and any neurosurgical center can adopt this procedure. This technique has great potential. This procedure requires a stereotactic frame and MRI. There are only a few neurosurgical complications which are almost same as burr hole evacuation of chronic SDH.
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Neurosurgery Imaging and Techniques