Computerized Direction => Microelectrode Placement => Intraoperative testing
After the frame or feducials are placed on the patient and a CAT Scan and/or an MRI is performed, calculations using specialized computer software is done to determine the coordinates for placement of the DBS electrodes. The trajectory is reviewed by the operating surgeon and usually a neuroradiologist to confirm the safest route to the target location.
A recording microelectrode is placed down the trajectory path before placing the stimulating electrode. The target nucleus can be "mapped" by "listening" to the different brain cells. Different brain cells have different sounds and different wave patterns. These sounds and wave patterns enable us to identify specific areas of the brain with specific types of brain cells. When the optimal location is found, the microelectrode is removed and replaced with the Deep Brain Stimulator Electrode.
Microelectrode Recording with a stereotactic frame and with frameless approach
Intraoperative microelectrode recording to determine final position for the stimulating microelectrode.
This small electrode is placed into a specific area of the brain. High frequency stimulation to the brain via the electrode overrides abnormal brain activity within these areas.
The surgeon is threading the Deep Brain Stimulation electrode through the attachment on the stereotactic frame. The system only allows the electrode to go to the exact spot set by the coordinates on the frame.
Intraoperative Testing of Patient with Esential Tremor
As the surgeon threads the electrode into place, watch this Essential Tremor patient's hand tremor almost stop when the electrode reaches target. This is called a "thalamotomy effect". Also notice that the patient is awake and fairly comfortable during the procedure. With the electrode in place, testing is done with different stimulation settings. After testing, one can see that the patient now has good tremor control with the current stimulation settings.
Intraoperative Testing of Patient with Parkinson's Disease
This Parkinson patient has severe tremor and rigidity. Watch the change in his hand control when we find the optimal settings while testing the electrode stimulation during surgery.