Operative Technique and Nuances for the Stereoelectroencephalographic (SEEG) Methodology Utilizing a Robotic Stereotactic Guidance System
June 9th, 2023
The SEEG methodology is simplified and made faster with a stereotactic robot. Careful attention must be paid to the registration of the preoperative volumetric MRI to the patient prior to use of the robot in the OR. The robot streamlines the procedure, leading to decreased operative times and accurate implantations.
SEEG, also known as stereoelectroencephalography, is a minimally invasive method of exploration of the human brain that takes into account the three-dimensional aspect of the epileptiform activity by analyzing the anatomoelectroclinical correlations. The main advantage of this method is to map epileptiform discharges in the brain in a minimally invasive fashion. Before beginning the SEEG procedure, help the patient into the supine position.
With the patient under general anesthesia, fix the patient's head in a three-point fixation holder and position the robot at the head of the patient such that the distance between the base of the robotic arm and the midpoint of the cranium is 70 centimeters. Lock the robot into position and secure the three-point head holder to the robot. Using the semi-automatic laser-based facial recognition system, register the pre-operative volumetric MRI with the patient, following all of the prompts given by the robot.
Use the set-distance calibration tool to calibrate the laser and use the laser to manually select the preset anatomical facial landmarks. After the robot automatically scans the facial surface, correlate additional independent surface landmarks with the registered MRI to confirm the accuracy of the registration. For bolt implantation, drape the patient in standard sterile fashion and drape the robotic working arm with sterile plastic.
Attach a drilling platform with a 2.5-millimeter working cannula to the robotic arm and select the desired trajectory for each bolt to be implanted on the touchscreen of the robot. Step on the robot pedal to initiate the movement of the robotic arm to the first trajectory. When the correct position is reached, the arm will be automatically locked by the robot.
Insert a two-millimeter drill through the working cannula and use it to create a pinhole through the entire thickness of the skull. Open the dura with an insulated dural perforator using monopolar cautery at a low setting. Screw the guide bolt firmly into each pinhole and use a sterile ruler to measure the distance from the drilling platform to the guide bolt.
Subtract this measured distance from the value of the distance platform-to-target used in planning the trajectory and record the result for later use as the final length of the implanted electrode. Measure and note the final length of the electrode and confirm that it matches the newly calculated length for the bolt. Then, give the electrode and bolt matching labels to prevent confusion during the electrode implantation.
When all of the bolts have been implanted, change surgical gloves and open a new sterile field. Insert a two-millimeter diameter stylet through a guide bolt to the intended depth of the electrode, as calculated after implantation of the matching bolt. Confirm that the electrode to be implanted matches the label of the implanted guide bolt and remove the stylet.
Immediately insert the electrode through the bolt and screw the electrode into the bolt for fixation, using fluoroscopic x-ray to confirm the correct placement of each electrode after it has been implanted. When all of the electrodes have been implanted, use a standard head bandaging technique to wrap the patient's head. Here, an appropriate operating room set up with a successful bolt placement and a successful electrode implantation for the SEEG methodology is shown.
Single positron emission computed tomography and magnetoelectroencephalography tests help in the creation of the anatomoelectroclinical hypothesis. In these representative images, an electrode was positioned in the frontal opercular and dorsal insular area. Here, a resection of the right operculum and insula in a post-operative T1 MRI is shown.
The SEEG method allows the three-dimensional mapping of the epileptiform activity by applying a minimally invasive technique of placing depth electrodes into the human brain.
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Overview
The SEEG methodology is enhanced through the use of a stereotactic robot, which simplifies and accelerates the procedure. Accurate registration of preoperative volumetric MRI to the patient is crucial for effective use of the robot in the operating room.
Key Study Components
Area of Science
- Neuroscience
- Electrophysiology
- Minimally invasive techniques
Background
- SEEG stands for stereoelectroencephalography.
- This method allows for the exploration of the human brain's three-dimensional epileptiform activity.
- It is designed to map epileptiform discharges in a minimally invasive manner.
- Proper patient positioning and robotic setup are essential for the procedure.
Purpose of Study
- To improve the efficiency of the SEEG procedure.
- To ensure accurate implantation of electrodes.
- To reduce operative times during brain exploration.
Methods Used
- Patient is positioned supine under general anesthesia.
- Head is fixed using a three-point fixation holder.
- The robotic arm is positioned at a specific distance from the cranium.
- A semi-automatic laser-based facial recognition system is used for MRI registration.
Main Results
- The use of the robot streamlines the SEEG procedure.
- Decreased operative times were observed.
- Accurate electrode implantations were achieved.
- Effective registration of MRI to the patient was confirmed.
Conclusions
- The stereotactic robot significantly enhances the SEEG methodology.
- Attention to preoperative imaging registration is vital.
- This approach may lead to improved patient outcomes in epilepsy treatment.
Frequently Asked Questions
Executive Industry Relevance
Precise stereotactic electrode implantation is critical for mapping epileptogenic networks in preclinical epilepsy models, enabling target validation through direct electrophysiological readouts. The robotic guidance system enhances reproducibility and reduces procedural variability, supporting mechanistic de-risking in target engagement studies. This approach improves predictive confidence in disease-relevant systems by providing standardized, quantifiable neural activity data.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of therapeutic hypotheses via three-dimensional mapping of epileptiform discharges in disease-relevant neural circuits.
- Operational Value: Facilitates biological de-risking by providing direct electrophysiological confirmation of target engagement in vivo.
Screening & Assay Development
- Scientific Value: Prepares validated biological systems for downstream workflows by establishing stable electrode-tissue interfaces for chronic recording.
- Operational Value: Addresses assay standardization and reproducibility through robotic precision in electrode placement, reducing inter-animal variability.
Translational & Preclinical Research
- Scientific Value: Supports disease-relevant system modeling by enabling anatomoelectroclinical correlation in preclinical epilepsy models.
- Operational Value: Ensures continuity from discovery through preclinical validation via consistent, implantable electrode platforms suitable for longitudinal studies.
Pipeline & Workflow Integration
The method integrates into the discovery continuum from target validation through lead identification by providing electrophysiological readouts that inform compound effects on neural network dynamics.
- Discovery Biology: Supports hypothesis testing and pathway clarification by enabling real-time monitoring of epileptiform activity across interconnected brain regions.
- Screening: Describes assay readiness through stable, chronic electrode implantation allowing repeated compound challenge studies.
- Analytics: Highlights quantitative dependent variable measurements such as spike frequency, amplitude, and propagation patterns that help teams compare pharmacological conditions.
- Translational Research: Connects to preclinical continuity via fluoroscopic confirmation of electrode placement and post-operative imaging validation.
- Enterprise Reuse: Frames the robotic stereotactic system as a reusable platform for multiple target validation campaigns across different epilepsy models.
Operational & Enterprise Impact
- Scientific Value: Predictive confidence through direct, minimally invasive measurement of epileptiform activity in intact neural circuits.
- Operational Value: Standardization, reproducibility, and scalability via robotic guidance reducing surgeon-dependent variability.
- Strategic Value: Better go/no-go decisions by providing objective electrophysiological endpoints for target prioritization.
- Portfolio Impact: Risk-adjusted prioritization through quantifiable reduction in epileptiform burden as a translational biomarker.
Implementation Considerations
- Required scientific expertise in stereotactic neurosurgery and electrophysiological signal interpretation.
- Instrumentation and analytical infrastructure needs including robotic arm, laser-based registration system, and intraoperative fluoroscopy.
- Cross-team standardization requirements for electrode labeling, trajectory planning, and post-implantation verification protocols.
- Adaptation considerations across model systems including adjustments for skull thickness, dura integrity, and target depth in various species.
- Practical limitations supported by source material: heavy reliance on accurate registration of preoperative volumetric MRI to the patient, which is a potential point of failure if surface landmark correlation is insufficient.
