Accuracy Of Electrode Implantation Research Articles

Connectomic deep brain stimulators in Parkinson`s sub cortical functional zones

Shaking palsy is a brain disease involving motor and non motor zones affecting circa 1 to 2%of humans>60 years age. To date there has been no invention for curing this chronic disease and to stop its progression. But existing therapeutic procedures can offer symptomatic relief to Parkinson patients. DBS is most successful therapy for the Parkinson`s yet depends on the accuracy of electrode implantation and location within the anatomical subcortical neural-structures. This study examines the likelihood of net-work-based induced stimuli and the application of connectomic DBS in Parkinson`s. The subthalamic nucleus is divided into3 sub zones, namely, limbic (anterior), associative (middle) and motor (posterior) as well as diffusion weighted imaging (D W I). The surgical targets are tiny (few millimeters) and good enough to neuroanatomical-structures within the b r a i n. STN (size:12×5×3mm3) and lies nearby internal capsule, medial lemniscus, corticospinal tract, plus red-nucleus. Through sub optimal lead insertion and over stimuli, flow of electrons can spread to these adjoining sucortics, thereby developing dyskinesias ( ). With time, DW-MRI plus f-MRI is used to study the anatomical-structural functional connectivity in advanced idiopathic Parkinson`s. Contrasting conventional lesion based stimulus hypothesis, the novel net stimulus hypothesis advocated that induced stimulus of exact circuits of b r a i n can modulate pathophysiological net-work, reinstate near the tissue region, thus producing stabilization-of human-brain-connectome within Parkinson`s. The DBS connectomes makes use of circuit based stimulus procedure instead of lesion-based stimulus, has transformed neuromodulation. Connectomes via DBS can be tailor made for every Parkinson plus enhance the operation. It`s just a sketch for human-brain-connectivity (HMC) transversely compound longitudinal-scales. Yet, it won`t yield cell information plus cotacts with cells at the level of micro scale.

Frame-based versus robot-assisted stereo-electro-encephalography for drug-resistant epilepsy.

Stereoelectroencephalography (SEEG) is an effective presurgical invasive evaluation for drug-resistant epilepsies. The introduction of robotic devices provides a simplified, accurate, and safe alternative to the conventional SEEG technique. We report our institutional experience with robot-assisted SEEG and compare its in vivo accuracy, operation efficiency, and safety with the more traditional SEEG workflow. All patients with medically refractory focal epilepsy who underwent SEEG depth electrode implantation between 2014 and 2022 were included in this study. Technical advancements of the robot-assisted technique are described. Analyses of patient demographics, electrode implantation accuracy, operation time, and procedure-related complications were performed. One hundred and sixty-six patients underwent 167 SEEG procedures. The first 141 procedures were performed using a conventional approach involving a Leksell stereotactic system, and the last 26 procedures were robot-assisted. Among the 1726 depth electrodes that were inserted, the median entry point localization error was as follows: conventional (1.0mm; range, 0.1-33.5mm) and robot-assisted (1.1mm; range, 0-4.8mm) (P = 0.17). The median target point localization error was as follows: conventional (2.8mm; range, 0.1-49mm) and robot-assisted (1.8mm; range, 0-30.3mm) (P < 0.001). The median operation time was significantly reduced with the robot-assisted workflow (90min vs. 77.5min; P < 0.01). Total complication rates were as follows: conventional (17.7%) and robot-assisted (11.5%) (P = 0.57). Major complication rates were 3.5% and 7.7% (P = 0.77), respectively. SEEG is a safe and highly accurate method that provides essential guidance for epilepsy surgery. Implementing SEEG in conjunction with multimodal planning systems and robotic devices can further increase safety margin, surgical efficiency, and accuracy.

Usefulness of Robotic Stereotactic Assistance (ROSA®) Device for Stereoelectroencephalography Electrode Implantation: A Systematic Review and Meta-analysis.

The aim of this study was to systematically review and meta-analyze the efficiency and safety of using the Robotic Stereotactic Assistance (ROSA®) device (Zimmer Biomet; Warsaw, IN, USA) for stereoelectroencephalography (SEEG) electrode implantation in patients with drug-resistant epilepsy. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a literature search was carried out. Overall, 855 nonduplicate relevant articles were determined, and 15 of them were selected for analysis. The benefits of the ROSA® device use in terms of electrode placement accuracy, as well as operative time length, perioperative complications, and seizure outcomes, were evaluated. Studies that were included reported on a total of 11,257 SEEG electrode implantations. The limited number of comparative studies hindered the comprehensive evaluation of the electrode implantation accuracy. Compared with frame-based or navigation-assisted techniques, ROSA®-assisted SEEG electrode implantation provided significant benefits for reduction of both overall operative time (mean difference [MD], -63.45 min; 95% confidence interval [CI] from -88.73 to -38.17 min; P < 0.00001) and operative time per implanted electrode (MD, -8.79 min; 95% CI from -14.37 to -3.21 min; P = 0.002). No significant differences existed in perioperative complications and seizure outcomes after the application of the ROSA® device and other techniques for electrode implantation. To conclude, the available evidence shows that the ROSA® device is an effective and safe surgical tool for trajectory-guided SEEG electrode implantation in patients with drug-resistant epilepsy, offering benefits for saving operative time and neither increasing the risk of perioperative complications nor negatively impacting seizure outcomes.

The Association Between Trajectory-Skull Angle and Accuracy of Stereoelectroencephalography Electrode Implantation in Drug-Resistant Epilepsy

OBJECTIVETo analyze the relationship between trajectory-skull angle and stereoelectroencephalography (SEEG) electrode implantation accuracy in drug-resistant epilepsy patients, aiming to guide clinical electrode placement and enhance surgical precision and safety. METHODSWe conducted a retrospective analysis of medical records and surgical characteristics of 32 consecutive patients diagnosed with drug-resistant epilepsy, who underwent SEEG procedures at our center from June 2020 to June 2023. To evaluate the accuracy of electrode implantation, we utilized preoperative and postoperative CT scans fused with SinoPlan software-planned trajectories. Entry radial error and target vector error were assessed as measurements of electrode implantation accuracy. RESULTSAfter adjusting for confounders, we found a significant positive correlation between trajectory-skull angle and entry radial error (β=0.02, 95% CI: 0.01–0.03, P<0.001). Likewise, a significant positive correlation existed between trajectory-skull angle and target vector error in all three models (β=0.03, 95% CI: 0.01–0.04, P<0.001). Additionally, a U-shaped relationship between trajectory-skull angle and target vector error was identified using smooth curve fitting. This U-shaped pattern persisted in both frame-based and robot-guided stereotactic techniques. According to the two-piecewise linear regression model, the inflection points were 9° in the frame-based group and 16° in the robot-guided group. CONCLUSIONSThis study establishes a significant positive linear correlation between trajectory-skull angle and entry radial error, along with a distinctive U-shaped pattern in the relationship between trajectory-skull angle and target vector error. Our findings suggest that trajectory-skull angles of 9° (frame-based) and 16° (robot-guided) may optimize the accuracy of target vector error.

The efficacy analysis of neurosurgical robot-assisted DBS in the treatment of elderly Parkinson's disease

Objective: To investigate the surgical efficacy of neurosurgery robot deep brain stimulation(DBS) in the treatment of elderly Parkinson's disease(PD). Methods: The clinical data of elderly patients (≥75 years) with PD who underwent neurosurgical robot-assisted DBS surgery in the Department of Neurosurgery of the General Hospital of Northern Theater Command from September 2016 to September 2022 were collected retrospectively. Operation time, electrode implantation duration, postoperative pneumocephalus volume, electrode implantation accuracy, the Tao's DBS surgery scale, perioperative complications were analyzed.The unified Parkinson's disease rating scales (UPDRS), UPDRS-Ⅲ, tremor, rigidity, bradykinesia, axial, Barthel Activities of Daily Living (ADL-Barthel), Levodopa Equivalent Daily Dose (LEDD), Montreal Cognitive Assessment (MoCA), Hamilton Anxiety Scale (HAMA) and Hamilton Depression Scale (HAMD) scores and mortality were assessed respectively before operation, 6, 12 and 24 months after operation and last follow-up. Results: A total of 25 elderly patients were enrolled, including 14 males and 11 females, aged(78.3±3.2) years. Nine patients had underlying diseases. Nine patients (36%) underwent bilateral Globus Pallidus pars Interna deep brain stimulation (GPi-DBS) and 16 patients (64%) underwent bilateral subthalamic nucleus deep brain stimulation (STN-DBS).The operation time was (1.56±0.19) hours, the electrode implantation duration was (1.01±0.19) hours, the pneumocephalus volume was 9.8(4.7, 23.3) cm3, and the electrode implantation accuracy was (0.84±0.24) mm, the Tao's DBS surgery scale was (80.2±6.2).The follow-up time [M(Q1, Q3)] was 57.3(27.9, 75.7) months. No serious complications such as intracranial hemorrhage, infection or poor wound healing occurred during the perioperative period. The improvement rate of UPDRS, UPDRS-Ⅲ, rigidity, bradykinesia, and LEDD at 6 months after surgery was significantly higher than that at 24 months after surgery and at the last follow-up (all P<0.05); the improvement rate of axial symptoms, ADL-Barthel score, and MoCA score at 6 months after surgery was significantly higher than that at the last follow-up (P<0.05). HAMD and HAMA scores showed no significant improvement during follow-up after surgery (both P>0.05). At the last follow-up, 12 patients died, with death time of (35.1±20.2) months after operation, and the death age of [M(Q1, Q3)] 80(79, 83)years. Conclusions: Robot-assisted DBS surgery for elderly patients with PD is accurate and safe, and the postoperative symptoms are significantly improved, and they can benefit from neuromodulation for long term, and the risks are controllable.

Frameless robot-assisted stereoelectroencephalography-guided radiofrequency: methodology, results, complications and stereotactic application accuracy in pediatric hypothalamic hamartomas

ObjectiveWe aimed to investigate the methodology, results, complications and stereotactic application accuracy of electrode implantation and its explanatory variables in stereoelectroencephalography-guided radiofrequency thermocoagulation (SEEG-RFTC) for pediatric hypothalamic hamartoma.MethodsChildren with hypothalamic hamartoma who underwent robot-assisted SEEG-RFTC between December 2017 and November 2021 were retrospectively analyzed. The methodology, seizure outcome, complications, in vivo accuracy of electrode implantation and its explanatory variables were analyzed.ResultsA total of 161 electrodes were implanted in 28 patients with 30 surgeries. Nine electrodes not following the planned trajectories due to intraoperative replanning were excluded, and the entry point and target point errors of 152 electrodes were statistically analyzed. The median entry point error was 0.87 mm (interquartile range, 0.50–1.41 mm), and the median target point error was 2.74 mm (interquartile range, 2.01–3.63 mm). Multifactor analysis showed that whether the electrode was bent (b = 2.16, p &amp;lt; 0.001), the length of the intracranial electrode (b = 0.02, p = 0.049), and the entry point error (b = 0.337, p = 0.017) had statistically significant effects on the target error. During follow-up (mean duration 31 months), 27 of 30 (90%) procedures were seizure-free. The implantation-related complication rate was 2.6% (4/152), and the major complication rate in all procedures was 6.7% (2/30).ConclusionRobot-assisted SEEG-RFTC is a safe, effective and accurate procedure for pediatric hypothalamic hamartoma. Explanatory variables significantly associated with the target point localization error at multivariate analysis include whether the intracranial electrode is bent, the intracranial electrode length and the entry point error.

Accuracy of Subthalamic Nucleus Electrode Implantation in Deep Brain Stimulation Surgery for Parkinson's Disease Treatment and Affecting Factors: Outcomes at Two Centers in Vietnam

Deep brain stimulation (DBS) surgery for Parkinson's Disease (PD) has become more and more popular in Vietnam. However, the accuracy of implantation and affecting factors are under investigation. The objective of this study is to evaluate the accuracy of the subthalamic nucleus (STN)-DBS electrode implantation technique for treatment PD at Nguyen Tri Phuong Hospital and University Medical Center. To investigate factors related to accuracy. We carried out a retrospective analysis of 58 patients with advanced PD who underwent STN-DBS surgery at Nguyen Tri Phuong Hospital and University Medical Center in Ho Chi Minh City, Viet Nam between June 2014 and July 2021 (115 leads total). All patients underwent the procedure with standard frame-based techniques under local anesthesia with microelectrode recording and macrostimuation test. Twenty-six female (44.8%) and thirty-two male (55.2%) patients with a mean age of 60.4 ± 8.3 years old (40-76 years) were included. Of total of 115 electrodes implanted, the mean target error (ΔT), radial error (ΔR), angle error (Δθ) were 1.94 ± 0.73 mm; 1.16 ± 0.69 mm; 2.22 ± 4.24 degrees, respectively. Vector error on each coordinate axis ΔX, ΔY, ΔZ were-0.35 ± 1.02 mm,+0.99 ± 0.82 mm,+0.73 ± 0.99 mm, respectively. There was a statistically significant correlation between subdural air volume, cortical shift, intracranial electrode bending, and accuracy. The current STN-DBS electrode implantation technique applied in our centers was quite accurate with acceptable error. More clinical trials are necessary to directly compare affecting factors to the accuracy of electrode implantation.

Intraoperative microelectrode recording under general anesthesia guided subthalamic nucleus deep brain stimulation for Parkinson's disease: One institution's experience.

Microelectrode recording (MER) guided subthalamic nucleus deep brain stimulation (STN-DBS) under local anesthesia (LA) is widely applied in the management of advanced Parkinson's disease (PD). Whereas, awake DBS under LA is painful and burdensome for PD patients. We analyzed the influence of general anesthesia (GA) on intraoperative MER, to assess the feasibility and effectiveness of GA in MER guided STN-DBS. Retrospective analysis was performed on the PD patients, who underwent bilateral MER guided STN-DBS in Wuhan Union Hospital from July 2019 to December 2021. The patients were assigned to LA or GA group according to the anesthetic methods implemented. Multidimensional parameters, including MER signals, electrode implantation accuracy, clinical outcome and adverse events, were analyzed. A total of 40 PD patients were enrolled in this study, including 18 in LA group and 22 in GA group. There were no statistically significant differences in patient demographics and baseline characteristics between two groups. Although, the parameters of MER signal, including frequency, inter-spike interval (ISI) and amplitude, were obviously interfered under GA, the waveforms of MER signals were recognizable and shared similar characteristics with LA group. Both LA and GA could achieve effective electrode implantation accuracy and clinical outcome. They also shared similar adverse events postoperatively. GA is viable and comparable to LA in MER guided STN-DBS for PD, regarding electrode implantation accuracy, clinical outcome and adverse events. Notably, GA is more friendly and acceptable to the patients who are incapable of enduring intraoperative MER under LA.

A Clinical Study of Patients with Primary Parkinson's Disease Undergoing Bilateral Deep Brain Stimulation (STN-DBS) Surgery in the Subthalamic Nucleus under General Anesthesia

To assess the efficacy and safety of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) under general anesthesia and to provide the basis for clinical research related to DBS surgeries under general anesthesia. A total of 60 patients with primary Parkinson's disease who underwent DBS surgery between January 2019 and December 2021at West China Hospital were enrolled for the study. Among them, 30 had the surgery while they were asleep, i.e., under general anesthesia, and 30, while they were awake, i.e., under local anesthesia. All the patients underwent bilateral STN-DBS surgery. Bispectral index (BIS) was used to monitor and control the depth of anesthesia. Microelectrode recording (MER) technology was used to record the characteristic signals of the bilateral subthalamic nuclei and verify their location during the operation. All patients completed the implantation of deep electrodes, connecting wires, and implantable stimulation generator (IPG) at one time. Postoperative thin-slice CT scans were done to reconstruct electrode images and to verify the accuracy of electrode implantation. The Unified Parkinson's Disease Rating Scale-Ⅲ (UPDRS-Ⅲ) was used to evaluate the preoperative vs. postoperative improvement in motor symptoms, and the results of intraoperative MER and the occurrence of surgery-related complications were documented and analyzed. All patients successfully completed the implantation surgery. The electrodes were accurately implanted at the right position and there was no significant difference between the general anesthesia group and the local anesthesia group in UPDRS-Ⅲ scores and medication dosage differences before and after the operation. No intracranial hemorrhage, cerebral infarction, or infection occurred after the operation, and 5 patients had temporary mental and behavioral abnormalities, which disappeared within 48 hours after the operation. The postoperative therapeutic effect of STN-DBS surgery for primary Parkinson's disease under general anesthesia is comparable to that of the traditional STN-DBS surgery under local anesthesia. When the operation is performed under general anesthesia, the incidence of surgery and anesthesia-related complications is low if patients are managed strictly, and patients would also experience improved surgical comfort.

The Effects of Different Anesthesia Methods on the Treatment of Parkinson's Disease by Bilateral Deep Brain Stimulation of the Subthalamic Nucleus.

BackgroundSubthalamic nucleus deep brain stimulation (STN–DBS) surgery for Parkinson’s disease (PD) is routinely performed at medical centers worldwide. However, it is debated whether general anesthesia (GA) or traditional local anesthetic (LA) is superior.PurposeThis study aims to compare the effects of LA and GA operation methods on clinical improvement in patients with PD, such as motor and non-motor symptoms, after STN–DBS surgery at our center.MethodA total of 157 patients with PD were retrospectively identified as having undergone surgery under LA (n = 81) or GA (n = 76) states. In this study, the Unified Parkinson’s Disease Rating Scale Motor Score (UPDRS-III) in three states, levodopa-equivalent-daily-dose (LEDD), surgical duration, intraoperative microelectrode recording (iMER) signal length, postoperative intracranial volume, electrode implantation error, neuropsychological function, quality of life scores, and complication rates were collected and compared. All patients with PD were routinely followed up at 6, 12, 18, and 24 months postoperatively.ResultOverall improvement in UPDRS-III was demonstrated at postoperative follow-up, and there was no significant difference between the two groups in medication-off, stimulation-off state and medication-off, stimulation-on state. However, UPDRS-III scores in medication-on, stimulation-on state under GA was significantly lower than that in the LA group. During postoperative follow-up, LEDD in the LA group (6, 12, 18, and 24 months, postoperatively) was significantly lower than in the GA group. However, there were no significant differences at baseline or 1-month between the two groups. The GA group had a shorter surgical duration, lower intracranial volume, and longer iMER signal length than the LA group. However, there was no significant group difference in electrode implantation accuracy and complication rates. Additionally, the Hamilton Anxiety Scale (HAMA) was significantly lower in the GA group than the LA group at 1-month follow-up, but this difference disappeared at longer follow-up. Besides, there was no significant group difference in the 39-item Parkinson’s Disease Questionnaire (PDQ-39) scale scores.ConclusionAlthough both groups showed overall motor function improvement without a significant postoperative difference, the GA group seemed superior in surgical duration, intracranial volume, and iMER signal length. As the accuracy of electrode implantation can be ensured by iMER monitoring, DBS with GA will become more widely accepted.

Sinovation SR1-3D surgery robot-assisted subthalamic nucleus deep brain stimulation in Parkinson's disease

ObjectiveTo summarize and think about the surgical process of subthalamic nucleus deep brain stimulation assisted by Sinovation SR1-3D surgery robot in Parkinson's disease patients. MethodsTo summarize the clinical data, preoperative preparations, surgical procedures, and postoperative recovery of a Parkinson's patient who underwent robot-assisted deep brain stimulation in Jiangxi Provincial People's Hospital in 2021. Discussion to guide future clinical work. ResultsWith the assistance of the robot, the deep electrode was accurately implanted in the designated position. The postoperative symptoms of the patient were improved, and there were no obvious postoperative complications. ConclusionIn deep brain stimulation surgery, the use of robots can improve the accuracy of electrode implantation, improve patient symptoms, and reduce postoperative complications.

Targeting accuracy of robot-assisted deep brain stimulation surgery in childhood-onset dystonia: a single-center prospective cohort analysis of 45 consecutive cases.

Deep brain stimulation (DBS) is an established treatment for pediatric dystonia. The accuracy of electrode implantation is multifactorial and remains a challenge in this age group, mainly due to smaller anatomical targets in very young patients compared to adults, and also due to anatomical abnormalities frequently associated with some etiologies of dystonia. Data on the accuracy of robot-assisted DBS surgery in children are limited. The aim of the current paper was to assess the accuracy of robot-assisted implantation of DBS leads in a series of patients with childhood-onset dystonia. Forty-five children with dystonia undergoing implantation of DBS leads under general anesthesia between 2017 and 2019 were included. Robot-assisted stereotactic implantation of the DBS leads was performed. The final position of the electrodes was verified with an intraoperative 3D scanner (O-arm). Coordinates of the planned electrode target and actual electrode position were obtained and compared, looking at the radial error, depth error, absolute error, and directional error, as well as the euclidean distance. Functional assessment data prospectively collected by a multidisciplinary pediatric complex motor disorders team were analyzed with regard to motor skills, individualized goal achievement, and patients' and caregivers' expectations. A total of 90 DBS electrodes were implanted and 48.5% of the patients were female. The mean age was 11.0 ± 0.6 years (range 3-18 years). All patients received bilateral DBS electrodes into the globus pallidus internus. The median absolute errors in x-, y-, and z-axes were 0.85 mm (range 0.00-3.25 mm), 0.75 mm (range 0.05-2.45 mm), and 0.75 mm (range 0.00-3.50 mm), respectively. The median euclidean distance from the target to the actual electrode position was 1.69 ± 0.92 mm, and the median radial error was 1.21 ± 0.79. The robot-assisted technique was easily integrated into the authors' surgical practice, improving accuracy and efficiency, and reducing surgical time significantly along the learning curve. No major perioperative complications occurred. Robot-assisted stereotactic implantation of DBS electrodes in the pediatric age group is a safe and accurate surgical method. Greater accuracy was present in this cohort in comparison to previous studies in which conventional stereotactic frame-based techniques were used. Robotic DBS surgery and neuroradiological advances may result in further improvement in surgical targeting and, consequently, in better clinical outcome in the pediatric population.

Neuromodulation of the Pudendal Nerve Assisted by 3D Printed: A New Method of Neuromodulation for Lower Urinary Tract Dysfunction

Electrical stimulation of peripheral nerves by implanted electrodes is an effective treatment for certain pelvic floor diseases. As well as intravesical electrical stimulation, this predominantly includes stimulation of the sacral nerve, tibial nerve, and pudendal nerve. The pudendal nerve is one of the main nerves that stimulate pelvic floor muscles, external urethral meatus, and the anal sphincter and pelvic organs, and it may have effects on frequent urination, urgency, dysuria, and perineal pain. It is difficult to locate because of its anatomical course, however, leading to difficulties fixing the electrode, which increases the difficulty of pudendal nerve electrical stimulation in clinical practice. In the current study 3D printed navigation was used to solve these problems. Combined with autopsy data and patient pelvic and nerve data, a personalized design was generated. Neural modulation of the pudendal nerve was achieved by implanting the lead with the guidance of 3D printed navigation. 3D printed navigation can maximize the phase II conversion rate, reduce the difficulty of surgery, shorten the operation time, reduce damage to additional organs and blood vessels, and increase the accuracy of electrode implantation, and it can be performed while the patient is awake. It is an accurate, reversible, efficient, and minimally invasive surgery.

A comparative study of asleep and awake deep brain stimulation robot-assisted surgery for Parkinson\u2019s disease

To compare the differences between asleep and awake robot-assisted deep brain stimulation (DBS) surgery for Parkinson’s Disease (PD), we conducted this retrospective cohort study included 153 PD patients undergoing bilateral robot-assisted DBS from June 2017 to August 2019, of which 58 cases were performed under general anesthesia (GA) and 95 cases under local anesthesia (LA). Procedure duration, stimulation parameters, electrode implantation accuracy, intracranial air, intraoperative electrophysiological signal length, complications, and Unified PD Rating Scale (UPDRS) measurements were recorded and compared. The clinical evaluation was conducted by two raters who were blinded to the choice of anesthesia. Procedure duration was significantly shorter in the GA group, while on stimulation off medication motor scores (UPDRS-III) were significantly improved in both the GA and LA group. ANCOVA covariated for the baseline UPDRS-III and levodopa challenge exhibited no significant differences. In terms of amplitude, frequency, and pulse width, the stimulation parameters used for DBS power-on were similar. There were no significant differences in electrode implantation accuracy, intraoperative electrophysiological signal length, or intracerebral hemorrhage (no occurrences in either group). The pneumocephalus volume was significantly smaller in the GA group. Six patients exhibited transient throat discomfort associated with tracheal intubation in the GA group. The occurrence of surgical incision infection was similar in both groups. Compared with the awake group, the asleep group exhibited a shorter procedure duration with a similar electrode implantation accuracy and short-term motor improvement. Robot-assisted asleep DBS surgery is a promising surgical method for PD.

Stereoencephalography Electrode Placement Accuracy and Utility Using a Frameless Insertion Platform Without a Rigid Cannula.

Implantation of depth electrodes to localize epileptogenic foci in patients with drug-resistant epilepsy can be accomplished using traditional rigid frame-based, custom frameless, and robotic stereotactic systems. To evaluate the accuracy of electrode implantation using the FHC microTargeting platform, a custom frameless platform, without a rigid insertion cannula. A total of 182 depth electrodes were implanted in 13 consecutive patients who underwent stereoelectroencephalography (SEEG) for drug-resistant epilepsy using the microTargeting platform and depth electrodes without a rigid guide cannula. MATLAB was utilized to evaluate targeting accuracy. Three manual coordinate measurements with high inter-rater reliability were averaged. Patients were predominantly male (77%) with average age 35.62 (SD 11.0, range 21-57) and average age of epilepsy onset at 13.4 (SD 7.2, range 3-26). A mean of 14 electrodes were implanted (range 10-18). Mean operative time was 144 min (range 104-176). Implantation of 3 out of 182 electrodes resulted in nonoperative hemorrhage (2 small subdural hematomas and one small subarachnoid hemorrhage). Putative location of onset was identified in all patients. We demonstrated a median lateral target point localization error (LTPLE) of 3.95 mm (IQR 2.18-6.23), a lateral entry point localization error (LEPLE) of 1.98 mm (IQR 1.2-2.85), a target depth error of 1.71 mm (IQR 1.03-2.33), and total target point localization error (TPLE) of 4.95 mm (IQR 2.98-6.85). Utilization of the FHC microTargeting platform without the use of insertion cannulae is safe, effective, and accurate. Localization of seizure foci was accomplished in all patients and accuracy of depth electrode placement was satisfactory.

Correlation analysis between intracranial air and electrode implantation accuracy in DBS

Objective: To analyze the correlation between intracranial air and electrode displacement after deep brain stimulation. Compared the accuracy of the electrodes on both sides while bilateral intracranial air. Methods: A total of 133 patients with bilateral DBS from February 2017 to February 2019 in neurosurgery department of the General Hospital of Northern Theater Command were included. A total of 266 electrodes were implanted, including 160 sides of subthalamic nucleus, 2 sides of ventromedial nucleus of thalamus and 104 sides of Globus pallidus interior. All patients underwent three-dimensional reconstruction of the head 2 hours after operation and 1 week after operation, which was fused with the preoperative surgical plan.The volume of the intracranial air is obtained by summing up the CT layer-by-layer measurements after surgery. The distance between the implanted electrode and the preoperative target on the X and Y axes in the target plane is measured.Values were expressed as means±SEM,and the t test was performed. Bivariate correlation analysis using linear correlation analysis.P<0.05 was considered statistically significant. Results: There was no statistically significant difference in the fusion error of the electrode between 2 hours and 1 week after surgery on the X-axis. But there was significant difference on the Y-axis. The difference between intracranial air volume and two fusion errors was not linearly correlated on X axis, but linearly positively correlated on Y axis. Conclusion: Intracranial air volume is an important factor affecting the accuracy of DBS surgery. The larger intracranial air volume, the larger the displacement of electrodes on Y axis.

Analysis of intra-operative target location of subthalamic nucleus in deep brain stimulation surgery for Parkinson′s disease with bispectral index monitoring under general anesthesia

Objective To explore the feasibility of using electrophysiology to locate STN targets in the treatment of Parkinson′s disease (PD) by deep brain stimulation (DBS) with bispectral index (BIS) monitoring under general anesthesia. Methods The data of 22 PD patients treated by bilateral STN-DBS at Department of Neurosurgery, the First Hospital of China Medical University from September 2017 to May 2019 were retrospectively analyzed. All patients completed surgery with BIS monitoring under general anesthesia. All STN nuclei were located based on microelectrode recording (MER). Postoperative MRI was fused with preoperative MRI to evaluate the accuracy of electrode implantation. Results The discharge in the sensory-motor area of STN were recorded by MER in all 44 sides during asleep DBS. Microelectrodes were implanted and STN electrophysiological signals were recorded for 40 sides when BIS value was maintained above 70. For the other 4 sides when BIS value was maintained between 30 and 60, and the discharge frequency and amplitude were only about 50% of those when BIS value was maintained above 70. The electrophysiological length of STN was 3.5-7.5(5.2±0.9) mm on the right side and 3.5-7.5(5.5±1.0)mm on the left side, respectively. After intracranial electrode was implanted and when BIS value ≥80, 18 patients could complete the stimulation test for clinical symptoms and side effects, and 4 patients could only complete the test for motor side effects. Postoperative MRI showed that all electrode targets were located in STN nucleus, and the radial error was (1.10±0.45)mm on the right side and (1.24±0.56)mm on the left side. No intracranial hemorrhage, infection or other complications occurred. Conclusions During the surgery of asleep STN-DBS, clear and typical STN discharge could be recorded in MER with BIS (≥70) monitoring. The target localization seems accurate. Key words: Parkinson disease; Anesthesia, general; Deep brain stimulation; Bispectral index; Microelectrode recording

Precision study of stereotactic electroencephalograph electrode implantation under neuronavigation in children with refractory epilepsy

Objective To explore the accuracy of stereotactic electroencephalograph (SEEG) electrode implantation under neuronavigation in children with refractory epilepsy. Methods Twenty-one children with refractory epilepsy underwent SEEG electrode implantation for identification of epileptogenic zone at Neurosurgery Department of Shenzhen Children's Hospital from March 2016 to December 2017 and were retrospective enrolled into this study MR surface registration and CT registration with anatomic markers were used for the electrode implantation. The accuracy of electrode implantation was compared between the 2 registration methods. The correlation between the depth of electrode implantation (the distance from cortical entry point to target) and the error of target and the error of entry point was analyzed. Results A total of 139 electrodes were implanted in 21 patients. Among them, 56 electrodes were implanted by MR surface registration method, and 83 implanted electrodes were placed by CT anatomical marker registration method. The registration time, registration error, electrode entry error and target error of MR Surface registration group were (37±9) min, (2.3±0.5) mm, (2.7±0.7) mm and (3.1±0.5) mm; those in anatomical marker registration group were (10±4) min, (1.1±0.3) mm, (1.5±0.5) mm, (2.2±0.6) mm respectively. The differences were statistically significant (all P<0.05) in the comparison between the 2 groups. In 139 electrodes, the electrode implantation depth was (4.7±1.7) mm, the entry point error was (2.1±1.3) mm, and the target error was (2.8±1.2) mm. Correlation analysis showed that the depth of electrode implantation was positively correlated with the target error (r=0.57, P=0.034), and there was no correlation with the error of the entry point (r=0.27, P=0.121). None of the patients had complications such as bleeding and infection after electrode implantation. After epileptogenic zonectomy, all patients were followed up for 6 months and included 20 cases as Engel Ⅰ and 1 case as Engel Ⅱ. Conclusion In children with refractory epilepsy, the accuracy of SEEG electrode implantation under neuronavigation seems to be relatively high. Compared with MR surface registration method, the registration efficiency and the accuracy of electrode implantation can be improved by using CT anatomical marker registration. Key words: Epilepsy; Child; Error; Neuronavigation; Stereoelectroencephalography

Techniques for placement of stereotactic electroencephalographic depth electrodes: Comparison of implantation and tracking accuracies in a cadaveric human study.

Stereotactic electroencephalography (SEEG) is used for the evaluation and identification of the epileptogenic zone (EZ) in patients suffering from medically refractory seizures and relies upon the accurate implantation of depth electrodes. Accurate implantation is critical for identification of the EZ. Multiple electrodes and implantation systems exist, but these have not previously been systematically evaluated for implantation accuracy. This study compares the accuracy of two SEEG electrode implantation methods. Thirteen "technique 1" electrodes (applying guiding bolts and external stylets) and 13 "technique 2" electrodes (without guiding bolts and external stylets) were implanted into four cadaver heads (52 total of each) according to each product's instructions for use using a stereotactic robot. Postimplantation computed tomography scans were compared to preimplantation computed tomography scans and to the previously defined targets. Electrode entry and final depth location were measured by Euclidean coordinates. The mean errors of each technique were compared using linear mixed effects models. Primary analysis revealed that the mean error difference of the technique 1 and 2 electrodes at entry and target favored the technique 1 electrode implantation accuracy (P<0.001). Secondary analysis demonstrated that orthogonal implantation trajectories were more accurate than oblique trajectories at entry for technique 1 electrodes (P=0.002). Furthermore, deep implantations were significantly less accurate than shallow implantations for technique 2 electrodes (P=0.005), but not for technique 1 electrodes (P=0.50). Technique 1 displays greater accuracy following SEEG electrode implantation into human cadaver heads. Increased implantation accuracy may lead to increased success in identifying the EZ and increased seizure freedom rates following surgery.

S92 Intraoperative electrophysiological examinations during deep brain stimulation: Its role and controversies

In the present lecture we provide an overview on the electrophysiological procedures (microelectrode recording and intraoperative stimulation) during deep brain stimulation surgery. The technical requirements and the improvements during microelectrode recording will be also discussed. Currently there are conflicting data on the role of microelectrode recording during deep brain stimulation electrode implantation. Whereas, some centers never perform microelectrode recording during DBS surgery, others claim that it may improve the accuracy of electrode implantation and is associated with better outcome and meaningful clinical benefit. On the other hand, some data suggest that microelectrode recording can increase the risk of intraoperative hemorrhage while other data do not support this theory. In the lecture, all of these controversial issues will be covered.