The value of SINO robot combined with Angio Render technology-assisted stereo-electroencephalography electrode implantation for the treatment of drug-resistant epilepsy.

BACKGROUND AND OBJECTIVE: Stereo-electroencephalography (SEEG) electrodes are implanted using a variety of stereotactic technologies to treat refractory epilepsy. The value of SINO-robot for SEEG electrode implantation is rarely reported. The aim of the current study was to assess the value of SINO-robot in conjunction with Angio Render technology, in SEEG electrode implantation. We also assess its efficacy by examining factors such as localization error, operation time, and complications. METHODS: Between June 2018 and October 2020, we retrospectively reviewed 58 patients who underwent SEEG implantation to resect or ablate their epileptogenic zone (EZ) while minimizing the risk of hemorrhage. SINO-robot combined with Angio Render technology-assisted SEEG electrode implantation was used to visualize each patient' blood vessel in a 3D plane. The 3D view functionality was used to increase the safety and accuracy of the implantation, and reducing the risk of hemorrhage by avoiding said blood vessel. RESULTS: In this study, 634 SEEG electrodes were implanted in 58 patients. The mean 10.92(range 5- 18) leads per patient. The mean entry point localization error (EPLE) was 0.94 ± 0.23 mm (range: 0.39- 1.63 mm), and the mean target point localization error (TPLE) was 1.49 ± 0.37 mm (range: 0.80-2.78 mm). The mean operating time per lead (MOTPL) was 6. 18 ± 1.80 min (range: 3.02- 14.61 min). And the mean depth of electrodes was 56.96± 3.62 mm (range:27.23-124.85 mm). At a follow-up of at least one year, totally 81.57% (47/58) of patients achieved an Engel class I of seizure freedom. There were 2 patients with asymptomatic brain hematomas following SEEG placement, and no late complications or mortality in this cohort. CONCLUSIONS: SINO-robot in conjunction with Angio Render technology assist, in SEEG electrode implantation is safe and accurate in mitigating the risk of intracranial hemorrhage in patients suffering from drug-resistant epilepsy.

Evaluation of MRI post-processing methods combined with PET in detecting focal cortical dysplasia lesions for patients with MRI-negative epilepsy.

OBJECTIVE: Accurate detection of focal cortical dysplasia (FCD) through magnetic resonance imaging (MRI) plays a pivotal role in the preoperative assessment of epilepsy. The integration of multimodal imaging has demonstrated substantial value in both diagnosing FCD and devising effective surgical strategies. This study aimed to enhance MRI post-processing by incorporating positron emission tomography (PET) analysis. We sought to compare the diagnostic efficacy of diverse image post-processing methodologies in patients presenting MRI-negative FCD. METHODS: In this retrospective investigation, we assembled a cohort of patients with negative preoperative MRI results. T1-weighted volumetric sequences were subjected to morphometric analysis program (MAP) and composite parametric map (CPM) post-processing techniques. We independently co-registered images derived from various methods with PET scans. The alignment was subsequently evaluated, and its correlation was correlated with postoperative seizure outcomes. RESULTS: A total of 41 patients were enrolled in the study. In the PET-MAP(p = 0.0189) and PET-CPM(p = 0.00041) groups, compared with the non-overlap group, the overlap group significantly associated with better postoperative outcomes. In PET(p = 0.234), CPM(p = 0.686) and MAP(p = 0.672), there is no statistical significance between overlap and seizure-free outcomes. The sensitivity of using the CPM alone outperformed the MAP (0.65 vs 0.46). The use of PET-CPM demonstrated superior sensitivity (0.96), positive predictive value (0.83), and negative predictive value (0.91), whereas the MAP displayed superior specificity (0.71). CONCLUSIONS: Our findings suggested a superiority in sensitivity of CPM in detecting potential FCD lesions compared to MAP, especially when it is used in combination with PET for diagnosis of MRI-negative epilepsy patients. Moreover, we confirmed the superiority of synergizing metabolic imaging (PET) with quantitative maps derived from structural imaging (MAP or CPM) to enhance the identification of subtle epileptogenic zones (EZs). This study serves to illuminate the potential of integrated multimodal techniques in advancing our capability to pinpoint elusive pathological features in epilepsy cases.

Diffusion spectrum imaging based semi-automatic optic radiation tractography for vision preservation in SEEG-guided radiofrequency thermocoagulation.

OBJECTIVE: To assess the efficacy and safety of stereoelectroencephalography (SEEG)-guided radiofrequency thermocoagulation (RFTC), using diffusion spectrum imaging (DSI) tractography to preoperatively delineate the optic radiation (OR) and reduce the risk of visual field defects (VFDs) where the epileptogenic zones (EZs) are located in or close to the eloquent visual areas. METHODS: We prospectively followed up twenty-four consecutive patients (12 males and 12 females) who underwent SEEG-guided RFTC in or near the OR pathway. A distance of ≥ 3.5 mm away from the OR on the targeted electrodes contacts that exhibited relevant ictal onset patterns, IEDs and EES during SEEG recordings, was required as our selection criterion prior to performing RFTC, enough to theoretically prevent VFDs. Using default tracking parameters, the optic radiation was tracked semi-automatically in DSI-studio. RESULTS: There were 12 male and 12 female patients ranging in age from 6 to 57 years, with follow-up period ranging from 6 to 37 months. Nineteen patients responded to RFTC (R+, 79.16 %), and 5 patients did not benefit from RFTC (R-, 20.83 %). The preoperative application of DSI semi-automatic based OR tractography was successful in the protection of the OR in all 24 patients. Three patients experienced a neurologic deficit following RFTC, and five patients had a partial quadrant visual field deficit prior to surgery that did not worsen, and none of the remaining nineteen patients had a quadrant visual field deficit. CONCLUSION: Our study validates the safety and efficacy of SEEG-RFTC as a viable therapeutic approach for epileptic foci situated in or adjacent to the visual eloquent regions. We demonstrate that DSI-based tractography offers superior precision in delineating the OR compared to DTI. We establish that implementing a criterion of a minimum distance of ≥ 3.5 mm in radius from the OR on the targeted electrode contacts prior to conducting RFTC can effectively mitigate the risk of VFDs.

Managing delayed or missed pregabalin doses in patients with focal epilepsy: a Monte Carlo simulation study.

BACKGROUND: Delayed or missed doses are inevitable in epilepsy pharmacotherapy. The current remedial measures recommended by the United States Food and Drug Administration (FDA) for non-adherence are generic and lack clinical evidence. AIM: To assess remedial strategies for delayed or missed pregabalin doses in patients with epilepsy using Monte Carlo simulations. METHOD: Monte Carlo simulations were performed using a published population pharmacokinetic model for pregabalin. The applicability of five proposed remedial regimens as well as FDA recommendations was evaluated by simulating various poor adherence scenarios in eight populations, including those with renal dysfunction. RESULTS: All proposed remedial strategies were associated with delay duration and renal function. When delays are relatively short, an immediate regular dose is advised. The cut-off time points for taking the regular dose as a remedial regimen were 1, 2, 4, and 12 h for patients with mild renal impairment and normal renal function, moderate renal impairment, severe renal impairment, and end-stage renal disease, respectively. However, when delay aligns closely with a dosing interval, a regular dose combined with a partial dose proves effective. Generally, supplementing 1.3-fold the regular dose at the next scheduled time adequately compensates for the missed dose. CONCLUSION: Model-based simulations provided quantitative evidence for the effectiveness and feasibility of remedial strategies for missed or delayed pregabalin doses.

Preserved microstructural integrity of the corticospinal tract in patients with glioma-induced motor epilepsy: a study using mean apparent propagator magnetic resonance imaging.

BACKGROUND: To compare the microstructural integrity of the corticospinal tract (CST) between glioma patients with motor epilepsy and without epilepsy using mean apparent propagator magnetic resonance imaging (MAP-MRI). METHODS: A total of 26 patients with glioma adjacent to the CST pathway (10 with motor epilepsy and 16 without epilepsy) and 13 matched healthy controls underwent brain structural and diffusion MRI. The morphological characteristics of the CST (tract volume, tract number, and average length) were extracted, and diffusion parameter values including mean squared displacement (MSD), q-space inverse variance (QIV), return-to-origin probability (RTOP), return-to-axis probabilities (RTAP), return-to-plane probabilities (RTPP), fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) along the CST were evaluated. The CST features were compared between healthy and affected sides and the relative CST features were compared across the three groups of participants. A receiver operating characteristic (ROC) curve was plotted to assess the performance of each relative CST characteristic for glioma-induced CST changes. RESULTS: For patients without epilepsy, the tract number, tract volume, FA, RD, MSD, QIV, and RTAP changed significantly on the affected CST side compared with those on the healthy CST side (P=0.002, 0.002, 0.030 0.017, 0.039, 0.044, and 0.002, respectively). In contrast, for patients with motor epilepsy, no significant difference was found between the affected and healthy side in almost all CST features except RTPP (P=0.028). Compared with patients with motor epilepsy, the relative tract number, tract volume, AD, and RTAP were significantly lower (P=0.027, 0.018, 0.040, and 0.027, respectively) in patients without epilepsy, and their areas under the curve (AUCs) were 0.763, 0.781, 0.744, and 0.763, respectively. No significant difference was found between patients with motor epilepsy and matched healthy controls. CONCLUSIONS: The MAP-MRI is a promising approach for evaluating CST changes. It provides additional information reflecting the microstructural complexity of the CST and demonstrates the preserved microstructural integrity of the CST in glioma patients with motor epilepsy.

Accuracy and Feasibility Analysis of SEEG Electrode Implantation using the VarioGuide Frameless Navigation System in Patients with Drug-Resistant Epilepsy.

OBJECTIVE: The objective of the study was to evaluate the feasibility and accuracy of frameless stereoelectroencephalography (SEEG) electrode implantation in patients with drug-resistant epilepsy using the VarioGuide system. METHODS: The VarioGuide frameless navigation system was used to implant SEEG electrodes in patients with medically drug-resistant epilepsy. Demographic data, surgery duration, number of electrodes, and complications were retrospectively analyzed. Accuracy was compared by measuring the distance between the planned and actual electrode positions as determined by postoperative computed tomography images. RESULTS: A total of 141 SEEG electrodes were implanted in 19 patients from May 2015 to December 2018 with an average of 7.42 (range: 4-10) leads per patient. The average entry point localization error (EPLE) was 1.96 ± 0.47 mm (range: 0.32-3.29) and average target point localization error (TPLE) was 2.47 ± 0.79 mm (range: 0.72-4.83). The average operating time per lead (OTPL) was 14.16 ± 2.68 minutes (range: 8.64-21.58). No complications occurred. CONCLUSION: The VarioGuide frameless navigation system can be an effective method for SEEG electrode implantation in patients with drug-resistant epilepsy, particularly when the electrodes are concentrated in a relatively small region and the number of implanted electrodes is small.