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Jorge Gonzalezmartinez - One of the best experts on this subject based on the ideXlab platform.
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Stereoelectroencephalography guided laser ablations in patients with neocortical pharmacoresistant focal epilepsy concept and operative technique
Operative Neurosurgery, 2018Co-Authors: Louis Ross, Imad Najm, Ahsa M Naduvil, Jua Ulacio, Jorge GonzalezmartinezAbstract:BACKGROUND Laser ablation surgery has had encouraging results in the treatment of multiple intracranial diseases including primary and metastatic brain tumors, radiation necrosis, and epilepsy. The use of the Stereoelectroencephalography (SEEG) method in combination with laser thermocoagulation therapy with the goal of modulating epileptic networks in patients with neocortical nonlesional phamacoresistant epilepsy has not been previously described. OBJECTIVE To describe the novel methodological and conceptual aspects related to SEEG-guided laser ablations in patients with magnetic resonance imaging (MRI)-negative pharmacoresistant neocortical focal epilepsy. METHODS Guided by previous SEEG intracranial data, a laser ablation probe was inserted by using a robotic guidance device in a 17-yr-old medically refractory epilepsy patient with difficult to localize seizures and nonlesional MRI. The laser applicator position was confirmed by MRI, targeting the left mesial rostral superior frontal gyrus. The ablation was performed under multiplanar digital imaging views and real-time thermal imaging and treatment estimates in each plane. A postablation MRI (contrasted T1 sequence) confirmed the ablation's location and size. RESULTS The entire procedure was achieved in approximately 100 min. The actual ablation was performed in less than 3 min. Approximately, additional 30 min preoperatively were used for positioning and robot registration. Precise placement of laser application (in comparison with preplanned trajectories) was achieved using the robotic guidance and confirmed by the intraoperative magnetic resonance images. No complications were reported. The patient has been seizure-free since surgery. The follow-up period is 20 mo. Two additional patients, treated with similar methodology, are also described. CONCLUSION The preliminary experience with the described method shows the feasibility of a unique combination of the SEEG methodology with laser thermocoagulation in patients with neocortical MRI-negative pharmacoresistant focal epilepsy.
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indications technique and safety profile of insular Stereoelectroencephalography electrode implantation in medically intractable epilepsy
Journal of Neurosurgery, 2017Co-Authors: Soha Alomar, Jeffrey P Mullin, Saksith Smithason, Jorge GonzalezmartinezAbstract:OBJECTIVE Insular epilepsy is relatively rare; however, exploring the insular cortex when preoperative workup raises the suspicion of insular epilepsy is of paramount importance for accurate localization of the epileptogenic zone and achievement of seizure freedom. The authors review their clinical experience with Stereoelectroencephalography (SEEG) electrode implantation in patients with medically intractable epilepsy and suspected insular involvement. METHODS A total of 198 consecutive cases in which patients underwent SEEG implantation with a total of 1556 electrodes between June 2009 and April 2013 were reviewed. The authors identified patients with suspected insular involvement based on seizure semiology, scalp EEG data, and preoperative imaging (MRI, PET, and SPECT or magnetoencephalography [MEG]). Patients with at least 1 insular electrode based on the postoperative 3D reconstruction of CT fused with the preoperative MRI were included. RESULTS One hundred thirty-five patients with suspected insular epilepsy underwent insular implantation of a total of 303 electrodes (1-6 insular electrodes per patient) with a total of 562 contacts. Two hundred sixty-eight electrodes (88.5%) were implanted orthogonally through the frontoparietal or temporal operculum (420 contacts). Thirty-five electrodes (11.5%) were implanted by means of an oblique trajectory either through a frontal or a parietal entry point (142 contacts). Nineteen patients (14.07%) had insular electrodes placed bilaterally. Twenty-three patients (17.04% of the insular implantation group and 11.6% of the whole SEEG cohort) were confirmed by SEEG to have ictal onset zones in the insula. None of the patients experienced any intracerebral hemorrhage related to the insular electrodes. After insular resection, 5 patients (33.3%) had Engel Class I outcomes, 6 patients (40%) had Engel Class II, 3 patients (20%) had Engel Class III, and 1 patient (6.66%) had Engel Class IV. CONCLUSIONS Insula exploration with stereotactically placed depth electrodes is a safe technique. Orthogonal electrodes are implanted when the hypothesis suggests opercular involvement; however, oblique electrodes allow a higher insular sampling rate.
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cortico cortical evoked potentials for sites of early versus late seizure spread in Stereoelectroencephalography
Epilepsy Research, 2015Co-Authors: Bradley C Lega, Imad Najm, William Bingaman, Sasha Dionisio, Patrick M Flanigan, Dileep Nair, Jorge GonzalezmartinezAbstract:Summary Cortico-cortical evoked potentials offer the possibility of understanding connectivity within seizure networks to improve diagnosis and more accurately identify candidates for seizure surgery. We sought to determine if cortico-cortical evoked potentials and post-stimulation oscillatory changes differ for sites of EARLY versus LATE ictal spread. 37 patients undergoing Stereoelectroencephalography were tested using a cortico-cortical evoked potential paradigm. All electrodes were classified according to the speed of ictal spread. EARLY spread sites were matched to a LATE spread site equidistant from the onset zone. Root-mean-square was used to quantify evoked responses and post-stimulation gamma band power and coherence were extracted and compared. Sites of EARLY spread exhibited significantly greater evoked responses after stimulation across all patients ( t (36)=2.973, p =0.004). Stimulation elicited enhanced gamma band activity at EARLY spread sites ( t (36)=2.61, p =0.03, FDR corrected); this gamma band oscillation was highly coherent with the onset zone. Cortico-cortical evoked potentials and post-stimulation changes in gamma band activity differ between sites of EARLY versus LATE ictal spread. The oscillatory changes can help visualize connectivity within the seizure network.
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Stereoelectroencephalography in children and adolescents with difficult to localize refractory focal epilepsy
Neurosurgery, 2014Co-Authors: Jorge Gonzalezmartinez, Juan Bulacio, Jeffrey P Mullin, Rei Enatsu, Imad Najm, Ajay Gupta, William Bingaman, Elaine Wyllie, Deepak LachhwaniAbstract:Background Although Stereoelectroencephalography (SEEG) has been shown to be a valuable tool for preoperative decision making in focal epilepsy, there are few reports addressing the utility and safety of SEEG methodology applied to children and adolescents. Objective To present the results of our early experience using SEEG in pediatric patients with difficult-to-localize epilepsy who were not considered candidates for subdural grid evaluation. Methods Thirty children and adolescents with the diagnosis of medically refractory focal epilepsy (not considered ideal candidates for subdural grids and strip placement) underwent SEEG implantation. Demographics, electrophysiological localization of the hypothetical epileptogenic zone, complications, and seizure outcome after resections were analyzed. Results Eighteen patients (60%) underwent resections after SEEG implantations. In patients who did not undergo resections (12 patients), reasons included failure to localize the epileptogenic zone (4 patients); multifocal epileptogenic zone (4 patients); epileptogenic zone located in eloquent cortex, preventing resection (3 patients); and improvement in seizures after the implantation (1 patient). In patients who subsequently underwent resections, 10 patients (55.5%) were seizure free (Engel class I) and 5 patients (27.7%) experienced seizure improvement (Engel class II or III) at the end of the follow-up period (mean, 25.9 months; range, 12 to 47 months). The complication rate in SEEG implantations was 3%. Conclusion The SEEG methodology is safe and should be considered in children/adolescents with difficult-to-localize epilepsy. When applied to highly complex and difficult-to-localize pediatric patients, SEEG may provide an additional opportunity for seizure freedom in association with a low morbidity rate.
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stereotactic placement of depth electrodes in medically intractable epilepsy
Journal of Neurosurgery, 2014Co-Authors: Jorge Gonzalezmartinez, Juan Bulacio, Jeffrey P Mullin, Sumeet Vadera, Gwyneth Hughes, Stephen E Jones, Rei Enatsu, Imad NajmAbstract:Object Despite its long-reported successful record, with almost 60 years of clinical use, the technical complexity regarding the placement of Stereoelectroencephalography (SEEG) depth electrodes may have contributed to the limited widespread application of the technique in centers outside Europe. The authors report on a simplified and novel SEEG surgical technique in the extraoperative mapping of refractory focal epilepsy. Methods The proposed technique was applied in patients with medically refractory focal epilepsy. Data regarding general demographic information, method of electrode implantation, time of implantation, number of implanted electrodes, seizure outcome after SEEG-guided resections, and complications were prospectively collected. Results From March 2009 to April 2012, 122 patients underwent SEEG depth electrode implantation at the Cleveland Clinic Epilepsy Center in which the authors' technique was used. There were 65 male and 57 female patients whose mean age was 33 years (range 5–68 years)...
Imad Najm - One of the best experts on this subject based on the ideXlab platform.
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Stereoelectroencephalography guided laser ablations in patients with neocortical pharmacoresistant focal epilepsy concept and operative technique
Operative Neurosurgery, 2018Co-Authors: Louis Ross, Imad Najm, Ahsa M Naduvil, Jua Ulacio, Jorge GonzalezmartinezAbstract:BACKGROUND Laser ablation surgery has had encouraging results in the treatment of multiple intracranial diseases including primary and metastatic brain tumors, radiation necrosis, and epilepsy. The use of the Stereoelectroencephalography (SEEG) method in combination with laser thermocoagulation therapy with the goal of modulating epileptic networks in patients with neocortical nonlesional phamacoresistant epilepsy has not been previously described. OBJECTIVE To describe the novel methodological and conceptual aspects related to SEEG-guided laser ablations in patients with magnetic resonance imaging (MRI)-negative pharmacoresistant neocortical focal epilepsy. METHODS Guided by previous SEEG intracranial data, a laser ablation probe was inserted by using a robotic guidance device in a 17-yr-old medically refractory epilepsy patient with difficult to localize seizures and nonlesional MRI. The laser applicator position was confirmed by MRI, targeting the left mesial rostral superior frontal gyrus. The ablation was performed under multiplanar digital imaging views and real-time thermal imaging and treatment estimates in each plane. A postablation MRI (contrasted T1 sequence) confirmed the ablation's location and size. RESULTS The entire procedure was achieved in approximately 100 min. The actual ablation was performed in less than 3 min. Approximately, additional 30 min preoperatively were used for positioning and robot registration. Precise placement of laser application (in comparison with preplanned trajectories) was achieved using the robotic guidance and confirmed by the intraoperative magnetic resonance images. No complications were reported. The patient has been seizure-free since surgery. The follow-up period is 20 mo. Two additional patients, treated with similar methodology, are also described. CONCLUSION The preliminary experience with the described method shows the feasibility of a unique combination of the SEEG methodology with laser thermocoagulation in patients with neocortical MRI-negative pharmacoresistant focal epilepsy.
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cortico cortical evoked potentials for sites of early versus late seizure spread in Stereoelectroencephalography
Epilepsy Research, 2015Co-Authors: Bradley C Lega, Imad Najm, William Bingaman, Sasha Dionisio, Patrick M Flanigan, Dileep Nair, Jorge GonzalezmartinezAbstract:Summary Cortico-cortical evoked potentials offer the possibility of understanding connectivity within seizure networks to improve diagnosis and more accurately identify candidates for seizure surgery. We sought to determine if cortico-cortical evoked potentials and post-stimulation oscillatory changes differ for sites of EARLY versus LATE ictal spread. 37 patients undergoing Stereoelectroencephalography were tested using a cortico-cortical evoked potential paradigm. All electrodes were classified according to the speed of ictal spread. EARLY spread sites were matched to a LATE spread site equidistant from the onset zone. Root-mean-square was used to quantify evoked responses and post-stimulation gamma band power and coherence were extracted and compared. Sites of EARLY spread exhibited significantly greater evoked responses after stimulation across all patients ( t (36)=2.973, p =0.004). Stimulation elicited enhanced gamma band activity at EARLY spread sites ( t (36)=2.61, p =0.03, FDR corrected); this gamma band oscillation was highly coherent with the onset zone. Cortico-cortical evoked potentials and post-stimulation changes in gamma band activity differ between sites of EARLY versus LATE ictal spread. The oscillatory changes can help visualize connectivity within the seizure network.
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Stereoelectroencephalography in children and adolescents with difficult to localize refractory focal epilepsy
Neurosurgery, 2014Co-Authors: Jorge Gonzalezmartinez, Juan Bulacio, Jeffrey P Mullin, Rei Enatsu, Imad Najm, Ajay Gupta, William Bingaman, Elaine Wyllie, Deepak LachhwaniAbstract:Background Although Stereoelectroencephalography (SEEG) has been shown to be a valuable tool for preoperative decision making in focal epilepsy, there are few reports addressing the utility and safety of SEEG methodology applied to children and adolescents. Objective To present the results of our early experience using SEEG in pediatric patients with difficult-to-localize epilepsy who were not considered candidates for subdural grid evaluation. Methods Thirty children and adolescents with the diagnosis of medically refractory focal epilepsy (not considered ideal candidates for subdural grids and strip placement) underwent SEEG implantation. Demographics, electrophysiological localization of the hypothetical epileptogenic zone, complications, and seizure outcome after resections were analyzed. Results Eighteen patients (60%) underwent resections after SEEG implantations. In patients who did not undergo resections (12 patients), reasons included failure to localize the epileptogenic zone (4 patients); multifocal epileptogenic zone (4 patients); epileptogenic zone located in eloquent cortex, preventing resection (3 patients); and improvement in seizures after the implantation (1 patient). In patients who subsequently underwent resections, 10 patients (55.5%) were seizure free (Engel class I) and 5 patients (27.7%) experienced seizure improvement (Engel class II or III) at the end of the follow-up period (mean, 25.9 months; range, 12 to 47 months). The complication rate in SEEG implantations was 3%. Conclusion The SEEG methodology is safe and should be considered in children/adolescents with difficult-to-localize epilepsy. When applied to highly complex and difficult-to-localize pediatric patients, SEEG may provide an additional opportunity for seizure freedom in association with a low morbidity rate.
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stereotactic placement of depth electrodes in medically intractable epilepsy
Journal of Neurosurgery, 2014Co-Authors: Jorge Gonzalezmartinez, Juan Bulacio, Jeffrey P Mullin, Sumeet Vadera, Gwyneth Hughes, Stephen E Jones, Rei Enatsu, Imad NajmAbstract:Object Despite its long-reported successful record, with almost 60 years of clinical use, the technical complexity regarding the placement of Stereoelectroencephalography (SEEG) depth electrodes may have contributed to the limited widespread application of the technique in centers outside Europe. The authors report on a simplified and novel SEEG surgical technique in the extraoperative mapping of refractory focal epilepsy. Methods The proposed technique was applied in patients with medically refractory focal epilepsy. Data regarding general demographic information, method of electrode implantation, time of implantation, number of implanted electrodes, seizure outcome after SEEG-guided resections, and complications were prospectively collected. Results From March 2009 to April 2012, 122 patients underwent SEEG depth electrode implantation at the Cleveland Clinic Epilepsy Center in which the authors' technique was used. There were 65 male and 57 female patients whose mean age was 33 years (range 5–68 years)...
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Stereoelectroencephalography in the difficult to localize refractory focal epilepsy early experience from a north american epilepsy center
Epilepsia, 2013Co-Authors: Jorge Gonzalezmartinez, Juan Bulacio, William Bingaman, Andreas V Alexopoulos, Lara Jehi, Imad NajmAbstract:Summary Purpose: Stereo-electroencephalography (SEEG) enables precise recordings from deep cortical structures, multiple noncontiguous lobes, as well as bilateral explorations while avoiding large craniotomies. Despite a long reported successful record, its application in the United States has not been widely adopted. We report on our initial experience with the SEEG methodology in the extraoperative mapping of refractory focal epilepsy in patients who were not considered optimal surgical candidates for other methods of invasive monitoring. We focused on the applied surgical technique and its utility and efficacy in this subgroup of patients. Methods: Between March 2009 and May 2011, 100 patients with the diagnosis of medically refractory focal epilepsy who were not considered optimal candidates for subdural grids and strips placement underwent SEEG implantation at Cleveland Clinic Epilepsy Center. Demographics, noninvasive clinical data, number and location of implanted electrodes, electrophysiologic localization of the epileptic zone, complications, and short-term seizure outcome after resection were prospectively collected and analyzed. Key Findings: Mean age was 32 years (range 5–68 years); 54 were male and 46 female. The mean follow-up after resection was 15 months. In total, 1,310 electrodes were implanted. Analyses of the SEEG recordings resulted in the electrographic localization of the epileptogenic focus in 96 patients. In the group of 75 patients who underwent resection, only 53 had at least 12 months follow-up. From this group, 33 patients (62.3%) were seizure-free at the end of the follow-up period. The presence of abnormal pathologic finding was strongly associated with postoperative seizure control (p = 0.005). The risk of hemorrhagic complications per electrode was 0.2%. Significance: In patients who are not considered to be ideal candidates for subdural grids and strips implantation, the SEEG methodology is a safe, useful and reliable alternative option for invasive monitoring in patients with refractory focal epilepsy, providing an additional mean for seizure localization and control in a “difficult to localize” subgroup of patients.
Helene Catenoix - One of the best experts on this subject based on the ideXlab platform.
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surgical techniques Stereoelectroencephalography guided radiofrequency thermocoagulation seeg guided rf tc
Seizure-european Journal of Epilepsy, 2020Co-Authors: Pierre Bourdillon, Sylvain Rheims, Alexandra Montavont, Jean Isnard, Helene Catenoix, Karine Ostrowskycoste, Marc GuenotAbstract:Stereoelectroencephalography-guided radiofrequency-thermocoagulation (SEEG-guided RF-TC) consists of coupling SEEG investigation with RF-TC stereotactic lesioning directly through the recording electrodes. In this systematic review the surgical technique, indications, and outcomes are described. Maximum accuracy is reached when a frame-based procedure with a robotic assistance and a per-operative vascular X-ray imaging are performed. Monitoring of the lesioning procedure based on the impedance, a sharp modification of which indicates that the thermocoagulation has reached its maximum volume, allows the optimization of the lesion size. The first indication concerns patients in whom a SEEG is required to determine whether surgery is feasible and in whom resection is indeed possible. Even if surgery is performed owing to insufficient efficacy of SEEG-guided RF-TC, the procedure remains interesting owing to its high positive predictive value for good outcome after surgery. The second indication concerns patients in whom phase I non-invasive investigations have concluded to surgical contraindication and who may still undergo SEEG in a purely therapeutic perspective (small deep zones inaccessible to surgery and network nodes of large epileptic networks). Lastly, SEEG-guided RF-TC can be considered as a first-line treatment for periventricular nodular heterotopia (PNH). Independently of indication, the overall seizure-free rate is 23% and the responder rate is 58%. The best results are obtained for PNH (38% seizure-free and 81% responders), while the worst results have been reported for temporal lobe-epilepsy in a dedicated study. The overall complication rate is 2.5%. More evidence is needed to help determine the exact place of SEEG-guided RF-TC in the surgical management algorithm.
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pain behavior without pain sensation an epileptic syndrome of symbolism for pain
Pain, 2020Co-Authors: Koichi Hagiwara, Sylvain Rheims, Alexandra Montavont, Marc Guenot, Helene Catenoix, Luis Garcialarrea, Leon Tremblay, Jean IsnardAbstract:"Asymbolia for pain" has shown the potentiality of diseased insular networks to dissociate sensory from affective-behavioral dimensions of pain, resulting in the lack of appropriate motor and affective responses despite preserved sensory aspect of pain. Here, we describe 4 patients with an inverse phenomenon of asymbolia for pain, namely an isolated "symbolism for pain" triggered by epileptic seizures, characterized by pain behavior without declarative pain sensation despite fully preserved contact and vigilance. Stereoelectroencephalography demonstrated in each case focal seizure discharges within the posterior insulo-opercular cortex, with little or no propagation to other cortical structures, especially those considered to drive subjective pain experiences. The pain behavior might reflect seizure propagation from the insula to brain networks serving for behavioral responses associated with pain, including the cingulate motor region and possibly also the basal ganglia. We propose that the isolated symbolism for pain is a novel epileptic syndrome of dissociation between pain perception and behaviors associated with the insular nociceptive-related networks.
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Stereoelectroencephalography (SEEG) and epilepsy surgery in posttraumatic epilepsy: A multicenter retrospective study
Epilepsy & Behavior, 2020Co-Authors: Alexane Fierain, Sylvain Rheims, Aileen Mcgonigal, Helene Catenoix, Romain Carron, Anca Nica, Stanislas Lagarde, Luc Valton, Agnès Trebuchon-da Fonseca, Fabrice BartolomeiAbstract:Purpose: Posttraumatic epilepsy (PTE) is a common cause of drug-resistant epilepsy, especially in young adults. Nevertheless, such patients are not common candidates for intracranial presurgical evaluation. We investigated the role of Stereoelectroencephalography (SEEG) in defining epileptogenicity and surgical strategy in patients with PTE. Methods: We analyzed ictal SEEG recordings from 18 patients. We determined the seizure onset zone (SOZ) by quantifying the epileptogenicity of the sampled structures, using the \"epileptogenicity index\" (EI). We also identified seizure onset patterns (SOPs) through visual and frequency analysis. Postsurgical outcome was assessed by Engel's classification. Results: The SOZ in PTE was most often located in temporal lobes, followed by frontal lobes. The SOZ was network-organized in the majority of the cases. Half of the SOP did not contain fast discharges. Half of the recordings showed SOZ that were less extensive than the posttraumatic lesions seen on brain magnetic resonance imaging (MRI). All but one operated patient benefited from tailored cortectomy. Only 3 patients were contraindicated for surgical resection due to bilateral epileptogenicity. The overall surgical outcome was good in majority of patients (67% Engel I). Conclusion: Despite the potential risk of bilateral or multifocal epilepsy, patients with PTE may benefit from presurgical assessment in well-selected cases. In this context, SEEG allows guidance of tailored resections adapted to the SOZ.
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Stereoelectroencephalography and surgical outcome in polymicrogyria related epilepsy a multicentric study
Annals of Neurology, 2017Co-Authors: Louis Maillard, Laura Tassi, Helene Catenoix, François Dubeau, Fabrice Bartolomei, Philippe Kahane, William Szurhaj, Anca Nica, Petr Marusic, Ioana MindrutaAbstract:OBJECTIVE: We aimed to (1) assess the concordance between various polymicrogyria (PMG) types and the associated epileptogenic zone (EZ), as defined by Stereoelectroencephalography (SEEG), and (2) determine the postsurgical seizure outcome in PMG-related drug-resistant epilepsy. METHODS: We retrospectively analyzed 58 cases: 49 had SEEG and 39 corticectomy or hemispherotomy. RESULTS: Mean age at SEEG or surgery was 28.3 years (range, 2-50). PMG was bilateral in 9 (16%) patients and unilateral in 49, including 17 (29%) unilobar, 12 (21%) multilobar, 15 (26%) perisylvian, and only 5 (9%) hemispheric. Twenty-eight (48%) patients additionally had schizencephaly, heterotopia, or focal cortical dysplasia. The SEEG-determined EZ was fully concordant with the PMG in only 8 (16%) cases, partially concordant in 74%, and discordant in 10%. The EZ included remote cortical areas in 21 (43%) cases and was primarily localized in those in 5 (10%), all related to the mesial temporal structures. All but 1 PMG patient with corticectomy or hemispherotomy had a unilateral PMG. At last follow-up (mean, 4.6 years; range, 1-16), 28 (72%) patients remained seizure free. Shorter epilepsy duration to surgery was an independent predictor of seizure freedom. INTERPRETATION: PMG-related drug-resistant epilepsy warrants a comprehensive presurgical evaluation, including SEEG investigations in most cases, given that the EZ may only partially overlap with the PMG or include solely remote cortical areas. Seizure freedom is feasible in a large proportion of patients. PMG extent should not deter from exploring the possibility of epilepsy surgery. Our data support the early consideration of epilepsy surgery in this patient group. Ann Neurol 2017;82:781-794.
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epileptogenic networks in nodular heterotopia a Stereoelectroencephalography study
Epilepsia, 2017Co-Authors: Francesca Pizzo, Aileen Mcgonigal, Nicolas Roehri, Helene Catenoix, Samuel Medina, Bernard Giusiano, Romain Carron, Didier Scavarda, Karine Ostrowsky, A LepineAbstract:Objective Defining the roles of heterotopic and normotopic cortex in the epileptogenic networks in patients with nodular heterotopia is challenging. To elucidate this issue, we compared heterotopic and normotopic cortex using quantitative signal analysis on Stereoelectroencephalography (SEEG) recordings. Methods Clinically relevant biomarkers of epileptogenicity during ictal (epileptogenicity index; EI) and interictal recordings (high-frequency oscillation and spike) were evaluated in 19 patients undergoing SEEG. These biomarkers were then compared between heterotopic cortex and neocortical regions. Seizures were classified as normotopic, heterotopic, or normoheterotopic according to respective values of quantitative analysis (EI ≥0.3). Results A total of 1,246 contacts were analyzed: 259 in heterotopic tissue (heterotopic cortex), 873 in neocortex in the same lobe of the lesion (local neocortex), and 114 in neocortex distant from the lesion (distant neocortex). No significant difference in EI values, high-frequency oscillations, and spike rate was found comparing local neocortex and heterotopic cortex at a patient level, but local neocortex appears more epileptogenic (p Significance This is the first quantitative SEEG study providing insight into the mechanisms generating seizures in nodular heterotopia. We demonstrate that both the heterotopic lesion and particularly the normotopic cortex are involved in the epileptogenic network. This could open new perspectives on multitarget treatments, other than resective surgery, aimed at modifying the epileptic network.
Marc Guenot - One of the best experts on this subject based on the ideXlab platform.
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surgical techniques Stereoelectroencephalography guided radiofrequency thermocoagulation seeg guided rf tc
Seizure-european Journal of Epilepsy, 2020Co-Authors: Pierre Bourdillon, Sylvain Rheims, Alexandra Montavont, Jean Isnard, Helene Catenoix, Karine Ostrowskycoste, Marc GuenotAbstract:Stereoelectroencephalography-guided radiofrequency-thermocoagulation (SEEG-guided RF-TC) consists of coupling SEEG investigation with RF-TC stereotactic lesioning directly through the recording electrodes. In this systematic review the surgical technique, indications, and outcomes are described. Maximum accuracy is reached when a frame-based procedure with a robotic assistance and a per-operative vascular X-ray imaging are performed. Monitoring of the lesioning procedure based on the impedance, a sharp modification of which indicates that the thermocoagulation has reached its maximum volume, allows the optimization of the lesion size. The first indication concerns patients in whom a SEEG is required to determine whether surgery is feasible and in whom resection is indeed possible. Even if surgery is performed owing to insufficient efficacy of SEEG-guided RF-TC, the procedure remains interesting owing to its high positive predictive value for good outcome after surgery. The second indication concerns patients in whom phase I non-invasive investigations have concluded to surgical contraindication and who may still undergo SEEG in a purely therapeutic perspective (small deep zones inaccessible to surgery and network nodes of large epileptic networks). Lastly, SEEG-guided RF-TC can be considered as a first-line treatment for periventricular nodular heterotopia (PNH). Independently of indication, the overall seizure-free rate is 23% and the responder rate is 58%. The best results are obtained for PNH (38% seizure-free and 81% responders), while the worst results have been reported for temporal lobe-epilepsy in a dedicated study. The overall complication rate is 2.5%. More evidence is needed to help determine the exact place of SEEG-guided RF-TC in the surgical management algorithm.
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pain behavior without pain sensation an epileptic syndrome of symbolism for pain
Pain, 2020Co-Authors: Koichi Hagiwara, Sylvain Rheims, Alexandra Montavont, Marc Guenot, Helene Catenoix, Luis Garcialarrea, Leon Tremblay, Jean IsnardAbstract:"Asymbolia for pain" has shown the potentiality of diseased insular networks to dissociate sensory from affective-behavioral dimensions of pain, resulting in the lack of appropriate motor and affective responses despite preserved sensory aspect of pain. Here, we describe 4 patients with an inverse phenomenon of asymbolia for pain, namely an isolated "symbolism for pain" triggered by epileptic seizures, characterized by pain behavior without declarative pain sensation despite fully preserved contact and vigilance. Stereoelectroencephalography demonstrated in each case focal seizure discharges within the posterior insulo-opercular cortex, with little or no propagation to other cortical structures, especially those considered to drive subjective pain experiences. The pain behavior might reflect seizure propagation from the insula to brain networks serving for behavioral responses associated with pain, including the cingulate motor region and possibly also the basal ganglia. We propose that the isolated symbolism for pain is a novel epileptic syndrome of dissociation between pain perception and behaviors associated with the insular nociceptive-related networks.
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how can we explain the frontal presentation of insular lobe epilepsy the impact of non linear analysis of insular seizures
Clinical Neurophysiology, 2017Co-Authors: Koichi Hagiwara, Sylvain Rheims, Marc Guenot, François Mauguière, Luis Garcialarrea, Julien Jung, Romain Bouet, Chifaou Abdallah, Jean IsnardAbstract:Abstract Objective For a decade it has been known that the insular lobe epilepsy can mimic frontal lobe epilepsy. We aimed to clarify the pattern of functional coupling occurring during the frontal presentation. Methods We analyzed five insular lobe epilepsy patients. Frontal semiology was predominant for three of them, whereas insular semiology was predominant for the two others. We applied the non-linear regression analysis to Stereoelectroencephalography-recorded seizures. A directed functional coupling index was calculated during clonic discharge periods that were accompanied either with frontal or insular semiology. Results We found significant functional coupling between the insula and mesial frontal/cingulate regions, with the former being a leader region for seizures propagation. Extra-insular regions showed significantly less or even no coupling with the mesial hemispheric regions. The three patients with frontal semiology showed strong couplings with the mesial frontal as well as cingulate regions, including the medial orbitofrontal cortex, pre-SMA/SMA, and the anterior to posterior cingulate. The two patients with the insular semiology only showed couplings between the insula and cingulate regions. Conclusions The frontal semiology was expressed by strong functional couplings between the insula and mesial frontal regions. Significance The insular origin of seizure should be considered in cryptogenic mesial frontal epilepsies.
Sylvain Rheims - One of the best experts on this subject based on the ideXlab platform.
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surgical techniques Stereoelectroencephalography guided radiofrequency thermocoagulation seeg guided rf tc
Seizure-european Journal of Epilepsy, 2020Co-Authors: Pierre Bourdillon, Sylvain Rheims, Alexandra Montavont, Jean Isnard, Helene Catenoix, Karine Ostrowskycoste, Marc GuenotAbstract:Stereoelectroencephalography-guided radiofrequency-thermocoagulation (SEEG-guided RF-TC) consists of coupling SEEG investigation with RF-TC stereotactic lesioning directly through the recording electrodes. In this systematic review the surgical technique, indications, and outcomes are described. Maximum accuracy is reached when a frame-based procedure with a robotic assistance and a per-operative vascular X-ray imaging are performed. Monitoring of the lesioning procedure based on the impedance, a sharp modification of which indicates that the thermocoagulation has reached its maximum volume, allows the optimization of the lesion size. The first indication concerns patients in whom a SEEG is required to determine whether surgery is feasible and in whom resection is indeed possible. Even if surgery is performed owing to insufficient efficacy of SEEG-guided RF-TC, the procedure remains interesting owing to its high positive predictive value for good outcome after surgery. The second indication concerns patients in whom phase I non-invasive investigations have concluded to surgical contraindication and who may still undergo SEEG in a purely therapeutic perspective (small deep zones inaccessible to surgery and network nodes of large epileptic networks). Lastly, SEEG-guided RF-TC can be considered as a first-line treatment for periventricular nodular heterotopia (PNH). Independently of indication, the overall seizure-free rate is 23% and the responder rate is 58%. The best results are obtained for PNH (38% seizure-free and 81% responders), while the worst results have been reported for temporal lobe-epilepsy in a dedicated study. The overall complication rate is 2.5%. More evidence is needed to help determine the exact place of SEEG-guided RF-TC in the surgical management algorithm.
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pain behavior without pain sensation an epileptic syndrome of symbolism for pain
Pain, 2020Co-Authors: Koichi Hagiwara, Sylvain Rheims, Alexandra Montavont, Marc Guenot, Helene Catenoix, Luis Garcialarrea, Leon Tremblay, Jean IsnardAbstract:"Asymbolia for pain" has shown the potentiality of diseased insular networks to dissociate sensory from affective-behavioral dimensions of pain, resulting in the lack of appropriate motor and affective responses despite preserved sensory aspect of pain. Here, we describe 4 patients with an inverse phenomenon of asymbolia for pain, namely an isolated "symbolism for pain" triggered by epileptic seizures, characterized by pain behavior without declarative pain sensation despite fully preserved contact and vigilance. Stereoelectroencephalography demonstrated in each case focal seizure discharges within the posterior insulo-opercular cortex, with little or no propagation to other cortical structures, especially those considered to drive subjective pain experiences. The pain behavior might reflect seizure propagation from the insula to brain networks serving for behavioral responses associated with pain, including the cingulate motor region and possibly also the basal ganglia. We propose that the isolated symbolism for pain is a novel epileptic syndrome of dissociation between pain perception and behaviors associated with the insular nociceptive-related networks.
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Stereoelectroencephalography (SEEG) and epilepsy surgery in posttraumatic epilepsy: A multicenter retrospective study
Epilepsy & Behavior, 2020Co-Authors: Alexane Fierain, Sylvain Rheims, Aileen Mcgonigal, Helene Catenoix, Romain Carron, Anca Nica, Stanislas Lagarde, Luc Valton, Agnès Trebuchon-da Fonseca, Fabrice BartolomeiAbstract:Purpose: Posttraumatic epilepsy (PTE) is a common cause of drug-resistant epilepsy, especially in young adults. Nevertheless, such patients are not common candidates for intracranial presurgical evaluation. We investigated the role of Stereoelectroencephalography (SEEG) in defining epileptogenicity and surgical strategy in patients with PTE. Methods: We analyzed ictal SEEG recordings from 18 patients. We determined the seizure onset zone (SOZ) by quantifying the epileptogenicity of the sampled structures, using the \"epileptogenicity index\" (EI). We also identified seizure onset patterns (SOPs) through visual and frequency analysis. Postsurgical outcome was assessed by Engel's classification. Results: The SOZ in PTE was most often located in temporal lobes, followed by frontal lobes. The SOZ was network-organized in the majority of the cases. Half of the SOP did not contain fast discharges. Half of the recordings showed SOZ that were less extensive than the posttraumatic lesions seen on brain magnetic resonance imaging (MRI). All but one operated patient benefited from tailored cortectomy. Only 3 patients were contraindicated for surgical resection due to bilateral epileptogenicity. The overall surgical outcome was good in majority of patients (67% Engel I). Conclusion: Despite the potential risk of bilateral or multifocal epilepsy, patients with PTE may benefit from presurgical assessment in well-selected cases. In this context, SEEG allows guidance of tailored resections adapted to the SOZ.
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how can we explain the frontal presentation of insular lobe epilepsy the impact of non linear analysis of insular seizures
Clinical Neurophysiology, 2017Co-Authors: Koichi Hagiwara, Sylvain Rheims, Marc Guenot, François Mauguière, Luis Garcialarrea, Julien Jung, Romain Bouet, Chifaou Abdallah, Jean IsnardAbstract:Abstract Objective For a decade it has been known that the insular lobe epilepsy can mimic frontal lobe epilepsy. We aimed to clarify the pattern of functional coupling occurring during the frontal presentation. Methods We analyzed five insular lobe epilepsy patients. Frontal semiology was predominant for three of them, whereas insular semiology was predominant for the two others. We applied the non-linear regression analysis to Stereoelectroencephalography-recorded seizures. A directed functional coupling index was calculated during clonic discharge periods that were accompanied either with frontal or insular semiology. Results We found significant functional coupling between the insula and mesial frontal/cingulate regions, with the former being a leader region for seizures propagation. Extra-insular regions showed significantly less or even no coupling with the mesial hemispheric regions. The three patients with frontal semiology showed strong couplings with the mesial frontal as well as cingulate regions, including the medial orbitofrontal cortex, pre-SMA/SMA, and the anterior to posterior cingulate. The two patients with the insular semiology only showed couplings between the insula and cingulate regions. Conclusions The frontal semiology was expressed by strong functional couplings between the insula and mesial frontal regions. Significance The insular origin of seizure should be considered in cryptogenic mesial frontal epilepsies.