1
|
Wu S, Issa NP, Rose SL, Haider HA, Nordli DR, Towle VL, Warnke PC, Tao JX. Depth versus surface: A critical review of subdural and depth electrodes in intracranial electroencephalographic studies. Epilepsia 2024; 65:1868-1878. [PMID: 38722693 DOI: 10.1111/epi.18002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 04/05/2024] [Accepted: 04/24/2024] [Indexed: 07/17/2024]
Abstract
Intracranial electroencephalographic (IEEG) recording, using subdural electrodes (SDEs) and stereoelectroencephalography (SEEG), plays a pivotal role in localizing the epileptogenic zone (EZ). SDEs, employed for superficial cortical seizure foci localization, provide information on two-dimensional seizure onset and propagation. In contrast, SEEG, with its three-dimensional sampling, allows exploration of deep brain structures, sulcal folds, and bihemispheric networks. SEEG offers the advantages of fewer complications, better tolerability, and coverage of sulci. Although both modalities allow electrical stimulation, SDE mapping can tessellate cortical gyri, providing the opportunity for a tailored resection. With SEEG, both superficial gyri and deep sulci can be stimulated, and there is a lower risk of afterdischarges and stimulation-induced seizures. Most systematic reviews and meta-analyses have addressed the comparative effectiveness of SDEs and SEEG in localizing the EZ and achieving seizure freedom, although discrepancies persist in the literature. The combination of SDEs and SEEG could potentially overcome the limitations inherent to each technique individually, better delineating seizure foci. This review describes the strengths and limitations of SDE and SEEG recordings, highlighting their unique indications in seizure localization, as evidenced by recent publications. Addressing controversies in the perceived usefulness of the two techniques offers insights that can aid in selecting the most suitable IEEG in clinical practice.
Collapse
Affiliation(s)
- Shasha Wu
- Department of Neurology, University of Chicago, Chicago, Illinois, USA
| | - Naoum P Issa
- Department of Neurology, University of Chicago, Chicago, Illinois, USA
| | - Sandra L Rose
- Department of Neurology, University of Chicago, Chicago, Illinois, USA
| | - Hiba A Haider
- Department of Neurology, University of Chicago, Chicago, Illinois, USA
| | - Douglas R Nordli
- Department of Pediatrics, University of Chicago, Chicago, Illinois, USA
| | - Vernon L Towle
- Department of Neurology, University of Chicago, Chicago, Illinois, USA
| | - Peter C Warnke
- Department of Neurological Surgery, University of Chicago, Chicago, Illinois, USA
| | - James X Tao
- Department of Neurology, University of Chicago, Chicago, Illinois, USA
| |
Collapse
|
2
|
Jha R, Chua MMJ, Sarkis R, Tobochnik S, Rolston JD. Predictors of SOZ localization, subsequent surgical intervention, and seizure outcomes in iEEG. Ann Clin Transl Neurol 2024; 11:1787-1797. [PMID: 38831617 PMCID: PMC11251470 DOI: 10.1002/acn3.52084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/10/2024] [Accepted: 04/24/2024] [Indexed: 06/05/2024] Open
Abstract
OBJECTIVE A third of the patients who undergo intracranial EEG (iEEG) for seizure-onset zone (SOZ) localization do not proceed to resective surgery for epilepsy, and over half of those who do continue to have seizures following treatment. To better identify candidates who are more likely to see benefits from undergoing iEEG, we investigated preoperative and iEEG peri-operative features associated with the localization of a putative SOZ, undergoing subsequent surgical treatment, and seizure outcomes. METHODS We conducted a retrospective cohort study of consecutive patients who underwent iEEG from 2001 to 2022 at two institutions. Outcomes included SOZ identification, proceeding to surgical treatment (resection vs. neuromodulation), and subsequent seizure freedom. RESULTS We identified 329 unique patients who were followed for a median of 3.9 (IQR:7) years, with a minimum of 2-year follow-up for seizure outcomes analyses. Multivariate analysis identified lateralized and lobar localization on scalp EEG (OR 3.8, p = 0.001) to be associated with SOZ localization. Patients with unilateral localization on scalp EEG (OR 3.0, p = 0.003), unilateral preimplantation hypothesis (OR 3.1, p = 0.001), and lesional preoperative MRI (OR 2.1, p = 0.033) were more likely to undergo resection than neuromodulation. Similarly, a unilateral pre-implantation hypothesis (OR 2.6, p < 0.001) favored seizure freedom, whereas prior neuromodulation (OR 0.3, p = 0.013) decreased the odds. Larger number of preoperative anti-seizure medications (ASMs) did not influence seizure freedom rates but did decrease favorable (Engel I, II) seizure outcomes (OR 0.7, p = 0.026). INTERPRETATION Non-invasive localization data prior to iEEG are associated with subsequent resection and seizure freedom, independent of iEEG localization. Factors predictive of SOZ localization are not necessarily predictive of post-operative seizure freedom.
Collapse
Affiliation(s)
- Rohan Jha
- Harvard Medical SchoolBostonMassachusettsUSA
| | - Melissa M. J. Chua
- Department of NeurosurgeryBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Rani Sarkis
- Department of NeurologyBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - Steven Tobochnik
- Department of NeurologyBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| | - John D. Rolston
- Harvard Medical SchoolBostonMassachusettsUSA
- Department of NeurosurgeryBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
| |
Collapse
|
3
|
Castellano JF, Singla S, Barot N, Aronson JP. Stereoelectroencephalography-Guided Radiofrequency Thermocoagulation: Diagnostic and Therapeutic Implications. Brain Sci 2024; 14:110. [PMID: 38391685 PMCID: PMC10887298 DOI: 10.3390/brainsci14020110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/15/2024] [Accepted: 01/21/2024] [Indexed: 02/24/2024] Open
Abstract
Despite recent medical therapeutic advances, approximately one third of patients do not attain seizure freedom with medications. This drug-resistant epilepsy population suffers from heightened morbidity and mortality. In appropriate patients, resective epilepsy surgery is far superior to continued medical therapy. Despite this efficacy, there remain drawbacks to traditional epilepsy surgery, such as the morbidity of open neurosurgical procedures as well as neuropsychological adverse effects. SEEG-guided Radiofrequency Thermocoagulation (SgRFTC) is a minimally invasive, electrophysiology-guided intervention with both diagnostic and therapeutic implications for drug-resistant epilepsy that offers a convenient adjunct or alternative to ablative and resective approaches. We review the international experience with this procedure, including methodologies, diagnostic benefit, therapeutic benefit, and safety considerations. We propose a framework in which SgRFTC may be incorporated into intracranial EEG evaluations alongside passive recording. Lastly, we discuss the potential role of SgRFTC in both delineating and reorganizing epilepsy networks.
Collapse
Affiliation(s)
- James F Castellano
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Shobhit Singla
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Niravkumar Barot
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Joshua P Aronson
- Department of Neurosurgery, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| |
Collapse
|
4
|
Abel TJ, Muthiah N, Hect JL, Gonzalez-Martinez J, Salehi A, Smyth MD, Smith KJ. Cost-effectiveness of invasive monitoring strategies in epilepsy surgery. J Neurosurg 2022:1-7. [PMID: 36585866 DOI: 10.3171/2022.11.jns221744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 11/17/2022] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Drug-resistant epilepsy occurs in up to 40% of patients with epilepsy who may be considered for epilepsy surgery. For drug-resistant focal epilepsy, up to 50% of patients require invasive monitoring prior to surgery. Of the most common invasive monitoring strategies (subdural electrodes [SDEs] and stereo-electroencephalography [sEEG]), the most cost-effective strategy is unknown despite substantial differences in morbidity profiles. METHODS Using data collected from an internationally representative sample published in available systematic reviews and meta-analyses, this economic evaluation study employs a decision analysis model to simulate the risks and benefits of SDE and sEEG invasive monitoring strategies. In this model, patients faced differing risks of morbidity, mortality, resection, and seizure freedom depending on which invasive monitoring strategy they underwent. A range of cost values was obtained from a recently published single-center cost-utility analysis. The model considers a base case simulation of a characteristic patient with drug-resistant epilepsy using clinical parameters obtained from systematic reviews of invasive monitoring available in the literature. The main outcome measure was the probability of a positive outcome after invasive monitoring, which was defined as improvement in seizures without a complication. Cost-effectiveness was measured using an incremental cost-effectiveness ratio (ICER). RESULTS Invasive monitoring with sEEG had an increased cost of $274 and increased probability of effectiveness of 0.02 compared with SDEs, yielding an ICER of $12,630 per positive outcome obtained. Sensitivity analyses varied parameters widely and revealed consistent model results across the range of clinical parameters reported in the literature. One-way sensitivity analyses revealed that invasive monitoring strategy costs were the most influential parameter for model outcome. CONCLUSIONS In this analysis, based on available observational data and estimates of complication costs, invasive monitoring with either SDEs or sEEG was nearly equivalent in terms of cost-effectiveness.
Collapse
Affiliation(s)
- Taylor J Abel
- 1Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh.,Departments of2Bioengineering and
| | - Nallammai Muthiah
- 1Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh
| | - Jasmine L Hect
- 1Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh
| | - Jorge Gonzalez-Martinez
- 1Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh
| | - Afshin Salehi
- 3Department of Neurosurgery, University of Nebraska, Omaha, Nebraska; and
| | - Matthew D Smyth
- 4Department of Neurosurgery, Johns Hopkins All Children's Hospital, Tampa, Florida
| | | |
Collapse
|
5
|
Ong S, Kullmann A, Mertens S, Rosa D, Diaz-Botia CA. Electrochemical Testing of a New Polyimide Thin Film Electrode for Stimulation, Recording, and Monitoring of Brain Activity. MICROMACHINES 2022; 13:1798. [PMID: 36296151 PMCID: PMC9611492 DOI: 10.3390/mi13101798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 10/13/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
Subdural electrode arrays are used for monitoring cortical activity and functional brain mapping in patients with seizures. Until recently, the only commercially available arrays were silicone-based, whose thickness and lack of conformability could impact their performance. We designed, characterized, manufactured, and obtained FDA clearance for 29-day clinical use (510(k) K192764) of a new thin-film polyimide-based electrode array. This study describes the electrochemical characterization undertaken to evaluate the quality and reliability of electrical signal recordings and stimulation of these new arrays. Two testing paradigms were performed: a short-term active soak with electrical stimulation and a 29-day passive soak. Before and after each testing paradigm, the arrays were evaluated for their electrical performance using Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV) and Voltage Transients (VT). In all tests, the impedance remained within an acceptable range across all frequencies. The different CV curves showed no significant changes in shape or area, which is indicative of stable electrode material. The electrode polarization remained within appropriate limits to avoid hydrolysis.
Collapse
|
6
|
Sivaraju A, Hirsch L, Gaspard N, Farooque P, Gerrard J, Xu Y, Deng Y, Damisah E, Blumenfeld H, Spencer DD. Factors Predicting Outcome After Intracranial EEG Evaluation in Patients With Medically Refractory Epilepsy. Neurology 2022; 99:e1-e10. [PMID: 35508395 PMCID: PMC9259091 DOI: 10.1212/wnl.0000000000200569] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 03/04/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES The aim of this study was to identify predictors of a resective surgery and subsequent seizure freedom following intracranial EEG (ICEEG) for seizure-onset localization. METHODS This is a retrospective chart review of 178 consecutive patients with medically refractory epilepsy who underwent ICEEG monitoring from 2002 to 2015. Univariable and multivariable regression analysis identified independent predictors of resection vs other options. Stepwise Akaike information criteria with the aid of clinical consideration were used to select the best multivariable model for predicting resection and outcome. Discrete time survival analysis was used to analyze the factors predicting seizure-free outcome. Cumulative probability of seizure freedom was analyzed using Kaplan-Meier curves and compared between resection and nonresection groups. Additional univariate analysis was performed on 8 select clinical scenarios commonly encountered during epilepsy surgical evaluations. RESULTS Multivariable analysis identified the presence of a lesional MRI, presurgical hypothesis suggesting temporal lobe onset, and a nondominant hemisphere implant as independent predictors of resection (p < 0.0001, area under the receiver operating characteristic curve 0.80, 95% CI 0.73-0.87). Focal ICEEG onset and undergoing a resective surgery predicted absolute seizure freedom at the 5-year follow-up. Patients who underwent resective surgery were more likely to be seizure-free at 5 years compared with continued medical treatment or neuromodulation (60% vs 7%; p < 0.0001, hazard ratio 0.16, 95% CI 0.09-0.28). Even patients thought to have unfavorable predictors (nonlesional MRI or extratemporal lobe hypothesis or dominant hemisphere implant) had ≥50% chance of seizure freedom at 5 years if they underwent resection. DISCUSSION Unfavorable predictors, including having nonlesional extratemporal epilepsy, should not deter a thorough presurgical evaluation, including with invasive recordings in many cases. Resective surgery without functional impairment offers the best chance for sustained seizure freedom and should always be considered first. CLASSIFICATION OF EVIDENCE This study provides Class II evidence that the presence of a lesional MRI, presurgical hypothesis suggesting temporal lobe onset, and a nondominant hemisphere implant are independent predictors of resection. Focal ICEEG onset and undergoing resection are independent predictors of 5-year seizure freedom.
Collapse
Affiliation(s)
- Adithya Sivaraju
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT.
| | - Lawrence Hirsch
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT
| | - Nicolas Gaspard
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT
| | - Pue Farooque
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT
| | - Jason Gerrard
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT
| | - Yunshan Xu
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT
| | - Yanhong Deng
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT
| | - Eyiyemisi Damisah
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT
| | - Hal Blumenfeld
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT
| | - Dennis D Spencer
- From the Comprehensive Epilepsy Center (A.S., L.H., N.G., P.F., H.B.), Department of Neurology, Yale University School of Medicine, New Haven, CT; Service de Neurologie (N.G.), Université Libre de Bruxelles-Hôpital Erasme, Belgium; Comprehensive Epilepsy Center (J.G., E.D., D.D.S.), Department of Neurosurgery, Yale University School of Medicine, New Haven; and Yale Center for Analytical Sciences (Y.X., Y.D.), Yale School of Public Health, New Haven, CT
| |
Collapse
|
7
|
Kullmann A, Kridner D, Mertens S, Christianson M, Rosa D, Diaz-Botia CA. First Food and Drug Administration Cleared Thin-Film Electrode for Intracranial Stimulation, Recording, and Monitoring of Brain Activity—Part 1: Biocompatibility Testing. Front Neurosci 2022; 16:876877. [PMID: 35573282 PMCID: PMC9100917 DOI: 10.3389/fnins.2022.876877] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/28/2022] [Indexed: 11/16/2022] Open
Abstract
Subdural strip and grid invasive electroencephalography electrodes are routinely used for surgical evaluation of patients with drug-resistant epilepsy (DRE). Although these electrodes have been in the United States market for decades (first FDA clearance 1985), their fabrication, materials, and properties have hardly changed. Existing commercially available electrodes are made of silicone, are thick (>0.5 mm), and do not optimally conform to brain convolutions. New thin-film polyimide electrodes (0.08 mm) have been manufactured to address these issues. While different thin-film electrodes are available for research use, to date, only one electrode is cleared by Food and Drug Administration (FDA) for use in clinical practice. This study describes the biocompatibility tests that led to this clearance. Biocompatibility was tested using standard methods according to International Organization for Standardization (ISO) 10993. Electrodes and appropriate control materials were bent, folded, and placed in the appropriate extraction vehicles, or implanted. The extracts were used for in vitro and in vivo tests, to assess the effects of any potential extractable and leachable materials that may be toxic to the body. In vitro studies included cytotoxicity tested in L929 cell line, genotoxicity tested using mouse lymphoma assay (MLA) and Ames assay, and hemolysis tested in rabbit whole blood samples. The results indicated that the electrodes were non-cytotoxic, non-mutagenic, non-clastogenic, and non-hemolytic. In vivo studies included sensitization tested in guinea pigs, irritation tested in rabbits, acute systemic toxicity testing in mice, pyrogenicity tested in rabbits, and a prolonged 28-day subdural implant in sheep. The results indicated that the electrodes induced no sensitization and irritation, no weight loss, and no temperature increase. Histological examination of the sheep brain tissue showed no or minimal immune cell accumulation, necrosis, neovascularization, fibrosis, and astrocyte infiltration, with no differences from the control material. In summary, biocompatibility studies indicated that these new thin-film electrodes are appropriate for human use. As a result, the electrodes were cleared by the FDA for use in clinical practice [510(k) K192764], making it the first thin-film subdural electrode to progress from research to clinic. Its readiness as a commercial product ensures availability to all patients undergoing surgical evaluation for DRE.
Collapse
|
8
|
King-Stephens D. Approximation Is Not Randomization; Lessons From Comparative Observational Studies of Invasive EEG Methods. Epilepsy Curr 2022; 22:117-119. [PMID: 35444499 PMCID: PMC8988721 DOI: 10.1177/15357597221076220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
9
|
Delgado-Garcia G, Frauscher B. Future of Neurology & Technology: Stereoelectroencephalography in Presurgical Epilepsy Evaluation. Neurology 2022; 98:e437-e440. [PMID: 34799457 DOI: 10.1212/wnl.0000000000013088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Stereoelectroencephalography (SEEG) is not only a sophisticated and highly technological investigation but a new and better way to conceptualize the spatial and temporal dynamics of epileptic activity. The first intracranial investigations with SEEG were performed in France in the mid-twentieth century; however, its use in North America is much more recent. Given its significantly lower risk of complications and its ability to sample both superficial and deep structures and both hemispheres simultaneously, SEEG has become the preferred method to conduct intracranial EEG monitoring in most comprehensive epilepsy centers in North America. SEEG is an invasive neurophysiologic methodology used for advanced presurgical workup in the 20% of drug-resistant patients with more complex focal epilepsy in whom noninvasive investigations do not allow to decide on surgical candidacy. SEEG uses stereotactically implanted depth electrodes to map the origin and propagation of epileptic seizures by creating a 3-dimensional representation of the abnormal electrical activity in the brain. SEEG analysis takes into account the background, interictal, and ictal activity, as well as the results of cortical electrical stimulation procedures, to reliably delineate the epileptogenic network. By means of a clinical vignette, this article will walk general neurologists, but especially neurology trainees through the immense potential of this methodology. In summary, SEEG enables to accurately identify the epileptogenic zone in patients with drug-resistant focal epilepsy who otherwise would be not amenable to surgical treatment. In this patient population, SEEG is the best way to improve seizure control and achieve seizure freedom.
Collapse
Affiliation(s)
- Guillermo Delgado-Garcia
- From the Department of Clinical Neurosciences (G.D.-G.), Cumming School of Medicine, University of Calgary, Canada; Centro de Investigación y Desarrollo en Ciencias de La Salud (G.D.-G.), Universidad Autónoma de Nuevo León, Monterrey, Mexico; and Analytical Neurophysiology Lab & Epilepsy Program (B.F.), Montreal Neurological Institute and Hospital, McGill University, Canada
| | - Birgit Frauscher
- From the Department of Clinical Neurosciences (G.D.-G.), Cumming School of Medicine, University of Calgary, Canada; Centro de Investigación y Desarrollo en Ciencias de La Salud (G.D.-G.), Universidad Autónoma de Nuevo León, Monterrey, Mexico; and Analytical Neurophysiology Lab & Epilepsy Program (B.F.), Montreal Neurological Institute and Hospital, McGill University, Canada.
| |
Collapse
|
10
|
Anderson DN, Charlebois CM, Smith EH, Arain AM, Davis TS, Rolston JD. Probabilistic comparison of gray and white matter coverage between depth and surface intracranial electrodes in epilepsy. Sci Rep 2021; 11:24155. [PMID: 34921176 PMCID: PMC8683494 DOI: 10.1038/s41598-021-03414-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 11/23/2021] [Indexed: 11/20/2022] Open
Abstract
In this study, we quantified the coverage of gray and white matter during intracranial electroencephalography in a cohort of epilepsy patients with surface and depth electrodes. We included 65 patients with strip electrodes (n = 12), strip and grid electrodes (n = 24), strip, grid, and depth electrodes (n = 7), or depth electrodes only (n = 22). Patient-specific imaging was used to generate probabilistic gray and white matter maps and atlas segmentations. Gray and white matter coverage was quantified using spherical volumes centered on electrode centroids, with radii ranging from 1 to 15 mm, along with detailed finite element models of local electric fields. Gray matter coverage was highly dependent on the chosen radius of influence (RoI). Using a 2.5 mm RoI, depth electrodes covered more gray matter than surface electrodes; however, surface electrodes covered more gray matter at RoI larger than 4 mm. White matter coverage and amygdala and hippocampal coverage was greatest for depth electrodes at all RoIs. This study provides the first probabilistic analysis to quantify coverage for different intracranial recording configurations. Depth electrodes offer increased coverage of gray matter over other recording strategies if the desired signals are local, while subdural grids and strips sample more gray matter if the desired signals are diffuse.
Collapse
Affiliation(s)
- Daria Nesterovich Anderson
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA. .,Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA.
| | - Chantel M Charlebois
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Elliot H Smith
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA
| | - Amir M Arain
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Tyler S Davis
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA
| | - John D Rolston
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA. .,Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA.
| |
Collapse
|
11
|
Sokolov E, Sisterson ND, Hussein H, Plummer C, Corson D, Antony AR, Mettenburg JM, Ghearing GR, Pan JW, Urban A, Bagić A, Richardson RM, Kokkinos V. Intracranial monitoring contributes to seizure freedom for temporal lobectomy patients with nonconcordant preoperative data. Epilepsia Open 2021; 7:36-45. [PMID: 34786887 PMCID: PMC8886064 DOI: 10.1002/epi4.12483] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 03/10/2021] [Accepted: 03/19/2021] [Indexed: 11/20/2022] Open
Abstract
Objective The question of whether a patient with presumed temporal lobe seizures should proceed directly to temporal lobectomy surgery versus undergo intracranial monitoring arises commonly. We evaluate the effect of intracranial monitoring on seizure outcome in a retrospective cohort of consecutive subjects who specifically underwent an anterior temporal lobectomy (ATL) for refractory temporal lobe epilepsy (TLE). Methods We performed a retrospective analysis of 85 patients with focal refractory TLE who underwent ATL following: (a) intracranial monitoring via craniotomy and subdural/depth electrodes (SDE/DE), (b) intracranial monitoring via stereotactic electroencephalography (sEEG), or (c) no intracranial monitoring (direct ATL—dATL). For each subject, the presurgical primary hypothesis for epileptogenic zone localization was characterized as unilateral TLE, unilateral TLE plus (TLE+), or TLE with bilateral/poor lateralization. Results At one‐year and most recent follow‐up, Engel Class I and combined I/II outcomes did not differ significantly between the groups. Outcomes were better in the dATL group compared to the intracranial monitoring groups for lesional cases but were similar in nonlesional cases. Those requiring intracranial monitoring for a hypothesis of TLE+had similar outcomes with either intracranial monitoring approach. sEEG was the only approach used in patients with bilateral or poorly lateralized TLE, resulting in 77.8% of patients seizure‐free at last follow‐up. Importantly, for 85% of patients undergoing SEEG, recommendation for ATL resulted from modifying the primary hypothesis based on iEEG data. Significance Our study highlights the value of intracranial monitoring in equalizing seizure outcomes in difficult‐to‐treat TLE patients undergoing ATL.
Collapse
Affiliation(s)
- Elisaveta Sokolov
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | | | - Helweh Hussein
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Cheryl Plummer
- University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, PA, USA
| | - Danielle Corson
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA.,University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, PA, USA
| | - Arun R Antony
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Gena R Ghearing
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jullie W Pan
- University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, PA, USA.,Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alexandra Urban
- University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, PA, USA.,Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Anto Bagić
- University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, PA, USA.,Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA
| | - R Mark Richardson
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA.,University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, PA, USA
| | - Vasileios Kokkinos
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA.,University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, PA, USA
| |
Collapse
|