151
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Kasper BS, Rössler K, Hamer HM, Dörfler A, Blümcke I, Coras R, Roesch J, Mennecke A, Wellmer J, Sommer B, Lorber B, Lang JD, Graf W, Stefan H, Schwab S, Buchfelder M, Rampp S. Coregistrating magnetic source and magnetic resonance imaging for epilepsy surgery in focal cortical dysplasia. Neuroimage Clin 2018; 19:487-496. [PMID: 29984157 PMCID: PMC6029564 DOI: 10.1016/j.nicl.2018.04.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 04/18/2018] [Accepted: 04/28/2018] [Indexed: 11/29/2022]
Abstract
Background Epilepsy surgery for focal cortical dysplasia type II (FCD II) offers good chances for seizure freedom, but remains a challenge with respect to lesion detection, defining the epileptogenic zone and the optimal resection strategy. Integrating results from magnetic source imaging from magnetoencephalography (MEG) with magnetic resonance imaging (MRI) including MRI postprocessing may be useful for optimizing these goals. Methods We here present data from 21 adult FCD II patients, investigated during a 10 year period and evaluated including magnetic source imaging. 16 patients had epilepsy surgery, i.e. histopathologically verified FCD II, and a long follow up. We present our analysis of epileptogenic zones including MEG in relation to structural data according to MRI data and relate these results to surgical outcomes. Results FCD II in our cohort was characterized by high MEG yield and localization accuracy and MEG showed impact on surgical success-rates. MEG source localizations were detected in 95.2% of patients and were as close as 12.3 ± 8,1 mm to the MRI-lesion. After a mean follow up of >3 years, we saw >80% Engel I outcomes, with more favourable outcomes when the MEG source was completely resected (Fishers exact test 0,033). Conclusion We argue for a high value of conducting a combined MEG-MRI approach in the presurgical workup and the resection strategy in patients with FCD II related epilepsy.
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Affiliation(s)
- Burkhard S Kasper
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Karl Rössler
- Department of Neurosurgery, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Hajo M Hamer
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Arnd Dörfler
- Department of Neuroradiology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Ingmar Blümcke
- Department of Neuropathology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Roland Coras
- Department of Neuropathology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Julie Roesch
- Department of Neuroradiology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Angelika Mennecke
- Department of Neuroradiology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Jörg Wellmer
- Ruhr-Epileptology, University Hospital Knappschaftskrankenhaus, Ruhr-University Bochum, In der Schornau 23-25, Germany.
| | - Björn Sommer
- Department of Neurosurgery, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Bogdan Lorber
- Department of Neurology, University Medical Centre Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia.
| | - Johannes D Lang
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Wolfgang Graf
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Hermann Stefan
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Stefan Schwab
- Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Michael Buchfelder
- Department of Neurosurgery, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Stefan Rampp
- Department of Neurosurgery, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
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152
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Koren J, Gritsch G, Pirker S, Herta J, Perko H, Kluge T, Baumgartner C. Automatic ictal onset source localization in presurgical epilepsy evaluation. Clin Neurophysiol 2018; 129:1291-1299. [PMID: 29680731 DOI: 10.1016/j.clinph.2018.03.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 03/07/2018] [Accepted: 03/24/2018] [Indexed: 10/17/2022]
Abstract
OBJECTIVE To test the diagnostic accuracy of a new automatic algorithm for ictal onset source localization (IOSL) during routine presurgical epilepsy evaluation following STARD (Standards for Reporting of Diagnostic Accuracy) criteria. METHODS We included 28 consecutive patients with refractory focal epilepsy (25 patients with temporal lobe epilepsy (TLE) and 3 with extratemporal epilepsy) who underwent resective epilepsy surgery. Ictal EEG patterns were analyzed with a novel automatic IOSL algorithm. IOSL source localizations on a sublobar level were validated by comparison with actual resection sites and seizure free outcome 2 years after surgery. RESULTS Sensitivity of IOSL was 92.3% (TLE: 92.3%); specificity 60% (TLE: 50%); positive predictive value 66.7% (TLE: 66.7%); and negative predictive value 90% (TLE: 85.7%). The likelihood ratio was more than ten times higher for concordant IOSL results as compared to discordant results (p = 0.013). CONCLUSIONS We demonstrated the clinical feasibility of our IOSL approach yielding reasonable high performance measures on a sublobar level. SIGNIFICANCE Our IOSL method may contribute to a correct localization of the seizure onset zone in temporal lobe epilepsy and can readily be used in standard epilepsy monitoring settings. Further studies are needed for validation in extratemporal epilepsy.
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Affiliation(s)
- Johannes Koren
- Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Neurological Department, General Hospital Hietzing with Neurological Center Rosenhügel, Vienna, Austria
| | - Gerhard Gritsch
- Austrian Institute of Technology GmbH (AIT), Safety & Security Department, Vienna, Austria
| | - Susanne Pirker
- Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Neurological Department, General Hospital Hietzing with Neurological Center Rosenhügel, Vienna, Austria
| | - Johannes Herta
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Hannes Perko
- Austrian Institute of Technology GmbH (AIT), Safety & Security Department, Vienna, Austria
| | - Tilmann Kluge
- Austrian Institute of Technology GmbH (AIT), Safety & Security Department, Vienna, Austria
| | - Christoph Baumgartner
- Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Neurological Department, General Hospital Hietzing with Neurological Center Rosenhügel, Vienna, Austria; Department of Epileptology and Clinical Neurophysiology, Sigmund Freud University, Vienna, Austria.
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153
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Chassoux F, Navarro V, Catenoix H, Valton L, Vignal JP. Planning and management of SEEG. Neurophysiol Clin 2018; 48:25-37. [DOI: 10.1016/j.neucli.2017.11.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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154
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Abreu R, Leal A, Lopes da Silva F, Figueiredo P. EEG synchronization measures predict epilepsy-related BOLD-fMRI fluctuations better than commonly used univariate metrics. Clin Neurophysiol 2018; 129:618-635. [PMID: 29414405 DOI: 10.1016/j.clinph.2017.12.038] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 11/29/2017] [Accepted: 12/22/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVE We hypothesize that the hypersynchronization associated with epileptic activity is best described by EEG synchronization measures, and propose to use these as predictors of epilepsy-related BOLD fluctuations. METHODS We computed the phase synchronization index (PSI) and global field synchronization (GFS), within two frequency bands, a broadband (1-45 Hz) and a narrower band focused on the presence of epileptic activity (3-10 Hz). The associated epileptic networks were compared with those obtained using conventional unitary regressors and two power-weighted metrics (total power and root mean square frequency), on nine simultaneous EEG-fMRI datasets from four epilepsy patients, exhibiting inter-ictal epileptiform discharges (IEDs). RESULTS The average PSI within 3-10 Hz achieved the best performance across several measures reflecting reliability in all datasets. The results were cross-validated through electrical source imaging of the IEDs. The applicability of PSI when no IEDs are recorded on the EEG was evaluated on three additional patients, yielding partially plausible networks in all cases. CONCLUSIONS Epileptic networks can be mapped based on the EEG PSI metric within an IED-specific frequency band, performing better than commonly used EEG metrics. SIGNIFICANCE This is the first study to investigate EEG synchronization measures as potential predictors of epilepsy-related BOLD fluctuations.
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Affiliation(s)
- Rodolfo Abreu
- ISR-Lisboa/LARSyS and Department of Bioengineering, Instituto Superior Técnico - Universidade de Lisboa, Portugal.
| | - Alberto Leal
- Department of Neurophysiology, Centro Hospitalar Psiquiátrico de Lisboa, Lisbon, Portugal
| | | | - Patrícia Figueiredo
- ISR-Lisboa/LARSyS and Department of Bioengineering, Instituto Superior Técnico - Universidade de Lisboa, Portugal
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155
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van Klink N, Mol A, Ferrier C, Hillebrand A, Huiskamp G, Zijlmans M. Beamforming applied to surface EEG improves ripple visibility. Clin Neurophysiol 2018; 129:101-111. [DOI: 10.1016/j.clinph.2017.10.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 09/20/2017] [Accepted: 10/05/2017] [Indexed: 01/17/2023]
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156
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Palanca BJA, Maybrier HR, Mickle AM, Farber NB, Hogan RE, Trammel ER, Spencer JW, Bohnenkamp DD, Wildes TS, Ching S, Lenze E, Basner M, Kelz MB, Avidan MS. Cognitive and Neurophysiological Recovery Following Electroconvulsive Therapy: A Study Protocol. Front Psychiatry 2018; 9:171. [PMID: 29867602 PMCID: PMC5960711 DOI: 10.3389/fpsyt.2018.00171] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 04/13/2018] [Indexed: 01/01/2023] Open
Abstract
Electroconvulsive therapy (ECT) employs the elective induction of generalizes seizures as a potent treatment for severe psychiatric illness. As such, ECT provides an opportunity to rigorously study the recovery of consciousness, reconstitution of cognition, and electroencephalographic (EEG) activity following seizures. Fifteen patients with major depressive disorder refractory to pharmacologic therapy will be enrolled (Clinicaltrials.gov, NCT02761330). Adequate seizure duration will be confirmed following right unilateral ECT under etomidate anesthesia. Patients will then undergo randomization for the order in which they will receive three sequential treatments: etomidate + ECT, ketamine + ECT, and ketamine + sham ECT. Sessions will be repeated in the same sequence for a total of six treatments. Before each session, sensorimotor speed, working memory, and executive function will be assessed through a standardized cognitive test battery. After each treatment, the return of purposeful responsiveness to verbal command will be determined. At this point, serial cognitive assessments will begin using the same standardized test battery. The presence of delirium and changes in depression severity will also be ascertained. Sixty-four channel EEG will be acquired throughout baseline, ictal, and postictal epochs. Mixed-effects models will correlate the trajectories of cognitive recovery, clinical outcomes, and EEG metrics over time. This innovative research design will answer whether: (1) time to return of responsiveness will be prolonged with ketamine + ECT compared with ketamine + sham ECT; (2) time of restoration to baseline function in each cognitive domain will take longer after ketamine + ECT than after ketamine + sham ECT; (3) postictal delirium is associated with delayed restoration of baseline function in all cognitive domains; and (4) the sequence of reconstitution of cognitive domains following the three treatments in this study is similar to that occurring after an isoflurane general anesthetic (NCT01911195). Sub-studies will assess the relationships of cognitive recovery to the EEG preceding, concurrent, and following individual ECT sessions. Overall, this study will lead the development of biomarkers for tailoring the cogno-affective recovery of patients undergoing ECT.
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Affiliation(s)
- Ben J A Palanca
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, MO, United States.,Division of Biology and Biomedical Sciences, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - Hannah R Maybrier
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - Angela M Mickle
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - Nuri B Farber
- Department of Psychiatry, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - R Edward Hogan
- Department of Neurology, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - Emma R Trammel
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - J Wylie Spencer
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - Donald D Bohnenkamp
- Department of Psychiatry, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - Troy S Wildes
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - ShiNung Ching
- Division of Biology and Biomedical Sciences, Washington University School of Medicine in St. Louis, St Louis, MO, United States.,Department of Electrical Systems and Engineering, Washington University, St Louis, MO, United States
| | - Eric Lenze
- Department of Psychiatry, Washington University School of Medicine in St. Louis, St Louis, MO, United States
| | - Mathias Basner
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Max B Kelz
- Department of Anesthesiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Michael S Avidan
- Department of Anesthesiology, Washington University School of Medicine in St. Louis, St Louis, MO, United States.,Department of Surgery, Washington University School of Medicine in St. Louis, St Louis, MO, United States
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157
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Bach Justesen A, Eskelund Johansen AB, Martinussen NI, Wasserman D, Terney D, Meritam P, Gardella E, Beniczky S. Added clinical value of the inferior temporal EEG electrode chain. Clin Neurophysiol 2018; 129:291-295. [DOI: 10.1016/j.clinph.2017.09.113] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 09/20/2017] [Accepted: 09/28/2017] [Indexed: 10/18/2022]
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158
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Robinson AK, Venkatesh P, Boring MJ, Tarr MJ, Grover P, Behrmann M. Very high density EEG elucidates spatiotemporal aspects of early visual processing. Sci Rep 2017; 7:16248. [PMID: 29176609 PMCID: PMC5701165 DOI: 10.1038/s41598-017-16377-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/10/2017] [Indexed: 11/15/2022] Open
Abstract
Standard human EEG systems based on spatial Nyquist estimates suggest that 20–30 mm electrode spacing suffices to capture neural signals on the scalp, but recent studies posit that increasing sensor density can provide higher resolution neural information. Here, we compared “super-Nyquist” density EEG (“SND”) with Nyquist density (“ND”) arrays for assessing the spatiotemporal aspects of early visual processing. EEG was measured from 128 electrodes arranged over occipitotemporal brain regions (14 mm spacing) while participants viewed flickering checkerboard stimuli. Analyses compared SND with ND-equivalent subsets of the same electrodes. Frequency-tagged stimuli were classified more accurately with SND than ND arrays in both the time and the frequency domains. Representational similarity analysis revealed that a computational model of V1 correlated more highly with the SND than the ND array. Overall, SND EEG captured more neural information from visual cortex, arguing for increased development of this approach in basic and translational neuroscience.
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Affiliation(s)
- Amanda K Robinson
- Department of Psychology, Carnegie Mellon University, Pittsburgh, USA. .,Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, USA.
| | - Praveen Venkatesh
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, USA.,Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, USA
| | - Matthew J Boring
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, USA.,Department of Neuroscience, University of Pittsburgh, Pittsburgh, USA
| | - Michael J Tarr
- Department of Psychology, Carnegie Mellon University, Pittsburgh, USA.,Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, USA
| | - Pulkit Grover
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, USA.,Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, USA
| | - Marlene Behrmann
- Department of Psychology, Carnegie Mellon University, Pittsburgh, USA.,Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, USA
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159
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James CE, Oechslin MS, Michel CM, De Pretto M. Electrical Neuroimaging of Music Processing Reveals Mid-Latency Changes with Level of Musical Expertise. Front Neurosci 2017; 11:613. [PMID: 29163017 PMCID: PMC5682036 DOI: 10.3389/fnins.2017.00613] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 10/20/2017] [Indexed: 11/28/2022] Open
Abstract
This original research focused on the effect of musical training intensity on cerebral and behavioral processing of complex music using high-density event-related potential (ERP) approaches. Recently we have been able to show progressive changes with training in gray and white matter, and higher order brain functioning using (f)MRI [(functional) Magnetic Resonance Imaging], as well as changes in musical and general cognitive functioning. The current study investigated the same population of non-musicians, amateur pianists and expert pianists using spatio-temporal ERP analysis, by means of microstate analysis, and ERP source imaging. The stimuli consisted of complex musical compositions containing three levels of transgression of musical syntax at closure that participants appraised. ERP waveforms, microstates and underlying brain sources revealed gradual differences according to musical expertise in a 300–500 ms window after the onset of the terminal chords of the pieces. Within this time-window, processing seemed to concern context-based memory updating, indicated by a P3b-like component or microstate for which underlying sources were localized in the right middle temporal gyrus, anterior cingulate and right parahippocampal areas. Given that the 3 expertise groups were carefully matched for demographic factors, these results provide evidence of the progressive impact of training on brain and behavior.
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Affiliation(s)
- Clara E James
- School of Health Sciences, University of Applied Sciences and Arts Western Switzerland, Geneva, Switzerland.,Faculty of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland.,Neuroscience Center, University of Geneva, Geneva, Switzerland
| | - Mathias S Oechslin
- Faculty of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland.,Department of Education and Culture of the Canton of Thurgau, Frauenfeld, Switzerland
| | - Christoph M Michel
- Functional Brain Mapping Lab, Department of Fundamental Neurosciences, University of Geneva, Geneva, Switzerland.,Center for Biomedical Imaging (CIBM), Lausanne, Switzerland
| | - Michael De Pretto
- Faculty of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland.,Neurology Unit, Medicine Department, Faculty of Sciences, University of Fribourg, Fribourg, Switzerland
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160
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Neugebauer F, Möddel G, Rampp S, Burger M, Wolters CH. The Effect of Head Model Simplification on Beamformer Source Localization. Front Neurosci 2017; 11:625. [PMID: 29209157 PMCID: PMC5701642 DOI: 10.3389/fnins.2017.00625] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/26/2017] [Indexed: 11/13/2022] Open
Abstract
Beamformers are a widely-used tool in brain analysis with magnetoencephalography (MEG) and electroencephalography (EEG). For the construction of the beamformer filters realistic head volume conductor modeling is necessary for accurately computing the EEG and MEG leadfields, i.e., for solving the EEG and MEG forward problem. In this work, we investigate the influence of including realistic head tissue compartments into a finite element method (FEM) model on the beamformer's localization ability. Specifically, we investigate the effect of including cerebrospinal fluid, gray matter, and white matter distinction, as well as segmenting the skull bone into compacta and spongiosa, and modeling white matter anisotropy. We simulate an interictal epileptic measurement with white sensor noise. Beamformer filters are constructed with unit gain, unit array gain, and unit noise gain constraint. Beamformer source positions are determined by evaluating power and excess sample kurtosis (g2) of the source-waveforms at all source space nodes. For both modalities, we see a strong effect of modeling the cerebrospinal fluid and white and gray matter. Depending on the source position, both effects can each be in the magnitude of centimeters, rendering their modeling necessary for successful localization. Precise skull modeling mainly effected the EEG up to a few millimeters, while both modalities could profit from modeling white matter anisotropy to a smaller extent of 5-10 mm. The unit noise gain or neural activity index beamformer behaves similarly to the array gain beamformer when noise strength is sufficiently high. Variance localization seems more robust against modeling errors than kurtosis.
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Affiliation(s)
- Frank Neugebauer
- Institute for Biomagnetism und Biosignalanalysis, University of Münster, Münster, Germany
| | - Gabriel Möddel
- Department of Sleep Medicine and Neuromuscular Disorders, Epilepsy Center Münster-Osnabrück, University of Münster, Münster, Germany
| | - Stefan Rampp
- Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany
| | - Martin Burger
- Institute for Computational and Applied Mathematics, University of Münster, Münster, Germany
| | - Carsten H. Wolters
- Institute for Biomagnetism und Biosignalanalysis, University of Münster, Münster, Germany
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161
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162
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Hamid L, Al Farawn A, Merlet I, Japaridze N, Heute U, Stephani U, Galka A, Wendling F, Siniatchkin M. Source reconstruction via the spatiotemporal Kalman filter and LORETA from EEG time series with 32 or fewer electrodes. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2017:2218-2222. [PMID: 29060337 DOI: 10.1109/embc.2017.8037295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The clinical routine of non-invasive electroencephalography (EEG) is usually performed with 8-40 electrodes, especially in long-term monitoring, infants or emergency care. There is a need in clinical and scientific brain imaging to develop inverse solution methods that can reconstruct brain sources from these low-density EEG recordings. In this proof-of-principle paper we investigate the performance of the spatiotemporal Kalman filter (STKF) in EEG source reconstruction with 9-, 19- and 32- electrodes. We used simulated EEG data of epileptic spikes generated from lateral frontal and lateral temporal brain sources using state-of-the-art neuronal population models. For validation of source reconstruction, we compared STKF results to the location of the simulated source and to the results of low-resolution brain electromagnetic tomography (LORETA) standard inverse solution. STKF consistently showed less localization bias compared to LORETA, especially when the number of electrodes was decreased. The results encourage further research into the application of the STKF in source reconstruction of brain activity from low-density EEG recordings.
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163
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Seeck M, Koessler L, Bast T, Leijten F, Michel C, Baumgartner C, He B, Beniczky S. The standardized EEG electrode array of the IFCN. Clin Neurophysiol 2017; 128:2070-2077. [DOI: 10.1016/j.clinph.2017.06.254] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 05/10/2017] [Accepted: 06/20/2017] [Indexed: 11/17/2022]
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164
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Berchio C, Piguet C, Michel CM, Cordera P, Rihs TA, Dayer AG, Aubry JM. Dysfunctional gaze processing in bipolar disorder. NEUROIMAGE-CLINICAL 2017; 16:545-556. [PMID: 28971006 PMCID: PMC5608173 DOI: 10.1016/j.nicl.2017.09.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 09/01/2017] [Accepted: 09/05/2017] [Indexed: 01/15/2023]
Abstract
Gaze conveys emotional information, and humans present sensitivity to its direction from the earliest days of life. Bipolar disorder is a disease characterized by fluctuating states of emotional and cognitive dysregulation. To explore the role of attentional control on face processing in bipolar patients (BP) we used gaze direction as an emotion modulation parameter in a two-back Working Memory (WM) task while high-density EEG data were acquired. Since gaze direction influences emotional attributions to faces with neutral expressions as well, we presented neutral faces with direct and averted gaze. Nineteen euthymic BP and a sample of age- and gender-matched controls were examined. In BP we observed diminished P200 and augmented P300 evoked responses, differentially modulated by non-repeated or repeated faces, as well as by gaze direction. BP showed a reduced P200 amplitude, significantly stronger for faces with direct gaze than averted gaze. Source localization of P200 indicated decreased activity in sensory-motor regions and frontal areas suggestive of abnormal affective processing of neutral faces. The present study provides neurophysiological evidence for abnormal gaze processing in BP and suggests dysfunctional processing of direct eye contact as a prominent characteristic of bipolar disorder. This ERP study identified abnormalities in gaze processing in bipolar patients. We observed functional anomalies in the P200 and P300 evoked responses. BP showed a strong suppression of the P200 for faces with direct gaze. Source localization indicated decreased activity in sensory-motor regions.
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Affiliation(s)
- Cristina Berchio
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland.,Department of Mental Health and Psychiatry, Service of Psychiatric Specialties, Mood Disorders Unit University Hospitals of Geneva, Switzerland
| | - Camille Piguet
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland.,Department of Mental Health and Psychiatry, Service of Psychiatric Specialties, Mood Disorders Unit University Hospitals of Geneva, Switzerland
| | - Christoph M Michel
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland.,Biomedical Imaging Center (CIBM) Lausanne, Geneva, Switzerland
| | - Paolo Cordera
- Department of Mental Health and Psychiatry, Service of Psychiatric Specialties, Mood Disorders Unit University Hospitals of Geneva, Switzerland
| | - Tonia A Rihs
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
| | - Alexandre G Dayer
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland.,Department of Mental Health and Psychiatry, Service of Psychiatric Specialties, Mood Disorders Unit University Hospitals of Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - Jean-Michel Aubry
- Department of Mental Health and Psychiatry, Service of Psychiatric Specialties, Mood Disorders Unit University Hospitals of Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Geneva, Switzerland
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165
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Exploring the Epileptic Brain Network Using Time-Variant Effective Connectivity and Graph Theory. IEEE J Biomed Health Inform 2017; 21:1411-1421. [DOI: 10.1109/jbhi.2016.2607802] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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166
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Mendes Coelho VC, Morita ME, Amorim BJ, Ramos CD, Yasuda CL, Tedeschi H, Ghizoni E, Cendes F. Automated Online Quantification Method for 18F-FDG Positron Emission Tomography/CT Improves Detection of the Epileptogenic Zone in Patients with Pharmacoresistant Epilepsy. Front Neurol 2017; 8:453. [PMID: 28919879 PMCID: PMC5585153 DOI: 10.3389/fneur.2017.00453] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 08/15/2017] [Indexed: 12/02/2022] Open
Abstract
Aims To assess the validity of an online method to quantitatively evaluate cerebral hypometabolism in patients with pharmacoresistant focal epilepsy as a complement to the visual analysis of the 18F-FDG positron emission tomography (PET)/CT exam. Methods A total of 39 patients with pharmacoresistant epilepsy and probable focal cortical dysplasia [22 patients with frontal lobe epilepsy (FLE) and 17 with temporal lobe epilepsy (TLE)] underwent a presurgical evaluation including EEG, video-EEG, MRI, and 18F-FDG PET/CT. We conducted the automated quantification of their 18F-FDG PET/CT data and compared the results with those of the visual-PET analysis conducted by experienced nuclear medicine physicians. For each patient group, we calculated Cohen’s Kappa coefficient for the visual and quantitative analyses, as well as each method’s sensitivity, specificity, and positive and negative predictive values. Results For the TLE group, both the visual and quantitative analyses showed high agreement. Thus, although the quantitative analysis could be used as a complement, the visual analysis on its own was consistent and precise. For the FLE group, on the other hand, the visual analysis categorized almost half of the cases as normal, revealing very low agreement. For those patients, the quantitative analysis proved critical to identify the focal hypometabolism characteristic of the epileptogenic zone. Our results suggest that the quantitative analysis of 18F-FDG PET/CT data is critical for patients with extratemporal epilepsies, and especially those with subtle MRI findings. Furthermore, it can easily be used during the routine clinical evaluation of 18F-FDG PET/CT exams. Significance Our results show that quantification of 18F-FDG PET is an informative complementary method that can be added to the routine visual evaluation of patients with subtle lesions, particularly those in the frontal lobes.
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Affiliation(s)
| | - Marcia E Morita
- Neurology/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
| | - Barbara J Amorim
- Nuclear Medicine Department, Unicamp - University of Campinas, Campinas, Brazil
| | - Celso Darío Ramos
- Nuclear Medicine Department, Unicamp - University of Campinas, Campinas, Brazil
| | - Clarissa L Yasuda
- Neurology/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
| | - Helder Tedeschi
- Neurosurgery/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
| | - Enrico Ghizoni
- Neurosurgery/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
| | - Fernando Cendes
- Neurology/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
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167
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Cosandier-Rimélé D, Ramantani G, Zentner J, Schulze-Bonhage A, Dümpelmann M. A realistic multimodal modeling approach for the evaluation of distributed source analysis: application to sLORETA. J Neural Eng 2017; 14:056008. [DOI: 10.1088/1741-2552/aa7db1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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168
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Centeno M, Tierney TM, Perani S, Shamshiri EA, St Pier K, Wilkinson C, Konn D, Vulliemoz S, Grouiller F, Lemieux L, Pressler RM, Clark CA, Cross JH, Carmichael DW. Combined electroencephalography-functional magnetic resonance imaging and electrical source imaging improves localization of pediatric focal epilepsy. Ann Neurol 2017; 82:278-287. [PMID: 28749544 DOI: 10.1002/ana.25003] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 07/16/2017] [Accepted: 07/17/2017] [Indexed: 11/05/2022]
Abstract
OBJECTIVE Surgical treatment in epilepsy is effective if the epileptogenic zone (EZ) can be correctly localized and characterized. Here we use simultaneous electroencephalography-functional magnetic resonance imaging (EEG-fMRI) data to derive EEG-fMRI and electrical source imaging (ESI) maps. Their yield and their individual and combined ability to (1) localize the EZ and (2) predict seizure outcome were then evaluated. METHODS Fifty-three children with drug-resistant epilepsy underwent EEG-fMRI. Interictal discharges were mapped using both EEG-fMRI hemodynamic responses and ESI. A single localization was derived from each individual test (EEG-fMRI global maxima [GM]/ESI maximum) and from the combination of both maps (EEG-fMRI/ESI spatial intersection). To determine the localization accuracy and its predictive performance, the individual and combined test localizations were compared to the presumed EZ and to the postsurgical outcome. RESULTS Fifty-two of 53 patients had significant maps: 47 of 53 for EEG-fMRI, 44 of 53 for ESI, and 34 of 53 for both. The EZ was well characterized in 29 patients; 26 had an EEG-fMRI GM localization that was correct in 11, 22 patients had ESI localization that was correct in 17, and 12 patients had combined EEG-fMRI and ESI that was correct in 11. Seizure outcome following resection was correctly predicted by EEG-fMRI GM in 8 of 20 patients, and by the ESI maximum in 13 of 16. The combined EEG-fMRI/ESI region entirely predicted outcome in 9 of 9 patients, including 3 with no lesion visible on MRI. INTERPRETATION EEG-fMRI combined with ESI provides a simple unbiased localization that may predict surgery better than each individual test, including in MRI-negative patients. Ann Neurol 2017;82:278-287.
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Affiliation(s)
- Maria Centeno
- Developmental Imaging and Biophysics Section, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom.,Epilepsy Unit, Department of Neurophysiology, Great Ormond Street Hospital, London, United Kingdom
| | - Tim M Tierney
- Developmental Imaging and Biophysics Section, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Suejen Perani
- Developmental Imaging and Biophysics Section, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom.,Division of Neuroscience, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Elhum A Shamshiri
- Developmental Imaging and Biophysics Section, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Kelly St Pier
- Epilepsy Unit, Department of Neurophysiology, Great Ormond Street Hospital, London, United Kingdom
| | - Charlotte Wilkinson
- Epilepsy Unit, Department of Neurophysiology, Great Ormond Street Hospital, London, United Kingdom
| | - Daniel Konn
- Neurophysiology Department, University Hospital Southampton, Southampton, United Kingdom
| | - Serge Vulliemoz
- EEG and Epilepsy Unit, Department of Neurology, University Hospitals and Faculty of Medicine of Geneva, Geneva, Switzerland
| | - Frédéric Grouiller
- Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland
| | - Louis Lemieux
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom
| | - Ronit M Pressler
- Neuroscience Medicine, Great Ormond Street Hospital for Children, London, United Kingdom.,Clinical Neuroscience, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Christopher A Clark
- Developmental Imaging and Biophysics Section, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - J Helen Cross
- Neuroscience Medicine, Great Ormond Street Hospital for Children, London, United Kingdom.,Clinical Neuroscience, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - David W Carmichael
- Developmental Imaging and Biophysics Section, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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Abdallah C, Maillard LG, Rikir E, Jonas J, Thiriaux A, Gavaret M, Bartolomei F, Colnat-Coulbois S, Vignal JP, Koessler L. Localizing value of electrical source imaging: Frontal lobe, malformations of cortical development and negative MRI related epilepsies are the best candidates. NEUROIMAGE-CLINICAL 2017; 16:319-329. [PMID: 28856095 PMCID: PMC5565782 DOI: 10.1016/j.nicl.2017.08.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 07/24/2017] [Accepted: 08/07/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We aimed to prospectively assess the anatomical concordance of electric source localizations of interictal discharges with the epileptogenic zone (EZ) estimated by stereo-electroencephalography (SEEG) according to different subgroups: the type of epilepsy, the presence of a structural MRI lesion, the aetiology and the depth of the EZ. METHODS In a prospective multicentric observational study, we enrolled 85 consecutive patients undergoing pre-surgical SEEG investigation for focal drug-resistant epilepsy. Electric source imaging (ESI) was performed before SEEG. Source localizations were obtained from dipolar and distributed source methods. Anatomical concordance between ESI and EZ was defined according to 36 predefined sublobar regions. ESI was interpreted blinded to- and subsequently compared with SEEG estimated EZ. RESULTS 74 patients were finally analyzed. 38 patients had temporal and 36 extra-temporal lobe epilepsy. MRI was positive in 52. 41 patients had malformation of cortical development (MCD), 33 had another or an unknown aetiology. EZ was medial in 27, lateral in 13, and medio-lateral in 34. In the overall cohort, ESI completely or partly localized the EZ in 85%: full concordance in 13 cases and partial concordance in 50 cases. The rate of ESI full concordance with EZ was significantly higher in (i) frontal lobe epilepsy (46%; p = 0.05), (ii) cases of negative MRI (36%; p = 0.01) and (iii) MCD (27%; p = 0.03). The rate of ESI full concordance with EZ was not statistically different according to the depth of the EZ. SIGNIFICANCE We prospectively demonstrated that ESI more accurately estimated the EZ in subgroups of patients who are often the most difficult cases in epilepsy surgery: frontal lobe epilepsy, negative MRI and the presence of MCD.
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Affiliation(s)
- Chifaou Abdallah
- Neurology Department, University Hospital of Nancy, Nancy, France
| | - Louis G Maillard
- Neurology Department, University Hospital of Nancy, Nancy, France.,CRAN, UMR 7039, Lorraine University, Vandœuvre-les-Nancy Cedex, France.,CNRS, CRAN, UMR 7039, Vandœuvre-les-Nancy Cedex, France.,Medical Faculty, Lorraine University, Nancy, France
| | - Estelle Rikir
- Neurology Department, University Hospital of Sart-Tilman, Liege, Belgium.,Medical Faculty, Liege University, Liege, Belgium
| | - Jacques Jonas
- Neurology Department, University Hospital of Nancy, Nancy, France.,CRAN, UMR 7039, Lorraine University, Vandœuvre-les-Nancy Cedex, France.,CNRS, CRAN, UMR 7039, Vandœuvre-les-Nancy Cedex, France
| | - Anne Thiriaux
- Neurology department, University Hospital of Reims, Reims, France
| | - Martine Gavaret
- Clinical Neurophysiology Department, AP-HM, University Hospital la Timone, Marseille, France.,INSERM UMR 1106, Institut de Neurosciences des Systemes, Marseille, France.,Medical Faculty, Aix-Marseille University, Marseille, France
| | - Fabrice Bartolomei
- Clinical Neurophysiology Department, AP-HM, University Hospital la Timone, Marseille, France.,INSERM UMR 1106, Institut de Neurosciences des Systemes, Marseille, France.,Medical Faculty, Aix-Marseille University, Marseille, France
| | - Sophie Colnat-Coulbois
- Medical Faculty, Lorraine University, Nancy, France.,Neurosurgery Department, University Hospital of Nancy, Nancy, France
| | - Jean-Pierre Vignal
- Neurology Department, University Hospital of Nancy, Nancy, France.,CRAN, UMR 7039, Lorraine University, Vandœuvre-les-Nancy Cedex, France.,CNRS, CRAN, UMR 7039, Vandœuvre-les-Nancy Cedex, France
| | - Laurent Koessler
- Neurology Department, University Hospital of Nancy, Nancy, France.,CRAN, UMR 7039, Lorraine University, Vandœuvre-les-Nancy Cedex, France.,CNRS, CRAN, UMR 7039, Vandœuvre-les-Nancy Cedex, France
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170
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Zerouali Y, Ghaziri J, Nguyen DK. Multimodal investigation of epileptic networks: The case of insular cortex epilepsy. PROGRESS IN BRAIN RESEARCH 2017; 226:1-33. [PMID: 27323937 DOI: 10.1016/bs.pbr.2016.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The insula is a deep cortical structure sharing extensive synaptic connections with a variety of brain regions, including several frontal, temporal, and parietal structures. The identification of the insular connectivity network is obviously valuable for understanding a number of cognitive processes, but also for understanding epilepsy since insular seizures involve a number of remote brain regions. Ultimately, knowledge of the structure and causal relationships within the epileptic networks associated with insular cortex epilepsy can offer deeper insights into this relatively neglected type of epilepsy enabling the refining of the clinical approach in managing patients affected by it. In the present chapter, we first review the multimodal noninvasive tests performed during the presurgical evaluation of epileptic patients with drug refractory focal epilepsy, with particular emphasis on their value for the detection of insular cortex epilepsy. Second, we review the emerging multimodal investigation techniques in the field of epilepsy, that aim to (1) enhance the detection of insular cortex epilepsy and (2) unveil the architecture and causal relationships within epileptic networks. We summarize the results of these approaches with emphasis on the specific case of insular cortex epilepsy.
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Affiliation(s)
- Y Zerouali
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, QC, Canada; Ecole Polytechnique de Montréal, Montreal, QC, Canada
| | - J Ghaziri
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, QC, Canada
| | - D K Nguyen
- Research Centre, Centre hospitalier de l'Université de Montréal, Montreal, QC, Canada; CHUM-Hôpital Notre-Dame, Montreal, QC, Canada.
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171
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van Mierlo P, Strobbe G, Keereman V, Birot G, Gadeyne S, Gschwind M, Carrette E, Meurs A, Van Roost D, Vonck K, Seeck M, Vulliémoz S, Boon P. Automated long-term EEG analysis to localize the epileptogenic zone. Epilepsia Open 2017; 2:322-333. [PMID: 29588961 PMCID: PMC5862106 DOI: 10.1002/epi4.12066] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2017] [Indexed: 11/10/2022] Open
Abstract
Objective We investigated the performance of automatic spike detection and subsequent electroencephalogram (EEG) source imaging to localize the epileptogenic zone (EZ) from long-term EEG recorded during video-EEG monitoring. Methods In 32 patients, spikes were automatically detected in the EEG and clustered according to their morphology. The two spike clusters with most single events in each patient were averaged and localized in the brain at the half-rising time and peak of the spike using EEG source imaging. On the basis of the distance from the sources to the resection and the known patient outcome after surgery, the performance of the automated EEG analysis to localize the EZ was quantified. Results In 28 out of the 32 patients, the automatically detected spike clusters corresponded with the reported interictal findings. The median distance to the resection in patients with Engel class I outcome was 6.5 and 15 mm for spike cluster 1 and 27 and 26 mm for cluster 2, at the peak and the half-rising time of the spike, respectively. Spike occurrence (cluster 1 vs. cluster 2) and spike timing (peak vs. half-rising) significantly influenced the distance to the resection (p < 0.05). For patients with Engel class II, III, and IV outcomes, the median distance increased to 36 and 36 mm for cluster 1. Localizing spike cluster 1 at the peak resulted in a sensitivity of 70% and specificity of 100%, positive prediction value (PPV) of 100%, and negative predictive value (NPV) of 53%. Including the results of spike cluster 2 led to an increased sensitivity of 79% NPV of 55% and diagnostic OR of 11.4, while the specificity dropped to 75% and the PPV to 90%. Significance We showed that automated analysis of long-term EEG recordings results in a high sensitivity and specificity to localize the epileptogenic focus.
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Affiliation(s)
- Pieter van Mierlo
- Medical Image and Signal Processing Group Department of Electronics and Information Systems Ghent University-iMinds Medical IT Department Ghent Belgium.,Functional Brain Mapping Laboratory Department of Fundamental Neurosciences University of Geneva Geneva Switzerland
| | - Gregor Strobbe
- Medical Image and Signal Processing Group Department of Electronics and Information Systems Ghent University-iMinds Medical IT Department Ghent Belgium
| | - Vincent Keereman
- Medical Image and Signal Processing Group Department of Electronics and Information Systems Ghent University-iMinds Medical IT Department Ghent Belgium.,Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Gwénael Birot
- Functional Brain Mapping Laboratory Department of Fundamental Neurosciences University of Geneva Geneva Switzerland
| | - Stefanie Gadeyne
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Markus Gschwind
- Functional Brain Mapping Laboratory Department of Fundamental Neurosciences University of Geneva Geneva Switzerland.,Epilepsy and EEG Unit University Hospital of Geneva Geneva Switzerland
| | - Evelien Carrette
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Alfred Meurs
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Dirk Van Roost
- Department of Neurosurgery Ghent University Hospital Ghent Belgium
| | - Kristl Vonck
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
| | - Margitta Seeck
- Epilepsy and EEG Unit University Hospital of Geneva Geneva Switzerland
| | - Serge Vulliémoz
- Functional Brain Mapping Laboratory Department of Fundamental Neurosciences University of Geneva Geneva Switzerland.,Epilepsy and EEG Unit University Hospital of Geneva Geneva Switzerland
| | - Paul Boon
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology Department of Neurology Ghent University Hospital Ghent Belgium
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172
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Safety and EEG data quality of concurrent high-density EEG and high-speed fMRI at 3 Tesla. PLoS One 2017; 12:e0178409. [PMID: 28552957 PMCID: PMC5446172 DOI: 10.1371/journal.pone.0178409] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 05/13/2017] [Indexed: 11/19/2022] Open
Abstract
PURPOSE Concurrent EEG and fMRI is increasingly used to characterize the spatial-temporal dynamics of brain activity. However, most studies to date have been limited to conventional echo-planar imaging (EPI). There is considerable interest in integrating recently developed high-speed fMRI methods with high-density EEG to increase temporal resolution and sensitivity for task-based and resting state fMRI, and for detecting interictal spikes in epilepsy. In the present study using concurrent high-density EEG and recently developed high-speed fMRI methods, we investigate safety of radiofrequency (RF) related heating, the effect of EEG on cortical signal-to-noise ratio (SNR) in fMRI, and assess EEG data quality. MATERIALS AND METHODS The study compared EPI, multi-echo EPI, multi-band EPI and multi-slab echo-volumar imaging pulse sequences, using clinical 3 Tesla MR scanners from two different vendors that were equipped with 64- and 256-channel MR-compatible EEG systems, respectively, and receive only array head coils. Data were collected in 11 healthy controls (3 males, age range 18-70 years) and 13 patients with epilepsy (8 males, age range 21-67 years). Three of the healthy controls were scanned with the 256-channel EEG system, the other subjects were scanned with the 64-channel EEG system. Scalp surface temperature, SNR in occipital cortex and head movement were measured with and without the EEG cap. The degree of artifacts and the ability to identify background activity was assessed by visual analysis by a trained expert in the 64 channel EEG data (7 healthy controls, 13 patients). RESULTS RF induced heating at the surface of the EEG electrodes during a 30-minute scan period with stable temperature prior to scanning did not exceed 1.0° C with either EEG system and any of the pulse sequences used in this study. There was no significant decrease in cortical SNR due to the presence of the EEG cap (p > 0.05). No significant differences in the visually analyzed EEG data quality were found between EEG recorded during high-speed fMRI and during conventional EPI (p = 0.78). Residual ballistocardiographic artifacts resulted in 58% of EEG data being rated as poor quality. CONCLUSION This study demonstrates that high-density EEG can be safely implemented in conjunction with high-speed fMRI and that high-speed fMRI does not adversely affect EEG data quality. However, the deterioration of the EEG quality due to residual ballistocardiographic artifacts remains a significant constraint for routine clinical applications of concurrent EEG-fMRI.
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173
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Boom M, Raskin JS, Curry DJ, Weiner HL, Peters JM. Technological advances in pediatric epilepsy surgery: implications for tuberous sclerosis complex. FUTURE NEUROLOGY 2017. [DOI: 10.2217/fnl-2017-0005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In selected children with tuberous sclerosis complex, epilepsy surgery leads to seizure freedom or seizure reduction. The current standard involves a multimodal pre-surgical workup followed by invasive electrocorticographic monitoring and resective surgery. Recent insights in the disorder and novel technologies are changing the approach to pediatric epilepsy surgery in tuberous sclerosis complex. New evidence suggests tubers are poorly delineated, and epileptogenic activity may originate in the perituber tissue. Novel imaging modalities relevant to surgical planning include high-resolution MRI, α-methyl-l-tryptophan or fluorodeoxyglucose PET with diffusion tensor imaging. Advanced neurophysiological techniques have improved identification of the surgical target, including magnetoencephalography, electrical source imaging of high-density electroencephalograph data, and high-frequency oscillations in electrocorticography data. Simultaneously, novel surgical tools including stereo-electroencephalography and laser-induced thermal therapy have become available for children. This article reviews the literature in the light of these rapidly changing technologies.
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Affiliation(s)
- Merel Boom
- Division of Epilepsy & Clinical Neurophysiology, Boston Children’s Hospital & Harvard Medical School, 300 Longwood Avenue, BCH 3063, Boston, MA 02115, USA
| | - Jeffrey S Raskin
- Division of Pediatric Neurosurgery, Department of Surgery, Texas Children’s Hospital & Department of Neurosurgery, Baylor College of Medicine, 6701 Fannin St. Suite 1230.01, Houston, TX 77030, USA
| | - Daniel J Curry
- Division of Pediatric Neurosurgery, Department of Surgery, Texas Children’s Hospital & Department of Neurosurgery, Baylor College of Medicine, 6701 Fannin St. Suite 1230.01, Houston, TX 77030, USA
| | - Howard L Weiner
- Division of Pediatric Neurosurgery, Department of Surgery, Texas Children’s Hospital & Department of Neurosurgery, Baylor College of Medicine, 6701 Fannin St. Suite 1230.01, Houston, TX 77030, USA
| | - Jurriaan M Peters
- Division of Epilepsy & Clinical Neurophysiology, Boston Children’s Hospital & Harvard Medical School, 300 Longwood Avenue, BCH 3063, Boston, MA 02115, USA
- Computational Radiology Laboratory, Department of Radiology, Boston Children's Hospital and Harvard Medical School,300 Longwood Avenue, BCH 3429, Boston, MA 02115, SA
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174
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Multichannel interictal spike activity detection using time–frequency entropy measure. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2017; 40:413-425. [DOI: 10.1007/s13246-017-0550-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 04/05/2017] [Indexed: 11/26/2022]
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175
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Nemtsas P, Birot G, Pittau F, Michel CM, Schaller K, Vulliemoz S, Kimiskidis VK, Seeck M. Source localization of ictal epileptic activity based on high-density scalp EEG data. Epilepsia 2017; 58:1027-1036. [DOI: 10.1111/epi.13749] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2017] [Indexed: 02/05/2023]
Affiliation(s)
- Petros Nemtsas
- Laboratory of Clinical Neurophysiology; AHEPA Hospital; Aristotle University of Thessaloniki; Thessaloniki Greece
| | - Gwenael Birot
- Department of Fundamental Neurosciences; Functional Brain Mapping Lab; University of Geneva; Geneva Switzerland
| | - Francesca Pittau
- EEG & Epilepsy Unit; Department of Clinical Neurosciences; University Hospital of Geneva; Geneva Switzerland
| | - Christoph M. Michel
- Department of Fundamental Neurosciences; Functional Brain Mapping Lab; University of Geneva; Geneva Switzerland
- Center for Biomedical Imaging (CIBM) Lausanne; Geneva Switzerland
| | - Karl Schaller
- Department of Clinical Neurosciences; Neurosurgery Clinic; University Hospital of Geneva; Geneva Switzerland
| | - Serge Vulliemoz
- EEG & Epilepsy Unit; Department of Clinical Neurosciences; University Hospital of Geneva; Geneva Switzerland
| | - Vasilios K. Kimiskidis
- Laboratory of Clinical Neurophysiology; AHEPA Hospital; Aristotle University of Thessaloniki; Thessaloniki Greece
| | - Margitta Seeck
- EEG & Epilepsy Unit; Department of Clinical Neurosciences; University Hospital of Geneva; Geneva Switzerland
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176
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Martinez-Vargas JD, Strobbe G, Vonck K, van Mierlo P, Castellanos-Dominguez G. Improved Localization of Seizure Onset Zones Using Spatiotemporal Constraints and Time-Varying Source Connectivity. Front Neurosci 2017; 11:156. [PMID: 28428738 PMCID: PMC5382162 DOI: 10.3389/fnins.2017.00156] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 03/10/2017] [Indexed: 11/30/2022] Open
Abstract
Presurgical evaluation of brain neural activity is commonly carried out in refractory epilepsy patients to delineate as accurately as possible the seizure onset zone (SOZ) before epilepsy surgery. In practice, any subjective interpretation of electroencephalographic (EEG) recordings is hindered mainly because of the highly stochastic behavior of the epileptic activity. We propose a new method for dynamic source connectivity analysis that aims to accurately localize the seizure onset zones by explicitly including temporal, spectral, and spatial information of the brain neural activity extracted from EEG recordings. In particular, we encode the source nonstationarities in three critical stages of processing: Inverse problem solution, estimation of the time courses extracted from the regions of interest, and connectivity assessment. With the aim to correctly encode all temporal dynamics of the seizure-related neural network, a directed functional connectivity measure is employed to quantify the information flow variations over the time window of interest. Obtained results on simulated and real EEG data confirm that the proposed approach improves the accuracy of SOZ localization.
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Affiliation(s)
- Juan D Martinez-Vargas
- Signal Processing and Recognition Group, Universidad Nacional de ColombiaManizales, Colombia
| | - Gregor Strobbe
- Medical Image and Signal Processing Group, iMinds Medical IT Department, Ghent UniversityGhent, Belgium
| | - Kristl Vonck
- Laboratory for Clinical and Experimental Neurophysiology, Neurobiology and Neuropsychology, Ghent University HospitalGhent, Belgium
| | - Pieter van Mierlo
- Medical Image and Signal Processing Group, iMinds Medical IT Department, Ghent UniversityGhent, Belgium
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177
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Muhlhofer W, Tan Y, Mueller SG, Knowlton R. MRI
‐negative temporal lobe epilepsy—What do we know? Epilepsia 2017; 58:727-742. [DOI: 10.1111/epi.13699] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2017] [Indexed: 01/01/2023]
Affiliation(s)
- Wolfgang Muhlhofer
- University of California San Francisco (UCSF) San Francisco California U.S.A
- University of Alabama Birmingham (UAB) Birmingham Alabama U.S.A
| | - Yee‐Leng Tan
- University of California San Francisco (UCSF) San Francisco California U.S.A
- National Neuroscience Institute Singapore Singapore
| | - Susanne G. Mueller
- University of California San Francisco (UCSF) San Francisco California U.S.A
- Center for Imaging of Neurodegenerative Diseases (CIND) San Francisco California U.S.A
- Department of Radiology UCSF San Francisco CaliforniaU.S.A
| | - Robert Knowlton
- University of California San Francisco (UCSF) San Francisco California U.S.A
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Pittau F, Ferri L, Fahoum F, Dubeau F, Gotman J. Contributions of EEG-fMRI to Assessing the Epileptogenicity of Focal Cortical Dysplasia. Front Comput Neurosci 2017; 11:8. [PMID: 28265244 PMCID: PMC5316536 DOI: 10.3389/fncom.2017.00008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/02/2017] [Indexed: 12/16/2022] Open
Abstract
Purpose: To examine the ability of the BOLD response to EEG spikes to assess the epileptogenicity of the lesion in patients with focal cortical dysplasia (FCD). Method: Patients with focal epilepsy and FCD who underwent 3T EEG-fMRI from 2006 to 2010 were included. Diagnosis of FCD was based on neuroradiology (MRI+), or histopathology in MRI-negative cases (MRI−). Patients underwent 120 min EEG-fMRI recording session. Spikes similar to those recorded outside the scanner were marked in the filtered EEG. The lesion (in MRI+) or the removed cortex (in MRI−) was marked on the anatomical T1 sequence, blindly to the BOLD response, after reviewing the FLAIR images. For each BOLD response we assessed the concordance with the spike field and with the lesion in MRI+ or the removed cortex in MRI−. BOLD responses were considered “concordant” if the maximal t-value was inside the marking. Follow-up after resection was used as gold-standard. Results: Twenty patients were included (13 MRI+, 7 MRI−), but in seven the EEG was not active or there were artifacts during acquisition. In all 13 studied patients, at least one BOLD response was concordant with the spike field; in 9/13 (69%) at least one BOLD response was concordant with the lesion: in 6/7 (86%) MRI+ and in 3/6 (50%) MRI− patients. Conclusions: Our study shows a high level of concordance between FCD and BOLD response. This data could provide useful information especially for MRI negative patients. Moreover, it shows in almost all FCD patients, a metabolic involvement of remote cortical or subcortical structures, corroborating the concept of epileptic network.
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Affiliation(s)
- Francesca Pittau
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill UniversityQuébec, QC, Canada; Neurology Department, Geneva University HospitalsGeneva, Switzerland
| | - Lorenzo Ferri
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University Québec, QC, Canada
| | - Firas Fahoum
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University Québec, QC, Canada
| | - François Dubeau
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University Québec, QC, Canada
| | - Jean Gotman
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University Québec, QC, Canada
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179
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Feyissa AM, Britton JW, Van Gompel J, Lagerlund TL, So E, Wong-Kisiel LC, Cascino GC, Brinkman BH, Nelson CL, Watson R, Worrell GA. High density scalp EEG in frontal lobe epilepsy. Epilepsy Res 2017; 129:157-161. [PMID: 28073096 DOI: 10.1016/j.eplepsyres.2016.12.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 12/27/2016] [Accepted: 12/31/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE Localization of seizures in frontal lobe epilepsy using the 10-20 system scalp EEG is often challenging because neocortical seizure can spread rapidly, significant muscle artifact, and the suboptimal spatial resolution for seizure generators involving mesial frontal lobe cortex. Our aim in this study was to determine the value of visual interpretation of 76 channel high density EEG (hdEEG) monitoring (10-10 system) in patients with suspected frontal lobe epilepsy, and to evaluate concordance with MRI, subtraction ictal SPECT co-registered to MRI (SISCOM), conventional EEG, and intracranial EEG (iEEG). METHODS We performed a retrospective cohort study of 14 consecutive patients who underwent hdEEG monitoring for suspected frontal lobe seizures. The gold standard for localization was considered to be iEEG. Concordance of hdEEG findings with MRI, subtraction ictal SPECT co-registered to MRI (SISCOM), conventional 10-20 EEG, and iEEG as well as correlation of hdEEG localization with surgical outcome were examined. RESULTS hdEEG localization was concordant with iEEG in 12/14 and was superior to conventional EEG 3/14 (p<0.01) and SISCOM 3/12 (p<0.01). hdEEG correctly lateralized seizure onset in 14/14 cases, compared to 9/14 (p=0.04) cases with conventional EEG. Seven patients underwent surgical resection, of whom five were seizure free. CONCLUSIONS hdEEG monitoring should be considered in patients with suspected frontal epilepsy requiring localization of epileptogenic brain. hdEEG may assist in developing a hypothesis for iEEG monitoring and could potentially augment EEG source localization.
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Affiliation(s)
- Anteneh M Feyissa
- Department of Neurology, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL, 32224, United States.
| | - Jeffrey W Britton
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, United States.
| | - Jamie Van Gompel
- Departments of Neurological Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, United States.
| | - Terrance L Lagerlund
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, United States.
| | - Elson So
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, United States.
| | - Lilly C Wong-Kisiel
- Division of Child and Adolescent Neurology, Mayo Clinic Children's Center, 200 First Street SW, Rochester, MN, 55905, United States.
| | - Gregory C Cascino
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, United States.
| | - Benjamin H Brinkman
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, United States.
| | - Cindy L Nelson
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, United States.
| | - Robert Watson
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, United States.
| | - Gregory A Worrell
- Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, United States.
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180
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Erem B, Hyde DE, Peters JM, Duffy FH, Warfield SK. Dynamic Electrical Source Imaging (DESI) of Seizures and Interictal Epileptic Discharges Without Ensemble Averaging. IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:98-110. [PMID: 27479957 PMCID: PMC5217759 DOI: 10.1109/tmi.2016.2595329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We propose an algorithm for electrical source imaging of epileptic discharges that takes a data-driven approach to regularizing the dynamics of solutions. The method is based on linear system identification on short time segments, combined with a classical inverse solution approach. Whereas ensemble averaging of segments or epochs discards inter-segment variations by averaging across them, our approach explicitly models them. Indeed, it may even be possible to avoid the need for the time-consuming process of marking epochs containing discharges altogether. We demonstrate that this approach can produce both stable and accurate inverse solutions in experiments using simulated data and real data from epilepsy patients. In an illustrative example, we show that we are able to image propagation using this approach. We show that when applied to imaging seizure data, our approach reproducibly localized frequent seizure activity to within the margins of surgeries that led to patients' seizure freedom. The same approach could be used in the planning of epilepsy surgeries, as a way to localize potentially epileptogenic tissue that should be resected.
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181
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Sohrabpour A, Ye S, Worrell GA, Zhang W, He B. Noninvasive Electromagnetic Source Imaging and Granger Causality Analysis: An Electrophysiological Connectome (eConnectome) Approach. IEEE Trans Biomed Eng 2016; 63:2474-2487. [PMID: 27740473 PMCID: PMC5152676 DOI: 10.1109/tbme.2016.2616474] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Combined source-imaging techniques and directional connectivity analysis can provide useful information about the underlying brain networks in a noninvasive fashion. Source-imaging techniques have been used successfully to either determine the source of activity or to extract source time-courses for Granger causality analysis, previously. In this work, we utilize source-imaging algorithms to both find the network nodes [regions of interest (ROI)] and then extract the activation time series for further Granger causality analysis. The aim of this work is to find network nodes objectively from noninvasive electromagnetic signals, extract activation time-courses, and apply Granger analysis on the extracted series to study brain networks under realistic conditions. METHODS Source-imaging methods are used to identify network nodes and extract time-courses and then Granger causality analysis is applied to delineate the directional functional connectivity of underlying brain networks. Computer simulations studies where the underlying network (nodes and connectivity pattern) is known were performed; additionally, this approach has been evaluated in partial epilepsy patients to study epilepsy networks from interictal and ictal signals recorded by EEG and/or Magnetoencephalography (MEG). RESULTS Localization errors of network nodes are less than 5 mm and normalized connectivity errors of ∼20% in estimating underlying brain networks in simulation studies. Additionally, two focal epilepsy patients were studied and the identified nodes driving the epileptic network were concordant with clinical findings from intracranial recordings or surgical resection. CONCLUSION Our study indicates that combined source-imaging algorithms with Granger causality analysis can identify underlying networks precisely (both in terms of network nodes location and internodal connectivity). SIGNIFICANCE The combined source imaging and Granger analysis technique is an effective tool for studying normal or pathological brain conditions.
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Affiliation(s)
- Abbas Sohrabpour
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455 USA
| | - Shuai Ye
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455 USA
| | | | - Wenbo Zhang
- Minnesota Epilepsy Group, United Hospital, MN 55102 USA and also with the Department of Neurology, University of Minnesota, Minneapolis, 55455 USA
| | - Bin He
- Department of Biomedical Engineering, and the Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN 55455 USA
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182
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Epileptogenic Source Imaging Using Cross-Frequency Coupled Signals From Scalp EEG. IEEE Trans Biomed Eng 2016; 63:2607-2618. [DOI: 10.1109/tbme.2016.2613936] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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183
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Complex patterns of spatially extended generators of epileptic activity: Comparison of source localization methods cMEM and 4-ExSo-MUSIC on high resolution EEG and MEG data. Neuroimage 2016; 143:175-195. [DOI: 10.1016/j.neuroimage.2016.08.044] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 08/18/2016] [Accepted: 08/20/2016] [Indexed: 11/23/2022] Open
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184
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Staljanssens W, Strobbe G, Holen RV, Birot G, Gschwind M, Seeck M, Vandenberghe S, Vulliémoz S, van Mierlo P. Seizure Onset Zone Localization from Ictal High-Density EEG in Refractory Focal Epilepsy. Brain Topogr 2016; 30:257-271. [PMID: 27853892 DOI: 10.1007/s10548-016-0537-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 11/04/2016] [Indexed: 10/20/2022]
Abstract
Epilepsy surgery is the most efficient treatment option for patients with refractory epilepsy. Before surgery, it is of utmost importance to accurately delineate the seizure onset zone (SOZ). Non-invasive EEG is the most used neuroimaging technique to diagnose epilepsy, but it is hard to localize the SOZ from EEG due to its low spatial resolution and because epilepsy is a network disease, with several brain regions becoming active during a seizure. In this work, we propose and validate an approach based on EEG source imaging (ESI) combined with functional connectivity analysis to overcome these problems. We considered both simulations and real data of patients. Ictal epochs of 204-channel EEG and subsets down to 32 channels were analyzed. ESI was done using realistic head models and LORETA was used as inverse technique. The connectivity pattern between the reconstructed sources was calculated, and the source with the highest number of outgoing connections was selected as SOZ. We compared this algorithm with a more straightforward approach, i.e. selecting the source with the highest power after ESI as the SOZ. We found that functional connectivity analysis estimated the SOZ consistently closer to the simulated EZ/RZ than localization based on maximal power. Performance, however, decreased when 128 electrodes or less were used, especially in the realistic data. The results show the added value of functional connectivity analysis for SOZ localization, when the EEG is obtained with a high-density setup. Next to this, the method can potentially be used as objective tool in clinical settings.
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Affiliation(s)
- Willeke Staljanssens
- MEDISIP, Department of Electronics and Information Systems, Ghent University, De Pintelaan 185, Building B Entrance 36, 9000, Ghent, Belgium. .,iMinds Medical IT, Ghent, Belgium.
| | - Gregor Strobbe
- MEDISIP, Department of Electronics and Information Systems, Ghent University, De Pintelaan 185, Building B Entrance 36, 9000, Ghent, Belgium.,iMinds Medical IT, Ghent, Belgium
| | - Roel Van Holen
- MEDISIP, Department of Electronics and Information Systems, Ghent University, De Pintelaan 185, Building B Entrance 36, 9000, Ghent, Belgium.,iMinds Medical IT, Ghent, Belgium
| | - Gwénaël Birot
- Functional Brain Mapping Laboratory, Department of Fundamental Neurosciences, University of Geneva, Campus Biotech, Geneva, Switzerland
| | - Markus Gschwind
- Functional Brain Mapping Laboratory, Department of Fundamental Neurosciences, University of Geneva, Campus Biotech, Geneva, Switzerland.,EEG and Epilepsy Unit, Neurology Department, University Hospitals and Faculty of Medicine of Geneva, Geneva, Switzerland
| | - Margitta Seeck
- EEG and Epilepsy Unit, Neurology Department, University Hospitals and Faculty of Medicine of Geneva, Geneva, Switzerland
| | - Stefaan Vandenberghe
- MEDISIP, Department of Electronics and Information Systems, Ghent University, De Pintelaan 185, Building B Entrance 36, 9000, Ghent, Belgium.,iMinds Medical IT, Ghent, Belgium
| | - Serge Vulliémoz
- Functional Brain Mapping Laboratory, Department of Fundamental Neurosciences, University of Geneva, Campus Biotech, Geneva, Switzerland.,EEG and Epilepsy Unit, Neurology Department, University Hospitals and Faculty of Medicine of Geneva, Geneva, Switzerland
| | - Pieter van Mierlo
- MEDISIP, Department of Electronics and Information Systems, Ghent University, De Pintelaan 185, Building B Entrance 36, 9000, Ghent, Belgium.,iMinds Medical IT, Ghent, Belgium.,Functional Brain Mapping Laboratory, Department of Fundamental Neurosciences, University of Geneva, Campus Biotech, Geneva, Switzerland
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185
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Sohrabpour A, Lu Y, Worrell G, He B. Imaging brain source extent from EEG/MEG by means of an iteratively reweighted edge sparsity minimization (IRES) strategy. Neuroimage 2016; 142:27-42. [PMID: 27241482 PMCID: PMC5124544 DOI: 10.1016/j.neuroimage.2016.05.064] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 05/09/2016] [Accepted: 05/26/2016] [Indexed: 11/23/2022] Open
Abstract
Estimating extended brain sources using EEG/MEG source imaging techniques is challenging. EEG and MEG have excellent temporal resolution at millisecond scale but their spatial resolution is limited due to the volume conduction effect. We have exploited sparse signal processing techniques in this study to impose sparsity on the underlying source and its transformation in other domains (mathematical domains, like spatial gradient). Using an iterative reweighting strategy to penalize locations that are less likely to contain any source, it is shown that the proposed iteratively reweighted edge sparsity minimization (IRES) strategy can provide reasonable information regarding the location and extent of the underlying sources. This approach is unique in the sense that it estimates extended sources without the need of subjectively thresholding the solution. The performance of IRES was evaluated in a series of computer simulations. Different parameters such as source location and signal-to-noise ratio were varied and the estimated results were compared to the targets using metrics such as localization error (LE), area under curve (AUC) and overlap between the estimated and simulated sources. It is shown that IRES provides extended solutions which not only localize the source but also provide estimation for the source extent. The performance of IRES was further tested in epileptic patients undergoing intracranial EEG (iEEG) recording for pre-surgical evaluation. IRES was applied to scalp EEGs during interictal spikes, and results were compared with iEEG and surgical resection outcome in the patients. The pilot clinical study results are promising and demonstrate a good concordance between noninvasive IRES source estimation with iEEG and surgical resection outcomes in the same patients. The proposed algorithm, i.e. IRES, estimates extended source solutions from scalp electromagnetic signals which provide relatively accurate information about the location and extent of the underlying source.
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Affiliation(s)
- Abbas Sohrabpour
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Yunfeng Lu
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | | | - Bin He
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA; Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN, USA.
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186
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Coito A, Michel CM, van Mierlo P, Vulliemoz S, Plomp G. Directed Functional Brain Connectivity Based on EEG Source Imaging: Methodology and Application to Temporal Lobe Epilepsy. IEEE Trans Biomed Eng 2016; 63:2619-2628. [PMID: 27775899 DOI: 10.1109/tbme.2016.2619665] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE The importance of functional brain connectivity to study physiological and pathological brain activity has been widely recognized. Here, we aimed to 1) review a methodological pipeline to investigate directed functional connectivity between brain regions using source signals derived from high-density EEG; 2) elaborate on some methodological challenges; and 3) apply this pipeline to temporal lobe epilepsy (TLE) patients and healthy controls to investigate directed functional connectivity differences in the theta and beta frequency bands during EEG epochs without visible pathological activity. METHODS The methodological pipeline includes: EEG acquisition and preprocessing, electrical-source imaging (ESI) using individual head models and distributed inverse solutions, parcellation of the gray matter in regions of interest, fixation of the dipole orientation for each region, computation of the spectral power in the source space, and directed functional connectivity estimation using Granger-causal modeling. We specifically analyzed how the signal-to-noise ratio (SNR) changes using different approaches for the dipole orientation fixation. We applied this pipeline to 20 left TLE patients, 20 right TLE patients, and 20 healthy controls. RESULTS Projecting each dipole to the predominant dipole orientation leads to a threefold SNR increase as compared to the norm of the dipoles. By comparing connectivity in TLE versus controls, we found significant frequency-specific outflow differences in physiologically plausible regions. CONCLUSION The results suggest that directed functional connectivity derived from ESI can help better understand frequency-specific resting-state network alterations underlying focal epilepsy. SIGNIFICANCE EEG-based directed functional connectivity could contribute to the search of new biomarkers of this disorder.
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187
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Lie OV, van Mierlo P. Seizure-Onset Mapping Based on Time-Variant Multivariate Functional Connectivity Analysis of High-Dimensional Intracranial EEG: A Kalman Filter Approach. Brain Topogr 2016; 30:46-59. [PMID: 27722839 DOI: 10.1007/s10548-016-0527-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 09/29/2016] [Indexed: 11/29/2022]
Abstract
The visual interpretation of intracranial EEG (iEEG) is the standard method used in complex epilepsy surgery cases to map the regions of seizure onset targeted for resection. Still, visual iEEG analysis is labor-intensive and biased due to interpreter dependency. Multivariate parametric functional connectivity measures using adaptive autoregressive (AR) modeling of the iEEG signals based on the Kalman filter algorithm have been used successfully to localize the electrographic seizure onsets. Due to their high computational cost, these methods have been applied to a limited number of iEEG time-series (<60). The aim of this study was to test two Kalman filter implementations, a well-known multivariate adaptive AR model (Arnold et al. 1998) and a simplified, computationally efficient derivation of it, for their potential application to connectivity analysis of high-dimensional (up to 192 channels) iEEG data. When used on simulated seizures together with a multivariate connectivity estimator, the partial directed coherence, the two AR models were compared for their ability to reconstitute the designed seizure signal connections from noisy data. Next, focal seizures from iEEG recordings (73-113 channels) in three patients rendered seizure-free after surgery were mapped with the outdegree, a graph-theory index of outward directed connectivity. Simulation results indicated high levels of mapping accuracy for the two models in the presence of low-to-moderate noise cross-correlation. Accordingly, both AR models correctly mapped the real seizure onset to the resection volume. This study supports the possibility of conducting fully data-driven multivariate connectivity estimations on high-dimensional iEEG datasets using the Kalman filter approach.
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Affiliation(s)
- Octavian V Lie
- Department of Neurology, University of Texas Health Science Center at San Antonio, 8300 Floyd Curl Drive MSC: 7883, San Antonio, TX, 78229-3900, USA.
| | - Pieter van Mierlo
- Functional Brain Mapping Laboratory, EEG and Epilepsy Unit, University of Geneva, Geneva, Switzerland.,iMinds Medical IT Department, Medical Image and Signal Processing Group, Ghent University, Ghent, Belgium
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188
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Beniczky S, Rosenzweig I, Scherg M, Jordanov T, Lanfer B, Lantz G, Larsson PG. Ictal EEG source imaging in presurgical evaluation: High agreement between analysis methods. Seizure 2016; 43:1-5. [PMID: 27764709 PMCID: PMC5176190 DOI: 10.1016/j.seizure.2016.09.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 09/24/2016] [Accepted: 09/30/2016] [Indexed: 11/17/2022] Open
Abstract
There was good agreement between different methods of ictal EEG source imaging. Ictal source imaging achieved an accuracy of 73% (for operated patients: 86%). Agreement between all methods did not necessarily imply accuracy of localization.
Purpose To determine the agreement between five different methods of ictal EEG source imaging, and to assess their accuracy in presurgical evaluation of patients with focal epilepsy. It was hypothesized that high agreement between methods was associated with higher localization-accuracy. Methods EEGs were recorded with a 64-electrode array. Thirty-eight seizures from 22 patients were analyzed using five different methods phase mapping, dipole fitting, CLARA, cortical-CLARA and minimum norm. Localization accuracy was determined at sub-lobar level. Reference standard was the final decision of the multidisciplinary epilepsy surgery team, and, for the operated patients, outcome one year after surgery. Results Agreement between all methods was obtained in 13 patients (59%) and between all but one methods in additional six patients (27%). There was a trend for minimum norm being less accurate than phase mapping, but none of the comparisons reached significance. Source imaging in cases with agreement between all methods was not more accurate than in the other cases. Ictal source imaging achieved an accuracy of 73% (for operated patients: 86%). Conclusion There was good agreement between different methods of ictal source imaging. However, good inter-method agreement did not necessarily imply accurate source localization, since all methods faced the limitations of the inverse solution.
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Affiliation(s)
- Sándor Beniczky
- Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark; Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark.
| | - Ivana Rosenzweig
- Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark; Sleep and Brain Plasticity Centre, Department of Neuroimaging, IOPPN, King's College and Imperial College, London, UK
| | | | | | | | - Göran Lantz
- Clinical Neurophysiology Unit, Department of Clinical Sciences, Lund University, Lund, Sweden; Electrical Geodesics, Inc., Eugene, OR, USA
| | - Pål Gunnar Larsson
- Clinical Neurophysiology Section, Department of Neurosurgery, Oslo University Hospital, Norway
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189
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Marino M, Liu Q, Brem S, Wenderoth N, Mantini D. Automated detection and labeling of high-density EEG electrodes from structural MR images. J Neural Eng 2016; 13:056003. [DOI: 10.1088/1741-2560/13/5/056003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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190
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Gschwind M, Seeck M. Transcranial direct-current stimulation as treatment in epilepsy. Expert Rev Neurother 2016; 16:1427-1441. [DOI: 10.1080/14737175.2016.1209410] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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191
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Russo A, Lallas M, Jayakar P, Miller I, Hyslop A, Dunoyer C, Resnick T, Duchowny M. The diagnostic utility of 3D-ESI rotating and moving dipole methodology in the pre-surgical evaluation of MRI-negative childhood epilepsy due to focal cortical dysplasia. Epilepsia 2016; 57:1450-7. [DOI: 10.1111/epi.13454] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2016] [Indexed: 01/31/2023]
Affiliation(s)
- Angelo Russo
- Child Neurology Unit; IRCCS; Institute of Neurological Sciences of Bologna; Bologna Italy
| | - Matt Lallas
- Department of Neurology and Comprehensive Epilepsy Program; Brain Institute; Nicklaus Children's Hospital; Miami Florida U.S.A
| | - Prasanna Jayakar
- Department of Neurology and Comprehensive Epilepsy Program; Brain Institute; Nicklaus Children's Hospital; Miami Florida U.S.A
| | - Ian Miller
- Department of Neurology and Comprehensive Epilepsy Program; Brain Institute; Nicklaus Children's Hospital; Miami Florida U.S.A
| | - Ann Hyslop
- Department of Neurology and Comprehensive Epilepsy Program; Brain Institute; Nicklaus Children's Hospital; Miami Florida U.S.A
| | - Catalina Dunoyer
- Department of Neurology and Comprehensive Epilepsy Program; Brain Institute; Nicklaus Children's Hospital; Miami Florida U.S.A
| | - Trevor Resnick
- Department of Neurology and Comprehensive Epilepsy Program; Brain Institute; Nicklaus Children's Hospital; Miami Florida U.S.A
- Department of Neurology; University of Miami Miller School of Medicine; Miami Florida U.S.A
| | - Michael Duchowny
- Department of Neurology and Comprehensive Epilepsy Program; Brain Institute; Nicklaus Children's Hospital; Miami Florida U.S.A
- Department of Neurology; University of Miami Miller School of Medicine; Miami Florida U.S.A
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192
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Bedside functional brain imaging in critically-ill children using high-density EEG source modeling and multi-modal sensory stimulation. NEUROIMAGE-CLINICAL 2016; 12:198-211. [PMID: 27453817 PMCID: PMC4942736 DOI: 10.1016/j.nicl.2016.06.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 06/24/2016] [Accepted: 06/30/2016] [Indexed: 12/03/2022]
Abstract
Acute brain injury is a common cause of death and critical illness in children and young adults. Fundamental management focuses on early characterization of the extent of injury and optimizing recovery by preventing secondary damage during the days following the primary injury. Currently, bedside technology for measuring neurological function is mainly limited to using electroencephalography (EEG) for detection of seizures and encephalopathic features, and evoked potentials. We present a proof of concept study in patients with acute brain injury in the intensive care setting, featuring a bedside functional imaging set-up designed to map cortical brain activation patterns by combining high density EEG recordings, multi-modal sensory stimulation (auditory, visual, and somatosensory), and EEG source modeling. Use of source-modeling allows for examination of spatiotemporal activation patterns at the cortical region level as opposed to the traditional scalp potential maps. The application of this system in both healthy and brain-injured participants is demonstrated with modality-specific source-reconstructed cortical activation patterns. By combining stimulation obtained with different modalities, most of the cortical surface can be monitored for changes in functional activation without having to physically transport the subject to an imaging suite. The results in patients in an intensive care setting with anatomically well-defined brain lesions suggest a topographic association between their injuries and activation patterns. Moreover, we report the reproducible application of a protocol examining a higher-level cortical processing with an auditory oddball paradigm involving presentation of the patient's own name. This study reports the first successful application of a bedside functional brain mapping tool in the intensive care setting. This application has the potential to provide clinicians with an additional dimension of information to manage critically-ill children and adults, and potentially patients not suited for magnetic resonance imaging technologies. We demonstrate the use of high-density EEG combined with multi-modality sensory stimulation and source modeling to generate functional brain activation maps. This is the first demonstration of source-level monitoring of functional brain responses in multiple modalities in children with acute brain injuries in ICU. The set-up is designed to examine higher-level cortical processing by using an auditory oddball paradigm involving the subject’s own name.
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Mayoral M, Marti-Fuster B, Carreño M, Carrasco JL, Bargalló N, Donaire A, Rumià J, Perissinotti A, Lomeña F, Pintor L, Boget T, Setoain X. Seizure-onset zone localization by statistical parametric mapping in visually normal18F-FDG PET studies. Epilepsia 2016; 57:1236-44. [DOI: 10.1111/epi.13427] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Maria Mayoral
- Nuclear Medicine Department; Hospital Clinic; Barcelona Spain
| | - Berta Marti-Fuster
- Biomedical Imaging Group; Biomedical Research Networking Center in Bioengineering; Biomaterials and Nanomedicine (CIBER-BBN); Barcelona Spain
- Biophysics and Bioengineering Unit; Physiological Sciences Department I; School of Medicine; University of Barcelona; Spain
| | - Mar Carreño
- Neurology Department; Hospital Clinic; Barcelona Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
| | - Josep L. Carrasco
- Biostatistics; Public Health Department; School of Medicine; University of Barcelona; Barcelona Spain
| | - Núria Bargalló
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
- Radiology Department; Hospital Clinic; Barcelona Spain
| | - Antonio Donaire
- Neurology Department; Hospital Clinic; Barcelona Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
| | - Jordi Rumià
- Neurosurgery Department; Hospital Clinic; Barcelona Spain
| | | | - Francisco Lomeña
- Nuclear Medicine Department; Hospital Clinic; Barcelona Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
| | - Luis Pintor
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
- Psychiatry and Psychology Department; Hospital Clinic; Barcelona Spain
| | - Teresa Boget
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
- Psychiatry and Psychology Department; Hospital Clinic; Barcelona Spain
| | - Xavier Setoain
- Nuclear Medicine Department; Hospital Clinic; Barcelona Spain
- Biomedical Imaging Group; Biomedical Research Networking Center in Bioengineering; Biomaterials and Nanomedicine (CIBER-BBN); Barcelona Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
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194
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Toth M, Kondakor I, Faludi B. Differences of brain electrical activity between moderate and severe obstructive sleep apneic patients: a LORETA study. J Sleep Res 2016; 25:596-604. [DOI: 10.1111/jsr.12403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/02/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Marton Toth
- Department of Neurology; University of Pécs; Pécs Hungary
| | - Istvan Kondakor
- Department of Neurology; Balassa Janos Teaching Hospital; Szekszárd Hungary
| | - Bela Faludi
- Department of Neurology; University of Pécs; Pécs Hungary
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195
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Advances in EEG: home video telemetry, high frequency oscillations and electrical source imaging. J Neurol 2016; 263:2139-44. [DOI: 10.1007/s00415-016-8159-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 05/02/2016] [Accepted: 05/02/2016] [Indexed: 10/21/2022]
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196
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Pellegrino G, Hedrich T, Chowdhury R, Hall JA, Lina JM, Dubeau F, Kobayashi E, Grova C. Source localization of the seizure onset zone from ictal EEG/MEG data. Hum Brain Mapp 2016; 37:2528-46. [PMID: 27059157 DOI: 10.1002/hbm.23191] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 03/07/2016] [Accepted: 03/10/2016] [Indexed: 11/08/2022] Open
Abstract
INTRODUCTION Surgical treatment of drug-resistant epilepsy relies on the identification of the seizure onset zone (SOZ) and often requires intracranial EEG (iEEG). We have developed a new approach for non-invasive magnetic and electric source imaging of the SOZ (MSI-SOZ and ESI-SOZ) from ictal magnetoencephalography (MEG) and EEG recordings, using wavelet-based Maximum Entropy on the Mean (wMEM) method. We compared the performance of MSI-SOZ and ESI-SOZ with interictal spike source localization (MSI-spikes and ESI-spikes) and clinical localization of the SOZ (i.e., based on iEEG or lesion topography, denoted as clinical-SOZ). METHODS A total of 46 MEG or EEG seizures from 13 patients were analyzed. wMEM was applied around seizure onset, centered on the frequency band showing the strongest power change. Principal component analysis applied to spatiotemporal reconstructed wMEM sources (0.4-1 s around seizure onset) identified the main spatial pattern of ictal oscillations. Qualitative sublobar concordance and quantitative measures of distance and spatial overlaps were estimated to compare MSI/ESI-SOZ with MSI/ESI-Spikes and clinical-SOZ. RESULTS MSI/ESI-SOZ were concordant with clinical-SOZ in 81% of seizures (MSI 90%, ESI 64%). MSI-SOZ was more accurate and identified sources closer to the clinical-SOZ (P = 0.012) and to MSI-Spikes (P = 0.040) as compared with ESI-SOZ. MSI/ESI-SOZ and MSI/ESI-Spikes did not differ in terms of concordance and distance from the clinical-SOZ. CONCLUSIONS wMEM allows non-invasive localization of the SOZ from ictal MEG and EEG. MSI-SOZ performs better than ESI-SOZ. MSI/ESI-SOZ can provide important additional information to MSI/ESI-Spikes during presurgical evaluation. Hum Brain Mapp 37:2528-2546, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Giovanni Pellegrino
- Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada.,Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Tanguy Hedrich
- Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada
| | - Rasheda Chowdhury
- Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada
| | - Jeffery A Hall
- Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Jean-Marc Lina
- Département de Génie Electrique, École de Technologie Supérieure, Montreal, Québec, Canada.,Centre De Recherches En Mathématiques, Montreal, Québec, Canada.,Centre D'etudes Avancées En Médecine Du Sommeil, Centre De Recherche De L'hôpital Sacré-Coeur De Montréal, Montreal, Québec, Canada
| | - Francois Dubeau
- Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Eliane Kobayashi
- Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada
| | - Christophe Grova
- Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada.,Neurology and Neurosurgery Department, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada.,Centre De Recherches En Mathématiques, Montreal, Québec, Canada.,Physics Department and PERFORM Centre, Concordia University, Montreal, Québec, Canada
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197
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Erem B, Martinez Orellana R, Hyde DE, Peters JM, Duffy FH, Stovicek P, Warfield SK, MacLeod RS, Tadmor G, Brooks DH. Extensions to a manifold learning framework for time-series analysis on dynamic manifolds in bioelectric signals. Phys Rev E 2016; 93:042218. [PMID: 27176304 PMCID: PMC4866516 DOI: 10.1103/physreve.93.042218] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Indexed: 11/07/2022]
Abstract
This paper addresses the challenge of extracting meaningful information from measured bioelectric signals generated by complex, large scale physiological systems such as the brain or the heart. We focus on a combination of the well-known Laplacian eigenmaps machine learning approach with dynamical systems ideas to analyze emergent dynamic behaviors. The method reconstructs the abstract dynamical system phase-space geometry of the embedded measurements and tracks changes in physiological conditions or activities through changes in that geometry. It is geared to extract information from the joint behavior of time traces obtained from large sensor arrays, such as those used in multiple-electrode ECG and EEG, and explore the geometrical structure of the low dimensional embedding of moving time windows of those joint snapshots. Our main contribution is a method for mapping vectors from the phase space to the data domain. We present cases to evaluate the methods, including a synthetic example using the chaotic Lorenz system, several sets of cardiac measurements from both canine and human hearts, and measurements from a human brain.
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Affiliation(s)
- Burak Erem
- Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | - Damon E Hyde
- Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Jurriaan M Peters
- Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Frank H Duffy
- Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Petr Stovicek
- General University Hospital, Charles University, 128 08 Prague, Czech Republic
| | - Simon K Warfield
- Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | - Gilead Tadmor
- Northeastern University, Boston, Massachusetts 02115, USA
| | - Dana H Brooks
- Northeastern University, Boston, Massachusetts 02115, USA
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198
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Mălîia MD, Meritam P, Scherg M, Fabricius M, Rubboli G, Mîndruţă I, Beniczky S. Epileptiform discharge propagation: Analyzing spikes from the onset to the peak. Clin Neurophysiol 2016; 127:2127-33. [DOI: 10.1016/j.clinph.2015.12.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 12/22/2015] [Accepted: 12/31/2015] [Indexed: 11/30/2022]
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199
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Mouthaan BE, Rados M, Barsi P, Boon P, Carmichael DW, Carrette E, Craiu D, Cross JH, Diehl B, Dimova P, Fabo D, Francione S, Gaskin V, Gil-Nagel A, Grigoreva E, Guekht A, Hirsch E, Hecimovic H, Helmstaedter C, Jung J, Kalviainen R, Kelemen A, Kimiskidis V, Kobulashvili T, Krsek P, Kuchukhidze G, Larsson PG, Leitinger M, Lossius MI, Luzin R, Malmgren K, Mameniskiene R, Marusic P, Metin B, Özkara C, Pecina H, Quesada CM, Rugg-Gunn F, Rydenhag B, Ryvlin P, Scholly J, Seeck M, Staack AM, Steinhoff BJ, Stepanov V, Tarta-Arsene O, Trinka E, Uzan M, Vogt VL, Vos SB, Vulliémoz S, Huiskamp G, Leijten FSS, Van Eijsden P, Braun KPJ. Current use of imaging and electromagnetic source localization procedures in epilepsy surgery centers across Europe. Epilepsia 2016; 57:770-6. [PMID: 27012361 DOI: 10.1111/epi.13347] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVE In 2014 the European Union-funded E-PILEPSY project was launched to improve awareness of, and accessibility to, epilepsy surgery across Europe. We aimed to investigate the current use of neuroimaging, electromagnetic source localization, and imaging postprocessing procedures in participating centers. METHODS A survey on the clinical use of imaging, electromagnetic source localization, and postprocessing methods in epilepsy surgery candidates was distributed among the 25 centers of the consortium. A descriptive analysis was performed, and results were compared to existing guidelines and recommendations. RESULTS Response rate was 96%. Standard epilepsy magnetic resonance imaging (MRI) protocols are acquired at 3 Tesla by 15 centers and at 1.5 Tesla by 9 centers. Three centers perform 3T MRI only if indicated. Twenty-six different MRI sequences were reported. Six centers follow all guideline-recommended MRI sequences with the proposed slice orientation and slice thickness or voxel size. Additional sequences are used by 22 centers. MRI postprocessing methods are used in 16 centers. Interictal positron emission tomography (PET) is available in 22 centers; all using 18F-fluorodeoxyglucose (FDG). Seventeen centers perform PET postprocessing. Single-photon emission computed tomography (SPECT) is used by 19 centers, of which 15 perform postprocessing. Four centers perform neither PET nor SPECT in children. Seven centers apply magnetoencephalography (MEG) source localization, and nine apply electroencephalography (EEG) source localization. Fourteen combinations of inverse methods and volume conduction models are used. SIGNIFICANCE We report a large variation in the presurgical diagnostic workup among epilepsy surgery centers across Europe. This diversity underscores the need for high-quality systematic reviews, evidence-based recommendations, and harmonization of available diagnostic presurgical methods.
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Affiliation(s)
- Brian E Mouthaan
- Department of (Child) Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Matea Rados
- Department of (Child) Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Péter Barsi
- MR Research Center, Semmelweis University, Budapest, Hungary
| | - Paul Boon
- Department of Neurology, Reference Center for Refractory Epilepsy, Ghent University Hospital, Ghent, Belgium
| | - David W Carmichael
- University College London Institute of Child Health, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Evelien Carrette
- Department of Neurology, Reference Center for Refractory Epilepsy, Ghent University Hospital, Ghent, Belgium
| | - Dana Craiu
- Pediatric Neurology Clinic, "Alexandru Obregia" Clinical Psychiatric Hospital, Bucharest, Romania.,Department 6, Pediatric Neurology Clinic, "Carol Davila" University of Medicine, Bucharest, Romania
| | - J Helen Cross
- University College London Institute of Child Health, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Beate Diehl
- National Hospital for Neurology and Neurosurgery, University College London Hospitals, London, United Kingdom.,Department of Clinical and Experimental Epilepsy, University College London, London, United Kingdom
| | - Petia Dimova
- Department of Neurosurgery, Epilepsy Surgery Center, St. Ivan Rilski University Hospital, Sofia, Bulgaria
| | - Daniel Fabo
- National Institute of Clinical Neurosciences, Budapest, Hungary
| | - Stefano Francione
- Claudio Munari Epilepsy Surgery Center, Niguarda Hospital, Milan, Italy
| | - Vladislav Gaskin
- Moscow Research and Clinical Center for Neuropsychiatry of the Healthcare Department of Moscow, Moscow, Russia.,Department of Neurology and Neurosurgery of Russian National Research Medical University, Moscow, Russia
| | - Antonio Gil-Nagel
- Department of Neuroimaging, Center for Biomedical Technology, Technical University of Madrid, Pozuelo de Alarcón, Spain
| | - Elena Grigoreva
- Scientific Research Institute of Emergency Care named after N.V. Sklifosovsky, Moscow, Russia
| | - Alla Guekht
- Moscow Research and Clinical Center for Neuropsychiatry of the Healthcare Department of Moscow, Moscow, Russia.,Department of Neurology and Neurosurgery of Russian National Research Medical University, Moscow, Russia
| | - Edouard Hirsch
- Medical and Surgical Epilepsy Unit, Hautepierre Hospital, University of Strasbourg, Strasbourg, France
| | - Hrvoje Hecimovic
- Department of Neurology, Zagreb Epilepsy Center, University Hospital, Zagreb, Croatia
| | - Christoph Helmstaedter
- Department of Epileptology, University Medical Center, University of Bonn, Bonn, Germany
| | - Julien Jung
- Department of Functional Neurology and Epileptology, Institute of Epilepsies (IDEE), Hospices Civils de Lyon, Lyon, France
| | - Reetta Kalviainen
- Department of Neurology, Kuopio University Hospital, Kuopio, Finland.,School of Medicine, University of Eastern Finland, Kuopio, Finland
| | - Anna Kelemen
- National Institute of Clinical Neurosciences, Budapest, Hungary
| | - Vasilios Kimiskidis
- Laboratory of Clinical Neurophysiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Teia Kobulashvili
- Department of Neurology, Christian-Doppler-Klinik, Paracelsus Medical University, and Center for Cognitive Neuroscience, Salzburg, Austria
| | - Pavel Krsek
- Department of Pediatric Neurology, 2nd Faculty of Medicine, Motol University Hospital, Charles University in Prague, Prague, Czech Republic
| | - Giorgi Kuchukhidze
- Department of Neurology, Christian-Doppler-Klinik, Paracelsus Medical University, and Center for Cognitive Neuroscience, Salzburg, Austria.,Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Pål G Larsson
- Department of Neurosurgery, Clinic of Surgery and Neuroscience, Oslo University Hospital, Oslo, Norway
| | - Markus Leitinger
- Department of Neurology, Christian-Doppler-Klinik, Paracelsus Medical University, and Center for Cognitive Neuroscience, Salzburg, Austria
| | - Morten I Lossius
- Department of Complex Epilepsy, National Center for Epilepsy (SSE), Oslo, Norway
| | - Roman Luzin
- Moscow Research and Clinical Center for Neuropsychiatry of the Healthcare Department of Moscow, Moscow, Russia.,Department of Neurology and Neurosurgery of Russian National Research Medical University, Moscow, Russia
| | - Kristina Malmgren
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Ruta Mameniskiene
- Clinic of Neurology and Neurosurgery, Faculty of Medicine, Vilnius University, Vilnius, Lithuania.,Center of Neurology, Vilnius University Hospital Santariškių Klinikos, Vilnius, Lithuania
| | - Petr Marusic
- Department of Neurology, 2nd Faculty of Medicine, Motol University Hospital, Charles University in Prague, Prague, Czech Republic
| | - Baris Metin
- Department of Psychology, Uskudar University, Uskudar, Istanbul, Turkey
| | - Cigdem Özkara
- Division of Clinical Electro-Neurophysiology, Department of Neurology, Cerrahpaa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Hrvoje Pecina
- Department of Neurology, Zagreb Epilepsy Center, University Hospital, Zagreb, Croatia
| | - Carlos M Quesada
- Department of Epileptology, University Medical Center, University of Bonn, Bonn, Germany
| | - Fergus Rugg-Gunn
- National Hospital for Neurology and Neurosurgery, University College London Hospitals, London, United Kingdom.,Department of Clinical and Experimental Epilepsy, University College London, London, United Kingdom
| | - Bertil Rydenhag
- Clinic of Neurology and Neurosurgery, Faculty of Medicine, Vilnius University, Vilnius, Lithuania.,Center of Neurology, Vilnius University Hospital Santariškių Klinikos, Vilnius, Lithuania
| | - Philippe Ryvlin
- Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland
| | - Julia Scholly
- Medical and Surgical Epilepsy Unit, Hautepierre Hospital, University of Strasbourg, Strasbourg, France
| | - Margitta Seeck
- EEG and Epilepsy Unit, Department of Clinical Neurosciences, University Hospital of Geneva, Geneva, Switzerland
| | | | | | - Valentin Stepanov
- Scientific Research Institute of Emergency Care named after N.V. Sklifosovsky, Moscow, Russia
| | - Oana Tarta-Arsene
- Pediatric Neurology Clinic, "Alexandru Obregia" Clinical Psychiatric Hospital, Bucharest, Romania.,Department 6, Pediatric Neurology Clinic, "Carol Davila" University of Medicine, Bucharest, Romania
| | - Eugen Trinka
- Department of Neurology, Christian-Doppler-Klinik, Paracelsus Medical University, and Center for Cognitive Neuroscience, Salzburg, Austria
| | - Mustafa Uzan
- Division of Clinical Electro-Neurophysiology, Department of Neurology, Cerrahpaa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Viola L Vogt
- Department of Epileptology, University Medical Center, University of Bonn, Bonn, Germany
| | - Sjoerd B Vos
- Translational Imaging Group, CMIC, University College London, London, United Kingdom.,MRI Unit, Epilepsy Society, Chalfont St Peter, United Kingdom
| | - Serge Vulliémoz
- EEG and Epilepsy Unit, Department of Clinical Neurosciences, University Hospital of Geneva, Geneva, Switzerland
| | - Geertjan Huiskamp
- Department of (Child) Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Frans S S Leijten
- Department of (Child) Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Pieter Van Eijsden
- Department of (Child) Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kees P J Braun
- Department of (Child) Neurology and Neurosurgery, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
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200
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Grova C, Aiguabella M, Zelmann R, Lina JM, Hall JA, Kobayashi E. Intracranial EEG potentials estimated from MEG sources: A new approach to correlate MEG and iEEG data in epilepsy. Hum Brain Mapp 2016; 37:1661-83. [PMID: 26931511 DOI: 10.1002/hbm.23127] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 12/18/2015] [Accepted: 01/17/2016] [Indexed: 01/19/2023] Open
Abstract
Detection of epileptic spikes in MagnetoEncephaloGraphy (MEG) requires synchronized neuronal activity over a minimum of 4cm2. We previously validated the Maximum Entropy on the Mean (MEM) as a source localization able to recover the spatial extent of the epileptic spike generators. The purpose of this study was to evaluate quantitatively, using intracranial EEG (iEEG), the spatial extent recovered from MEG sources by estimating iEEG potentials generated by these MEG sources. We evaluated five patients with focal epilepsy who had a pre-operative MEG acquisition and iEEG with MRI-compatible electrodes. Individual MEG epileptic spikes were localized along the cortical surface segmented from a pre-operative MRI, which was co-registered with the MRI obtained with iEEG electrodes in place for identification of iEEG contacts. An iEEG forward model estimated the influence of every dipolar source of the cortical surface on each iEEG contact. This iEEG forward model was applied to MEG sources to estimate iEEG potentials that would have been generated by these sources. MEG-estimated iEEG potentials were compared with measured iEEG potentials using four source localization methods: two variants of MEM and two standard methods equivalent to minimum norm and LORETA estimates. Our results demonstrated an excellent MEG/iEEG correspondence in the presumed focus for four out of five patients. In one patient, the deep generator identified in iEEG could not be localized in MEG. MEG-estimated iEEG potentials is a promising method to evaluate which MEG sources could be retrieved and validated with iEEG data, providing accurate results especially when applied to MEM localizations. Hum Brain Mapp 37:1661-1683, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Christophe Grova
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Québec, Canada.,Multimodal Functional Imaging Lab, Biomedical Engineering Department, McGill University, Montreal, Québec, Canada.,Physics Department and PERFORM Centre, Concordia University, Montreal, Québec, Canada.,Centre De Recherches En Mathématiques, Montreal, Québec, Canada
| | - Maria Aiguabella
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Québec, Canada
| | - Rina Zelmann
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Québec, Canada
| | - Jean-Marc Lina
- Centre De Recherches En Mathématiques, Montreal, Québec, Canada.,Electrical Engineering Department, Ecole De Technologie Supérieure, Montreal, Québec, Canada.,Centre D'etudes Avancées En Médecine Du Sommeil, Centre De Recherche De L'hôpital Sacré-Coeur De Montréal, Montreal, Québec, Canada
| | - Jeffery A Hall
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Québec, Canada
| | - Eliane Kobayashi
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Québec, Canada
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