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Stern MA, Cole ER, Gross RE, Berglund K. Seizure event detection using intravital two-photon calcium imaging data. NEUROPHOTONICS 2024; 11:024202. [PMID: 38274784 PMCID: PMC10809036 DOI: 10.1117/1.nph.11.2.024202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/20/2023] [Accepted: 12/26/2023] [Indexed: 01/27/2024]
Abstract
Significance Intravital cellular calcium imaging has emerged as a powerful tool to investigate how different types of neurons interact at the microcircuit level to produce seizure activity, with newfound potential to understand epilepsy. Although many methods exist to measure seizure-related activity in traditional electrophysiology, few yet exist for calcium imaging. Aim To demonstrate an automated algorithmic framework to detect seizure-related events using calcium imaging-including the detection of pre-ictal spike events, propagation of the seizure wavefront, and terminal spreading waves for both population-level activity and that of individual cells. Approach We developed an algorithm for precise recruitment detection of population and individual cells during seizure-associated events, which broadly leverages averaged population activity and high-magnitude slope features to detect single-cell pre-ictal spike and seizure recruitment. We applied this method to data recorded using awake in vivo two-photon calcium imaging during pentylenetetrazol-induced seizures in mice. Results We demonstrate that our detected recruitment times are concordant with visually identified labels provided by an expert reviewer and are sufficiently accurate to model the spatiotemporal progression of seizure-associated traveling waves. Conclusions Our algorithm enables accurate cell recruitment detection and will serve as a useful tool for researchers investigating seizure dynamics using calcium imaging.
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Affiliation(s)
- Matthew A. Stern
- Emory University School of Medicine, Department of Neurosurgery, Atlanta, Georgia, United States
| | - Eric R. Cole
- Emory University School of Medicine, Department of Neurosurgery, Atlanta, Georgia, United States
- Emory University, Georgia Institute of Technology, Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Robert E. Gross
- Emory University School of Medicine, Department of Neurosurgery, Atlanta, Georgia, United States
- Emory University, Georgia Institute of Technology, Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Ken Berglund
- Emory University School of Medicine, Department of Neurosurgery, Atlanta, Georgia, United States
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2
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Withers CP, Diamond JM, Yang B, Snyder K, Abdollahi S, Sarlls J, Chapeton JI, Theodore WH, Zaghloul KA, Inati SK. Identifying sources of human interictal discharges with travelling wave and white matter propagation. Brain 2023; 146:5168-5181. [PMID: 37527460 PMCID: PMC11046055 DOI: 10.1093/brain/awad259] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/30/2023] [Accepted: 07/19/2023] [Indexed: 08/03/2023] Open
Abstract
Interictal epileptiform discharges have been shown to propagate from focal epileptogenic sources as travelling waves or through more rapid white matter conduction. We hypothesize that both modes of propagation are necessary to explain interictal discharge timing delays. We propose a method that, for the first time, incorporates both propagation modes to identify unique potential sources of interictal activity. We retrospectively analysed 38 focal epilepsy patients who underwent intracranial EEG recordings and diffusion-weighted imaging for epilepsy surgery evaluation. Interictal discharges were detected and localized to the most likely source based on relative delays in time of arrival across electrodes, incorporating travelling waves and white matter propagation. We assessed the influence of white matter propagation on distance of spread, timing and clinical interpretation of interictal activity. To evaluate accuracy, we compared our source localization results to earliest spiking regions to predict seizure outcomes. White matter propagation helps to explain the timing delays observed in interictal discharge sequences, underlying rapid and distant propagation. Sources identified based on differences in time of receipt of interictal discharges are often distinct from the leading electrode location. Receipt of activity propagating rapidly via white matter can occur earlier than more local activity propagating via slower cortical travelling waves. In our cohort, our source localization approach was more accurate in predicting seizure outcomes than the leading electrode location. Inclusion of white matter in addition to travelling wave propagation in our model of discharge spread did not improve overall accuracy but allowed for identification of unique and at times distant potential sources of activity, particularly in patients with persistent postoperative seizures. Since distant white matter propagation can occur more rapidly than local travelling wave propagation, combined modes of propagation within an interictal discharge sequence can decouple the commonly assumed relationship between spike timing and distance from the source. Our findings thus highlight the clinical importance of recognizing the presence of dual modes of propagation during interictal discharges, as this may be a cause of clinical mislocalization.
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Affiliation(s)
- C Price Withers
- Neurophysiology of Epilepsy Unit, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joshua M Diamond
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Braden Yang
- Neurophysiology of Epilepsy Unit, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kathryn Snyder
- Neurophysiology of Epilepsy Unit, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shervin Abdollahi
- Neurophysiology of Epilepsy Unit, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joelle Sarlls
- NIH MRI Research Facility, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julio I Chapeton
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - William H Theodore
- Clinical Epilepsy Section, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kareem A Zaghloul
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sara K Inati
- Neurophysiology of Epilepsy Unit, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
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Stern MA, Cole ER, Gross RE, Berglund K. Seizure Event Detection Using Intravital Two-Photon Calcium Imaging Data. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.28.558338. [PMID: 37808822 PMCID: PMC10557641 DOI: 10.1101/2023.09.28.558338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Significance Genetic cellular calcium imaging has emerged as a powerful tool to investigate how different types of neurons interact at the microcircuit level to produce seizure activity, with newfound potential to understand epilepsy. Although many methods exist to measure seizure-related activity in traditional electrophysiology, few yet exist for calcium imaging. Aim To demonstrate an automated algorithmic framework to detect seizure-related events using calcium imaging - including the detection of pre-ictal spike events, propagation of the seizure wavefront, and terminal spreading waves for both population-level activity and that of individual cells. Approach We developed an algorithm for precise recruitment detection of population and individual cells during seizure-associated events, which broadly leverages averaged population activity and high-magnitude slope features to detect single-cell pre-ictal spike and seizure recruitment. We applied this method to data recorded using awake in vivo two-photon calcium imaging during pentylenetetrazol induced seizures in mice. Results We demonstrate that our detected recruitment times are concordant with visually identified labels provided by an expert reviewer and are sufficiently accurate to model the spatiotemporal progression of seizure-associated traveling waves. Conclusions Our algorithm enables accurate cell recruitment detection and will serve as a useful tool for researchers investigating seizure dynamics using calcium imaging.
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Affiliation(s)
- Matthew A. Stern
- Authors Contributed Equally
- Emory University School of Medicine, Department of Neurosurgery, Atlanta, GA, United States
| | - Eric R. Cole
- Authors Contributed Equally
- Emory University School of Medicine, Department of Neurosurgery, Atlanta, GA, United States
- Emory University and Georgia Institute of Technology, Coulter Department of Biomedical Engineering, Atlanta, GA, United States
| | - Robert E. Gross
- Emory University School of Medicine, Department of Neurosurgery, Atlanta, GA, United States
- Emory University and Georgia Institute of Technology, Coulter Department of Biomedical Engineering, Atlanta, GA, United States
| | - Ken Berglund
- Emory University School of Medicine, Department of Neurosurgery, Atlanta, GA, United States
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Diamond JM, Withers CP, Chapeton JI, Rahman S, Inati SK, Zaghloul KA. Interictal discharges in the human brain are travelling waves arising from an epileptogenic source. Brain 2023; 146:1903-1915. [PMID: 36729683 PMCID: PMC10411927 DOI: 10.1093/brain/awad015] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/27/2022] [Accepted: 01/08/2023] [Indexed: 02/03/2023] Open
Abstract
While seizure activity may be electrographically widespread, increasing evidence has suggested that ictal discharges may in fact represent travelling waves propagated from a focal seizure source. Interictal epileptiform discharges (IEDs) are an electrographic manifestation of excessive hypersynchronization of cortical activity that occur between seizures and are considered a marker of potentially epileptogenic tissue. The precise relationship between brain regions demonstrating IEDs and those involved in seizure onset, however, remains poorly understood. Here, we hypothesize that IEDs likewise reflect the receipt of travelling waves propagated from the same regions which give rise to seizures. Forty patients from our institution who underwent invasive monitoring for epilepsy, proceeded to surgery and had at least one year of follow-up were included in our study. Interictal epileptiform discharges were detected using custom software, validated by a clinical epileptologist. We show that IEDs reach electrodes in sequences with a consistent temporal ordering, and this ordering matches the timing of receipt of ictal discharges, suggesting that both types of discharges spread as travelling waves. We use a novel approach for localization of ictal discharges, in which time differences of discharge receipt at nearby electrodes are used to compute source location; similar algorithms have been used in acoustics and geophysics. We find that interictal discharges co-localize with ictal discharges. Moreover, interictal discharges tend to localize to the resection territory in patients with good surgical outcome and outside of the resection territory in patients with poor outcome. The seizure source may originate at, and also travel to, spatially distinct IED foci. Our data provide evidence that interictal discharges may represent travelling waves of pathological activity that are similar to their ictal counterparts, and that both ictal and interictal discharges emerge from common epileptogenic brain regions. Our findings have important clinical implications, as they suggest that seizure source localizations may be derived from interictal discharges, which are much more frequent than seizures.
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Affiliation(s)
- Joshua M Diamond
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - C Price Withers
- Clinical Epilepsy Section, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julio I Chapeton
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shareena Rahman
- Office of the Clinical Director, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sara K Inati
- Clinical Epilepsy Section, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kareem A Zaghloul
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
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Eisenkolb VM, Held LM, Utzschmid A, Lin XX, Krieg SM, Meyer B, Gempt J, Jacob SN. Human acute microelectrode array recordings with broad cortical access, single-unit resolution, and parallel behavioral monitoring. Cell Rep 2023; 42:112467. [PMID: 37141095 DOI: 10.1016/j.celrep.2023.112467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 01/06/2023] [Accepted: 04/18/2023] [Indexed: 05/05/2023] Open
Abstract
There are vast gaps in our understanding of the organization and operation of the human nervous system at the level of individual neurons and their networks. Here, we report reliable and robust acute multichannel recordings using planar microelectrode arrays (MEAs) implanted intracortically in awake brain surgery with open craniotomies that grant access to large parts of the cortical hemisphere. We obtained high-quality extracellular neuronal activity at the microcircuit, local field potential level and at the cellular, single-unit level. Recording from the parietal association cortex, a region rarely explored in human single-unit studies, we demonstrate applications on these complementary spatial scales and describe traveling waves of oscillatory activity as well as single-neuron and neuronal population responses during numerical cognition, including operations with uniquely human number symbols. Intraoperative MEA recordings are practicable and can be scaled up to explore cellular and microcircuit mechanisms of a wide range of human brain functions.
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Affiliation(s)
- Viktor M Eisenkolb
- Translational Neurotechnology Laboratory, Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Lisa M Held
- Translational Neurotechnology Laboratory, Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Alexander Utzschmid
- Translational Neurotechnology Laboratory, Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Xiao-Xiong Lin
- Translational Neurotechnology Laboratory, Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; Graduate School of Systemic Neurosciences, Ludwig Maximilians University Munich, Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany
| | - Sandro M Krieg
- Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Bernhard Meyer
- Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Jens Gempt
- Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany
| | - Simon N Jacob
- Translational Neurotechnology Laboratory, Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany; Department of Neurosurgery, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675 Munich, Germany.
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6
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Campbell JM, Davis TS, Anderson DN, Arain A, Inman CS, Smith EH, Rolston JD. Subsets of cortico-cortical evoked potentials propagate as traveling waves. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.27.534002. [PMID: 37034691 PMCID: PMC10081214 DOI: 10.1101/2023.03.27.534002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Emerging evidence suggests that the temporal dynamics of cortico-cortical evoked potentials (CCEPs) may be used to characterize the patterns of information flow between and within brain networks. At present, however, the spatiotemporal dynamics of CCEP propagation cortically and subcortically are incompletely understood. We hypothesized that CCEPs propagate as an evoked traveling wave emanating from the site of stimulation. To elicit CCEPs, we applied single-pulse stimulation to stereoelectroencephalography (SEEG) electrodes implanted in 21 adult patients with intractable epilepsy. For each robust CCEP, we measured the timing of the maximal descent in evoked local field potentials and broadband high-gamma power (70-150 Hz) envelopes relative to the distance between the recording and stimulation contacts using three different metrics (i.e., Euclidean distance, path length, geodesic distance), representing direct, subcortical, and transcortical propagation, respectively. Many evoked responses to single-pulse electrical stimulation appear to propagate as traveling waves (~17-30%), even in the sparsely sampled, three-dimensional SEEG space. These results provide new insights into the spatiotemporal dynamics of CCEP propagation.
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Affiliation(s)
- Justin M. Campbell
- MD-PhD Program, School of Medicine, University of Utah, Salt Lake City, UT, USA
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, USA
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA
| | - Tyler S. Davis
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA
| | - Daria Nesterovich Anderson
- School of Biomedical Engineering, Faculty of Engineering, University of Sydney, Sydney, New South Wales, Australia
| | - Amir Arain
- Department of Neurology, University of Utah, Salt Lake City, UT, USA
| | - Cory S. Inman
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, USA
- Department of Psychology, University of Utah, Salt Lake City, UT, USA
| | - Elliot H. Smith
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, USA
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA
| | - John D. Rolston
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
- Department of Neurosurgery, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA, USA
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7
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Tobochnik S, Bateman LM, Akman CI, Anbarasan D, Bazil CW, Bell M, Choi H, Feldstein NA, Kent PF, McBrian D, McKhann GM, Mendiratta A, Pack AM, Sands TT, Sheth SA, Srinivasan S, Schevon CA. Tracking Multisite Seizure Propagation Using Ictal High-Gamma Activity. J Clin Neurophysiol 2022; 39:592-601. [PMID: 34812578 PMCID: PMC8611231 DOI: 10.1097/wnp.0000000000000833] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 12/28/2020] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Spatial patterns of long-range seizure propagation in epileptic networks have not been well characterized. Here, we use ictal high-gamma activity (HGA) as a proxy of intense neuronal population firing to map the spatial evolution of seizure recruitment. METHODS Ictal HGA (80-150 Hz) was analyzed in 13 patients with 72 seizures recorded by stereotactic depth electrodes, using previously validated methods. Distinct spatial clusters of channels with the ictal high-gamma signature were identified, and seizure hubs were defined as stereotypically recruited nonoverlapping clusters. Clusters correlated with asynchronous seizure terminations to provide supportive evidence for independent seizure activity at these sites. The spatial overlap between seizure hubs and interictal ripples was compared. RESULTS Ictal HGA was detected in 71% of seizures and 10% of implanted contacts, enabling tracking of contiguous and noncontiguous seizure recruitment. Multiple seizure hubs were identified in 54% of cases, including 43% of patients thought preoperatively to have unifocal epilepsy. Noncontiguous recruitment was associated with asynchronous seizure termination (odds ratio = 19.7; p = 0.029). Interictal ripples demonstrated greater spatial overlap with ictal HGA in cases with single seizure hubs compared with those with multiple hubs (100% vs. 66% per patient; p = 0.03). CONCLUSIONS Ictal HGA may serve as a useful adjunctive biomarker to distinguish contiguous seizure spread from propagation to remote seizure sites. High-gamma sites were found to cluster in stereotyped seizure hubs rather than being broadly distributed. Multiple hubs were common even in cases that were considered unifocal.
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Affiliation(s)
- Steven Tobochnik
- Brigham and Women’s Hospital, Department of Neurology, Boston, MA
| | - Lisa M. Bateman
- Columbia University Medical Center, Department of Neurology, New York, NY
| | - Cigdem I. Akman
- Columbia University Medical Center, Division of Child Neurology, New York, NY
| | | | - Carl W. Bazil
- Columbia University Medical Center, Department of Neurology, New York, NY
| | - Michelle Bell
- Columbia University Medical Center, Department of Neurology, New York, NY
| | - Hyunmi Choi
- Columbia University Medical Center, Department of Neurology, New York, NY
| | - Neil A. Feldstein
- Columbia University Medical Center, Department of Neurological Surgery, New York, NY
| | - Paul F. Kent
- Columbia University Medical Center, Department of Neurology, New York, NY
| | - Danielle McBrian
- Columbia University Medical Center, Division of Child Neurology, New York, NY
| | - Guy M. McKhann
- Columbia University Medical Center, Department of Neurological Surgery, New York, NY
| | - Anil Mendiratta
- Columbia University Medical Center, Department of Neurology, New York, NY
| | - Alison M. Pack
- Columbia University Medical Center, Department of Neurology, New York, NY
| | - Tristan T. Sands
- Columbia University Medical Center, Division of Child Neurology, New York, NY
| | - Sameer A. Sheth
- Baylor College of Medicine, Department of Neurosurgery, Houston, TX
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Schlafly ED, Marshall FA, Merricks EM, Eden UT, Cash SS, Schevon CA, Kramer MA. Multiple Sources of Fast Traveling Waves during Human Seizures: Resolving a Controversy. J Neurosci 2022; 42:6966-6982. [PMID: 35906069 PMCID: PMC9464018 DOI: 10.1523/jneurosci.0338-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 05/26/2022] [Accepted: 06/18/2022] [Indexed: 11/21/2022] Open
Abstract
During human seizures, organized waves of voltage activity rapidly sweep across the cortex. Two contradictory theories describe the source of these fast traveling waves: either a slowly advancing narrow region of multiunit activity (an ictal wavefront) or a fixed cortical location. Limited observations and different analyses prevent resolution of these incompatible theories. Here we address this disagreement by combining the methods and microelectrode array recordings (N = 11 patients, 2 females, N = 31 seizures) from previous human studies to analyze the traveling wave source. We find, inconsistent with both existing theories, a transient relationship between the ictal wavefront and traveling waves, and multiple stable directions of traveling waves in many seizures. Using a computational model that combines elements of both existing theories, we show that interactions between an ictal wavefront and fixed source reproduce the traveling wave dynamics observed in vivo We conclude that combining both existing theories can generate the diversity of ictal traveling waves.SIGNIFICANCE STATEMENT The source of voltage discharges that propagate across cortex during human seizures remains unknown. Two candidate theories exist, each proposing a different discharge source. Support for each theory consists of observations from a small number of human subject recordings, analyzed with separately developed methods. How the different, limited data and different analysis methods impact the evidence for each theory is unclear. To resolve these differences, we combine the unique, human microelectrode array recordings collected separately for each theory and analyze these combined data with a unified approach. We show that neither existing theory adequately describes the data. We then propose a new theory that unifies existing proposals and successfully reproduces the voltage discharge dynamics observed in vivo.
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Affiliation(s)
- Emily D Schlafly
- Graduate Program in Neuroscience, Boston University, Boston, Massachusetts 02215
| | - François A Marshall
- Department of Mathematics and Statistics & Center for Systems Neuroscience, Boston University, Boston, Massachusetts 02215
| | - Edward M Merricks
- Department of Neurology, Columbia University, New York, New York 10032
| | - Uri T Eden
- Department of Mathematics and Statistics & Center for Systems Neuroscience, Boston University, Boston, Massachusetts 02215
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital & Harvard Medical School, Boston, Massachusetts 02114
| | | | - Mark A Kramer
- Department of Mathematics and Statistics & Center for Systems Neuroscience, Boston University, Boston, Massachusetts 02215
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9
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Multimodal, Multiscale Insights into Hippocampal Seizures Enabled by Transparent, Graphene-Based Microelectrode Arrays. eNeuro 2022; 9:ENEURO.0386-21.2022. [PMID: 35470227 PMCID: PMC9087744 DOI: 10.1523/eneuro.0386-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 04/14/2022] [Accepted: 04/15/2022] [Indexed: 11/21/2022] Open
Abstract
Hippocampal seizures are a defining feature of mesial temporal lobe epilepsy (MTLE). Area CA1 of the hippocampus is commonly implicated in the generation of seizures, which may occur because of the activity of endogenous cell populations or of inputs from other regions within the hippocampal formation. Simultaneously observing activity at the cellular and network scales in vivo remains challenging. Here, we present a novel technology for simultaneous electrophysiology and multicellular calcium imaging of CA1 pyramidal cells (PCs) in mice enabled by a transparent graphene-based microelectrode array (Gr MEA). We examine PC firing at seizure onset, oscillatory coupling, and the dynamics of the seizure traveling wave as seizures evolve. Finally, we couple features derived from both modalities to predict the speed of the traveling wave using bootstrap aggregated regression trees. Analysis of the most important features in the regression trees suggests a transition among states in the evolution of hippocampal seizures.
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10
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Smith EH, Liou JY, Merricks EM, Davis T, Thomson K, Greger B, House P, Emerson RG, Goodman R, McKhann GM, Sheth S, Schevon C, Rolston JD. Human interictal epileptiform discharges are bidirectional traveling waves echoing ictal discharges. eLife 2022; 11:73541. [PMID: 35050851 PMCID: PMC8813051 DOI: 10.7554/elife.73541] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Interictal epileptiform discharges (IEDs), also known as interictal spikes, are large intermittent electrophysiological events observed between seizures in patients with epilepsy. Although they occur far more often than seizures, IEDs are less studied, and their relationship to seizures remains unclear. To better understand this relationship, we examined multi-day recordings of microelectrode arrays implanted in human epilepsy patients, allowing us to precisely observe the spatiotemporal propagation of IEDs, spontaneous seizures, and how they relate. These recordings showed that the majority of IEDs are traveling waves, traversing the same path as ictal discharges during seizures, and with a fixed direction relative to seizure propagation. Moreover, the majority of IEDs, like ictal discharges, were bidirectional, with one predominant and a second, less frequent antipodal direction. These results reveal a fundamental spatiotemporal similarity between IEDs and ictal discharges. These results also imply that most IEDs arise in brain tissue outside the site of seizure onset and propagate toward it, indicating that the propagation of IEDs provides useful information for localizing the seizure focus.
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Affiliation(s)
- Elliot H Smith
- Department of Neurolosurgery, University of Utah, Salt Lake City, United States
| | - Jyun-You Liou
- Department of Anesthesiology, Weill Cornell Medicine, New York, United States
| | - Edward M Merricks
- Department of Neurology, Columbia University Medical Center, New York CIty, United States
| | - Tyler Davis
- Department of Neurosurgery, University of Utah, Salt Lake City, United States
| | - Kyle Thomson
- Departments of Neurosurgery, University of Utah, Salt Lake City, United States
| | - Bradley Greger
- Department of Bioengineering, Arizona State University, Tempe, United States
| | - Paul House
- Neurosurgical Associates, LLC, Murray, United States
| | | | | | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Medical Center, New York, United States
| | - Sameer Sheth
- Department of Neurological Surgery, Baylor College of Medicine, Houston, United States
| | - Catherine Schevon
- Department of Neurology, Columbia University, New York, United States
| | - John D Rolston
- Departments of Neurosurgery, University of Utah, Salt Lake City, United States
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11
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Kleen JK, Speidel BA, Baud MO, Rao VR, Ammanuel SG, Hamilton LS, Chang EF, Knowlton RC. Accuracy of omni-planar and surface casting of epileptiform activity for intracranial seizure localization. Epilepsia 2021; 62:947-959. [PMID: 33634855 PMCID: PMC8276628 DOI: 10.1111/epi.16841] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/23/2021] [Accepted: 01/23/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Intracranial electroencephalography (ICEEG) recordings are performed for seizure localization in medically refractory epilepsy. Signal quantifications such as frequency power can be projected as heatmaps on personalized three-dimensional (3D) reconstructed cortical surfaces to distill these complex recordings into intuitive cinematic visualizations. However, simultaneously reconciling deep recording locations and reliably tracking evolving ictal patterns remain significant challenges. METHODS We fused oblique magnetic resonance imaging (MRI) slices along depth probe trajectories with cortical surface reconstructions and projected dynamic heatmaps using a simple mathematical metric of epileptiform activity (line-length). This omni-planar and surface casting of epileptiform activity approach (OPSCEA) thus illustrated seizure onset and spread among both deep and superficial locations simultaneously with minimal need for signal processing supervision. We utilized the approach on 41 patients at our center implanted with grid, strip, and/or depth electrodes for localizing medically refractory seizures. Peri-ictal data were converted into OPSCEA videos with multiple 3D brain views illustrating all electrode locations. Five people of varying expertise in epilepsy (medical student through epilepsy attending level) attempted to localize the seizure-onset zones. RESULTS We retrospectively compared this approach with the original ICEEG study reports for validation. Accuracy ranged from 73.2% to 97.6% for complete or overlapping onset lobe(s), respectively, and ~56.1% to 95.1% for the specific focus (or foci). Higher answer certainty for a given case predicted better accuracy, and scorers had similar accuracy across different training levels. SIGNIFICANCE In an era of increasing stereo-EEG use, cinematic visualizations fusing omni-planar and surface functional projections appear to provide a useful adjunct for interpreting complex intracranial recordings and subsequent surgery planning.
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Affiliation(s)
- Jonathan K Kleen
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, California, USA
| | - Benjamin A Speidel
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, California, USA
| | - Maxime O Baud
- Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Vikram R Rao
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, California, USA
| | - Simon G Ammanuel
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, California, USA
| | - Liberty S Hamilton
- Department of Speech, Language, and Hearing Sciences and Department of Neurology, The University of Texas at Austin, Austin, Texas, USA
| | - Edward F Chang
- Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, California, USA
| | - Robert C Knowlton
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, California, USA
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12
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Diamond JM, Diamond BE, Trotta MS, Dembny K, Inati SK, Zaghloul KA. Travelling waves reveal a dynamic seizure source in human focal epilepsy. Brain 2021; 144:1751-1763. [PMID: 33693588 DOI: 10.1093/brain/awab089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/08/2020] [Accepted: 12/23/2020] [Indexed: 11/14/2022] Open
Abstract
Treatment of patients with drug-resistant focal epilepsy relies upon accurate seizure localization. Ictal activity captured by intracranial EEG has traditionally been interpreted to suggest that the underlying cortex is actively involved in seizures. Here, we hypothesize that such activity instead reflects propagated activity from a relatively focal seizure source, even during later time points when ictal activity is more widespread. We used the time differences observed between ictal discharges in adjacent electrodes to estimate the location of the hypothesized focal source and demonstrated that the seizure source, localized in this manner, closely matches the clinically and neurophysiologically determined brain region giving rise to seizures. Moreover, we determined this focal source to be a dynamic entity that moves and evolves over the time course of a seizure. Our results offer an interpretation of ictal activity observed by intracranial EEG that challenges the traditional conceptualization of the seizure source.
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Affiliation(s)
- Joshua M Diamond
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Benjamin E Diamond
- J.P. Morgan AI Research, Corporate and Investment Bank, JP Morgan Chase & Co., New York, NY 10017, USA
| | - Michael S Trotta
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kate Dembny
- Clinical Epilepsy Section, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sara K Inati
- Clinical Epilepsy Section, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kareem A Zaghloul
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD 20892, USA
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13
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Ming Q, Liou JY, Yang F, Li J, Chu C, Zhou Q, Wu D, Xu S, Luo P, Liang J, Li D, Pryor KO, Lin W, Schwartz TH, Ma H. Isoflurane-Induced Burst Suppression Is a Thalamus-Modulated, Focal-Onset Rhythm With Persistent Local Asynchrony and Variable Propagation Patterns in Rats. Front Syst Neurosci 2021; 14:599781. [PMID: 33510621 PMCID: PMC7835516 DOI: 10.3389/fnsys.2020.599781] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/14/2020] [Indexed: 11/13/2022] Open
Abstract
Background: Inhalational anesthetic-induced burst suppression (BS) is classically considered a bilaterally synchronous rhythm. However, local asynchrony has been predicted in theoretical studies and reported in patients with pre-existing focal pathology. Method: We used high-speed widefield calcium imaging to study the spatiotemporal dynamics of isoflurane-induced BS in rats. Results: We found that isoflurane-induced BS is not a globally synchronous rhythm. In the neocortex, neural activity first emerged in a spatially shifting, variably localized focus. Subsequent propagation across the whole cortex was rapid, typically within <100 milliseconds, giving the superficial resemblance to global synchrony. Neural activity remained locally asynchronous during the bursts, forming complex recurrent propagating waves. Despite propagation variability, spatial sequences of burst propagation were largely preserved between the hemispheres, and neural activity was highly correlated between the homotopic areas. The critical role of the thalamus in cortical burst initiation was demonstrated by using unilateral thalamic tetrodotoxin injection. Conclusion: The classical impression that anesthetics-induced BS is a state of global brain synchrony is inaccurate. Bursts are a series of shifting local cortical events facilitated by thalamic projection that unfold as rapid, bilaterally asynchronous propagating waves.
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Affiliation(s)
- Qianwen Ming
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Jyun-You Liou
- Department of Anesthesiology, New York-Presbyterian Hospital/Weill Cornell Medicine, New York, NY, United States
| | - Fan Yang
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Jing Li
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Chaojia Chu
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Qingchen Zhou
- Department of Radiology, The First Hospital of Jilin University, Changchun, China
| | - Dan Wu
- Department of Radiology, The First Hospital of Jilin University, Changchun, China
| | - Shujia Xu
- Department of Radiology, The First Hospital of Jilin University, Changchun, China
| | - Peijuan Luo
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Jianmin Liang
- Department of Pediatrics, The First Hospital of Jilin University, Changchun, China
| | - Dan Li
- Department of Radiology, The First Hospital of Jilin University, Changchun, China
| | - Kane O Pryor
- Department of Anesthesiology, New York-Presbyterian Hospital/Weill Cornell Medicine, New York, NY, United States
| | - Weihong Lin
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Theodore H Schwartz
- Department of Neurological Surgery and Brain and Mind Research Institute, Weill Cornell Medicine of Cornell University, NewYork-Presbyterian Hospital, New York, NY, United States
| | - Hongtao Ma
- Department of Neurology, The First Hospital of Jilin University, Changchun, China.,Department of Neurological Surgery and Brain and Mind Research Institute, Weill Cornell Medicine of Cornell University, NewYork-Presbyterian Hospital, New York, NY, United States
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14
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Liou JY, Baird-Daniel E, Zhao M, Daniel A, Schevon CA, Ma H, Schwartz TH. Burst suppression uncovers rapid widespread alterations in network excitability caused by an acute seizure focus. Brain 2020; 142:3045-3058. [PMID: 31436790 DOI: 10.1093/brain/awz246] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 06/19/2019] [Accepted: 06/22/2019] [Indexed: 01/25/2023] Open
Abstract
Burst suppression is an electroencephalogram pattern of globally symmetric alternating high amplitude activity and isoelectricity that can be induced by general anaesthetics. There is scattered evidence that burst suppression may become spatially non-uniform in the setting of underlying pathology. Here, we induced burst suppression with isoflurane in rodents and then created a neocortical acute seizure focus with injection of 4-aminopyridine (4-AP) in somatosensory cortex. Burst suppression events were recorded before and after creation of the focus using bihemispheric wide-field calcium imaging and multielectrode arrays. We find that the seizure focus elicits a rapid alteration in triggering, initiation, and propagation of burst suppression events. Compared with the non-seizing brain, bursts are triggered from the thalamus, initiate in regions uniquely outside the epileptic focus, elicit marked increases of multiunit activity and propagate towards the seizure focus. These findings support the rapid, widespread impact of focal epilepsy on the extended brain network.
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Affiliation(s)
- Jyun-You Liou
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA.,Department of Anesthesiology, Weill Cornell Medicine, New York, New York, NY, USA
| | - Eliza Baird-Daniel
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA
| | - Mingrui Zhao
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA
| | - Andy Daniel
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA
| | - Catherine A Schevon
- Department of Neurology, Columbia University Medical Center, New York, New York, USA
| | - Hongtao Ma
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA
| | - Theodore H Schwartz
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA
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15
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Dorfer C, Rydenhag B, Baltuch G, Buch V, Blount J, Bollo R, Gerrard J, Nilsson D, Roessler K, Rutka J, Sharan A, Spencer D, Cukiert A. How technology is driving the landscape of epilepsy surgery. Epilepsia 2020; 61:841-855. [PMID: 32227349 PMCID: PMC7317716 DOI: 10.1111/epi.16489] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 03/03/2020] [Accepted: 03/04/2020] [Indexed: 12/24/2022]
Abstract
This article emphasizes the role of the technological progress in changing the landscape of epilepsy surgery and provides a critical appraisal of robotic applications, laser interstitial thermal therapy, intraoperative imaging, wireless recording, new neuromodulation techniques, and high-intensity focused ultrasound. Specifically, (a) it relativizes the current hype in using robots for stereo-electroencephalography (SEEG) to increase the accuracy of depth electrode placement and save operating time; (b) discusses the drawback of laser interstitial thermal therapy (LITT) when it comes to the need for adequate histopathologic specimen and the fact that the concept of stereotactic disconnection is not new; (c) addresses the ratio between the benefits and expenditure of using intraoperative magnetic resonance imaging (MRI), that is, the high technical and personnel expertise needed that might restrict its use to centers with a high case load, including those unrelated to epilepsy; (d) soberly reviews the advantages, disadvantages, and future potentials of neuromodulation techniques with special emphasis on the differences between closed and open-loop systems; and (e) provides a critical outlook on the clinical implications of focused ultrasound, wireless recording, and multipurpose electrodes that are already on the horizon. This outlook shows that although current ultrasonic systems do have some limitations in delivering the acoustic energy, further advance of this technique may lead to novel treatment paradigms. Furthermore, it highlights that new data streams from multipurpose electrodes and wireless transmission of intracranial recordings will become available soon once some critical developments will be achieved such as electrode fidelity, data processing and storage, heat conduction as well as rechargeable technology. A better understanding of modern epilepsy surgery will help to demystify epilepsy surgery for the patients and the treating physicians and thereby reduce the surgical treatment gap.
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Affiliation(s)
- Christian Dorfer
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Bertil Rydenhag
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Neurosurgery, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Gordon Baltuch
- Center for Functional and Restorative Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Vivek Buch
- Center for Functional and Restorative Neurosurgery, University of Pennsylvania, Philadelphia, PA, USA
| | - Jeffrey Blount
- Division of Neurosurgery, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Robert Bollo
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Jason Gerrard
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
| | - Daniel Nilsson
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Neurosurgery, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Karl Roessler
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria.,Department of Neurosurgery, University of Erlangen, Erlangen, Germany
| | - James Rutka
- Division of Pediatric Neurosurgery, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Ashwini Sharan
- Department of Neurosurgery and Neurology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Dennis Spencer
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
| | - Arthur Cukiert
- Neurology and Neurosurgery Clinic Sao Paulo, Clinica Neurologica Cukiert, Sao Paulo, Brazil
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16
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Liou JY, Smith EH, Bateman LM, Bruce SL, McKhann GM, Goodman RR, Emerson RG, Schevon CA, Abbott LF. A model for focal seizure onset, propagation, evolution, and progression. eLife 2020; 9:50927. [PMID: 32202494 PMCID: PMC7089769 DOI: 10.7554/elife.50927] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 03/04/2020] [Indexed: 12/16/2022] Open
Abstract
We developed a neural network model that can account for major elements common to human focal seizures. These include the tonic-clonic transition, slow advance of clinical semiology and corresponding seizure territory expansion, widespread EEG synchronization, and slowing of the ictal rhythm as the seizure approaches termination. These were reproduced by incorporating usage-dependent exhaustion of inhibition in an adaptive neural network that receives global feedback inhibition in addition to local recurrent projections. Our model proposes mechanisms that may underline common EEG seizure onset patterns and status epilepticus, and postulates a role for synaptic plasticity in the emergence of epileptic foci. Complex patterns of seizure activity and bi-stable seizure end-points arise when stochastic noise is included. With the rapid advancement of clinical and experimental tools, we believe that this model can provide a roadmap and potentially an in silico testbed for future explorations of seizure mechanisms and clinical therapies.
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Affiliation(s)
- Jyun-You Liou
- Department of Physiology and Cellular Biophysics, Columbia University, New York, United States.,Department of Anesthesiology, NewYork-Presbyterian Hospital/Weill Cornell Medicine, New York, United States.,Department of Neurology, Columbia University Medical Center, New York, United States
| | - Elliot H Smith
- Department of Neurological Surgery, Columbia University Medical Center, New York, United States
| | - Lisa M Bateman
- Department of Neurology, Columbia University Medical Center, New York, United States
| | - Samuel L Bruce
- Vagelos College of Physicians & Surgeons, Columbia University, New York, United States
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Medical Center, New York, United States
| | - Robert R Goodman
- Department of Neurological Surgery, Columbia University Medical Center, New York, United States
| | - Ronald G Emerson
- Department of Neurology, Columbia University Medical Center, New York, United States
| | - Catherine A Schevon
- Department of Neurology, Columbia University Medical Center, New York, United States
| | - L F Abbott
- Department of Physiology and Cellular Biophysics, Columbia University, New York, United States.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Department of Neuroscience, Columbia University, New York, United States
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17
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Tryba AK, Merricks EM, Lee S, Pham T, Cho S, Nordli DR, Eissa TL, Goodman RR, McKhann GM, Emerson RG, Schevon CA, van Drongelen W. Role of paroxysmal depolarization in focal seizure activity. J Neurophysiol 2019; 122:1861-1873. [PMID: 31461373 DOI: 10.1152/jn.00392.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We analyze the role of inhibition in sustaining focal epileptic seizure activity. We review ongoing seizure activity at the mesoscopic scale that can be observed with microelectrode arrays as well as at the macroscale of standard clinical EEG. We provide clinical, experimental, and modeling data to support the hypothesis that paroxysmal depolarization (PD) is a critical component of the ictal machinery. We present dual-patch recordings in cortical cultures showing reduced synaptic transmission associated with presynaptic occurrence of PD, and we find that the PD threshold is cell size related. We further find evidence that optically evoked PD activity in parvalbumin neurons can promote propagation of neuronal excitation in neocortical networks in vitro. Spike sorting results from microelectrode array measurements around ictal wave propagation in human focal seizures demonstrate a strong increase in putative inhibitory firing with an approaching excitatory wave, followed by a sudden reduction of firing at passage. At the macroscopic level, we summarize evidence that this excitatory ictal wave activity is strongly correlated with oscillatory activity across a centimeter-sized cortical network. We summarize Wilson-Cowan-type modeling showing how inhibitory function is crucial for this behavior. Our findings motivated us to develop a network motif of neurons in silico, governed by a reduced version of the Hodgkin-Huxley formalism, to show how feedforward, feedback, PD, and local failure of inhibition contribute to observed dynamics across network scales. The presented multidisciplinary evidence suggests that the PD not only is a cellular marker or epiphenomenon but actively contributes to seizure activity.NEW & NOTEWORTHY We present mechanisms of ongoing focal seizures across meso- and macroscales of microelectrode array and standard clinical recordings, respectively. We find modeling, experimental, and clinical evidence for a dual role of inhibition across these scales: local failure of inhibition allows propagation of a mesoscopic ictal wave, whereas inhibition elsewhere remains intact and sustains macroscopic oscillatory activity. We present evidence for paroxysmal depolarization as a mechanism behind this dual role of inhibition in shaping ictal activity.
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Affiliation(s)
- Andrew K Tryba
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - Edward M Merricks
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Somin Lee
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - Tuan Pham
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - SungJun Cho
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - Douglas R Nordli
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - Tahra L Eissa
- Department of Applied Mathematics, University of Colorado Boulder, Boulder, Colorado
| | - Robert R Goodman
- Department of Neurosurgery, Northwell Health/Lenox Hill Hospital, New York, New York
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | | | - Catherine A Schevon
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Wim van Drongelen
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
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18
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Schevon CA, Tobochnik S, Eissa T, Merricks E, Gill B, Parrish RR, Bateman LM, McKhann GM, Emerson RG, Trevelyan AJ. Multiscale recordings reveal the dynamic spatial structure of human seizures. Neurobiol Dis 2019; 127:303-311. [PMID: 30898669 DOI: 10.1016/j.nbd.2019.03.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/11/2019] [Accepted: 03/15/2019] [Indexed: 02/07/2023] Open
Abstract
The cellular activity underlying human focal seizures, and its relationship to key signatures in the EEG recordings used for therapeutic purposes, has not been well characterized despite many years of investigation both in laboratory and clinical settings. The increasing use of microelectrodes in epilepsy surgery patients has made it possible to apply principles derived from laboratory research to the problem of mapping the spatiotemporal structure of human focal seizures, and characterizing the corresponding EEG signatures. In this review, we describe results from human microelectrode studies, discuss some data interpretation pitfalls, and explain the current understanding of the key mechanisms of ictogenesis and seizure spread.
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Affiliation(s)
- Catherine A Schevon
- Department of Neurology, Columbia University Medical Center, New York, NY, USA.
| | - Steven Tobochnik
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Tahra Eissa
- Department of Applied Mathematics, University of Colorado at Boulder, Boulder, CO, USA
| | - Edward Merricks
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Brian Gill
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA
| | - R Ryley Parrish
- Institute for Aging, Newcastle University, Newcastle-Upon-Tyne, UK
| | - Lisa M Bateman
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA
| | - Ronald G Emerson
- Department of Neurology, Weill Cornell Medical Center, New York, NY, USA
| | - Andrew J Trevelyan
- Department of Neurology, Columbia University Medical Center, New York, NY, USA; Institute for Aging, Newcastle University, Newcastle-Upon-Tyne, UK
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19
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Smith EH, Rolston JD. Oscillations Travel Around the Human Brain. Neurosurgery 2018; 83:E205-E206. [DOI: 10.1093/neuros/nyy402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Theta and Alpha Oscillations Are Traveling Waves in the Human Neocortex. Neuron 2018; 98:1269-1281.e4. [PMID: 29887341 DOI: 10.1016/j.neuron.2018.05.019] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/30/2018] [Accepted: 05/11/2018] [Indexed: 12/12/2022]
Abstract
Human cognition requires the coordination of neural activity across widespread brain networks. Here, we describe a new mechanism for large-scale coordination in the human brain: traveling waves of theta and alpha oscillations. Examining direct brain recordings from neurosurgical patients performing a memory task, we found contiguous clusters of cortex in individual patients with oscillations at specific frequencies within 2 to 15 Hz. These oscillatory clusters displayed spatial phase gradients, indicating that they formed traveling waves that propagated at ∼0.25-0.75 m/s. Traveling waves were relevant behaviorally because their propagation correlated with task events and was more consistent when subjects performed the task well. Human traveling theta and alpha waves can be modeled by a network of coupled oscillators because the direction of wave propagation correlated with the spatial orientation of local frequency gradients. Our findings suggest that oscillations support brain connectivity by organizing neural processes across space and time.
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