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Kim J, Hong J, Park K, Lee S, Hoang AT, Pak S, Zhao H, Ji S, Yang S, Chung CK, Yang S, Ahn JH. Injectable 2D Material-Based Sensor Array for Minimally Invasive Neural Implants. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2400261. [PMID: 38741451 DOI: 10.1002/adma.202400261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/16/2024] [Indexed: 05/16/2024]
Abstract
Intracranial implants for diagnosis and treatment of brain diseases have been developed over the past few decades. However, the platform of conventional implantable devices still relies on invasive probes and bulky sensors in conjunction with large-area craniotomy and provides only limited biometric information. Here, an implantable multi-modal sensor array that can be injected through a small hole in the skull and inherently spread out for conformal contact with the cortical surface is reported. The injectable sensor array, composed of graphene multi-channel electrodes for neural recording and electrical stimulation and MoS2-based sensors for monitoring intracranial temperature and pressure, is designed based on a mesh structure whose elastic restoring force enables the contracted device to spread out. It is demonstrated that the sensor array injected into a rabbit's head can detect epileptic discharges on the surface of the cortex and mitigate it by electrical stimulation while monitoring both intracranial temperature and pressure. This method provides good potential for implanting a variety of functional devices via minimally invasive surgery.
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Affiliation(s)
- Jejung Kim
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Juyeong Hong
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Kyungtai Park
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Sangwon Lee
- gBrain Inc., Incheon, 21984, Republic of Korea
| | - Anh Tuan Hoang
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Sojeong Pak
- Department of Neuroscience, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong
| | - Huilin Zhao
- Department of Neuroscience, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong
| | - Seunghyeon Ji
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Sungchil Yang
- Department of Nanobioengineering, Incheon National University, Incheon, 22012, Republic of Korea
| | - Chun Kee Chung
- Department of Neurosurgery, Seoul National University Hospital, Seoul, 03080, Republic of Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Sunggu Yang
- gBrain Inc., Incheon, 21984, Republic of Korea
- Department of Neuroscience, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong
| | - Jong-Hyun Ahn
- School of Electrical and Electronic Engineering, Yonsei University, Seoul, 03722, Republic of Korea
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2
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Lieberman S, Rivera DA, Morton R, Hingorani A, Southard TL, Johnson L, Reukauf J, Radwanski RE, Zhao M, Nishimura N, Bracko O, Schwartz TH, Schaffer CB. Circumscribing Laser Cuts Attenuate Seizure Propagation in a Mouse Model of Focal Epilepsy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2300747. [PMID: 38810146 PMCID: PMC11304327 DOI: 10.1002/advs.202300747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 02/24/2024] [Indexed: 05/31/2024]
Abstract
In partial onset epilepsy, seizures arise focally in the brain and often propagate. Patients frequently become refractory to medical management, leaving neurosurgery, which can cause neurologic deficits, as a primary treatment. In the cortex, focal seizures spread through horizontal connections in layers II/III, suggesting that severing these connections can block seizures while preserving function. Focal neocortical epilepsy is induced in mice, sub-surface cuts are created surrounding the seizure focus using tightly-focused femtosecond laser pulses, and electrophysiological recordings are acquired at multiple locations for 3-12 months. Cuts reduced seizure frequency in most animals by 87%, and only 5% of remaining seizures propagated to the distant electrodes, compared to 80% in control animals. These cuts produced a modest decrease in cortical blood flow that recovered and left a ≈20-µm wide scar with minimal collateral damage. When placed over the motor cortex, cuts do not cause notable deficits in a skilled reaching task, suggesting they hold promise as a novel neurosurgical approach for intractable focal cortical epilepsy.
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Affiliation(s)
- Seth Lieberman
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNY14853USA
- College of Veterinary MedicineCornell UniversityIthacaNY14853USA
| | - Daniel A. Rivera
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNY14853USA
| | - Ryan Morton
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNY14853USA
| | - Amrit Hingorani
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNY14853USA
| | | | - Lynn Johnson
- Statistical Consulting UnitCornell UniversityIthacaNY14853USA
| | - Jennifer Reukauf
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNY14853USA
- College of Veterinary MedicineCornell UniversityIthacaNY14853USA
| | - Ryan E. Radwanski
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNY14853USA
| | - Mingrui Zhao
- Department of Neurological SurgeryWeill Cornell Medicine of Cornell UniversityNew YorkNY10065USA
- Brain and Mind Research InstituteWeill Cornell Medicine of Cornell UniversityNew YorkNY10021USA
| | - Nozomi Nishimura
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNY14853USA
| | - Oliver Bracko
- Department of BiologyThe University of MiamiCoral GablesFL33134USA
| | - Theodore H. Schwartz
- Department of Neurological SurgeryWeill Cornell Medicine of Cornell UniversityNew YorkNY10065USA
- Brain and Mind Research InstituteWeill Cornell Medicine of Cornell UniversityNew YorkNY10021USA
| | - Chris B. Schaffer
- Meinig School of Biomedical EngineeringCornell UniversityIthacaNY14853USA
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Fernández-Torre JL, Hernández-Hernández MA, Cherchi MS, Mato-Mañas D, de Lucas EM, Gómez-Ruiz E, Vázquez-Higuera JL, Fanjul-Vélez F, Arce-Diego JL, Martín-Láez R. Comparison of Continuous Intracortical and Scalp Electroencephalography in Comatose Patients with Acute Brain Injury. Neurocrit Care 2024:10.1007/s12028-024-02016-z. [PMID: 38918336 DOI: 10.1007/s12028-024-02016-z] [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: 11/29/2023] [Accepted: 05/16/2024] [Indexed: 06/27/2024]
Abstract
BACKGROUND Depth electroencephalography (dEEG) is a recent invasive monitoring technique used in patients with acute brain injury. This study aimed to describe in detail the clinical manifestations of nonconvulsive seizures (NCSzs) with and without a surface EEG correlate, analyze their long-standing effects, and provide data that contribute to understanding the significance of certain scalp EEG patterns observed in critically ill patients. METHODS We prospectively enrolled a cohort of 33 adults with severe acute brain injury admitted to the neurological intensive care unit. All of them underwent multimodal invasive monitoring, including dEEG. All patients were scanned on a 3T magnetic resonance imaging scanner at 6 months after hospital discharge, and mesial temporal atrophy (MTA) was calculated using a visual scale. RESULTS In 21 (65.6%) of 32 study participants, highly epileptiform intracortical patterns were observed. A total of 11 (34.3%) patients had electrographic or electroclinical seizures in the dEEG, of whom 8 had both spontaneous and stimulus-induced (SI) seizures, and 3 patients had only spontaneous intracortical seizures. An unequivocal ictal scalp correlate was observed in only 3 (27.2%) of the 11 study participants. SI-NCSzs occurred during nursing care, medical procedures, and family visits. Subtle clinical manifestations, such as restlessness, purposeless stereotyped movements of the upper limbs, ventilation disturbances, jerks, head movements, hyperextension posturing, chewing, and oroalimentary automatisms, occurred during intracortical electroclinical seizures. MTA was detected in 18 (81.8%) of the 22 patients. There were no statistically significant differences between patients with MTA with and without seizures or status epilepticus. CONCLUSIONS Most NCSzs in critically ill comatose patients remain undetectable on scalp EEG. SI-NCSzs frequently occur during nursing care, medical procedures, and family visits. Semiology of NCSzs included ictal minor signs and subtle symptoms, such as breathing pattern changes manifested as patient-ventilator dyssynchrony.
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Affiliation(s)
- José L Fernández-Torre
- Department of Clinical Neurophysiology, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain.
- Department of Physiology and Pharmacology, School of Medicine, University of Cantabria, 39008, Santander, Cantabria, Spain.
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain.
| | - Miguel A Hernández-Hernández
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Intensive Medicine, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
| | - Marina S Cherchi
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Intensive Medicine, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
| | - David Mato-Mañas
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Neurosurgery, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
| | - Enrique Marco de Lucas
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Radiology, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
- Department of Medical-Surgical Sciences, School of Medicine, University of Cantabria, 39008, Santander, Cantabria, Spain
| | - Elsa Gómez-Ruiz
- Department of Psychiatry, Marqués de Valdecilla University Hospital Santander, 39008, Cantabria, Spain
| | - José L Vázquez-Higuera
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Neurology, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
| | - Félix Fanjul-Vélez
- Biomedical Engineering Group, Tecnología Electrónica, Ingeniería de Sistemas y Automática (TEISA) Department, University of Cantabria, 39005, Santander, Cantabria, Spain
| | - José L Arce-Diego
- Biomedical Engineering Group, Tecnología Electrónica, Ingeniería de Sistemas y Automática (TEISA) Department, University of Cantabria, 39005, Santander, Cantabria, Spain
| | - Rubén Martín-Láez
- Biomedical Research Institute (IDIVAL), 39011, Santander, Cantabria, Spain
- Department of Neurosurgery, Marqués de Valdecilla University Hospital, 39008, Santander, Cantabria, Spain
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4
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Wenzel M, Huberfeld G, Grayden DB, de Curtis M, Trevelyan AJ. A debate on the neuronal origin of focal seizures. Epilepsia 2023; 64 Suppl 3:S37-S48. [PMID: 37183507 DOI: 10.1111/epi.17650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/26/2023] [Accepted: 05/12/2023] [Indexed: 05/16/2023]
Abstract
A critical question regarding how focal seizures start is whether we can identify particular cell classes that drive the pathological process. This was the topic for debate at the recent International Conference for Technology and Analysis of Seizures (ICTALS) meeting (July 2022, Bern, CH) that we summarize here. The debate has been fueled in recent times by the introduction of powerful new ways to manipulate subpopulations of cells in relative isolation, mostly using optogenetics. The motivation for resolving the debate is to identify novel targets for therapeutic interventions through a deeper understanding of the etiology of seizures.
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Affiliation(s)
- Michael Wenzel
- Department of Epileptology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Gilles Huberfeld
- Neurology Department, Hopital Fondation Adolphe de Rothschild, Paris, France
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
| | - David B Grayden
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Medicine, St Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
- Graeme Clark Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | - Marco de Curtis
- Epilepsy Unit, Fondazione I.R.C.C.S., Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrew J Trevelyan
- Newcastle University Biosciences Institute, Medical School, Framlington Place, Newcastle upon Tyne, UK
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5
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Duraivel S, Rahimpour S, Chiang CH, Trumpis M, Wang C, Barth K, Harward SC, Lad SP, Friedman AH, Southwell DG, Sinha SR, Viventi J, Cogan GB. High-resolution neural recordings improve the accuracy of speech decoding. Nat Commun 2023; 14:6938. [PMID: 37932250 PMCID: PMC10628285 DOI: 10.1038/s41467-023-42555-1] [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: 12/21/2022] [Accepted: 10/13/2023] [Indexed: 11/08/2023] Open
Abstract
Patients suffering from debilitating neurodegenerative diseases often lose the ability to communicate, detrimentally affecting their quality of life. One solution to restore communication is to decode signals directly from the brain to enable neural speech prostheses. However, decoding has been limited by coarse neural recordings which inadequately capture the rich spatio-temporal structure of human brain signals. To resolve this limitation, we performed high-resolution, micro-electrocorticographic (µECoG) neural recordings during intra-operative speech production. We obtained neural signals with 57× higher spatial resolution and 48% higher signal-to-noise ratio compared to macro-ECoG and SEEG. This increased signal quality improved decoding by 35% compared to standard intracranial signals. Accurate decoding was dependent on the high-spatial resolution of the neural interface. Non-linear decoding models designed to utilize enhanced spatio-temporal neural information produced better results than linear techniques. We show that high-density µECoG can enable high-quality speech decoding for future neural speech prostheses.
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Affiliation(s)
| | - Shervin Rahimpour
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, USA
- Department of Neurosurgery, Clinical Neuroscience Center, University of Utah, Salt Lake City, UT, USA
| | - Chia-Han Chiang
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Michael Trumpis
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Charles Wang
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Katrina Barth
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Stephen C Harward
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, USA
- Duke Comprehensive Epilepsy Center, Duke School of Medicine, Durham, NC, USA
| | - Shivanand P Lad
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, USA
| | - Allan H Friedman
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, USA
| | - Derek G Southwell
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, USA
- Duke Comprehensive Epilepsy Center, Duke School of Medicine, Durham, NC, USA
- Department of Neurobiology, Duke School of Medicine, Durham, NC, USA
| | - Saurabh R Sinha
- Penn Epilepsy Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jonathan Viventi
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, USA.
- Duke Comprehensive Epilepsy Center, Duke School of Medicine, Durham, NC, USA.
- Department of Neurobiology, Duke School of Medicine, Durham, NC, USA.
| | - Gregory B Cogan
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, USA.
- Duke Comprehensive Epilepsy Center, Duke School of Medicine, Durham, NC, USA.
- Department of Neurology, Duke School of Medicine, Durham, NC, USA.
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA.
- Center for Cognitive Neuroscience, Duke University, Durham, NC, USA.
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6
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Sindhu KR, Ngo D, Ombao H, Olaya JE, Shrey DW, Lopour BA. A novel method for dynamically altering the surface area of intracranial EEG electrodes. J Neural Eng 2023; 20:026002. [PMID: 36720162 PMCID: PMC9990369 DOI: 10.1088/1741-2552/acb79f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 01/31/2023] [Indexed: 02/02/2023]
Abstract
Objective.Intracranial electroencephalogram (iEEG) plays a critical role in the treatment of neurological diseases, such as epilepsy and Parkinson's disease, as well as the development of neural prostheses and brain computer interfaces. While electrode geometries vary widely across these applications, the impact of electrode size on iEEG features and morphology is not well understood. Some insight has been gained from computer simulations, as well as experiments in which signals are recorded using electrodes of different sizes concurrently in different brain regions. Here, we introduce a novel method to record from electrodes of different sizes in the exact same location by changing the size of iEEG electrodes after implantation in the brain.Approach.We first present a theoretical model and anin vitrovalidation of the method. We then report the results of anin vivoimplementation in three human subjects with refractory epilepsy. We recorded iEEG data from three different electrode sizes and compared the amplitudes, power spectra, inter-channel correlations, and signal-to-noise ratio (SNR) of interictal epileptiform discharges, i.e. epileptic spikes.Main Results.We found that iEEG amplitude and power decreased as electrode size increased, while inter-channel correlation did not change significantly with electrode size. The SNR of epileptic spikes was generally highest in the smallest electrodes, but 39% of spikes had maximal SNR in larger electrodes. This likely depends on the precise location and spatial spread of each spike.Significance.Overall, this new method enables multi-scale measurements of electrical activity in the human brain that can facilitate our understanding of neurophysiology, treatment of neurological disease, and development of novel technologies.
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Affiliation(s)
| | - Duy Ngo
- Department of Statistics, Western Michigan University, Kalamazoo, MI, United States of America
| | - Hernando Ombao
- Statistics Program, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Joffre E Olaya
- Division of Neurosurgery, Children’s Hospital of Orange County, Orange, CA, United States of America
- Department of Neurosurgery, University of California, Irvine, Irvine, CA, United States of America
| | - Daniel W Shrey
- Division of Neurology, Children’s Hospital of Orange County, Orange, CA, United States of America
- Department of Pediatrics, University of California, Irvine, Irvine, CA, United States of America
| | - Beth A Lopour
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, United States of America
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7
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Buckmaster PS, Reyes B, Kahn T, Wyeth M. Ventral Hippocampal Formation Is the Primary Epileptogenic Zone in a Rat Model of Temporal Lobe Epilepsy. J Neurosci 2022; 42:7482-7495. [PMID: 35995562 PMCID: PMC9525166 DOI: 10.1523/jneurosci.0429-22.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 08/04/2022] [Accepted: 08/10/2022] [Indexed: 01/12/2023] Open
Abstract
Temporal lobe epilepsy is common, but mechanisms of seizure initiation are unclear. We evaluated seizure initiation in female and male rats that had been systemically treated with pilocarpine, a widely used model of temporal lobe epilepsy. Local field potential (LFP) recordings from many brain regions revealed variable sites of earliest recorded seizure activity, but mostly the ventral hippocampal formation. To test whether inactivation of the ventral hippocampal formation would reduce seizures, mini-osmotic pumps were used to continually and focally deliver TTX. High doses of TTX infused unilaterally into the ventral hippocampal formation blocked seizures reversibly but also reduced LFP amplitudes in remote brain regions, indicating distant effects. A lower dose did not reduce LFP amplitudes in remote brain regions but did not reduce seizures when infused unilaterally. Instead, seizures tended to initiate in the contralateral ventral hippocampal formation. Bilateral infusion of the lower dose into the ventral hippocampal formation reduced seizure frequency 85%. Similar bilateral treatment in the amygdala was not effective. Bilateral infusion of the dorsal hippocampus reduced seizure frequency, but only 17%. Together, these findings reveal that the ventral hippocampal formation is a primary bilaterally independent epileptogenic zone, and the dorsal hippocampus is a secondary epileptogenic zone in pilocarpine-treated rats. This is consistent with many human patients, and the results further validate the LFP method for identifying seizure onset zones. Finally, the findings are more consistent with a focal mechanism of ictogenesis rather than one involving a network of interdependent nodes.SIGNIFICANCE STATEMENT To better understand how seizures start, investigators need to know where seizures start in the animal models they study. In the widely used pilocarpine-treated rat model of temporal lobe epilepsy, earliest seizure activity was most frequently recorded in the ventral hippocampal formation. Confirming the primary role of the ventral hippocampal formation, seizure frequency was reduced most effectively when it was inactivated focally, bilaterally, and continually with infused TTX. These findings suggest that the ventral hippocampal formation is the primary site of seizure initiation in this animal model of temporal lobe epilepsy, consistent with findings in many human patients.
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Affiliation(s)
- Paul S Buckmaster
- Departments of Comparative Medicine
- Neurology & Neurological Sciences, Stanford University, Stanford, California 94305
| | - Bianca Reyes
- Departments of Comparative Medicine
- College of Veterinary Medicine, Tuskegee University, Tuskegee, Alabama 36088
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8
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Sun J, Barth K, Qiao S, Chiang CH, Wang C, Rahimpour S, Trumpis M, Duraivel S, Dubey A, Wingel KE, Rachinskiy I, Voinas AE, Ferrentino B, Southwell DG, Haglund MM, Friedman AH, Lad SP, Doyle WK, Solzbacher F, Cogan G, Sinha SR, Devore S, Devinsky O, Friedman D, Pesaran B, Viventi J. Intraoperative microseizure detection using a high-density micro-electrocorticography electrode array. Brain Commun 2022; 4:fcac122. [PMID: 35663384 PMCID: PMC9155612 DOI: 10.1093/braincomms/fcac122] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 02/10/2022] [Accepted: 05/24/2022] [Indexed: 11/14/2022] Open
Abstract
One-third of epilepsy patients suffer from medication-resistant seizures. While surgery to remove epileptogenic tissue helps some patients, 30-70% of patients continue to experience seizures following resection. Surgical outcomes may be improved with more accurate localization of epileptogenic tissue. We have previously developed novel thin-film, subdural electrode arrays with hundreds of microelectrodes over a 100-1000 mm2 area to enable high-resolution mapping of neural activity. Here, we used these high-density arrays to study microscale properties of human epileptiform activity. We performed intraoperative micro-electrocorticographic recordings in nine patients with epilepsy. In addition, we recorded from four patients with movement disorders undergoing deep brain stimulator implantation as non-epileptic controls. A board-certified epileptologist identified microseizures, which resembled electrographic seizures normally observed with clinical macroelectrodes. Recordings in epileptic patients had a significantly higher microseizure rate (2.01 events/min) than recordings in non-epileptic subjects (0.01 events/min; permutation test, P = 0.0068). Using spatial averaging to simulate recordings from larger electrode contacts, we found that the number of detected microseizures decreased rapidly with increasing contact diameter and decreasing contact density. In cases in which microseizures were spatially distributed across multiple channels, the approximate onset region was identified. Our results suggest that micro-electrocorticographic electrode arrays with a high density of contacts and large coverage are essential for capturing microseizures in epilepsy patients and may be beneficial for localizing epileptogenic tissue to plan surgery or target brain stimulation.
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Affiliation(s)
- James Sun
- Center for Neural Science, New York University, New York, NY, USA
| | - Katrina Barth
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Shaoyu Qiao
- Center for Neural Science, New York University, New York, NY, USA
| | - Chia-Han Chiang
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Charles Wang
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Shervin Rahimpour
- Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA
- Department of Neurosurgery, Clinical Neuroscience Center, University of Utah, Salt Lake City, UT, USA
| | - Michael Trumpis
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | | | - Agrita Dubey
- Center for Neural Science, New York University, New York, NY, USA
| | - Katie E. Wingel
- Center for Neural Science, New York University, New York, NY, USA
| | - Iakov Rachinskiy
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Alex E. Voinas
- Center for Neural Science, New York University, New York, NY, USA
| | | | - Derek G. Southwell
- Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Michael M. Haglund
- Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA
| | - Allan H. Friedman
- Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA
| | - Shivanand P. Lad
- Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA
| | - Werner K. Doyle
- Department of Neurosurgery, NYU Grossman School of Medicine, New York, NY, USA
| | - Florian Solzbacher
- Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT, USA
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
- Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT, USA
| | - Gregory Cogan
- Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA
- Department of Psychology and Neuroscience, Duke University, Durham, NC, USA
- Center for Cognitive Neuroscience, Duke University, Durham, NC, USA
- Duke Comprehensive Epilepsy Center, Duke University School of Medicine, Durham, NC, USA
- Department of Neurology, Duke University School of Medicine, Durham, NC, USA
| | - Saurabh R. Sinha
- Duke Comprehensive Epilepsy Center, Duke University School of Medicine, Durham, NC, USA
- Department of Neurology, Duke University School of Medicine, Durham, NC, USA
| | - Sasha Devore
- Department of Neurology, NYU Grossman School of Medicine, New York, NY, USA
| | - Orrin Devinsky
- Department of Neurosurgery, NYU Grossman School of Medicine, New York, NY, USA
- Department of Neurology, NYU Grossman School of Medicine, New York, NY, USA
- Department of Psychiatry, NYU Grossman School of Medicine, New York, NY, USA
| | - Daniel Friedman
- Department of Neurology, NYU Grossman School of Medicine, New York, NY, USA
| | - Bijan Pesaran
- Center for Neural Science, New York University, New York, NY, USA
- Department of Neurology, NYU Grossman School of Medicine, New York, NY, USA
| | - Jonathan Viventi
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
- Duke Comprehensive Epilepsy Center, Duke University School of Medicine, Durham, NC, USA
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9
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Lau LA, Staley KJ, Lillis KP. In vitro ictogenesis is stochastic at the single neuron level. Brain 2022; 145:531-541. [PMID: 34431994 PMCID: PMC9014754 DOI: 10.1093/brain/awab312] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/13/2021] [Accepted: 07/30/2021] [Indexed: 11/14/2022] Open
Abstract
Seizure initiation is the least understood and most disabling element of epilepsy. Studies of ictogenesis require high speed recordings at cellular resolution in the area of seizure onset. However, in vivo seizure onset areas cannot be determined at the level of resolution necessary to enable such studies. To circumvent these challenges, we used novel GCaMP7-based calcium imaging in the organotypic hippocampal slice culture model of post-traumatic epilepsy in mice. Organotypic hippocampal slice cultures generate spontaneous, recurrent seizures in a preparation in which it is feasible to image the activity of the entire network (with no unseen inputs existing). Chronic calcium imaging of the entire hippocampal network, with paired electrophysiology, revealed three patterns of seizure onset: (i) low amplitude fast activity; (ii) sentinel spike; and (iii) spike burst and low amplitude fast activity onset. These patterns recapitulate common features of human seizure onset, including low voltage fast activity and spike discharges. Weeks-long imaging of seizure activity showed a characteristic evolution in onset type and a refinement of the seizure onset zone. Longitudinal tracking of individual neurons revealed that seizure onset is stochastic at the single neuron level, suggesting that seizure initiation activates neurons in non-stereotyped sequences seizure to seizure. This study demonstrates for the first time that transitions to seizure are not initiated by a small number of neuronal 'bad actors' (such as overly connected hub cells), but rather by network changes which enable the onset of pathology among large populations of neurons.
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Affiliation(s)
- Lauren A Lau
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02115, USA
| | - Kevin J Staley
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02115, USA
| | - Kyle P Lillis
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02115, USA
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10
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Lehongre K, Lambrecq V, Whitmarsh S, Frazzini V, Cousyn L, Soleil D, Fernandez-Vidal S, Mathon B, Houot M, Lemarechal JD, Clemenceau S, Hasboun D, Adam C, Navarro V. Long-term deep intracerebral microelectrode recordings in patients with drug-resistant epilepsy: proposed guidelines based on 10-year experience. Neuroimage 2022; 254:119116. [PMID: 35318150 DOI: 10.1016/j.neuroimage.2022.119116] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 02/23/2022] [Accepted: 03/15/2022] [Indexed: 02/08/2023] Open
Abstract
PURPOSE Human neuronal activity, recorded in vivo from microelectrodes, may offer valuable insights into physiological mechanisms underlying human cognition and pathophysiological mechanisms of brain diseases, in particular epilepsy. Continuous and long-term recordings are necessary to monitor non predictable pathological and physiological activities like seizures or sleep. Because of their high impedance, microelectrodes are more sensitive to noise than macroelectrodes. Low noise levels are crucial to detect action potentials from background noise, and to further isolate single neuron activities. Therefore, long-term recordings of multi-unit activity remains a challenge. We shared here our experience with microelectrode recordings and our efforts to reduce noise levels in order to improve signal quality. We also provided detailed technical guidelines for the connection, recording, imaging and signal analysis of microelectrode recordings. RESULTS During the last 10 years, we implanted 122 bundles of Behnke-Fried hybrid macro-microelectrodes, in 56 patients with pharmacoresistant focal epilepsy. Microbundles were implanted in the temporal lobe (74%), as well as frontal (15%), parietal (6%) and occipital (5%) lobes. Low noise levels depended on our technical setup. The noise reduction was mainly obtained after electrical insulation of the patient's recording room and the use of a reinforced microelectrode model, reaching median root mean square values of 5.8 µV. Seventy percent of the bundles could record multi-units activities (MUA), on around 3 out of 8 wires per bundle and for an average of 12 days. Seizures were recorded by microelectrodes in 91% of patients, when recorded continuously, and MUA were recorded during seizures for 75 % of the patients after the insulation of the room. Technical guidelines are proposed for (i) electrode tails manipulation and protection during surgical bandage and connection to both clinical and research amplifiers, (ii) electrical insulation of the patient's recording room and shielding, (iii) data acquisition and storage, and (iv) single-units activities analysis. CONCLUSIONS We progressively improved our recording setup and are now able to record (i) microelectrode signals with low noise level up to 3 weeks duration, and (ii) MUA from an increased number of wires . We built a step by step procedure from electrode trajectory planning to recordings. All these delicate steps are essential for continuous long-term recording of units in order to advance in our understanding of both the pathophysiology of ictogenesis and the neuronal coding of cognitive and physiological functions.
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Affiliation(s)
- Katia Lehongre
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France
| | - Virginie Lambrecq
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France; AP-HP, Département de Neurophysiologie, Hôpital Pitié-Salpêtrière, DMU Neurosciences, Paris, France; AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, DMU Neurosciences, Paris, France
| | - Stephen Whitmarsh
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France
| | - Valerio Frazzini
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France; AP-HP, Département de Neurophysiologie, Hôpital Pitié-Salpêtrière, DMU Neurosciences, Paris, France; AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, DMU Neurosciences, Paris, France
| | - Louis Cousyn
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France; AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, DMU Neurosciences, Paris, France
| | - Daniel Soleil
- Bureau d'Etudes CEMS, 801 Route d'Eyguieres, 13 560 Senas, France
| | - Sara Fernandez-Vidal
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France
| | - Bertrand Mathon
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France; AP-HP, Service de Neurochirurgie, Hôpital Pitié-Salpêtrière, Paris, France
| | - Marion Houot
- Centre of Excellence of Neurodegenerative Disease (CoEN), AP-HP, Pitié-Salpêtrière Hospital, Paris, France; Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, AP-HP, Pitié-Salpêtrière Hospital, Paris, France.; Clinical Investigation Centre, Institut du Cerveau et de la Moelle épinière (ICM), Pitié-Salpêtrière Hospital Paris, France
| | - Jean-Didier Lemarechal
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France; Institut de Neurosciences des Systèmes, Aix-Marseille Université, Marseille, France
| | | | - Dominique Hasboun
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France; AP-HP, Service de Neuroradiologie, Pitié-Salpêtrière Hospital, Paris, France
| | - Claude Adam
- AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, DMU Neurosciences, Paris, France
| | - Vincent Navarro
- Sorbonne Université, Paris Brain Institute - Institut du Cerveau, ICM, INSERM, CNRS, APHP, Pitié-Salpêtrière Hospital, Paris France; AP-HP, Département de Neurophysiologie, Hôpital Pitié-Salpêtrière, DMU Neurosciences, Paris, France; AP-HP, Epilepsy Unit, Pitié-Salpêtrière Hospital, DMU Neurosciences, Paris, France; AP-HP, Center of Reference for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France.
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11
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Gliske SV. High frequency oscillations and interictal discharges at 50 μm spatial resolution. Clin Neurophysiol 2021; 132:2894-2895. [PMID: 34563456 PMCID: PMC8675397 DOI: 10.1016/j.clinph.2021.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 08/29/2021] [Indexed: 11/19/2022]
Affiliation(s)
- Stephen V Gliske
- Department of Neurosurgery, University of Nebraska Medical Center, Omaha, NE, USA.
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12
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Jurak P, Cimbalnik J, Klimes P, Daniel P, Brazdil M. Ultra-fast oscillation detection in EEG signal from deep-brain microelectrodes. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:265-268. [PMID: 34891287 DOI: 10.1109/embc46164.2021.9629481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
For the last decades, ripples 80-200Hz (R)and fast ripples 200-500Hz (FR) were intensively studied as biomarkers of the epileptogenic zone (EZ). Recently, Very fast ripples 500-1000Hz (VFR) and ultra-fast ripples 1000-2000Hz (UFR) recorded using standard clinical macro electrodes have been shown to be more specific for EZ. High-sampled microelectrode recordings can bring new insights into this phenomenon of high frequency, multiunit activity. Unfortunately, visual detection of such events is extremely time consuming and unreliable. Here we present a detector of ultra-fast oscillations (UFO, >1kHz). In an example of two patients, we detected 951 UFOs which were more frequent in epileptic (8.6/min) vs. non-epileptic hippocampus (1.3/min). Our detection method can serve as a tool for exploring extremely high frequency events from microelectrode recordings.
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13
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Khambhati AN, Shafi A, Rao VR, Chang EF. Long-term brain network reorganization predicts responsive neurostimulation outcomes for focal epilepsy. Sci Transl Med 2021; 13:13/608/eabf6588. [PMID: 34433640 DOI: 10.1126/scitranslmed.abf6588] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/12/2021] [Accepted: 06/15/2021] [Indexed: 12/21/2022]
Abstract
Responsive neurostimulation (RNS) devices, able to detect imminent seizures and to rapidly deliver electrical stimulation to the brain, are effective in reducing seizures in some patients with focal epilepsy. However, therapeutic response to RNS is often slow, is highly variable, and defies prognostication based on clinical factors. A prevailing view holds that RNS efficacy is primarily mediated by acute seizure termination; yet, stimulations greatly outnumber seizures and occur mostly in the interictal state, suggesting chronic modulation of brain networks that generate seizures. Here, using years-long intracranial neural recordings collected during RNS therapy, we found that patients with the greatest therapeutic benefit undergo progressive, frequency-dependent reorganization of interictal functional connectivity. The extent of this reorganization scales directly with seizure reduction and emerges within the first year of RNS treatment, enabling potential early prediction of therapeutic response. Our findings reveal a mechanism for RNS that involves network plasticity and may inform development of next-generation devices for epilepsy.
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Affiliation(s)
- Ankit N Khambhati
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA 94143, USA.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Alia Shafi
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA 94143, USA.,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Vikram R Rao
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143, USA. .,Department of Neurology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Edward F Chang
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA 94143, USA. .,Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143, USA
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14
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Yang JC, Paulk AC, Salami P, Lee SH, Ganji M, Soper DJ, Cleary D, Simon M, Maus D, Lee JW, Nahed BV, Jones PS, Cahill DP, Cosgrove GR, Chu CJ, Williams Z, Halgren E, Dayeh S, Cash SS. Microscale dynamics of electrophysiological markers of epilepsy. Clin Neurophysiol 2021; 132:2916-2931. [PMID: 34419344 DOI: 10.1016/j.clinph.2021.06.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/22/2021] [Accepted: 06/29/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Interictal discharges (IIDs) and high frequency oscillations (HFOs) are established neurophysiologic biomarkers of epilepsy, while microseizures are less well studied. We used custom poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) microelectrodes to better understand these markers' microscale spatial dynamics. METHODS Electrodes with spatial resolution down to 50 µm were used to record intraoperatively in 30 subjects. IIDs' degree of spread and spatiotemporal paths were generated by peak-tracking followed by clustering. Repeating HFO patterns were delineated by clustering similar time windows. Multi-unit activity (MUA) was analyzed in relation to IID and HFO timing. RESULTS We detected IIDs encompassing the entire array in 93% of subjects, while localized IIDs, observed across < 50% of channels, were seen in 53%. IIDs traveled along specific paths. HFOs appeared in small, repeated spatiotemporal patterns. Finally, we identified microseizure events that spanned 50-100 µm. HFOs covaried with MUA, but not with IIDs. CONCLUSIONS Overall, these data suggest that irritable cortex micro-domains may form part of an underlying pathologic architecture which could contribute to the seizure network. SIGNIFICANCE These results, supporting the possibility that epileptogenic cortex comprises a mosaic of irritable domains, suggests that microscale approaches might be an important perspective in devising novel seizure control therapies.
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Affiliation(s)
- Jimmy C Yang
- Department of Neurosurgery, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA; Department of Neurology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Angelique C Paulk
- Department of Neurology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Pariya Salami
- Department of Neurology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Sang Heon Lee
- Department of Electrical and Computer Engineering, University of California, San Diego; 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Mehran Ganji
- Department of Electrical and Computer Engineering, University of California, San Diego; 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Daniel J Soper
- Department of Neurology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Daniel Cleary
- Department of Neurosurgery, University of California, San Diego; 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Mirela Simon
- Department of Neurology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Douglas Maus
- Department of Neurology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Jong Woo Lee
- Department of Neurology, Brigham and Women's Hospital, 60 Fenwood Rd., Boston, MA 02115, USA
| | - Brian V Nahed
- Department of Neurosurgery, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Pamela S Jones
- Department of Neurosurgery, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Daniel P Cahill
- Department of Neurosurgery, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Garth Rees Cosgrove
- Department of Neurosurgery, Brigham and Women's Hospital, 60 Fenwood Rd., Boston, MA 02115, USA
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Ziv Williams
- Department of Neurosurgery, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA
| | - Eric Halgren
- Department of Radiology, University of California, San Diego; 9500 Gilman Dr.; La Jolla, CA 92093, USA
| | - Shadi Dayeh
- Department of Electrical and Computer Engineering, University of California, San Diego; 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114, USA.
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15
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Pototskiy E, Dellinger JR, Bumgarner S, Patel J, Sherrerd-Smith W, Musto AE. Brain injuries can set up an epileptogenic neuronal network. Neurosci Biobehav Rev 2021; 129:351-366. [PMID: 34384843 DOI: 10.1016/j.neubiorev.2021.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 08/01/2021] [Indexed: 10/20/2022]
Abstract
Development of epilepsy or epileptogenesis promotes recurrent seizures. As of today, there are no effective prophylactic therapies to prevent the onset of epilepsy. Contributing to this deficiency of preventive therapy is the lack of clarity in fundamental neurobiological mechanisms underlying epileptogenesis and lack of reliable biomarkers to identify patients at risk for developing epilepsy. This limits the development of prophylactic therapies in epilepsy. Here, neural network dysfunctions reflected by oscillopathies and microepileptiform activities, including neuronal hyperexcitability and hypersynchrony, drawn from both clinical and experimental epilepsy models, have been reviewed. This review suggests that epileptogenesis reflects a progressive and dynamic dysfunction of specific neuronal networks which recruit further interconnected groups of neurons, with this resultant pathological network mediating seizure occurrence, recurrence, and progression. In the future, combining spatial and temporal resolution of neuronal non-invasive recordings from patients at risk of developing epilepsy, together with analytics and computational tools, may contribute to determining whether the brain is undergoing epileptogenesis in asymptomatic patients following brain injury.
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Affiliation(s)
- Esther Pototskiy
- Department of Anatomy & Pathology, Eastern Virginia Medical School, Department of Pathology, Norfolk, Virginia, USA; College of Sciences, Old Dominion University, Norfolk, Virginia
| | - Joshua Ryan Dellinger
- Department of Anatomy & Pathology, Eastern Virginia Medical School, Department of Pathology, Norfolk, Virginia, USA
| | - Stuart Bumgarner
- Department of Anatomy & Pathology, Eastern Virginia Medical School, Department of Pathology, Norfolk, Virginia, USA
| | - Jay Patel
- Department of Anatomy & Pathology, Eastern Virginia Medical School, Department of Pathology, Norfolk, Virginia, USA
| | - William Sherrerd-Smith
- Department of Anatomy & Pathology, Eastern Virginia Medical School, Department of Pathology, Norfolk, Virginia, USA
| | - Alberto E Musto
- Department of Anatomy & Pathology, Eastern Virginia Medical School, Department of Pathology, Norfolk, Virginia, USA; Department of Neurology, Eastern Virginia Medical School, Department of Pathology, Norfolk, Virginia, USA.
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16
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Paulk AC, Yang JC, Cleary DR, Soper DJ, Halgren M, O’Donnell AR, Lee SH, Ganji M, Ro YG, Oh H, Hossain L, Lee J, Tchoe Y, Rogers N, Kiliç K, Ryu SB, Lee SW, Hermiz J, Gilja V, Ulbert I, Fabó D, Thesen T, Doyle WK, Devinsky O, Madsen JR, Schomer DL, Eskandar EN, Lee JW, Maus D, Devor A, Fried SI, Jones PS, Nahed BV, Ben-Haim S, Bick SK, Richardson RM, Raslan AM, Siler DA, Cahill DP, Williams ZM, Cosgrove GR, Dayeh SA, Cash SS. Microscale Physiological Events on the Human Cortical Surface. Cereb Cortex 2021; 31:3678-3700. [PMID: 33749727 PMCID: PMC8258438 DOI: 10.1093/cercor/bhab040] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 01/14/2023] Open
Abstract
Despite ongoing advances in our understanding of local single-cellular and network-level activity of neuronal populations in the human brain, extraordinarily little is known about their "intermediate" microscale local circuit dynamics. Here, we utilized ultra-high-density microelectrode arrays and a rare opportunity to perform intracranial recordings across multiple cortical areas in human participants to discover three distinct classes of cortical activity that are not locked to ongoing natural brain rhythmic activity. The first included fast waveforms similar to extracellular single-unit activity. The other two types were discrete events with slower waveform dynamics and were found preferentially in upper cortical layers. These second and third types were also observed in rodents, nonhuman primates, and semi-chronic recordings from humans via laminar and Utah array microelectrodes. The rates of all three events were selectively modulated by auditory and electrical stimuli, pharmacological manipulation, and cold saline application and had small causal co-occurrences. These results suggest that the proper combination of high-resolution microelectrodes and analytic techniques can capture neuronal dynamics that lay between somatic action potentials and aggregate population activity. Understanding intermediate microscale dynamics in relation to single-cell and network dynamics may reveal important details about activity in the full cortical circuit.
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Affiliation(s)
- Angelique C Paulk
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Jimmy C Yang
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Daniel R Cleary
- Departments of Neurosciences and Radiology, University of California San Diego, La Jolla, CA 92093, USA
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
- Department of Neurosurgery, University of California San Diego, La Jolla, CA 92093, USA
| | - Daniel J Soper
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Mila Halgren
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
- McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Sang Heon Lee
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Mehran Ganji
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Yun Goo Ro
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Hongseok Oh
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Lorraine Hossain
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
| | - Jihwan Lee
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Youngbin Tchoe
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Nicholas Rogers
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Kivilcim Kiliç
- Departments of Neurosciences and Radiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Sang Baek Ryu
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Seung Woo Lee
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - John Hermiz
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Vikash Gilja
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA
| | - István Ulbert
- Research Centre for Natural Sciences, Institute of Cognitive Neuroscience and Psychology, 1519 Budapest, Hungary
- Pázmány Péter Catholic University, Faculty of Information Technology and Bionics, H-1444 Budapest, Hungary
| | - Daniel Fabó
- Epilepsy Centrum, National Institute of Clinical Neurosciences, 1145 Budapest, Hungary
| | - Thomas Thesen
- Department of Biomedical Sciences, University of Houston College of Medicine, Houston, TX 77204, USA
- Comprehensive Epilepsy Center, New York University School of Medicine, New York City, NY 10016, USA
| | - Werner K Doyle
- Comprehensive Epilepsy Center, New York University School of Medicine, New York City, NY 10016, USA
| | - Orrin Devinsky
- Comprehensive Epilepsy Center, New York University School of Medicine, New York City, NY 10016, USA
| | - Joseph R Madsen
- Departments of Neurosurgery, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Donald L Schomer
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Emad N Eskandar
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
- Albert Einstein College of Medicine, Montefiore Medical Center, Department of Neurosurgery, Bronx, NY 10467, USA
| | - Jong Woo Lee
- Department of Neurology, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Douglas Maus
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Anna Devor
- Departments of Neurosciences and Radiology, University of California San Diego, La Jolla, CA 92093, USA
| | - Shelley I Fried
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
- Boston VA Healthcare System, 150 South Huntington Avenue, Boston, MA 02130, USA
| | - Pamela S Jones
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Brian V Nahed
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Sharona Ben-Haim
- Department of Neurosurgery, University of California San Diego, La Jolla, CA 92093, USA
| | - Sarah K Bick
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | | | - Ahmed M Raslan
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR 97239, USA
| | - Dominic A Siler
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR 97239, USA
| | - Daniel P Cahill
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Ziv M Williams
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - G Rees Cosgrove
- Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Shadi A Dayeh
- Department of Neurosurgery, University of California San Diego, La Jolla, CA 92093, USA
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
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17
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Chiang CH, Wang C, Barth K, Rahimpour S, Trumpis M, Duraivel S, Rachinskiy I, Dubey A, Wingel KE, Wong M, Witham NS, Odell T, Woods V, Bent B, Doyle W, Friedman D, Bihler E, Reiche CF, Southwell DG, Haglund MM, Friedman AH, Lad SP, Devore S, Devinsky O, Solzbacher F, Pesaran B, Cogan G, Viventi J. Flexible, high-resolution thin-film electrodes for human and animal neural research. J Neural Eng 2021; 18:10.1088/1741-2552/ac02dc. [PMID: 34010815 PMCID: PMC8496685 DOI: 10.1088/1741-2552/ac02dc] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 05/19/2021] [Indexed: 11/11/2022]
Abstract
Objective.Brain functions such as perception, motor control, learning, and memory arise from the coordinated activity of neuronal assemblies distributed across multiple brain regions. While major progress has been made in understanding the function of individual neurons, circuit interactions remain poorly understood. A fundamental obstacle to deciphering circuit interactions is the limited availability of research tools to observe and manipulate the activity of large, distributed neuronal populations in humans. Here we describe the development, validation, and dissemination of flexible, high-resolution, thin-film (TF) electrodes for recording neural activity in animals and humans.Approach.We leveraged standard flexible printed-circuit manufacturing processes to build high-resolution TF electrode arrays. We used biocompatible materials to form the substrate (liquid crystal polymer; LCP), metals (Au, PtIr, and Pd), molding (medical-grade silicone), and 3D-printed housing (nylon). We designed a custom, miniaturized, digitizing headstage to reduce the number of cables required to connect to the acquisition system and reduce the distance between the electrodes and the amplifiers. A custom mechanical system enabled the electrodes and headstages to be pre-assembled prior to sterilization, minimizing the setup time required in the operating room. PtIr electrode coatings lowered impedance and enabled stimulation. High-volume, commercial manufacturing enables cost-effective production of LCP-TF electrodes in large quantities.Main Results. Our LCP-TF arrays achieve 25× higher electrode density, 20× higher channel count, and 11× reduced stiffness than conventional clinical electrodes. We validated our LCP-TF electrodes in multiple human intraoperative recording sessions and have disseminated this technology to >10 research groups. Using these arrays, we have observed high-frequency neural activity with sub-millimeter resolution.Significance.Our LCP-TF electrodes will advance human neuroscience research and improve clinical care by enabling broad access to transformative, high-resolution electrode arrays.
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Affiliation(s)
- Chia-Han Chiang
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
- These authors contributed equally to this work
| | - Charles Wang
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
- These authors contributed equally to this work
| | - Katrina Barth
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
| | - Shervin Rahimpour
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, United States of America
| | - Michael Trumpis
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
| | | | - Iakov Rachinskiy
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
| | - Agrita Dubey
- Center for Neural Science, New York University, NY, NY, United States of America
| | - Katie E Wingel
- Center for Neural Science, New York University, NY, NY, United States of America
| | - Megan Wong
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
| | - Nicholas S Witham
- Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT, United States of America
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America
| | - Thomas Odell
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America
| | - Virginia Woods
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
| | - Brinnae Bent
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
| | - Werner Doyle
- Department of Neurosurgery, NYU Langone Medical Center, New York City, NY, United States of America
| | - Daniel Friedman
- Department of Neurology, NYU Grossman School of Medicine, NY, NY, United States of America
| | | | - Christopher F Reiche
- Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT, United States of America
| | - Derek G Southwell
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, United States of America
| | - Michael M Haglund
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, United States of America
| | - Allan H Friedman
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, United States of America
| | - Shivanand P Lad
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, United States of America
| | - Sasha Devore
- Department of Neurology, NYU Grossman School of Medicine, NY, NY, United States of America
| | - Orrin Devinsky
- Department of Neurosurgery, NYU Langone Medical Center, New York City, NY, United States of America
- Department of Neurology, NYU Grossman School of Medicine, NY, NY, United States of America
- Comprehensive Epilepsy Center, NYU Langone Health, NY, NY, United States of America
| | - Florian Solzbacher
- Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT, United States of America
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States of America
- Department of Materials Science & Engineering, University of Utah, Salt Lake City, UT, United States of America
| | - Bijan Pesaran
- Center for Neural Science, New York University, NY, NY, United States of America
- Department of Neurology, NYU Grossman School of Medicine, NY, NY, United States of America
| | - Gregory Cogan
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, United States of America
- Department of Psychology and Neuroscience, Duke University, Durham, NC, United States of America
- Center for Cognitive Neuroscience, Duke University, Durham, NC, United States of America
- Duke Comprehensive Epilepsy Center, Duke School of Medicine, Durham, NC, United States of America
| | - Jonathan Viventi
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
- Department of Neurosurgery, Duke School of Medicine, Durham, NC, United States of America
- Department of Neurobiology, Duke School of Medicine, Durham, NC, United States of America
- Duke Comprehensive Epilepsy Center, Duke School of Medicine, Durham, NC, United States of America
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18
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In vivo calcium imaging reveals disordered interictal network dynamics in epileptic stxbp1b zebrafish. iScience 2021; 24:102558. [PMID: 34142057 PMCID: PMC8184515 DOI: 10.1016/j.isci.2021.102558] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 03/29/2021] [Accepted: 05/17/2021] [Indexed: 12/19/2022] Open
Abstract
STXBP1 mutations are associated with encephalopathy, developmental delay, intellectual disability, and epilepsy. While neural networks are known to operate at a critical state in the healthy brain, network behavior during pathological epileptic states remains unclear. Examining activity during periods between well-characterized ictal-like events (i.e., interictal period) could provide a valuable step toward understanding epileptic networks. To study these networks in the context of STXBP1 mutations, we combine a larval zebrafish model with in vivo fast confocal calcium imaging and extracellular local field potential recordings. Stxbp1b mutants display transient periods of elevated activity among local clusters of interacting neurons. These network "cascade" events were significantly larger in size and duration in mutants. At mesoscale resolution, cascades exhibit neurodevelopmental abnormalities. At single-cell scale, we describe spontaneous hyper-synchronized neuronal ensembles. That calcium imaging reveals uniquely disordered brain states during periods between pathological ictal-like seizure events is striking and represents a potential interictal biomarker.
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19
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Tamim I, Chung DY, de Morais AL, Loonen ICM, Qin T, Misra A, Schlunk F, Endres M, Schiff SJ, Ayata C. Spreading depression as an innate antiseizure mechanism. Nat Commun 2021; 12:2206. [PMID: 33850125 PMCID: PMC8044138 DOI: 10.1038/s41467-021-22464-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 03/15/2021] [Indexed: 12/16/2022] Open
Abstract
Spreading depression (SD) is an intense and prolonged depolarization in the central nervous systems from insect to man. It is implicated in neurological disorders such as migraine and brain injury. Here, using an in vivo mouse model of focal neocortical seizures, we show that SD may be a fundamental defense against seizures. Seizures induced by topical 4-aminopyridine, penicillin or bicuculline, or systemic kainic acid, culminated in SDs at a variable rate. Greater seizure power and area of recruitment predicted SD. Once triggered, SD immediately suppressed the seizure. Optogenetic or KCl-induced SDs had similar antiseizure effect sustained for more than 30 min. Conversely, pharmacologically inhibiting SD occurrence during a focal seizure facilitated seizure generalization. Altogether, our data indicate that seizures trigger SD, which then terminates the seizure and prevents its generalization.
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Affiliation(s)
- Isra Tamim
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Charité-Universitätsmedizin Berlin, Klinik und Hochschulambulanz für Neurologie und Centrum für Schlaganfallforschung Berlin (CSB), Berlin, Germany
| | - David Y Chung
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Andreia Lopes de Morais
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Inge C M Loonen
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tao Qin
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Amrit Misra
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Frieder Schlunk
- Charité-Universitätsmedizin Berlin, Klinik und Hochschulambulanz für Neurologie und Centrum für Schlaganfallforschung Berlin (CSB), Berlin, Germany
| | - Matthias Endres
- Charité-Universitätsmedizin Berlin, Klinik und Hochschulambulanz für Neurologie und Centrum für Schlaganfallforschung Berlin (CSB), Berlin, Germany
| | - Steven J Schiff
- Center for Neural Engineering, Departments of Engineering Science and Mechanics and Physics, The Pennsylvania State University, State College, PA, USA
| | - Cenk Ayata
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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20
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Abstract
Neuromodulation, including first-generation open-loop devices and second-generation closed-loop devices, is a valuable but poorly understood therapeutic option for patients with drug-refractory epilepsy. The precise therapy a patient receives is contingent on the relationship between the patient's own unique neurophysiology and the custom programming of detection and stimulation parameters. Recent evidence demonstrates that therapeutic efficacy can be achieved through neuromodulation of seizure networks, rather than simple disruption of seizure evolution. Nevertheless, the improvement in outcomes achieved combined with its minimally invasive, nondestructive nature make closed-loop stimulation a promising therapy for additional indications, such as generalized and pediatric epilepsy.
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Affiliation(s)
- Nathaniel D Sisterson
- Department of Neurological Surgery, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Vasileios Kokkinos
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, 429A Thier, Boston, MA 02114, USA.
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21
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Driscoll N, Rosch RE, Murphy BB, Ashourvan A, Vishnubhotla R, Dickens OO, Johnson ATC, Davis KA, Litt B, Bassett DS, Takano H, Vitale F. Multimodal in vivo recording using transparent graphene microelectrodes illuminates spatiotemporal seizure dynamics at the microscale. Commun Biol 2021; 4:136. [PMID: 33514839 PMCID: PMC7846732 DOI: 10.1038/s42003-021-01670-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 12/24/2020] [Indexed: 01/21/2023] Open
Abstract
Neurological disorders such as epilepsy arise from disrupted brain networks. Our capacity to treat these disorders is limited by our inability to map these networks at sufficient temporal and spatial scales to target interventions. Current best techniques either sample broad areas at low temporal resolution (e.g. calcium imaging) or record from discrete regions at high temporal resolution (e.g. electrophysiology). This limitation hampers our ability to understand and intervene in aberrations of network dynamics. Here we present a technique to map the onset and spatiotemporal spread of acute epileptic seizures in vivo by simultaneously recording high bandwidth microelectrocorticography and calcium fluorescence using transparent graphene microelectrode arrays. We integrate dynamic data features from both modalities using non-negative matrix factorization to identify sequential spatiotemporal patterns of seizure onset and evolution, revealing how the temporal progression of ictal electrophysiology is linked to the spatial evolution of the recruited seizure core. This integrated analysis of multimodal data reveals otherwise hidden state transitions in the spatial and temporal progression of acute seizures. The techniques demonstrated here may enable future targeted therapeutic interventions and novel spatially embedded models of local circuit dynamics during seizure onset and evolution.
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Affiliation(s)
- Nicolette Driscoll
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - Richard E Rosch
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Brendan B Murphy
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
| | - Arian Ashourvan
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
| | - Ramya Vishnubhotla
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Olivia O Dickens
- Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - A T Charlie Johnson
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Kathryn A Davis
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Brian Litt
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Danielle S Bassett
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Electrical & Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA
- Santa Fe Institute, Santa Fe, NM, USA
| | - Hajime Takano
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
| | - Flavia Vitale
- Center for Neuroengineering and Therapeutics, University of Pennsylvania, Philadelphia, PA, USA.
- Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA.
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Department of Physical Medicine and Rehabilitation, University of Pennsylvania, Philadelphia, PA, USA.
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22
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Chari A, Budhdeo S, Sparks R, Barone DG, Marcus HJ, Pereira EAC, Tisdall MM. Brain-Machine Interfaces: The Role of the Neurosurgeon. World Neurosurg 2020; 146:140-147. [PMID: 33197630 DOI: 10.1016/j.wneu.2020.11.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 12/26/2022]
Abstract
Neurotechnology is set to expand rapidly in the coming years as technological innovations in hardware and software are translated to the clinical setting. Given our unique access to patients with neurologic disorders, expertise with which to guide appropriate treatments, and technical skills to implant brain-machine interfaces (BMIs), neurosurgeons have a key role to play in the progress of this field. We outline the current state and key challenges in this rapidly advancing field, including implant technology, implant recipients, implantation methodology, implant function, and ethical, regulatory, and economic considerations. Our key message is to encourage the neurosurgical community to proactively engage in collaborating with other health care professionals, engineers, scientists, ethicists, and regulators in tackling these issues. By doing so, we will equip ourselves with the skills and expertise to drive the field forward and avoid being mere technicians in an industry driven by those around us.
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Affiliation(s)
- Aswin Chari
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom; Department of Neurosurgery, Great Ormond Street Hospital, London, United Kingdom.
| | - Sanjay Budhdeo
- Department for Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, United Kingdom; Department of Neurology, National Hospital for Neurology and Neurosurgery, London, United Kingdom; OwkinInc, New York, New York, USA
| | - Rachel Sparks
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Damiano G Barone
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Hani J Marcus
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, United Kingdom; Wellcome EPSRC Centre for Interventional and Surgical Sciences, University College London, London, United Kingdom
| | - Erlick A C Pereira
- Neurosciences Research Centre, Molecular and Clinical Sciences Research Institute, St George's, University of London, United Kingdom
| | - Martin M Tisdall
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom; Department of Neurosurgery, Great Ormond Street Hospital, London, United Kingdom
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23
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Martínez CGB, Niediek J, Mormann F, Andrzejak RG. Seizure Onset Zone Lateralization Using a Non-linear Analysis of Micro vs. Macro Electroencephalographic Recordings During Seizure-Free Stages of the Sleep-Wake Cycle From Epilepsy Patients. Front Neurol 2020; 11:553885. [PMID: 33041993 PMCID: PMC7527464 DOI: 10.3389/fneur.2020.553885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 08/12/2020] [Indexed: 11/23/2022] Open
Abstract
The application of non-linear signal analysis techniques to biomedical data is key to improve our knowledge about complex physiological and pathological processes. In particular, the use of non-linear techniques to study electroencephalographic (EEG) recordings can provide an advanced characterization of brain dynamics. In epilepsy these dynamics are altered at different spatial scales of neuronal organization. We therefore apply non-linear signal analysis to EEG recordings from epilepsy patients derived with intracranial hybrid electrodes, which are composed of classical macro contacts and micro wires. Thereby, these electrodes record EEG at two different spatial scales. Our aim is to test the degree to which the analysis of the EEG recorded at these different scales allows us to characterize the neuronal dynamics affected by epilepsy. For this purpose, we retrospectively analyzed long-term recordings performed during five nights in three patients during which no seizures took place. As a benchmark we used the accuracy with which this analysis allows determining the hemisphere that contains the seizure onset zone, which is the brain area where clinical seizures originate. We applied the surrogate-corrected non-linear predictability score (ψ), a non-linear signal analysis technique which was shown previously to be useful for the lateralization of the seizure onset zone from classical intracranial EEG macro contact recordings. Higher values of ψ were found predominantly for signals recorded from the hemisphere containing the seizure onset zone as compared to signals recorded from the opposite hemisphere. These differences were found not only for the EEG signals recorded with macro contacts, but also for those recorded with micro wires. In conclusion, the information obtained from the analysis of classical macro EEG contacts can be complemented by the one of micro wire EEG recordings. This combined approach may therefore help to further improve the degree to which quantitative EEG analysis can contribute to the diagnostics in epilepsy patients.
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Affiliation(s)
- Cristina G B Martínez
- Department of Communication and Information Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Johannes Niediek
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Florian Mormann
- Department of Epileptology, University of Bonn, Bonn, Germany
| | - Ralph G Andrzejak
- Department of Communication and Information Technologies, Universitat Pompeu Fabra, Barcelona, Spain
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24
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Jobst BC, Bartolomei F, Diehl B, Frauscher B, Kahane P, Minotti L, Sharan A, Tardy N, Worrell G, Gotman J. Intracranial EEG in the 21st Century. Epilepsy Curr 2020; 20:180-188. [PMID: 32677484 PMCID: PMC7427159 DOI: 10.1177/1535759720934852] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Intracranial electroencephalography (iEEG) has been the mainstay of identifying the seizure onset zone (SOZ), a key diagnostic procedure in addition to neuroimaging when considering epilepsy surgery. In many patients, iEEG has been the basis for resective epilepsy surgery, to date still the most successful treatment for drug-resistant epilepsy. Intracranial EEG determines the location and resectability of the SOZ. Advances in recording and implantation of iEEG provide multiple options in the 21st century. This not only includes the choice between subdural electrodes (SDE) and stereoelectroencephalography (SEEG) but also includes the implantation and recordings from microelectrodes. Before iEEG implantation, especially in magnetic resonance imaging -negative epilepsy, a clear hypothesis for seizure generation and propagation should be based on noninvasive methods. Intracranial EEG implantation should be planned by a multidisciplinary team considering epileptic networks. Recordings from SDE and SEEG have both their advantages and disadvantages. Stereo-EEG seems to have a lower rate of complications that are clinically significant, but has limitations in spatial sampling of the cortical surface. Stereo-EEG can sample deeper areas of the brain including deep sulci and hard to reach areas such as the insula. To determine the epileptogenic zone, interictal and ictal information should be taken into consideration. Interictal spiking, low frequency slowing, as well as high frequency oscillations may inform about the epileptogenic zone. Ictally, high frequency onsets in the beta/gamma range are usually associated with the SOZ, but specialized recordings with combined macro and microelectrodes may in the future educate us about onset in higher frequency bands. Stimulation of intracranial electrodes triggering habitual seizures can assist in identifying the SOZ. Advanced computational methods such as determining the epileptogenicity index and similar measures may enhance standard clinical interpretation. Improved techniques to record and interpret iEEG may in the future lead to a greater proportion of patients being seizure free after epilepsy surgery.
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Affiliation(s)
- Barbara C Jobst
- Geisel School of Medicine at Dartmouth and Dartmouth-Hitchcock Medical Center, Hanover, NH, USA
| | - Fabrice Bartolomei
- Aix Marseille University, INSERM, INS, Inst Neurosci Syst, Marseille, France.,APHM, Timone hospital, Epileptology department, Marseille, France
| | - Beate Diehl
- National Hospital for Neurology and Neurosurgery, University College London, London, United Kingdom
| | - Birgit Frauscher
- Montreal Neurological Institute & Hospital, McGill University, Montreal, Quebec, Canada
| | - Philippe Kahane
- Neurology Department & INSERM U1216, Grenoble-Alpes University and Hospital, Grenoble, France
| | - Lorella Minotti
- Neurology Department & INSERM U1216, Grenoble-Alpes University and Hospital, Grenoble, France
| | - Ashwini Sharan
- National Hospital for Neurology and Neurosurgery, Jefferson University, Philadelphia, PA, USA
| | - Nastasia Tardy
- Neurology Department & INSERM U1216, Grenoble-Alpes University and Hospital, Grenoble, France
| | | | - Jean Gotman
- Montreal Neurological Institute & Hospital, McGill University, Montreal, Quebec, Canada
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25
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Kokkinos V, Sisterson ND, Wozny TA, Richardson RM. Association of Closed-Loop Brain Stimulation Neurophysiological Features With Seizure Control Among Patients With Focal Epilepsy. JAMA Neurol 2020; 76:800-808. [PMID: 30985902 DOI: 10.1001/jamaneurol.2019.0658] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance A bidirectional brain-computer interface that performs neurostimulation has been shown to improve seizure control in patients with refractory epilepsy, but the therapeutic mechanism is unknown. Objective To investigate whether electrographic effects of responsive neurostimulation (RNS), identified in electrocorticographic (ECOG) recordings from the device, are associated with patient outcomes. Design, Setting, and Participants Retrospective review of ECOG recordings and accompanying clinical meta-data from 11 consecutive patients with focal epilepsy who were implanted with a neurostimulation system between January 28, 2015, and June 6, 2017, with 22 to 112 weeks of follow-up. Recorded ECOG data were obtained from the manufacturer; additional system-generated meta-data, including recording and detection settings, were collected directly from the manufacturer's management system using an in-house, custom-built platform. Electrographic seizure patterns were identified in RNS recordings and evaluated in the time-frequency domain, which was locked to the onset of the seizure pattern. Main Outcomes and Measures Patterns of electrophysiological modulation were identified and then classified according to their latency of onset in relation to triggered stimulation events. Seizure control after RNS implantation was assessed by 3 main variables: mean frequency of seizure occurrence, estimated mean severity of seizures, and mean duration of seizures. Overall seizure outcomes were evaluated by the extended Personal Impact of Epilepsy Scale questionnaires, a patient-reported outcome measure of 3 domains (seizure characteristics, medication adverse effects, and quality of life), with a range of possible scores from 0 to 300 in which lower scores indicate worse status, and the Engel scale, which comprises 4 classes (I-IV) in which lower numbers indicate greater improvement. Results Electrocorticographic data from 11 patients (8 female; mean [range] age, 35 [19-65] years; mean [range] duration of epilepsy, 19 [5-37] years) were analyzed. Two main categories of electrophysiological signatures of stimulation-induced modulation of the seizure network were discovered: direct and indirect effects. Direct effects included ictal inhibition and early frequency modulation but were not associated with improved clinical outcomes (odds ratio [OR], 0.67; 95% CI, 0.06-7.35; P > .99). Only indirect effects-those occurring remote from triggered stimulation-were associated with improved clinical outcomes (OR, infinity; 95% CI, -infinity to infinity; P = .02). These indirect effects included spontaneous ictal inhibition, frequency modulation, fragmentation, and ictal duration modulation. Conclusions and Relevance These findings suggest that RNS effectiveness may be explained by long-term, stimulation-induced modulation of seizure network activity rather than by direct effects on each detected seizure.
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Affiliation(s)
- Vasileios Kokkinos
- Brain Modulation Laboratory, Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, Pennsylvania
| | - Nathaniel D Sisterson
- Medical student, Brain Modulation Laboratory, Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Thomas A Wozny
- Brain Modulation Laboratory, Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - R Mark Richardson
- Brain Modulation Laboratory, Department of Neurological Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, Pennsylvania.,University of Pittsburgh Brain Institute, Pittsburgh, Pennsylvania
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26
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Chari A, Thornton RC, Tisdall MM, Scott RC. Microelectrode recordings in human epilepsy: a case for clinical translation. Brain Commun 2020; 2:fcaa082. [PMID: 32954332 PMCID: PMC7472902 DOI: 10.1093/braincomms/fcaa082] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 04/21/2020] [Accepted: 04/28/2020] [Indexed: 12/25/2022] Open
Abstract
With their 'all-or-none' action potential responses, single neurons (or units) are accepted as the basic computational unit of the brain. There is extensive animal literature to support the mechanistic importance of studying neuronal firing as a way to understand neuronal microcircuits and brain function. Although most studies have emphasized physiology, there is increasing recognition that studying single units provides novel insight into system-level mechanisms of disease. Microelectrode recordings are becoming more common in humans, paralleling the increasing use of intracranial electroencephalography recordings in the context of presurgical evaluation in focal epilepsy. In addition to single-unit data, microelectrode recordings also record local field potentials and high-frequency oscillations, some of which may be different to that recorded by clinical macroelectrodes. However, microelectrodes are being used almost exclusively in research contexts and there are currently no indications for incorporating microelectrode recordings into routine clinical care. In this review, we summarize the lessons learnt from 65 years of microelectrode recordings in human epilepsy patients. We cover the electrode constructs that can be utilized, principles of how to record and process microelectrode data and insights into ictal dynamics, interictal dynamics and cognition. We end with a critique on the possibilities of incorporating single-unit recordings into clinical care, with a focus on potential clinical indications, each with their specific evidence base and challenges.
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Affiliation(s)
- Aswin Chari
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
- Department of Neurosurgery, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Rachel C Thornton
- Department of Clinical Neurophysiology, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Martin M Tisdall
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
- Department of Neurosurgery, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Rodney C Scott
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
- Department of Neurological Sciences, University of Vermont, Burlington, VT 05405, USA
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27
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Salami P, Peled N, Nadalin JK, Martinet LE, Kramer MA, Lee JW, Cash SS. Seizure onset location shapes dynamics of initiation. Clin Neurophysiol 2020; 131:1782-1797. [PMID: 32512346 DOI: 10.1016/j.clinph.2020.04.168] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/24/2020] [Accepted: 04/13/2020] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Ictal electrographic patterns are widely thought to reflect underlying neural mechanisms of seizures. Here we studied the degree to which seizure patterns are consistent in a given patient, relate to particular brain regions and if two candidate biomarkers (high-frequency oscillations, HFOs; infraslow activity, ISA) and network activity, as assessed with cross-frequency interactions, can discriminate between seizure types. METHODS We analyzed temporal changes in low and high frequency oscillations recorded during seizures, as well as phase-amplitude coupling (PAC) to monitor the interactions between delta/theta and ripple/fast ripple frequency bands at seizure onset. RESULTS Seizures of multiple electrographic patterns were observed in a given patient and brain region. While there was an increase in HFO rate across different electrographic patterns, there are specific relationships between types of HFO activity and onset region. Similarly, changes in PAC dynamics were more closely related to seizure onset region than they were to electrographic patterns while ISA was a poor indicator for seizure onset. CONCLUSIONS Our findings suggest that the onset region sculpts neurodynamics at seizure initiation and that unique features of the cytoarchitecture and/or connectivity of that region play a significant role in determining seizure mechanism. SIGNIFICANCE To learn how seizures are initiated, researchers would do well to consider other aspects of their manifestation, in addition to their electrographic patterns. Examination of onset pattern in conjunction with the interactions between different oscillatory frequencies in the context of different brain regions might be more informative and lead to more reliable clinical inference as well as novel therapeutic approaches.
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Affiliation(s)
- Pariya Salami
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Noam Peled
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Jessica K Nadalin
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - Louis-Emmanuel Martinet
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - Jong W Lee
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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28
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Despouy E, Curot J, Reddy L, Nowak LG, Deudon M, Sol JC, Lotterie JA, Denuelle M, Maziz A, Bergaud C, Thorpe SJ, Valton L, Barbeau EJ. Recording local field potential and neuronal activity with tetrodes in epileptic patients. J Neurosci Methods 2020; 341:108759. [PMID: 32389603 DOI: 10.1016/j.jneumeth.2020.108759] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 01/27/2023]
Abstract
BACKGROUND Recordings with tetrodes have proven to be more effective in isolating single neuron spiking activity than with single microwires. However, tetrodes have never been used in humans. We report on the characteristics, safety, compatibility with clinical intracranial recordings in epileptic patients, and performance, of a new type of hybrid electrode equipped with tetrodes. NEW METHOD 240 standard clinical macroelectrodes and 102 hybrid electrodes were implanted in 28 patients. Hybrids (diameter 800 μm) are made of 6 or 9 macro-contacts and 2 or 3 tetrodes (diameter 70-80 μm). RESULTS No clinical complication or adverse event was associated with the hybrids. Impedance and noise of recordings were stable over time. The design enabled multiscale spatial analyses that revealed physiopathological events which were sometimes specific to one tetrode, but could not be recorded on the macro-contacts. After spike sorting, the single-unit yield was similar to other hybrid electrodes and was sometimes as high as >10 neurons per tetrode. COMPARISON WITH EXISTING METHOD(S) This new hybrid electrode has a smaller diameter than other available hybrid electrodes. It provides novel spatial information due to the configuration of the tetrodes. The single-unit yield appears promising. CONCLUSIONS This new hybrid electrode is safe, easy to use, and works satisfactorily for conducting multi-scale seizure and physiological analyses.
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Affiliation(s)
- Elodie Despouy
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse F-31330, France; Centre National de la Recherche Scientifique CerCo, Toulouse F-31052, France; DIXI Medical, Chaudefontaine F-25640 France
| | - Jonathan Curot
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse F-31330, France; Centre National de la Recherche Scientifique CerCo, Toulouse F-31052, France; Explorations Neurophysiologiques, Hôpital Purpan, Université de Toulouse, Toulouse F-31300, France
| | - Leila Reddy
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse F-31330, France; Centre National de la Recherche Scientifique CerCo, Toulouse F-31052, France
| | - Lionel G Nowak
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse F-31330, France; Centre National de la Recherche Scientifique CerCo, Toulouse F-31052, France
| | - Martin Deudon
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse F-31330, France; Centre National de la Recherche Scientifique CerCo, Toulouse F-31052, France
| | - Jean-Christophe Sol
- INSERM, U1214, TONIC, Toulouse Mind and Brain Institute, Toulouse F-31052, France; Neurochirurgie, Hôpital Purpan, Université de Toulouse, Toulouse F-31300, France
| | - Jean-Albert Lotterie
- INSERM, U1214, TONIC, Toulouse Mind and Brain Institute, Toulouse F-31052, France; Radiochirurgie Stéréotaxique, Hôpital Purpan, Université de Toulouse, Toulouse F-31300, France
| | - Marie Denuelle
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse F-31330, France; Centre National de la Recherche Scientifique CerCo, Toulouse F-31052, France; Explorations Neurophysiologiques, Hôpital Purpan, Université de Toulouse, Toulouse F-31300, France
| | - Ali Maziz
- LAAS-CNRS, Université de Toulouse, CNRS, Toulouse F-31400, France
| | | | - Simon J Thorpe
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse F-31330, France; Centre National de la Recherche Scientifique CerCo, Toulouse F-31052, France
| | - Luc Valton
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse F-31330, France; Centre National de la Recherche Scientifique CerCo, Toulouse F-31052, France; Explorations Neurophysiologiques, Hôpital Purpan, Université de Toulouse, Toulouse F-31300, France
| | - Emmanuel J Barbeau
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse F-31330, France; Centre National de la Recherche Scientifique CerCo, Toulouse F-31052, France.
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29
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Wyeth M, Nagendran M, Buckmaster PS. Ictal onset sites and γ-aminobutyric acidergic neuron loss in epileptic pilocarpine-treated rats. Epilepsia 2020; 61:856-867. [PMID: 32242932 DOI: 10.1111/epi.16490] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/28/2020] [Accepted: 03/04/2020] [Indexed: 01/07/2023]
Abstract
OBJECTIVE The present study tested whether ictal onset sites are regions of more severe interneuron loss in epileptic pilocarpine-treated rats, a model of human temporal lobe epilepsy. METHODS Local field potential recordings were evaluated to identify ictal onset sites. Electrode sites were visualized in Nissl-stained sections. Adjacent sections were processed with proximity ligation in situ hybridization for glutamic acid decarboxylase 2 (Gad2). Gad2 neuron profile numbers at ictal onset sites were compared to contralateral regions. Other sections were processed with immunocytochemistry for reelin or nitric oxide synthase (NOS), which labeled major subtypes of granule cell layer-associated interneurons. Stereology was used to estimate numbers of reelin and NOS granule cell layer-associated interneurons per hippocampus. RESULTS Ictal onset sites varied between and within rats but were mostly in the ventral hippocampus and were frequently bilateral. There was no conclusive evidence of more severe Gad2 neuron profile loss at sites of earliest seizure activity compared to contralateral regions. Numbers of granule cell layer-associated NOS neurons were reduced in the ventral hippocampus. SIGNIFICANCE In epileptic pilocarpine-treated rats, ictal onset sites were mostly in the ventral hippocampus, where there was loss of granule cell layer-associated NOS interneurons. These findings suggest the hypothesis that loss of granule cell layer-associated NOS interneurons in the ventral hippocampus is a mechanism of temporal lobe epilepsy.
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Affiliation(s)
- Megan Wyeth
- Department of Comparative Medicine, Stanford University, Stanford, California
| | - Monica Nagendran
- Department of Medicine-Pulmonary and Critical Care, Stanford University, Stanford, California
| | - Paul S Buckmaster
- Department of Comparative Medicine, Stanford University, Stanford, California.,Department of Neurology & Neurological Sciences, Stanford University, Stanford, California
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30
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Chaudhary U, Mrachacz‐Kersting N, Birbaumer N. Neuropsychological and neurophysiological aspects of brain‐computer‐interface (BCI) control in paralysis. J Physiol 2020; 599:2351-2359. [DOI: 10.1113/jp278775] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 01/17/2020] [Indexed: 01/17/2023] Open
Affiliation(s)
- Ujwal Chaudhary
- Institute of Medical Psychology and Behavioral Neurobiology University of Tübingen Germany
- Wyss‐Center for Bio‐ and Neuro‐Engineering Geneva Switzerland
| | | | - Niels Birbaumer
- Institute of Medical Psychology and Behavioral Neurobiology University of Tübingen Germany
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31
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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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32
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Zaveri HP, Schelter B, Schevon CA, Jiruska P, Jefferys JGR, Worrell G, Schulze-Bonhage A, Joshi RB, Jirsa V, Goodfellow M, Meisel C, Lehnertz K. Controversies on the network theory of epilepsy: Debates held during the ICTALS 2019 conference. Seizure 2020; 78:78-85. [PMID: 32272333 DOI: 10.1016/j.seizure.2020.03.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/13/2020] [Accepted: 03/15/2020] [Indexed: 12/21/2022] Open
Abstract
Debates on six controversial topics on the network theory of epilepsy were held during two debate sessions, as part of the International Conference for Technology and Analysis of Seizures, 2019 (ICTALS 2019) convened at the University of Exeter, UK, September 2-5 2019. The debate topics were (1) From pathologic to physiologic: is the epileptic network part of an existing large-scale brain network? (2) Are micro scale recordings pertinent for defining the epileptic network? (3) From seconds to years: do we need all temporal scales to define an epileptic network? (4) Is it necessary to fully define the epileptic network to control it? (5) Is controlling seizures sufficient to control the epileptic network? (6) Does the epileptic network want to be controlled? This article, written by the organizing committee for the debate sessions and the debaters, summarizes the arguments presented during the debates on these six topics.
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Affiliation(s)
- Hitten P Zaveri
- Department of Neurology, Yale University, New Haven, CT 06520, USA
| | - Björn Schelter
- Institute for Complex Systems and Mathematical Biology, University of Aberdeen, Aberdeen AB24 3UE, UK
| | | | - Premysl Jiruska
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - John G R Jefferys
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic; Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
| | - Gregory Worrell
- Mayo Systems Electrophysiology Laboratory, Departments of Neurology and Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Rasesh B Joshi
- Department of Neurobiology and Anatomy, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Viktor Jirsa
- Institut de Neurosciences des Systèmes, Aix Marseille University, Marseille, France
| | - Marc Goodfellow
- Living Systems Institute, University of Exeter, Exeter, UK; Wellcome Trust Centre for Biomedical Modelling and Analysis, University of Exeter, Exeter, UK; EPSRC Centre for Predictive Modelling in Healthcare, University of Exeter, Exeter, UK
| | - Christian Meisel
- Department of Neurology, Boston Children's Hospital, 300 Longwood Ave, Boston, MA 02115, USA; Department of Neurology, University Clinic Carl Gustav Carus, Fetscherstrasse 74, 01307 Dresden, Germany
| | - Klaus Lehnertz
- Department of Epileptology, University of Bonn, Venusberg Campus 1, 53127 Bonn, Germany; Interdisciplinary Center for Complex Systems, University of Bonn, Brühler Str. 7, 53175 Bonn, Germany.
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33
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Tatum WO, McKay JH, ReFaey K, Feyissa AM, Ryan D, Ritaccio A, Middlebrooks E, Yelvington K, Roth G, Acton E, Grewal S, Chaichana K, Quinones-Hinojosa A. Detection of after-discharges during intraoperative functional brain mapping in awake brain tumor surgery using a novel high-density circular grid. Clin Neurophysiol 2020; 131:828-835. [PMID: 32066101 DOI: 10.1016/j.clinph.2019.12.416] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/21/2019] [Accepted: 12/14/2019] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To evaluate intraoperative use of a novel high-density circular grid in detecting after-discharges (AD) on electrocorticography (ECoG) during functional brain mapping (FBM). METHODS FBM during glioma surgery (10/2016 to 5/2019) recorded ADs using a 22-channel circular grid compared to conventional strip electrodes. ADs were analyzed for detection, duration, amplitude, morphology, histology, direction, and clinical signs. RESULTS Thirty-two patients (mean age 54.2 years; r = 30-75) with glioma (WHO grade II-IV; 20 grade IV) had surgery. ADs during FBM were more likely in patients with wild-type as opposed to IDH-1 mutants (p < 0.0001) using more contacts compared with linear strip electrodes (p = 0.0001). More sensors tended to be involved in ADs detected by the circular grid vs strips (6.61 vs 3.43; p = 0.16) at lower stimulus intensity (3.14 mA vs 4.13 mA; p = 0.09). No difference in the number of cortical stimulations before resection was present (38.9 mA vs 47.9 mA; p = 0.26). ADs longer than 10 seconds were 32.5 seconds (circular grid) vs 58.4 (strips) (p = 0.12). CONCLUSIONS High-density circular grids detect ADs in 360 degrees during FBM for glioma resection. Provocation of ADs was more likely in patients with wild-type than IDH-1 mutation. SIGNIFICANCE Circular grids offer high-resolution ECoG during intraoperative FBM for detection of ADs.
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Affiliation(s)
- William O Tatum
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA.
| | - Jake H McKay
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
| | - Karim ReFaey
- Department of Neurosurgery, Mayo Clinic, Jacksonville, FL, USA
| | | | - Dan Ryan
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
| | | | | | - Kirsten Yelvington
- Department of Clinical Neurophysiology, Mayo Clinic, Jacksonville, FL, USA
| | | | - Emily Acton
- University of Pennsylvania, Philadelphia, PA, USA
| | - Sanjeet Grewal
- Department of Neurosurgery, Mayo Clinic, Jacksonville, FL, USA
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34
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Breithausen B, Kautzmann S, Boehlen A, Steinhäuser C, Henneberger C. Limited contribution of astroglial gap junction coupling to buffering of extracellular K + in CA1 stratum radiatum. Glia 2019; 68:918-931. [PMID: 31743499 DOI: 10.1002/glia.23751] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/25/2019] [Accepted: 10/29/2019] [Indexed: 12/21/2022]
Abstract
Astrocytes form large networks, in which individual cells are connected via gap junctions. It is thought that this astroglial gap junction coupling contributes to the buffering of extracellular K+ increases. However, it is largely unknown how the control of extracellular K+ by astroglial gap junction coupling depends on the underlying activity patterns and on the magnitude of extracellular K+ increases. We explored this dependency in acute hippocampal slices (CA1, stratum radiatum) by direct K+ -sensitive microelectrode recordings and acute pharmacological inhibition of gap junctions. K+ transients evoked by synaptic and axonal activity were largely unaffected by acute astroglial uncoupling in slices obtained from young and adult rats. Iontophoretic K+ -application enabled us to generate K+ gradients with defined spatial properties and magnitude. By varying the K+ -iontophoresis position and protocol, we found that acute pharmacological uncoupling increases the amplitude of K+ transients once their initial amplitude exceeded ~10 mM. Our experiments demonstrate that the contribution of gap junction coupling to buffering of extracellular K+ gradients is limited to large and localized K+ increases.
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Affiliation(s)
- Björn Breithausen
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany
| | - Steffen Kautzmann
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany
| | - Anne Boehlen
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany.,Institute of Neurology, University College London, London, UK.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
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35
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Gill BJA, Wu X, Khan FA, Sosunov AA, Liou JY, Dovas A, Eissa TL, Banu MA, Bateman LM, McKhann GM, Canoll P, Schevon C. Ex vivo multi-electrode analysis reveals spatiotemporal dynamics of ictal behavior at the infiltrated margin of glioma. Neurobiol Dis 2019; 134:104676. [PMID: 31731042 PMCID: PMC8147009 DOI: 10.1016/j.nbd.2019.104676] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/22/2019] [Accepted: 11/11/2019] [Indexed: 01/02/2023] Open
Abstract
The purpose of this study is to develop a platform in which the cellular and molecular underpinnings of chronic focal neocortical lesional epilepsy can be explored and use it to characterize seizure-like events (SLEs) in an ex vivo model of infiltrating high-grade glioma. Microelectrode arrays were used to study electrophysiologic changes in ex vivo acute brain slices from a PTEN/p53 deleted, PDGF-B driven mouse model of high-grade glioma. Electrode locations were co-registered to the underlying histology to ascertain the influence of the varying histologic landscape on the observed electrophysiologic changes. Peritumoral, infiltrated, and tumor sites were sampled in tumor-bearing slices. Following the addition of zero Mg2+ solution, all three histologic regions in tumor-bearing slices showed significantly greater increases in firing rates when compared to the control sites. Tumor-bearing slices demonstrated increased proclivity for SLEs, with 40 events in tumor-bearing slices and 5 events in control slices (p-value = .0105). Observed SLEs were characterized by either low voltage fast (LVF) onset patterns or short bursts of repetitive widespread, high amplitude low frequency discharges. Seizure foci comprised areas from all three histologic regions. The onset electrode was found to be at the infiltrated margin in 50% of cases and in the peritumoral region in 36.9% of cases. These findings reveal a landscape of histopathologic and electrophysiologic alterations associated with ictogenesis and spread of tumor-associated seizures.
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Affiliation(s)
- Brian J A Gill
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA.
| | - Xiaoping Wu
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA
| | - Farhan A Khan
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA
| | - Alexander A Sosunov
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA
| | - Jyun-You Liou
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Athanassios Dovas
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Tahra L Eissa
- Department of Applied Mathematics, University of Colorado at Boulder, Boulder, CO, USA
| | - Matei A Banu
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA
| | - 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
| | - Peter Canoll
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Catherine Schevon
- Department of Neurology, Columbia University Medical Center, New York, NY, USA
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36
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Wenzel M, Hamm JP, Peterka DS, Yuste R. Acute Focal Seizures Start As Local Synchronizations of Neuronal Ensembles. J Neurosci 2019; 39:8562-8575. [PMID: 31427393 PMCID: PMC6807279 DOI: 10.1523/jneurosci.3176-18.2019] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 07/27/2019] [Accepted: 08/09/2019] [Indexed: 11/21/2022] Open
Abstract
Understanding seizure formation and spread remains a critical goal of epilepsy research. We used fast in vivo two-photon calcium imaging in male mouse neocortex to reconstruct, with single-cell resolution, the dynamics of acute (4-aminopyridine) focal cortical seizures as they originate within a spatially confined seizure initiation site (intrafocal region), and subsequently propagate into neighboring cortical areas (extrafocal region). We find that seizures originate as local neuronal ensembles within the initiation site. This abnormal hyperactivity engages increasingly larger areas in a saltatory fashion until it breaks into neighboring cortex, where it proceeds smoothly and is then detected electrophysiologically (LFP). Interestingly, PV inhibitory interneurons have spatially heterogeneous activity in intrafocal and extrafocal territories, ruling out a simple role of inhibition in seizure formation and spread. We propose a two-step model for the progression of focal seizures, where neuronal ensembles activate first, generating a microseizure, followed by widespread neural activation in a traveling wave through neighboring cortex during macroseizures.SIGNIFICANCE STATEMENT We have used calcium imaging in mouse sensory cortex in vivo to reconstruct the onset of focal seizures elicited by local injection of the chemoconvulsant 4-aminopyridine. We demonstrate at cellular resolution that acute focal seizures originate as increasingly synchronized local neuronal ensembles. Because of its spatial confinement, this process may at first be undetectable even by nearby LFP electrodes. Further, we establish spatial footprints of local neural subtype activity that correspond to consecutive steps of seizure microprogression. Such footprints could facilitate determining the recording location (e.g., inside/outside an epileptogenic focus) in high-resolution studies, even in the absence of a priori knowledge about where exactly a seizure started.
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Affiliation(s)
- Michael Wenzel
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, New York 10027
| | - Jordan P Hamm
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, New York 10027
| | - Darcy S Peterka
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, New York 10027
| | - Rafael Yuste
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, New York 10027
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37
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Abstract
Continuous electroencephalography (cEEG) monitoring is becoming increasingly used in neurologic and non-neurologic intensive care units (ICUs). Non-convulsive seizures (NCSz) and periodic discharges (PDs) are commonly seen in critically ill patients. Some of these PD patterns, also known as the ictal-interictal continuum (IIC), are associated with an increased risk of seizures and poor outcome. However, we do not fully understand the significance of these periodic patterns and the decision of how aggressively to treat remains controversial. IIC patterns are associated with pathophysiologic changes that closely resemble those of seizures. Here we make the argument that, rather than feature description on EEG, associated changes in brain physiology should dictate management choices.
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38
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Tatum WO, Feyissa AM, ReFaey K, Grewal SS, Alvi MA, Castro-Apolo R, Roth G, Segura-Duran I, Mahato D, Ruiz-Garcia H, Pamias-Portalatin E, Yelvington K, Chaichana K, Bechtle P, Quinones-Hinojosa A. Periodic focal epileptiform discharges. Clin Neurophysiol 2019; 130:1320-1328. [DOI: 10.1016/j.clinph.2019.04.718] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/30/2019] [Accepted: 04/22/2019] [Indexed: 11/16/2022]
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39
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Nagappan S, Liu L, Fetcho R, Nguyen J, Nishimura N, Radwanski RE, Lieberman S, Baird-Daniel E, Ma H, Zhao M, Schaffer CB, Schwartz TH. In Vivo Femtosecond Laser Subsurface Cortical Microtransections Attenuate Acute Rat Focal Seizures. Cereb Cortex 2019; 29:3415-3426. [PMID: 30192931 PMCID: PMC6644864 DOI: 10.1093/cercor/bhy210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/03/2018] [Indexed: 12/27/2022] Open
Abstract
Recent evidence shows that seizures propagate primarily through supragranular cortical layers. To selectively modify these circuits, we developed a new technique using tightly focused, femtosecond infrared laser pulses to make as small as ~100 µm-wide subsurface cortical incisions surrounding an epileptic focus. We use this "laser scalpel" to produce subsurface cortical incisions selectively to supragranular layers surrounding an epileptic focus in an acute rodent seizure model. Compared with sham animals, these microtransections completely blocked seizure initiation and propagation in 1/3 of all animals. In the remaining animals, seizure frequency was reduced by 2/3 and seizure propagation reduced by 1/3. In those seizures that still propagated, it was delayed and reduced in amplitude. When the recording electrode was inside the partially isolated cube and the seizure focus was on the outside, the results were even more striking. In spite of these microtransections, somatosensory responses to tail stimulation were maintained but with reduced amplitude. Our data show that just a single enclosing wall of laser cuts limited to supragranular layers led to a significant reduction in seizure initiation and propagation with preserved cortical function. Modification of this concept may be a useful treatment for human epilepsy.
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Affiliation(s)
| | - Lena Liu
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Robert Fetcho
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - John Nguyen
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Nozomi Nishimura
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Ryan E Radwanski
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
- Department of Neurological Surgery, Weill Cornell Medicine of Cornell University, 525 East 68th Street, Box 99, New York, NY, USA
| | - Seth Lieberman
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Eliza Baird-Daniel
- Department of Neurological Surgery, Weill Cornell Medicine of Cornell University, 525 East 68th Street, Box 99, New York, NY, USA
| | - Hongtao Ma
- Department of Neurological Surgery, Weill Cornell Medicine of Cornell University, 525 East 68th Street, Box 99, New York, NY, USA
- Brain and Mind Research Institute, Weill Cornell Medicine of Cornell University, New York Presbyterian Hospital, New York, NY, USA
| | - Mingrui Zhao
- Department of Neurological Surgery, Weill Cornell Medicine of Cornell University, 525 East 68th Street, Box 99, New York, NY, USA
- Brain and Mind Research Institute, Weill Cornell Medicine of Cornell University, New York Presbyterian Hospital, New York, NY, USA
| | - Chris B Schaffer
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Theodore H Schwartz
- Department of Neurological Surgery, Weill Cornell Medicine of Cornell University, 525 East 68th Street, Box 99, New York, NY, USA
- Brain and Mind Research Institute, Weill Cornell Medicine of Cornell University, New York Presbyterian Hospital, New York, NY, USA
- Department of Neurological Surgery, Sackler Brain and Spine Institute, Weill Cornell Medicine of Cornell University, New York Presbyterian Hospital, New York, NY, USA
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40
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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 PMCID: PMC6588430 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] [MESH Headings] [Grants] [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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41
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Despouy E, Curot J, Denuelle M, Deudon M, Sol JC, Lotterie JA, Reddy L, Nowak LG, Pariente J, Thorpe SJ, Valton L, Barbeau EJ. Neuronal spiking activity highlights a gradient of epileptogenicity in human tuberous sclerosis lesions. Clin Neurophysiol 2019; 130:537-547. [DOI: 10.1016/j.clinph.2018.12.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 12/12/2018] [Accepted: 12/25/2018] [Indexed: 11/26/2022]
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42
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Network Properties Revealed during Multi-Scale Calcium Imaging of Seizure Activity in Zebrafish. eNeuro 2019; 6:eN-NWR-0041-19. [PMID: 30895220 PMCID: PMC6424556 DOI: 10.1523/eneuro.0041-19.2019] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 02/08/2019] [Indexed: 12/02/2022] Open
Abstract
Seizures are characterized by hypersynchronization of neuronal networks. Understanding these networks could provide a critical window for therapeutic control of recurrent seizure activity, i.e., epilepsy. However, imaging seizure networks has largely been limited to microcircuits in vitro or small “windows” in vivo. Here, we combine fast confocal imaging of genetically encoded calcium indicator (GCaMP)-expressing larval zebrafish with local field potential (LFP) recordings to study epileptiform events at whole-brain and single-neuron levels in vivo. Using an acute seizure model (pentylenetetrazole, PTZ), we reliably observed recurrent electrographic ictal-like events associated with generalized activation of all major brain regions and uncovered a well-preserved anterior-to-posterior seizure propagation pattern. We also examined brain-wide network synchronization and spatiotemporal patterns of neuronal activity in the optic tectum microcircuit. Brain-wide and single-neuronal level analysis of PTZ-exposed and 4-aminopyridine (4-AP)-exposed zebrafish revealed distinct network dynamics associated with seizure and non-seizure hyperexcitable states, respectively. Neuronal ensembles, comprised of coactive neurons, were also uncovered during interictal-like periods. Taken together, these results demonstrate that macro- and micro-network calcium motifs in zebrafish may provide a greater understanding of epilepsy.
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43
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Woods V, Trumpis M, Bent B, Palopoli-Trojani K, Chiang CH, Wang C, Yu C, Insanally MN, Froemke RC, Viventi J. Long-term recording reliability of liquid crystal polymer µECoG arrays. J Neural Eng 2018; 15:066024. [PMID: 30246690 PMCID: PMC6342453 DOI: 10.1088/1741-2552/aae39d] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The clinical use of microsignals recorded over broad cortical regions is largely limited by the chronic reliability of the implanted interfaces. APPROACH We evaluated the chronic reliability of novel 61-channel micro-electrocorticographic (µECoG) arrays in rats chronically implanted for over one year and using accelerated aging. Devices were encapsulated with polyimide (PI) or liquid crystal polymer (LCP), and fabricated using commercial manufacturing processes. In vitro failure modes and predicted lifetimes were determined from accelerated soak testing. Successful designs were implanted epidurally over the rodent auditory cortex. Trends in baseline signal level, evoked responses and decoding performance were reported for over one year of implantation. MAIN RESULTS Devices fabricated with LCP consistently had longer in vitro lifetimes than PI encapsulation. Our accelerated aging results predicted device integrity beyond 3.4 years. Five implanted arrays showed stable performance over the entire implantation period (247-435 d). Our regression analysis showed that impedance predicted signal quality and information content only in the first 31 d of recordings and had little predictive value in the chronic phase (>31 d). In the chronic phase, site impedances slightly decreased yet decoding performance became statistically uncorrelated with impedance. We also employed an improved statistical model of spatial variation to measure sensitivity to locally varying fields, which is typically concealed in standard signal power calculations. SIGNIFICANCE These findings show that µECoG arrays can reliably perform in chronic applications in vivo for over one year, which facilitates the development of a high-density, clinically viable interface.
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Affiliation(s)
- Virginia Woods
- Department of Biomedical Engineering, Duke University, Durham, NC, United States of America
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44
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Bazan NG. Docosanoids and elovanoids from omega-3 fatty acids are pro-homeostatic modulators of inflammatory responses, cell damage and neuroprotection. Mol Aspects Med 2018; 64:18-33. [PMID: 30244005 DOI: 10.1016/j.mam.2018.09.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/19/2018] [Indexed: 02/06/2023]
Abstract
The functional significance of the selective enrichment of the omega-3 essential fatty acid docosahexaenoic acid (DHA; 22C and 6 double bonds) in cellular membrane phospholipids of the nervous system is being clarified by defining its specific roles on membrane protein function and by the uncovering of the bioactive mediators, docosanoids and elovanoids (ELVs). Here, we describe the preferential uptake and DHA metabolism in photoreceptors and brain as well as the significance of the Adiponectin receptor 1 in DHA retention and photoreceptor cell (PRC) survival. We now know that this integral membrane protein is engaged in DHA retention as a necessary event for the function of PRCs and retinal pigment epithelial (RPE) cells. We present an overview of how a) NPD1 selectively mediates preconditioning rescue of RPE and PR cells; b) NPD1 restores aberrant neuronal networks in experimental epileptogenesis; c) the decreased ability to biosynthesize NPD1 in memory hippocampal areas of early stages of Alzheimer's disease takes place; d) NPD1 protection of dopaminergic circuits in an in vitro model using neurotoxins; and e) bioactivity elicited by DHA and NPD1 activate a neuroprotective gene-expression program that includes the expression of Bcl-2 family members affected by Aβ42, DHA, or NPD1. In addition, we highlight ELOVL4 (ELOngation of Very Long chain fatty acids-4), specifically the neurological and ophthalmological consequences of its mutations, and their role in providing precursors for the biosynthesis of ELVs. Then we outline evidence of ELVs ability to protect RPE cells, which sustain PRC integrity. In the last section, we present a summary of the protective bioactivity of docosanoids and ELVs in experimental ischemic stroke. The identification of early mechanisms of neural cell survival mediated by DHA-synthesized ELVs and docosanoids contributes to the understanding of cell function, pro-homeostatic cellular modulation, inflammatory responses, and innate immunity, opening avenues for prevention and therapeutic applications in neurotrauma, stroke and neurodegenerative diseases.
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Affiliation(s)
- Nicolas G Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA.
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45
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A Brain-Heart Biomarker for Epileptogenesis. J Neurosci 2018; 38:8473-8483. [PMID: 30150365 DOI: 10.1523/jneurosci.1130-18.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/17/2018] [Accepted: 08/08/2018] [Indexed: 12/19/2022] Open
Abstract
Postinjury epilepsy is an potentially preventable sequela in as many as 20% of patients with brain insults. For these cases biomarkers of epileptogenesis are critical to facilitate identification of patients at high-risk of developing epilepsy and to introduce effective anti-epileptogenic interventions. Here, we demonstrate that delayed brain-heart coincidences serve as a reliable biomarker. In a murine model of post-infection acquired epilepsy, we used long-term simultaneous measurements of the brain activity via electroencephalography and autonomic cardiac activity via electrocardiography, in male mice, to quantitatively track brain-heart interactions during epileptogenesis. We find that abnormal cortical discharges precede abnormal fluctuations in the cardiac rhythm at the resolution of single beat-to-beat intervals. The delayed brain-heart coincidence is detectable as early as the onset of chronic measurements, 2-14 weeks before the first seizure, only in animals that become epileptic, and increases during epileptogenesis. Therefore, delayed brain-heart coincidence serves as a biomarker of epileptogenesis and could be used for phenotyping, diagnostic, and therapeutic purposes.SIGNIFICANCE STATEMENT No biomarker that readily predicts and tracks epileptogenesis currently exists for the wide range of human acquired epilepsies. Here, we used long-term measurements of brain and heart activity in a mouse model of post-infection acquired epilepsy to investigate the potential of brain-heart interaction as a biomarker of epileptogenesis. We found that delayed coincidences from brain to heart can clearly separate the mice that became epileptic from those that did not weeks before development of epilepsy. Our findings allow for phenotyping and tracking of epileptogenesis in this and likely other models of acquired epilepsy. Such capability is critical for efficient adjunctive treatment development and for tracking the efficacy of such treatments.
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46
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Afra P, Hanrahan SJ, Kellis SS, House P. Non ictal onset zone: A window to ictal dynamics. EPILEPSY & BEHAVIOR CASE REPORTS 2017; 8:123-127. [PMID: 29204348 PMCID: PMC5707213 DOI: 10.1016/j.ebcr.2017.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 10/03/2017] [Accepted: 10/11/2017] [Indexed: 11/24/2022]
Abstract
The focal and network concepts of epilepsy present different aspects of electroclinical phenomenon of seizures. Here, we present a 23-year-old man undergoing surgical evaluation with left fronto-temporal electrocorticography (ECoG) and microelectrode-array (MEA) in the middle temporal gyrus (MTG). We compare action-potential (AP) and local field potentials (LFP) recorded from MEA with ECoG. Seizure onset in the mesial-temporal lobe was characterized by changes in the pattern of AP-firing without clear changes in LFP or ECoG in MTG. This suggests simultaneous analysis of neuronal activity in differing spatial scales and frequency ranges provide complementary insights into how focal and network neurophysiological activity contribute to ictal activity.
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47
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Sinha N, Dauwels J, Kaiser M, Cash SS, Brandon Westover M, Wang Y, Taylor PN. Predicting neurosurgical outcomes in focal epilepsy patients using computational modelling. Brain 2016; 140:319-332. [PMID: 28011454 PMCID: PMC5278304 DOI: 10.1093/brain/aww299] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 10/08/2016] [Accepted: 10/10/2016] [Indexed: 01/03/2023] Open
Abstract
See Eissa and Schevon (doi:10.1093/aww332) for a scientific commentary on this article. Surgery can be a last resort for patients with intractable, medically refractory epilepsy. For many of these patients, however, there is substantial risk that the surgery will be ineffective. The prediction of who is likely to benefit from a surgical approach is crucial for being able to inform patients better, conduct principled prospective clinical trials, and ultimately tailor therapeutic approaches to these patients more effectively. Dynamical computational models, informed with patient data, can be used to make predictions and give mechanistic insight. In this study, we develop patient-specific dynamical network models of epileptogenic cortex. We infer the network connectivity matrix from non-seizure electrographic recordings of patients and use these connectivity matrices as the network structure in our model. The model simulates the dynamics of a bi-stable switch at every node in this network, meaning that every node starts in a background state, but has the ability to transit to a co-existing seizure state. Whether a transition happens in a node is partly determined by the stochastic nature of the input to the node, but also by the input the node receives from other connected nodes in the network. By conducting simulations with such a model, we can detect the average transition time for nodes in a given network, and therefore define nodes with a short transition time as highly epileptogenic. In a retrospective study, we found that in some patients the regions with high epileptogenicity in the model overlap with those identified clinically as the seizure onset zone. Moreover, it was found that the resection of these regions in the model reduces the overall likelihood of a seizure. Following removal of these regions in the model, we predicted surgical outcomes and compared these to actual patient outcomes. Our predictions were found to be 81.3% accurate on a dataset of 16 patients with intractable epilepsy. Intriguingly, in patients with unsuccessful outcomes, the proposed computational approach is able to suggest alternative resection sites. The model presented here gives mechanistic insight as to why surgery may be unsuccessful in some patients. This may aid clinicians in presurgical evaluation by providing a tool to explore various surgical options, offering complementary information to existing clinical techniques.
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Affiliation(s)
- Nishant Sinha
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore
| | - Justin Dauwels
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore
| | - Marcus Kaiser
- Interdisciplinary Computing and Complex BioSystems (ICOS) Research Group, School of Computing Science, Newcastle University, Newcastle upon Tyne, UK.,Institute of Neuroscience, Faculty of Medical Science, Newcastle University, Newcastle upon Tyne, UK
| | - Sydney S Cash
- Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - M Brandon Westover
- Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Yujiang Wang
- Interdisciplinary Computing and Complex BioSystems (ICOS) Research Group, School of Computing Science, Newcastle University, Newcastle upon Tyne, UK
| | - Peter N Taylor
- Interdisciplinary Computing and Complex BioSystems (ICOS) Research Group, School of Computing Science, Newcastle University, Newcastle upon Tyne, UK .,Institute of Neuroscience, Faculty of Medical Science, Newcastle University, Newcastle upon Tyne, UK.,Institute of Neurology, University College London, UK
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48
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Propagating Neural Source Revealed by Doppler Shift of Population Spiking Frequency. J Neurosci 2016; 36:3495-505. [PMID: 27013678 DOI: 10.1523/jneurosci.3525-15.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/28/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Electrical activity in the brain during normal and abnormal function is associated with propagating waves of various speeds and directions. It is unclear how both fast and slow traveling waves with sometime opposite directions can coexist in the same neural tissue. By recording population spikes simultaneously throughout the unfolded rodent hippocampus with a penetrating microelectrode array, we have shown that fast and slow waves are causally related, so a slowly moving neural source generates fast-propagating waves at ∼0.12 m/s. The source of the fast population spikes is limited in space and moving at ∼0.016 m/s based on both direct and Doppler measurements among 36 different spiking trains among eight different hippocampi. The fact that the source is itself moving can account for the surprising direction reversal of the wave. Therefore, these results indicate that a small neural focus can move and that this phenomenon could explain the apparent wave reflection at tissue edges or multiple foci observed at different locations in neural tissue. SIGNIFICANCE STATEMENT The use of novel techniques with an unfolded hippocampus and penetrating microelectrode array to record and analyze neural activity has revealed the existence of a source of neural signals that propagates throughout the hippocampus. The source itself is electrically silent, but its location can be inferred by building isochrone maps of population spikes that the source generates. The movement of the source can also be tracked by observing the Doppler frequency shift of these spikes. These results have general implications for how neural signals are generated and propagated in the hippocampus; moreover, they have important implications for the understanding of seizure generation and foci localization.
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49
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Freestone DR, Karoly PJ, Peterson ADH, Kuhlmann L, Lai A, Goodarzy F, Cook MJ. Seizure Prediction: Science Fiction or Soon to Become Reality? Curr Neurol Neurosci Rep 2016; 15:73. [PMID: 26404726 DOI: 10.1007/s11910-015-0596-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This review highlights recent developments in the field of epileptic seizure prediction. We argue that seizure prediction is possible; however, most previous attempts have used data with an insufficient amount of information to solve the problem. The review discusses four methods for gaining more information above standard clinical electrophysiological recordings. We first discuss developments in obtaining long-term data that enables better characterisation of signal features and trends. Then, we discuss the usage of electrical stimulation to probe neural circuits to obtain robust information regarding excitability. Following this, we present a review of developments in high-resolution micro-electrode technologies that enable neuroimaging across spatial scales. Finally, we present recent results from data-driven model-based analyses, which enable imaging of seizure generating mechanisms from clinical electrophysiological measurements. It is foreseeable that the field of seizure prediction will shift focus to a more probabilistic forecasting approach leading to improvements in the quality of life for the millions of people who suffer uncontrolled seizures. However, a missing piece of the puzzle is devices to acquire long-term high-quality data. When this void is filled, seizure prediction will become a reality.
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Affiliation(s)
- Dean R Freestone
- Department of Medicine, St. Vincent's Hospital Melbourne, The University of Melbourne, Fitzroy, VIC, Australia, 3065. .,Department of Statistics, Columbia University, New York, NY, 10027, USA.
| | - Philippa J Karoly
- Department of Medicine, St. Vincent's Hospital Melbourne, The University of Melbourne, Fitzroy, VIC, Australia, 3065.,Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, VIC, Australia, 3000
| | - Andre D H Peterson
- Department of Medicine, St. Vincent's Hospital Melbourne, The University of Melbourne, Fitzroy, VIC, Australia, 3065
| | - Levin Kuhlmann
- Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, VIC, Australia, 3000
| | - Alan Lai
- Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, VIC, Australia, 3000
| | - Farhad Goodarzy
- Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, VIC, Australia, 3000
| | - Mark J Cook
- Department of Medicine, St. Vincent's Hospital Melbourne, The University of Melbourne, Fitzroy, VIC, Australia, 3065.
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50
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Kalamangalam GP, Slater JD. Periodic Lateralized Epileptiform Discharges and Afterdischarges: Common Dynamic Mechanisms. J Clin Neurophysiol 2016; 32:331-40. [PMID: 25710632 DOI: 10.1097/wnp.0000000000000173] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE No neurophysiological hypothesis currently exists addressing how and why periodic lateralized epileptiform discharges (PLEDs) arise in certain types of brain disease. Based on spectral analysis of clinical scalp EEG traces, the authors formulated a general mechanism for the emergence of PLEDs. METHODS The authors retrospectively analyzed spectra of PLED time series and control EEG segments from the opposite hemisphere in 25 hospitalized neurological patients. The observations led to the development of a phenomenological model for PLED emergence. RESULTS Similar to that observed in our previous work with afterdischarges, an analytic relationship is found between the spectrum of the baseline EEG and the PLED EEG, characterized by "condensation" of the main baseline spectral cluster, with variable inclusion of higher harmonics of the condensate. CONCLUSIONS Periodic lateralized epileptiform discharges may arise by synchronization of preexisting local field potentials, through a variable combination of enhancement of excitatory neurotransmission and inactivation of inhibitory neurotransmission provoked by the PLED-associated disease process. Higher harmonics in the PLED spectrum may arise by recurrent feedback, possibly from entrained single units. A mechanism is suggested for PLED emergence in certain diseased brain states and the association of PLEDs with EEG seizures. The framework is a spatially extended version of that, which the authors proposed, underlies afterdischarge and analogous to the cooperative behavior seen in a variety of natural multi-oscillator systems.
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