1
|
Veciana de Las Heras M, Sala-Padro J, Pedro-Perez J, García-Parra B, Hernández-Pérez G, Falip M. Utility of Quantitative EEG in Neurological Emergencies and ICU Clinical Practice. Brain Sci 2024; 14:939. [PMID: 39335433 PMCID: PMC11430096 DOI: 10.3390/brainsci14090939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 08/22/2024] [Accepted: 09/11/2024] [Indexed: 09/30/2024] Open
Abstract
The electroencephalogram (EEG) is a cornerstone tool for the diagnosis, management, and prognosis of selected patient populations. EEGs offer significant advantages such as high temporal resolution, real-time cortical function assessment, and bedside usability. The quantitative EEG (qEEG) added the possibility of long recordings being processed in a compressive manner, making EEG revision more efficient for experienced users, and more friendly for new ones. Recent advancements in commercially available software, such as Persyst, have significantly expanded and facilitated the use of qEEGs, marking the beginning of a new era in its application. As a result, there has been a notable increase in the practical, real-world utilization of qEEGs in recent years. This paper aims to provide an overview of the current applications of qEEGs in daily neurological emergencies and ICU practice, and some elementary principles of qEEGs using Persyst software in clinical settings. This article illustrates basic qEEG patterns encountered in critical care and adopts the new terminology proposed for spectrogram reporting.
Collapse
Affiliation(s)
- Misericordia Veciana de Las Heras
- Neurology Service, Neurophysiology Department, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Jacint Sala-Padro
- Neurology Service, Epilepsy Unit, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Jordi Pedro-Perez
- Neurology Service, Neurophysiology Department, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Beliu García-Parra
- Neurology Service, Neurophysiology Department, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Guillermo Hernández-Pérez
- Neurology Service, Epilepsy Unit, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Merce Falip
- Neurology Service, Epilepsy Unit, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Greenblatt AS, Beniczky S, Nascimento FA. Pitfalls in scalp EEG: Current obstacles and future directions. Epilepsy Behav 2023; 149:109500. [PMID: 37931388 DOI: 10.1016/j.yebeh.2023.109500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 10/15/2023] [Accepted: 10/17/2023] [Indexed: 11/08/2023]
Abstract
Although electroencephalography (EEG) serves a critical role in the evaluation and management of seizure disorders, it is commonly misinterpreted, resulting in avoidable medical, social, and financial burdens to patients and health care systems. Overinterpretation of sharply contoured transient waveforms as being representative of interictal epileptiform abnormalities lies at the core of this problem. However, the magnitude of these errors is amplified by the high prevalence of paroxysmal events exhibited in clinical practice that compel investigation with EEG. Neurology training programs, which vary considerably both in the degree of exposure to EEG and the composition of EEG didactics, have not effectively addressed this widespread issue. Implementation of competency-based curricula in lieu of traditional educational approaches may enhance proficiency in EEG interpretation amongst general neurologists in the absence of formal subspecialty training. Efforts in this regard have led to the development of a systematic, high-fidelity approach to the interpretation of epileptiform discharges that is readily employable across medical centers. Additionally, machine learning techniques hold promise for accelerating accurate and reliable EEG interpretation, particularly in settings where subspecialty interpretive EEG services are not readily available. This review highlights common diagnostic errors in EEG interpretation, limitations in current educational paradigms, and initiatives aimed at resolving these challenges.
Collapse
Affiliation(s)
- Adam S Greenblatt
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Sándor Beniczky
- Department of Clinical Neurophysiology, Danish Epilepsy Center, Dianalund and Aarhus University Hospital, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Fábio A Nascimento
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
4
|
Devulder A, Macea J, Kalkanis A, De Winter F, Vandenbulcke M, Vandenberghe R, Testelmans D, Van Den Bossche MJA, Van Paesschen W. Subclinical epileptiform activity and sleep disturbances in Alzheimer's disease. Brain Behav 2023; 13:e3306. [PMID: 37950422 PMCID: PMC10726840 DOI: 10.1002/brb3.3306] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 10/16/2023] [Accepted: 10/22/2023] [Indexed: 11/12/2023] Open
Abstract
INTRODUCTION Subclinical epileptiform activity (SEA) and sleep disturbances are frequent in Alzheimer's disease (AD). Both have an important relation to cognition and potential therapeutic implications. We aimed to study a possible relationship between SEA and sleep disturbances in AD. METHODS In this cross-sectional study, we performed a 24-h ambulatory EEG and polysomnography in 48 AD patients without diagnosis of epilepsy and 34 control subjects. RESULTS SEA, mainly detected in frontotemporal brain regions during N2 with a median of three spikes/night [IQR1-17], was three times more prevalent in AD. AD patients had lower sleep efficacy, longer wake after sleep onset, more awakenings, more N1%, less REM sleep and a higher apnea-hypopnea index (AHI) and oxygen desaturation index (ODI). Sleep was not different between AD subgroup with SEA (AD-Epi+) and without SEA (AD-Epi-); however, compared to controls, REM% was decreased and AHI and ODI were increased in the AD-Epi+ subgroup. DISCUSSION Decreased REM sleep and more severe sleep-disordered breathing might be related to SEA in AD. These results could have diagnostic and therapeutic implications and warrant further study at the intersection between sleep and epileptiform activity in AD.
Collapse
Affiliation(s)
- Astrid Devulder
- Laboratory for Epilepsy Research, KU Leuven and Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Jaiver Macea
- Laboratory for Epilepsy Research, KU Leuven and Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Alexandros Kalkanis
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), KU Leuven and Department of Pulmonary DiseasesUniversity Hospitals LeuvenLeuvenBelgium
| | - François‐Laurent De Winter
- Division of Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven and Department of Geriatric PsychiatryUniversity Psychiatric Center (UPC) KU LeuvenLeuvenBelgium
| | - Mathieu Vandenbulcke
- Division of Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven and Department of Geriatric PsychiatryUniversity Psychiatric Center (UPC) KU LeuvenLeuvenBelgium
| | - Rik Vandenberghe
- Laboratory for Cognitive Neurology, KU Leuven and Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Dries Testelmans
- Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), KU Leuven and Department of Pulmonary DiseasesUniversity Hospitals LeuvenLeuvenBelgium
| | - Maarten J. A. Van Den Bossche
- Division of Neuropsychiatry, Department of Neurosciences, Leuven Brain Institute, KU Leuven and Department of Geriatric PsychiatryUniversity Psychiatric Center (UPC) KU LeuvenLeuvenBelgium
| | - Wim Van Paesschen
- Laboratory for Epilepsy Research, KU Leuven and Department of NeurologyUniversity Hospitals LeuvenLeuvenBelgium
| |
Collapse
|
5
|
van Nifterick AM, Mulder D, Duineveld DJ, Diachenko M, Scheltens P, Stam CJ, van Kesteren RE, Linkenkaer-Hansen K, Hillebrand A, Gouw AA. Resting-state oscillations reveal disturbed excitation-inhibition ratio in Alzheimer's disease patients. Sci Rep 2023; 13:7419. [PMID: 37150756 PMCID: PMC10164744 DOI: 10.1038/s41598-023-33973-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 04/21/2023] [Indexed: 05/09/2023] Open
Abstract
An early disruption of neuronal excitation-inhibition (E-I) balance in preclinical animal models of Alzheimer's disease (AD) has been frequently reported, but is difficult to measure directly and non-invasively in humans. Here, we examined known and novel neurophysiological measures sensitive to E-I in patients across the AD continuum. Resting-state magnetoencephalography (MEG) data of 86 amyloid-biomarker-confirmed subjects across the AD continuum (17 patients diagnosed with subjective cognitive decline, 18 with mild cognitive impairment (MCI) and 51 with dementia due to probable AD (AD dementia)), 46 healthy elderly and 20 young control subjects were reconstructed to source-space. E-I balance was investigated by detrended fluctuation analysis (DFA), a functional E/I (fE/I) algorithm, and the aperiodic exponent of the power spectrum. We found a disrupted E-I ratio in AD dementia patients specifically, by a lower DFA, and a shift towards higher excitation, by a higher fE/I and a lower aperiodic exponent. Healthy subjects showed lower fE/I ratios (< 1.0) than reported in previous literature, not explained by age or choice of an arbitrary threshold parameter, which warrants caution in interpretation of fE/I results. Correlation analyses showed that a lower DFA (E-I imbalance) and a lower aperiodic exponent (more excitation) was associated with a worse cognitive score in AD dementia patients. In contrast, a higher DFA in the hippocampi of MCI patients was associated with a worse cognitive score. This MEG-study showed E-I imbalance, likely due to increased excitation, in AD dementia, but not in early stage AD patients. To accurately determine the direction of shift in E-I balance, validations of the currently used markers and additional in vivo markers of E-I are required.
Collapse
Affiliation(s)
- Anne M van Nifterick
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands.
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands.
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands.
- Amsterdam Neuroscience, Systems and Network Neurosciences, Amsterdam, The Netherlands.
| | - Danique Mulder
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands
| | - Denise J Duineveld
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands
| | - Marina Diachenko
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Systems and Network Neurosciences, Amsterdam, The Netherlands
| | - Philip Scheltens
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Cornelis J Stam
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Systems and Network Neurosciences, Amsterdam, The Netherlands
| | - Ronald E van Kesteren
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Klaus Linkenkaer-Hansen
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Systems and Network Neurosciences, Amsterdam, The Netherlands
| | - Arjan Hillebrand
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Systems and Network Neurosciences, Amsterdam, The Netherlands
| | - Alida A Gouw
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| |
Collapse
|
6
|
Liu Y, Li C. Localizing targets for neuromodulation in drug-resistant epilepsy using intracranial EEG and computational model. Front Physiol 2022; 13:1015838. [PMCID: PMC9632660 DOI: 10.3389/fphys.2022.1015838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
Neuromodulation has emerged as a promising technique for the treatment of epilepsy. The target for neuromodulation is critical for the effectiveness of seizure control. About 30% of patients with drug-resistant epilepsy (DRE) fail to achieve seizure freedom after surgical intervention. It is difficult to find effective brain targets for neuromodulation in these patients because brain regions are damaged during surgery. In this study, we propose a novel approach for localizing neuromodulatory targets, which uses intracranial EEG and multi-unit computational models to simulate the dynamic behavior of epileptic networks through external stimulation. First, we validate our method on a multivariate autoregressive model and compare nine different methods of constructing brain networks. Our results show that the directed transfer function with surrogate analysis achieves the best performance. Intracranial EEGs of 11 DRE patients are further analyzed. These patients all underwent surgery. In three seizure-free patients, the localized targets are concordant with the resected regions. For the eight patients without seizure-free outcome, the localized targets in three of them are outside the resected regions. Finally, we provide candidate targets for neuromodulation in these patients without seizure-free outcome based on virtual resected epileptic network. We demonstrate the ability of our approach to locate optimal targets for neuromodulation. We hope that our approach can provide a new tool for localizing patient-specific targets for neuromodulation therapy in DRE.
Collapse
|
7
|
Hanke JM, Schindler KA, Seiler A. On the relationships between epilepsy, sleep, and Alzheimer's disease: A narrative review. Epilepsy Behav 2022; 129:108609. [PMID: 35176650 DOI: 10.1016/j.yebeh.2022.108609] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 12/21/2022]
Abstract
Epilepsy, sleep, and Alzheimer's disease (AD) are tightly and potentially causally interconnected. The aim of our review was to investigate current research directions on these relationships. Our hope is that they may indicate preventive measures and new treatment options for early neurodegeneration. We included articles that assessed all three topics and were published during the last ten years. We found that this literature corroborates connections on various pathophysiological levels, including sleep-stage-related epileptiform activity in AD, the negative consequences of different sleep disorders on epilepsy and cognition, common biochemical pathways as well as network dysfunctions. Here we provide a detailed overview of these topics and we discuss promising diagnostic and therapeutic consequences.
Collapse
Affiliation(s)
- Julie M Hanke
- Department of Neurology, Inselspital, Sleep-Wake-Epilepsy-Center, Bern University Hospital, University Bern, Bern, Switzerland
| | - Kaspar A Schindler
- Department of Neurology, Inselspital, Sleep-Wake-Epilepsy-Center, Bern University Hospital, University Bern, Bern, Switzerland
| | - Andrea Seiler
- Department of Neurology, Inselspital, Sleep-Wake-Epilepsy-Center, Bern University Hospital, University Bern, Bern, Switzerland.
| |
Collapse
|
8
|
Yu T, Liu X, Wu J, Wang Q. Electrophysiological Biomarkers of Epileptogenicity in Alzheimer's Disease. Front Hum Neurosci 2021; 15:747077. [PMID: 34916917 PMCID: PMC8669481 DOI: 10.3389/fnhum.2021.747077] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 11/01/2021] [Indexed: 11/13/2022] Open
Abstract
Cortical network hyperexcitability is an inextricable feature of Alzheimer’s disease (AD) that also might accelerate its progression. Seizures are reported in 10–22% of patients with AD, and subclinical epileptiform abnormalities have been identified in 21–42% of patients with AD without seizures. Accurate identification of hyperexcitability and appropriate intervention to slow the compromise of cognitive functions of AD might open up a new approach to treatment. Based on the results of several studies, epileptiform discharges, especially those with specific features (including high frequency, robust morphology, right temporal location, and occurrence during awake or rapid eye movement states), frequent small sharp spikes (SSSs), temporal intermittent rhythmic delta activities (TIRDAs), and paroxysmal slow wave events (PSWEs) recorded in long-term scalp electroencephalogram (EEG) provide sufficient sensitivity and specificity in detecting cortical network hyperexcitability and epileptogenicity of AD. In addition, magnetoencephalogram (MEG), foramen ovale (FO) electrodes, and computational approaches help to find subclinical seizures that are invisible on scalp EEGs. We performed a comprehensive analysis of the aforementioned electrophysiological biomarkers of AD-related seizures.
Collapse
Affiliation(s)
- Tingting Yu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Xiao Liu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China
| | - Jianping Wu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China.,Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, China
| | - Qun Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,China National Clinical Research Center for Neurological Diseases, Beijing, China.,Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China
| |
Collapse
|
9
|
Lam AD, Noebels J. Night Watch on the Titanic: Detecting Early Signs of Epileptogenesis in Alzheimer Disease. Epilepsy Curr 2020; 20:369-374. [PMID: 33081517 PMCID: PMC7818196 DOI: 10.1177/1535759720964775] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Aberrant cortical network excitability is an inextricable feature of Alzheimer disease (AD) that can negatively impact memory and accelerate cognitive decline. Surface electroencephalogram spikes and intracranial recordings of nocturnal silent seizures in human AD, coupled with the abnormal neural synchrony that precedes development of behavioral seizures in mouse AD models, build the case for epileptogenesis as an early therapeutic target for AD. Since most individuals with AD do not develop overt seizures, leveraging functional biomarkers of epilepsy risk to stratify a heterogeneous AD patient population for treatment is research priority for successful clinical trial design. Who will benefit from antiseizure interventions, which one, and when should it begin?
Collapse
Affiliation(s)
- Alice D. Lam
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Jeffrey Noebels
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
10
|
Human brain connectivity: Clinical applications for clinical neurophysiology. Clin Neurophysiol 2020; 131:1621-1651. [DOI: 10.1016/j.clinph.2020.03.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 12/12/2022]
|
11
|
Abstract
Temporal lobe epilepsy (TLE) is the most common type of drug-resistant focal epilepsy. Epilepsy can be conceptualized as a network disorder with the epileptogenic zone a critical node of the network. Temporal lobe networks can be identified on the microscale and macroscale, both during the interictal and ictal periods. This review summarizes the current understanding of TLE networks as studied by neurophysiological and imaging techniques discussing both functional and structural connectivity.
Collapse
|
12
|
Abou Jaoude M, Jing J, Sun H, Jacobs CS, Pellerin KR, Westover MB, Cash SS, Lam AD. Detection of mesial temporal lobe epileptiform discharges on intracranial electrodes using deep learning. Clin Neurophysiol 2020; 131:133-141. [PMID: 31760212 PMCID: PMC6879011 DOI: 10.1016/j.clinph.2019.09.031] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/10/2019] [Accepted: 09/16/2019] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Develop a high-performing algorithm to detect mesial temporal lobe (mTL) epileptiform discharges on intracranial electrode recordings. METHODS An epileptologist annotated 13,959 epileptiform discharges from a dataset of intracranial EEG recordings from 46 epilepsy patients. Using this dataset, we trained a convolutional neural network (CNN) to recognize mTL epileptiform discharges from a single intracranial bipolar channel. The CNN outputs from multiple bipolar channel inputs were averaged to generate the final detector output. Algorithm performance was estimated using a nested 5-fold cross-validation. RESULTS On the receiver-operating characteristic curve, our algorithm achieved an area under the curve (AUC) of 0.996 and a partial AUC (for specificity > 0.9) of 0.981. AUC on a precision-recall curve was 0.807. A sensitivity of 84% was attained at a false positive rate of 1 per minute. 35.9% of the false positive detections corresponded to epileptiform discharges that were missed during expert annotation. CONCLUSIONS Using deep learning, we developed a high-performing, patient non-specific algorithm for detection of mTL epileptiform discharges on intracranial electrodes. SIGNIFICANCE Our algorithm has many potential applications for understanding the impact of mTL epileptiform discharges in epilepsy and on cognition, and for developing therapies to specifically reduce mTL epileptiform activity.
Collapse
Affiliation(s)
- Maurice Abou Jaoude
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Jin Jing
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Haoqi Sun
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Claire S Jacobs
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Kyle R Pellerin
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - M Brandon Westover
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Sydney S Cash
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Alice D Lam
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
13
|
Hofer C, Kwitt R, Höller Y, Trinka E, Uhl A. An empirical assessment of appearance descriptors applied to MRI for automated diagnosis of TLE and MCI. Comput Biol Med 2019; 117:103592. [PMID: 32072961 DOI: 10.1016/j.compbiomed.2019.103592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 12/19/2019] [Accepted: 12/19/2019] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Differential diagnosis of mild cognitive impairment MCI and temporal lobe epilepsy TLE is a debated issue, specifically because these conditions may coincide in the elderly population. We evaluate automated differential diagnosis based on characteristics derived from structural brain MRI of different brain regions. METHODS In 22 healthy controls, 19 patients with MCI, and 17 patients with TLE we used scale invariant feature transform (SIFT), local binary patterns (LBP), and wavelet-based features and investigate their predictive performance for MCI and TLE. RESULTS The classification based on SIFT features resulted in an accuracy of 81% of MCI vs. TLE and reasonable generalizability. Local binary patterns yielded satisfactory diagnostic performance with up to 94.74% sensitivity and 88.24% specificity in the right Thalamus for the distinction of MCI vs. TLE, but with limited generalizable. Wavelet features yielded similar results as LPB with 94.74% sensitivity and 82.35% specificity but generalize better. SIGNIFICANCE Features beyond volume analysis are a valid approach when applied to specific regions of the brain. Most significant information could be extracted from the thalamus, frontal gyri, and temporal regions, among others. These results suggest that analysis of changes of the central nervous system should not be limited to the most typical regions of interest such as the hippocampus and parahippocampal areas. Region-independent approaches can add considerable information for diagnosis. We emphasize the need to characterize generalizability in future studies, as our results demonstrate that not doing so can lead to overestimation of classification results. LIMITATIONS The data used within this study allows for separation of MCI and TLE subjects using a simple age threshold. While we present a strong indication that the presented method is age-invariant and therefore agnostic to this situation, new data would be needed for a rigorous empirical assessment of this findings.
Collapse
Affiliation(s)
- Christoph Hofer
- Department of Computer Science, University of Salzburg, Austria.
| | - Roland Kwitt
- Department of Computer Science, University of Salzburg, Austria.
| | - Yvonne Höller
- Department of Neurology, Christian Doppler Medical Centre, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neuroscience, Paracelsus Medical University, Salzburg, Austria.
| | - Eugen Trinka
- Spinal Cord Injury & Tissue Regeneration Centre Salzburg, Paracelsus Medical University, Salzburg, Austria; Department of Neurology, Christian Doppler Medical Centre, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neuroscience, Paracelsus Medical University, Salzburg, Austria.
| | - Andreas Uhl
- Department of Computer Science, University of Salzburg, Austria.
| |
Collapse
|
14
|
Wang S, Wang ZI, Tang Y, Alexopoulos AV, Chen C, Katagiri M, Aung T, Najm IM, Ding M, Wang S, Chauvel P. Localization value of subclinical seizures on scalp video‐EEG in epilepsy presurgical evaluation. Epilepsia 2019; 60:2477-2485. [PMID: 31755095 DOI: 10.1111/epi.16383] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 10/18/2019] [Accepted: 10/18/2019] [Indexed: 02/05/2023]
Affiliation(s)
- Shan Wang
- Department of Neurology Epilepsy Center Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou China
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Z. Irene Wang
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Yingying Tang
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
- Department of Neurology West China Hospital Sichuan University Chengdu China
| | | | - Cong Chen
- Department of Neurology Epilepsy Center Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou China
| | - Masaya Katagiri
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Thandar Aung
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Imad M. Najm
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| | - Meiping Ding
- Department of Neurology Epilepsy Center Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou China
| | - Shuang Wang
- Department of Neurology Epilepsy Center Second Affiliated Hospital School of Medicine Zhejiang University Hangzhou China
| | - Patrick Chauvel
- Epilepsy Center Neurological Institute Cleveland Clinic Cleveland OH USA
| |
Collapse
|
15
|
Lam AD, Cole AJ, Cash SS. New Approaches to Studying Silent Mesial Temporal Lobe Seizures in Alzheimer's Disease. Front Neurol 2019; 10:959. [PMID: 31551916 PMCID: PMC6737997 DOI: 10.3389/fneur.2019.00959] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 08/20/2019] [Indexed: 12/13/2022] Open
Abstract
Silent seizures were discovered in mouse models of Alzheimer's disease over 10 years ago, yet it remains unclear whether these seizures are a salient feature of Alzheimer's disease in humans. Seizures that arise early in the course of Alzheimer's disease most likely originate from the mesial temporal lobe, one of the first structures affected by Alzheimer's disease pathology and one of the most epileptogenic regions of the brain. Several factors greatly limit our ability to identify mesial temporal lobe seizures in patients with Alzheimer's disease, however. First, mesial temporal lobe seizures can be difficult to recognize clinically, as their accompanying symptoms are often subtle or even non-existent. Second, electrical activity arising from the mesial temporal lobe is largely invisible on the scalp electroencephalogram (EEG), the mainstay of diagnosis for epilepsy in this population. In this review, we will describe two new approaches being used to study silent mesial temporal lobe seizures in Alzheimer's disease. We will first describe the methodology and application of foramen ovale electrodes, which captured the first recordings of silent mesial temporal lobe seizures in humans with Alzheimer's disease. We will then describe machine learning approaches being developed to non-invasively identify silent mesial temporal lobe seizures on scalp EEG. Both of these tools have the potential to elucidate the role of silent seizures in humans with Alzheimer's disease, which could have important implications for early diagnosis, prognostication, and development of targeted therapies for this population.
Collapse
Affiliation(s)
- Alice D. Lam
- Massachusetts General Hospital, Department of Neurology, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Andrew J. Cole
- Massachusetts General Hospital, Department of Neurology, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Sydney S. Cash
- Massachusetts General Hospital, Department of Neurology, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| |
Collapse
|
16
|
Driver J, DiRisio AC, Mitchell H, Threlkeld ZD, Gormley WB. Non-electrographic Seizures Due to Subdural Hematoma: A Case Series and Review of the Literature. Neurocrit Care 2019; 30:16-21. [PMID: 29476391 DOI: 10.1007/s12028-018-0503-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Seizures due to subdural hematoma (SDH) are a common finding, typically diagnosed using electroencephalography (EEG). At times, aggressive management of seizures is necessary to improve neurologic recovery and outcomes. Here, we present three patients who had undergone emergent SDH evacuation and showed postoperative focal deficits without accompanying electrographic epileptiform activity. After infarction and recurrent hemorrhage were ruled out, seizures were suspected despite a negative EEG. Patients were treated aggressively with AEDs and eventually showed clinical improvement. Long-term monitoring with EEG revealed electrographic seizures in a delayed fashion. EEG recordings are an important tool for seizure detection, but should be used as an adjunct to, rather than a replacement for, the clinical examination in the acute setting. At times, aggressive treatment of suspected postoperative seizures is warranted despite lack of corresponding electrographic activity and can improve clinical outcomes.
Collapse
Affiliation(s)
- Joseph Driver
- Department of Neurosurgery, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
| | - Aislyn C DiRisio
- Department of Neurosurgery, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA
| | - Heidi Mitchell
- Massachusetts General Hospital Institute of Health Professions, Boston, MA, USA
| | - Zachary D Threlkeld
- Department of Neurology, Massachusetts General Hospital and Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - William B Gormley
- Department of Neurosurgery, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA.
| |
Collapse
|
17
|
Emami A, Kunii N, Matsuo T, Shinozaki T, Kawai K, Takahashi H. Seizure detection by convolutional neural network-based analysis of scalp electroencephalography plot images. NEUROIMAGE-CLINICAL 2019; 22:101684. [PMID: 30711680 PMCID: PMC6357853 DOI: 10.1016/j.nicl.2019.101684] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 01/10/2019] [Accepted: 01/20/2019] [Indexed: 12/21/2022]
Abstract
We hypothesized that expert epileptologists can detect seizures directly by visually analyzing EEG plot images, unlike automated methods that analyze spectro-temporal features or complex, non-stationary features of EEG signals. If so, seizure detection could benefit from convolutional neural networks because their visual recognition ability is comparable to that of humans. We explored image-based seizure detection by applying convolutional neural networks to long-term EEG that included epileptic seizures. After filtering, EEG data were divided into short segments based on a given time window and converted into plot EEG images, each of which was classified by convolutional neural networks as ‘seizure’ or ‘non-seizure’. These resultant labels were then used to design a clinically practical index for seizure detection. The best true positive rate was obtained using a 1-s time window. The median true positive rate of convolutional neural networks labelling by seconds was 74%, which was higher than that of commercially available seizure detection software (20% by BESA and 31% by Persyst). For practical use, the median of detected seizure rate by minutes was 100% by convolutional neural networks, which was higher than the 73.3% by BESA and 81.7% by Persyst. The false alarm of convolutional neural networks' seizure detection was issued at 0.2 per hour, which appears acceptable for clinical practice. Moreover, we demonstrated that seizure detection improved when training was performed using EEG patterns similar to those of testing data, suggesting that adding a variety of seizure patterns to the training dataset will improve our method. Thus, artificial visual recognition by convolutional neural networks allows for seizure detection, which otherwise currently relies on skillful visual inspection by expert epileptologists during clinical diagnosis. Artificial visual recognition of scalp EEG plot images successfully detects seizures. CNN-based automatic detection performed better than commercial software. Customized CNN learning using large datasets improves detection.
Collapse
Affiliation(s)
- Ali Emami
- Research Center for Advanced Science and Technology, The University of Tokyo, Japan
| | - Naoto Kunii
- Department of Neurosurgery, Graduate School of Medicine, The University of Tokyo, Japan
| | | | - Takashi Shinozaki
- CiNet, National Institute of Information and Communications Technology, Japan
| | - Kensuke Kawai
- Department of Neurosurgery, Jichi Medical University, Japan.
| | - Hirokazu Takahashi
- Research Center for Advanced Science and Technology, The University of Tokyo, Japan.
| |
Collapse
|
18
|
Fan X, Gaspard N, Legros B, Lucchetti F, Ercek R, Nonclercq A. Seizure evolution can be characterized as path through synaptic gain space of a neural mass model. Eur J Neurosci 2018; 48:3097-3112. [PMID: 30194874 DOI: 10.1111/ejn.14142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 08/08/2018] [Accepted: 08/29/2018] [Indexed: 11/30/2022]
Abstract
Physiologically based models could facilitate better understanding of mechanisms underlying epileptic seizures. In this paper, we attempt to reveal the dynamic evolution of intracranial EEG activity during epileptic seizures based on synaptic gain identification procedure of a neural mass model. The distribution of average excitatory, slow and fast inhibitory synaptic gain in the parameter space and their temporal evolution, i.e., the path through the model parameter space, were analyzed in thirty seizures from ten temporal lobe epileptic patients. Results showed that the synaptic gain values located roughly on a plane before seizure onset, dispersed during seizure and returned to the plane when seizure terminated. Cluster analysis was performed on seizure paths and demonstrated consistency in synaptic gain evolution across different seizures from the individual patient. Furthermore, two patient groups were identified, each one corresponding to a specific synaptic gain evolution in the parameter space during a seizure. Results were validated by a bootstrapping approach based on comparison with random paths. The differences in the path revealed variations in EEG dynamics for patients despite showing identical seizure onset pattern. Our approach may have the potential to classify the epileptic patients into subgroups based on different mechanisms revealed by subtle changes in synaptic gains and further enable more robust decisions regarding treatment strategy.
Collapse
Affiliation(s)
- Xiaoya Fan
- Bio, Electro And Mechanical Systems (BEAMS), Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Nicolas Gaspard
- Department of Neurology, Hôpital Erasme, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Benjamin Legros
- Department of Neurology, Hôpital Erasme, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Federico Lucchetti
- Bio, Electro And Mechanical Systems (BEAMS), Université Libre de Bruxelles (ULB), Brussels, Belgium.,Laboratoire de Neurophysiologie Sensorielle et Cognitive, Hôpital Brugmann, Brussels, Belgium
| | - Rudy Ercek
- Laboratories of Image, Signal Processing and Acoustics (LISA), Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Antoine Nonclercq
- Bio, Electro And Mechanical Systems (BEAMS), Université Libre de Bruxelles (ULB), Brussels, Belgium
| |
Collapse
|
19
|
Naftulin JS, Ahmed OJ, Piantoni G, Eichenlaub JB, Martinet LE, Kramer MA, Cash SS. Ictal and preictal power changes outside of the seizure focus correlate with seizure generalization. Epilepsia 2018; 59:1398-1409. [PMID: 29897628 DOI: 10.1111/epi.14449] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The treatment of focal epilepsies is largely predicated on the concept that there is a "focus" from which the seizure emanates. Yet, the physiological context that determines if and how ictal activity starts and propagates remains poorly understood. To delineate these phenomena more completely, we studied activity outside the seizure-onset zone prior to and during seizure initiation. METHODS Stereotactic depth electrodes were implanted in 17 patients with longstanding pharmacoresistant epilepsy for lateralization and localization of the seizure-onset zone. Only seizures with focal onset in mesial temporal structures were used for analysis. Spectral analyses were used to quantify changes in delta, theta, alpha, beta, gamma, and high gamma frequency power, in regions inside and outside the area of seizure onset during both preictal and seizure initiation periods. RESULTS In the 78 seizures examined, an average of 9.26% of the electrode contacts outside of the seizure focus demonstrated changes in power at seizure onset. Of interest, seizures that were secondarily generalized, on average, showed power changes in a greater number of extrafocus electrode contacts at seizure onset (16.7%) compared to seizures that remained focal (3.8%). The majority of these extrafocus changes occupied the delta and theta bands in electrodes placed in the ipsilateral, lateral temporal lobe. Preictally, we observed extrafocal high-frequency power decrements, which also correlated with seizure spread. SIGNIFICANCE This widespread activity at and prior to the seizure-onset time further extends the notion of the ictogenic focus and its relationship to seizure spread. Further understanding of these extrafocus, periictal changes might help identify the neuronal dynamics underlying the initiation of seizures and how therapies can be devised to control seizure activity.
Collapse
Affiliation(s)
- Jason S Naftulin
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Omar J Ahmed
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Giovanni Piantoni
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Jean-Baptiste Eichenlaub
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | | | - Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, MA, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| |
Collapse
|
20
|
Lam AD, Maus D, Zafar SF, Cole AJ, Cash SS. SCOPE-mTL: A non-invasive tool for identifying and lateralizing mesial temporal lobe seizures prior to scalp EEG ictal onset. Clin Neurophysiol 2017; 128:1647-1655. [PMID: 28732342 DOI: 10.1016/j.clinph.2017.06.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/01/2017] [Accepted: 06/14/2017] [Indexed: 10/19/2022]
Abstract
OBJECTIVE In mesial temporal lobe (mTL) epilepsy, seizure onset can precede the appearance of a scalp EEG ictal pattern by many seconds. The ability to identify this early, occult mTL seizure activity could improve lateralization and localization of mTL seizures on scalp EEG. METHODS Using scalp EEG spectral features and machine learning approaches on a dataset of combined scalp EEG and foramen ovale electrode recordings in patients with mTL epilepsy, we developed an algorithm, SCOPE-mTL, to detect and lateralize early, occult mTL seizure activity, prior to the appearance of a scalp EEG ictal pattern. RESULTS Using SCOPE-mTL, 73% of seizures with occult mTL onset were identified as such, and no seizures that lacked an occult mTL onset were identified as having one. Predicted mTL seizure onset times were highly correlated with actual mTL seizure onset times (r=0.69). 50% of seizures with early mTL onset were lateralizable prior to scalp ictal onset, with 94% accuracy. CONCLUSIONS SCOPE-mTL can identify and lateralize mTL seizures prior to scalp EEG ictal onset, with high sensitivity, specificity, and accuracy. SIGNIFICANCE Quantitative analysis of scalp EEG can provide important information about mTL seizures, even in the absence of a visible scalp EEG ictal correlate.
Collapse
Affiliation(s)
- Alice D Lam
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Douglas Maus
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Sahar F Zafar
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Andrew J Cole
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Sydney S Cash
- Epilepsy Division, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| |
Collapse
|
21
|
Twele F, Schidlitzki A, Töllner K, Löscher W. The intrahippocampal kainate mouse model of mesial temporal lobe epilepsy: Lack of electrographic seizure-like events in sham controls. Epilepsia Open 2017; 2:180-187. [PMID: 29588947 PMCID: PMC5719860 DOI: 10.1002/epi4.12044] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2017] [Indexed: 12/13/2022] Open
Abstract
Objective There is an ongoing debate about definition of seizures in experimental models of acquired epilepsy and how important adequate sham controls are in this respect. For instance, several mouse and rat strains exhibit high-voltage rhythmic spike or spike-wave discharges in the cortical electroencephalogram (EEG), which has to be considered when using such strains for induction of epilepsy by status epilepticus, traumatic brain injury, or other means. Mice developing spontaneous recurrent nonconvulsive and convulsive seizures after intrahippocampal injection of kainate are increasingly being used as a model of mesial temporal lobe epilepsy. We performed a prospective study in which EEG alterations occurring in this model were compared with the EEGs in appropriate sham controls, using hippocampal electrodes and video-EEG monitoring. Methods Experiments with intrahippocampal kainate (or saline) injections started when mice were about 8 weeks of age. Continuous video-EEG recording via hippocampal electrodes was performed 6 weeks after surgery in kainate-injected mice and sham controls, that is, at an age of about 14 weeks. Three days of continuous video-EEG monitoring were compared between kainate-injected mice and experimental controls. Results As reported previously, kainate-injected mice exhibited two types of highly frequent electrographic seizures: high-voltage sharp waves, which were often monomorphic, and polymorphic hippocampal paroxysmal discharges. In addition, generalized convulsive clinical seizures were infrequently observed. None of these electrographic or electroclinical seizures were observed in sham controls. The only infrequently observed EEG abnormalities in sham controls were isolated spikes or spike clusters, which were also recorded in epileptic mice. Significance This study rigorously demonstrates, by explicit comparison with the EEGs of sham controls, that the nonconvulsive paroxysmal events observed in this model are consequences of the induced epilepsy and not features of the EEG expected to be seen in some experimental control mice or unintentionally induced by surgical procedures.
Collapse
Affiliation(s)
- Friederike Twele
- Department of Pharmacology, Toxicology, and PharmacyUniversity of Veterinary MedicineHanoverGermany.,Center for Systems Neuroscience Hanover Germany
| | - Alina Schidlitzki
- Department of Pharmacology, Toxicology, and PharmacyUniversity of Veterinary MedicineHanoverGermany.,Center for Systems Neuroscience Hanover Germany
| | - Kathrin Töllner
- Department of Pharmacology, Toxicology, and PharmacyUniversity of Veterinary MedicineHanoverGermany.,Center for Systems Neuroscience Hanover Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and PharmacyUniversity of Veterinary MedicineHanoverGermany.,Center for Systems Neuroscience Hanover Germany
| |
Collapse
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
Vossel KA, Ranasinghe KG, Beagle AJ, Mizuiri D, Honma SM, Dowling AF, Darwish SM, Van Berlo V, Barnes DE, Mantle M, Karydas AM, Coppola G, Roberson ED, Miller BL, Garcia PA, Kirsch HE, Mucke L, Nagarajan SS. Incidence and impact of subclinical epileptiform activity in Alzheimer's disease. Ann Neurol 2016; 80:858-870. [PMID: 27696483 DOI: 10.1002/ana.24794] [Citation(s) in RCA: 339] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 09/26/2016] [Accepted: 09/27/2016] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Seizures are more frequent in patients with Alzheimer's disease (AD) and can hasten cognitive decline. However, the incidence of subclinical epileptiform activity in AD and its consequences are unknown. Motivated by results from animal studies, we hypothesized higher than expected rates of subclinical epileptiform activity in AD with deleterious effects on cognition. METHODS We prospectively enrolled 33 patients (mean age, 62 years) who met criteria for AD, but had no history of seizures, and 19 age-matched, cognitively normal controls. Subclinical epileptiform activity was assessed, blinded to diagnosis, by overnight long-term video-electroencephalography (EEG) and a 1-hour resting magnetoencephalography exam with simultaneous EEG. Patients also had comprehensive clinical and cognitive evaluations, assessed longitudinally over an average period of 3.3 years. RESULTS Subclinical epileptiform activity was detected in 42.4% of AD patients and 10.5% of controls (p = 0.02). At the time of monitoring, AD patients with epileptiform activity did not differ clinically from those without such activity. However, patients with subclinical epileptiform activity showed faster declines in global cognition, determined by the Mini-Mental State Examination (3.9 points/year in patients with epileptiform activity vs 1.6 points/year in patients without; p = 0.006), and in executive function (p = 0.01). INTERPRETATION Extended monitoring detects subclinical epileptiform activity in a substantial proportion of patients with AD. Patients with this indicator of network hyperexcitability are at risk for accelerated cognitive decline and might benefit from antiepileptic therapies. These data call for more sensitive and comprehensive neurophysiological assessments in AD patient evaluations and impending clinical trials. Ann Neurol 2016;80:858-870.
Collapse
Affiliation(s)
- Keith A Vossel
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
- Gladstone Institute of Neurological Disease, San Francisco, CA
| | - Kamalini G Ranasinghe
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Alexander J Beagle
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Danielle Mizuiri
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Susanne M Honma
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Anne F Dowling
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Sonja M Darwish
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Victoria Van Berlo
- Department of Neurology and Semel Institute for Neuroscience and Human Behavior in the Department of Psychiatry, University of California Los Angeles, Los Angeles, CA
| | - Deborah E Barnes
- Departments of Psychiatry and Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA
- Veterans Affairs Medical Center, San Francisco, CA
| | - Mary Mantle
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
- Epilepsy Center, Department of Neurology, University of California San Francisco, San Francisco, CA
| | - Anna M Karydas
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Giovanni Coppola
- Department of Neurology and Semel Institute for Neuroscience and Human Behavior in the Department of Psychiatry, University of California Los Angeles, Los Angeles, CA
| | - Erik D Roberson
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL
| | - Bruce L Miller
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
| | - Paul A Garcia
- Epilepsy Center, Department of Neurology, University of California San Francisco, San Francisco, CA
| | - Heidi E Kirsch
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
- Epilepsy Center, Department of Neurology, University of California San Francisco, San Francisco, CA
| | - Lennart Mucke
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA
- Gladstone Institute of Neurological Disease, San Francisco, CA
| | - Srikantan S Nagarajan
- Biomagnetic Imaging Laboratory, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| |
Collapse
|
24
|
Fyfe I. Noninvasive detection of deep brain seizures. Nat Rev Neurol 2016; 12:492-3. [DOI: 10.1038/nrneurol.2016.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|