1
|
Li Z, Zhao B, Hu W, Zhang C, Wang X, Liu C, Mo J, Guo Z, Yang B, Yao Y, Shao X, Zhang J, Zhang K. Practical measurements distinguishing physiological and pathological stereoelectroencephalography channels based on high-frequency oscillations in the human brain. Epilepsia Open 2024. [PMID: 38808652 DOI: 10.1002/epi4.12950] [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: 08/30/2023] [Revised: 04/07/2024] [Accepted: 04/11/2024] [Indexed: 05/30/2024] Open
Abstract
OBJECTIVE The present study aimed to identify various distinguishing features for use in the accurate classification of stereoelectroencephalography (SEEG) channels based on high-frequency oscillations (HFOs) inside and outside the epileptogenic zone (EZ). METHODS HFOs were detected in patients with focal epilepsy who underwent SEEG. Subsequently, HFOs within the seizure-onset and early spread zones were defined as pathological HFOs, whereas others were defined as physiological. Three features of HFOs were identified at the channel level, namely, morphological repetition, rhythmicity, and phase-amplitude coupling (PAC). A machine-learning (ML) classifier was then built to distinguish two HFO types at the channel level by application of the above-mentioned features, and the contributions were quantified. Further verification of the characteristics and classifier performance was performed in relation to various conscious states, imaging results, EZ location, and surgical outcomes. RESULTS Thirty-five patients were included in this study, from whom 166 104 pathological HFOs in 255 channels and 53 374 physiological HFOs in 282 channels were entered into the analysis pipeline. The results revealed that the morphological repetitions of pathological HFOs were markedly higher than those of the physiological HFOs; this was also observed for rhythmicity and PAC. The classifier exhibited high accuracy in differentiating between the two forms of HFOs, as indicated by an area under the curve (AUC) of 0.89. Both PAC and rhythmicity contributed significantly to this distinction. The subgroup analyses supported these findings. SIGNIFICANCE The suggested HFO features can accurately distinguish between pathological and physiological channels substantially improving its usefulness in clinical localization. PLAIN LANGUAGE SUMMARY In this study, we computed three quantitative features associated with HFOs in each SEEG channel and then constructed a machine learning-based classifier for the classification of pathological and physiological channels. The classifier performed well in distinguishing the two channel types under different levels of consciousness as well as in terms of imaging results, EZ location, and patient surgical outcomes.
Collapse
Affiliation(s)
- Zilin Li
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Baotian Zhao
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Wenhan Hu
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- Stereotactic and Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Neurostimulation, Beijing, China
| | - Chao Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xiu Wang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Chang Liu
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jiajie Mo
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Zhihao Guo
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Bowen Yang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yuan Yao
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xiaoqiu Shao
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jianguo Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- Stereotactic and Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Neurostimulation, Beijing, China
| | - Kai Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- Stereotactic and Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Neurostimulation, Beijing, China
| |
Collapse
|
2
|
Cai Z, Jiang X, Bagić A, Worrell GA, Richardson M, He B. Spontaneous HFO Sequences Reveal Propagation Pathways for Precise Delineation of Epileptogenic Networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.02.592202. [PMID: 38746136 PMCID: PMC11092614 DOI: 10.1101/2024.05.02.592202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Epilepsy, a neurological disorder affecting millions worldwide, poses great challenges in precisely delineating the epileptogenic zone - the brain region generating seizures - for effective treatment. High-frequency oscillations (HFOs) are emerging as promising biomarkers; however, the clinical utility is hindered by the difficulties in distinguishing pathological HFOs from non- epileptiform activities at single electrode and single patient resolution and understanding their dynamic role in epileptic networks. Here, we introduce an HFO-sequencing approach to analyze spontaneous HFOs traversing cortical regions in 40 drug-resistant epilepsy patients. This data- driven method automatically detected over 8.9 million HFOs, pinpointing pathological HFO- networks, and unveiled intricate millisecond-scale spatiotemporal dynamics, stability, and functional connectivity of HFOs in prolonged intracranial EEG recordings. These HFO sequences demonstrated a significant improvement in localization of epileptic tissue, with an 818.47% increase in concordance with seizure-onset zone (mean error: 2.92 mm), compared to conventional benchmarks. They also accurately predicted seizure outcomes for 90% AUC based on pre-surgical information using generalized linear models. Importantly, this mapping remained reliable even with short recordings (mean standard deviation: 3.23 mm for 30-minute segments). Furthermore, HFO sequences exhibited distinct yet highly repetitive spatiotemporal patterns, characterized by pronounced synchrony and predominant inward information flow from periphery towards areas involved in propagation, suggesting a crucial role for excitation-inhibition balance in HFO initiation and progression. Together, these findings shed light on the intricate organization of epileptic network and highlight the potential of HFO-sequencing as a translational tool for improved diagnosis, surgical targeting, and ultimately, better outcomes for vulnerable patients with drug-resistant epilepsy. One Sentence Summary Pathological fast brain oscillations travel like traffic along varied routes, outlining recurrently visited neural sites emerging as critical hotspots in epilepsy network.
Collapse
|
3
|
Wendling F, Koksal-Ersoz E, Al-Harrach M, Yochum M, Merlet I, Ruffini G, Bartolomei F, Benquet P. Multiscale neuro-inspired models for interpretation of EEG signals in patients with epilepsy. Clin Neurophysiol 2024; 161:198-210. [PMID: 38520800 DOI: 10.1016/j.clinph.2024.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 03/06/2024] [Accepted: 03/11/2024] [Indexed: 03/25/2024]
Abstract
OBJECTIVE The aim is to gain insight into the pathophysiological mechanisms underlying interictal epileptiform discharges observed in electroencephalographic (EEG) and stereo-EEG (SEEG, depth electrodes) recordings performed during pre-surgical evaluation of patients with drug-resistant epilepsy. METHODS We developed novel neuro-inspired computational models of the human cerebral cortex at three different levels of description: i) microscale (detailed neuron models), ii) mesoscale (neuronal mass models) and iii) macroscale (whole brain models). Although conceptually different, micro- and mesoscale models share some similar features, such as the typology of neurons (pyramidal cells and three types of interneurons), their spatial arrangement in cortical layers, and their synaptic connectivity (excitatory and inhibitory). The whole brain model consists of a large-scale network of interconnected neuronal masses, with connectivity based on the human connectome. RESULTS For these three levels of description, the fine-tuning of free parameters and the quantitative comparison with real data allowed us to reproduce interictal epileptiform discharges with a high degree of fidelity and to formulate hypotheses about the cell- and network-related mechanisms underlying the generation of fast ripples and SEEG-recorded epileptic spikes and spike-waves. CONCLUSIONS The proposed models provide valuable insights into the pathophysiological mechanisms underlying the generation of epileptic events. The knowledge gained from these models effectively complements the clinical analysis of SEEG data collected during the evaluation of patients with epilepsy. SIGNIFICANCE These models are likely to play a key role in the mechanistic interpretation of epileptiform activity.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Fabrice Bartolomei
- APHM, Timone Hospital, Epileptology and Cerebral Rhythmology Department, Marseille, France; Univ Aix Marseille, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | | |
Collapse
|
4
|
Ye H, Chen C, Weiss SA, Wang S. Pathological and Physiological High-frequency Oscillations on Electroencephalography in Patients with Epilepsy. Neurosci Bull 2024; 40:609-620. [PMID: 37999861 PMCID: PMC11127900 DOI: 10.1007/s12264-023-01150-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 09/28/2023] [Indexed: 11/25/2023] Open
Abstract
High-frequency oscillations (HFOs) encompass ripples (80 Hz-200 Hz) and fast ripples (200 Hz-600 Hz), serving as a promising biomarker for localizing the epileptogenic zone in epilepsy. Spontaneous fast ripples are always pathological, while ripples may be physiological or pathological. Distinguishing physiological from pathological ripples is important not only for designating epileptogenic brain regions, but also for investigations that study ripples in the context of memory encoding, consolidation, and recall in patients with epilepsy. Many studies have sought to identify distinguishing features between pathological and physiological ripples over the past two decades. Physiological and pathological ripples differ with respect to their spatial location, cellular mechanisms, morphology, and coupling with background electroencephalographic activity. Retrospective studies have demonstrated that differentiating between pathological and physiological ripples can improve surgical outcome prediction. In this review, we summarize the characteristics, differences, and applications of pathological and physiological HFOs and discuss strategies for their clinical translation.
Collapse
Affiliation(s)
- Hongyi Ye
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Cong Chen
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Shennan A Weiss
- Department of Neurology, State University of New York Downstate, Brooklyn, NY, 11203, USA
- Department of Physiology and Pharmacology, State University of New York Downstate, Brooklyn, NY, 11203, USA
- Department of Neurology, New York City Health + Hospitals/Kings County, Brooklyn, NY, 11203, USA
| | - Shuang Wang
- Department of Neurology, Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China.
| |
Collapse
|
5
|
Kalogeropoulos K, Psarropoulou C. Immature Status Epilepticus Alters the Temporal Relationship between Hippocampal Interictal Epileptiform Discharges and High-frequency Oscillations. Neuroscience 2024; 543:108-120. [PMID: 38401712 DOI: 10.1016/j.neuroscience.2024.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
The aim was to investigate the long-term effects of a single episode of immature Status Epilepticus (SE) on the excitability of the septal and temporal hippocampus in vitro, by studying the relationship between interictal-like epileptiform discharges (IEDs) and high-frequency oscillations (HFOs; Ripples, Rs and Fast Ripples, FRs). A pentylenetetrazol-induced Status Epilepticus-(SE)-like generalized seizure was induced at postnatal day 20 in 22 male and female juvenile rats, sacrificed >40 days later to prepare hippocampal slices. Spontaneous IEDs induced by Mg2+-free ACSF were recorded from the CA3 area of temporal (T) or septal (S) slices. Recordings were band-pass filtered off-line revealing Rs and FRs and a series of measurements were conducted, with mean values compared with those obtained from age-matched controls (CTRs). In CTR S (vs T) slices, we recorded longer R & FR durations, a longer HFO-IED temporal overlap, higher FR peak power and more frequent FR initiation preceding IEDs (% events). Post-SE, in T slices all types of events duration (IED, R, FR) and the time lag between their onsets (R-IED, FR-IED, R-FR) increased, while FR/R peak power decreased; in S slices, the IED 1st population spike and the FR amplitudes, the R and FR peak power and the (percent) events where Rs or FRs preceded IEDs all decreased. The CA3 IED-HFO relationship offers insights to the septal-to-temporal synchronization patterns; its post-juvenile-SE changes indicate permanent modifications in the septotemporal excitability gradient. Moreover, these findings are in line to region-specific regulation of various currents post-SE, as reported in literature.
Collapse
Affiliation(s)
- Konstantinos Kalogeropoulos
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health Sciences, University of Ioannina, 45110, Greece.
| | - Caterina Psarropoulou
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health Sciences, University of Ioannina, 45110, Greece.
| |
Collapse
|
6
|
Přibylová L, Ševčík J, Eclerová V, Klimeš P, Brázdil M, Meijer HGE. Weak coupling of neurons enables very high-frequency and ultra-fast oscillations through the interplay of synchronized phase shifts. Netw Neurosci 2024; 8:293-318. [PMID: 38562290 PMCID: PMC10954350 DOI: 10.1162/netn_a_00351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/21/2023] [Indexed: 04/04/2024] Open
Abstract
Recently, in the past decade, high-frequency oscillations (HFOs), very high-frequency oscillations (VHFOs), and ultra-fast oscillations (UFOs) were reported in epileptic patients with drug-resistant epilepsy. However, to this day, the physiological origin of these events has yet to be understood. Our study establishes a mathematical framework based on bifurcation theory for investigating the occurrence of VHFOs and UFOs in depth EEG signals of patients with focal epilepsy, focusing on the potential role of reduced connection strength between neurons in an epileptic focus. We demonstrate that synchronization of a weakly coupled network can generate very and ultra high-frequency signals detectable by nearby microelectrodes. In particular, we show that a bistability region enables the persistence of phase-shift synchronized clusters of neurons. This phenomenon is observed for different hippocampal neuron models, including Morris-Lecar, Destexhe-Paré, and an interneuron model. The mechanism seems to be robust for small coupling, and it also persists with random noise affecting the external current. Our findings suggest that weakened neuronal connections could contribute to the production of oscillations with frequencies above 1000 Hz, which could advance our understanding of epilepsy pathology and potentially improve treatment strategies. However, further exploration of various coupling types and complex network models is needed.
Collapse
Affiliation(s)
- Lenka Přibylová
- Department of Mathematics and Statistics, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Jan Ševčík
- Department of Mathematics and Statistics, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Veronika Eclerová
- Department of Mathematics and Statistics, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Petr Klimeš
- Institute of Scientific Instruments, The Czech Academy of Sciences, Brno, Czech Republic
| | - Milan Brázdil
- Brno Epilepsy Center, Dept. of Neurology, St. Anne’s Univ. Hospital and Faculty of Medicine, Masaryk University, Brno, Czech Republic, member of the ERN EpiCARE
- Behavioral and Social Neuroscience Research Group, Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Hil G. E. Meijer
- Department of Applied Mathematics, Techmed Centre, University of Twente, Enschede, The Netherlands
| |
Collapse
|
7
|
Szalárdy O, Simor P, Ujma PP, Jordán Z, Halász L, Erőss L, Fabó D, Bódizs R. Temporal association between sleep spindles and ripples in the human anterior and mediodorsal thalamus. Eur J Neurosci 2024; 59:641-661. [PMID: 38221670 DOI: 10.1111/ejn.16240] [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: 05/30/2022] [Revised: 12/01/2023] [Accepted: 12/08/2023] [Indexed: 01/16/2024]
Abstract
Sleep spindles are major oscillatory components of Non-Rapid Eye Movement (NREM) sleep, reflecting hyperpolarization-rebound sequences of thalamocortical neurons. Reports suggest a link between sleep spindles and several forms of high-frequency oscillations which are considered as expressions of pathological off-line neural plasticity in the central nervous system. Here we investigated the relationship between thalamic sleep spindles and ripples in the anterior and mediodorsal nuclei (ANT and MD) of epilepsy patients. Whole-night LFP from the ANT and MD were co-registered with scalp EEG/polysomnography by using externalized leads in 15 epilepsy patients undergoing a Deep Brain Stimulation protocol. Slow (~12 Hz) and fast (~14 Hz) sleep spindles were present in the human ANT and MD and roughly, 20% of them were associated with ripples. Ripple-associated thalamic sleep spindles were characterized by longer duration and exceeded pure spindles in terms of spindle power as indicated by time-frequency analysis. Furthermore, ripple amplitude was modulated by the phase of sleep spindles within both thalamic nuclei. No signs of pathological processes were correlated with measures of ripple and spindle association, furthermore, the density of ripple-associated sleep spindles in the ANT showed a positive correlation with verbal comprehension. Our findings indicate the involvement of the human thalamus in coalescent spindle-ripple oscillations of NREM sleep.
Collapse
Affiliation(s)
- Orsolya Szalárdy
- Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary
- Institute of Cognitive Neuroscience and Psychology, Budapest, Hungary
| | - Péter Simor
- Institute of Psychology, ELTE, Eötvös Loránd University, Budapest, Hungary
- UR2NF, Neuropsychology and Functional Neuroimaging Research Unit at CRCN, Center for Research in Cognition and Neurosciences and UNI-ULB Neurosciences Institute, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Zsófia Jordán
- National Institute of Mental Health, Neurology and Neurosurgery, Budapest, Hungary
| | - László Halász
- National Institute of Mental Health, Neurology and Neurosurgery, Budapest, Hungary
| | - Loránd Erőss
- National Institute of Mental Health, Neurology and Neurosurgery, Budapest, Hungary
| | - Dániel Fabó
- National Institute of Mental Health, Neurology and Neurosurgery, Budapest, Hungary
| | - Róbert Bódizs
- Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary
| |
Collapse
|
8
|
Guo F, Li A, Liu Q, Guo D, Chen K, Yao D, Cui Y, Xia Y. Disruption of TLE epileptiform activity retarded the seizure and reduced pathological HFOs. Brain Res Bull 2024; 207:110869. [PMID: 38184151 DOI: 10.1016/j.brainresbull.2024.110869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/17/2023] [Accepted: 01/01/2024] [Indexed: 01/08/2024]
Abstract
In temporal lobe epilepsy (TLE), the epileptogenic zones, such as the temporal lobe structure, could generate pathological high-frequency oscillations (pHFOs, 250-500 Hz) before the ictal period. These pHFOs have also been observed during the process of seizures in both TLE patients and animals, exhibiting a critical role as promising biomarkers for TLE seizures. TLE seizures could be modulated via regulating the neural excitability in epileptogenic zones, for that TLE is primarily associated with the excitation-inhibition imbalance. However, whether these kinds of modulations could also impact the pHFOs characteristics during TLE seizures is still unclear. For this purpose, we pharmaco-genetically inhibited the principal cells (PCs) in the mouse CA3 region and tracked the difference in the behavioral and electrophysiological features during LiCl-pilocarpine-induced TLE seizure between the hM4Di+CNO (experimental) mice and mCherry+CNO (control) mice. Delayed latency, decreased averaged duration, and reduced counts of the generalized seizure were observed in the experimental mice. Besides, the electrophysiological characteristics, such as the firing rate of PCs and the count of pHFO, exhibited significant decline in the CA3 and CA1 regions. During TLE seizure, there existed strong phase-coupling between pHFO and PCs spike timing in the control mice, while it was abolished in the experimental mice. In addition, we also found that the counts of pHFO were significantly associated with the behavioral features, indicating the close relationships within them. Collectively, our findings suggested that alterations in pHFO and the retardation of seizures may be attributed to disruptions in neuronal excitability, and the variations of electrophysiological features were related to seizure severity during TLE seizures. These results provide valuable insights into the role of pHFOs in TLE and shed light on the underlying mechanisms involved.
Collapse
Affiliation(s)
- Fengru Guo
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Airui Li
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Qinjun Liu
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Daqing Guo
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Ke Chen
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Dezhong Yao
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yan Cui
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China.
| | - Yang Xia
- Department of Neurosurgery, Sichuan Provincial People's Hospital, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu 611731, China.
| |
Collapse
|
9
|
Chvojka J, Prochazkova N, Rehorova M, Kudlacek J, Kylarova S, Kralikova M, Buran P, Weissova R, Balastik M, Jefferys JGR, Novak O, Jiruska P. Mouse model of focal cortical dysplasia type II generates a wide spectrum of high-frequency activities. Neurobiol Dis 2024; 190:106383. [PMID: 38114051 DOI: 10.1016/j.nbd.2023.106383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/04/2023] [Accepted: 12/13/2023] [Indexed: 12/21/2023] Open
Abstract
High-frequency oscillations (HFOs) represent an electrographic biomarker of endogenous epileptogenicity and seizure-generating tissue that proved clinically useful in presurgical planning and delineating the resection area. In the neocortex, the clinical observations on HFOs are not sufficiently supported by experimental studies stemming from a lack of realistic neocortical epilepsy models that could provide an explanation of the pathophysiological substrates of neocortical HFOs. In this study, we explored pathological epileptiform network phenomena, particularly HFOs, in a highly realistic murine model of neocortical epilepsy due to focal cortical dysplasia (FCD) type II. FCD was induced in mice by the expression of the human pathogenic mTOR gene mutation during embryonic stages of brain development. Electrographic recordings from multiple cortical regions in freely moving animals with FCD and epilepsy demonstrated that the FCD lesion generates HFOs from all frequency ranges, i.e., gamma, ripples, and fast ripples up to 800 Hz. Gamma-ripples were recorded almost exclusively in FCD animals, while fast ripples occurred in controls as well, although at a lower rate. Gamma-ripple activity is particularly valuable for localizing the FCD lesion, surpassing the utility of fast ripples that were also observed in control animals, although at significantly lower rates. Propagating HFOs occurred outside the FCD, and the contralateral cortex also generated HFOs independently of the FCD, pointing to a wider FCD network dysfunction. Optogenetic activation of neurons carrying mTOR mutation and expressing Channelrhodopsin-2 evoked fast ripple oscillations that displayed spectral and morphological profiles analogous to spontaneous oscillations. This study brings experimental evidence that FCD type II generates pathological HFOs across all frequency bands and provides information about the spatiotemporal properties of each HFO subtype in FCD. The study shows that mutated neurons represent a functionally interconnected and active component of the FCD network, as they can induce interictal epileptiform phenomena and HFOs.
Collapse
Affiliation(s)
- Jan Chvojka
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic; Department of Circuit Theory, Faculty of Electrical Engineering, Czech Technical University in Prague, Prague, Czech Republic
| | - Natalie Prochazkova
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Monika Rehorova
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Kudlacek
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Salome Kylarova
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Michaela Kralikova
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Peter Buran
- Laboratory of Molecular Neurobiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Romana Weissova
- Laboratory of Molecular Neurobiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Balastik
- Laboratory of Molecular Neurobiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - John G R Jefferys
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Ondrej Novak
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Premysl Jiruska
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic.
| |
Collapse
|
10
|
Jiruska P, Freestone D, Gnatkovsky V, Wang Y. An update on the seizures beget seizures theory. Epilepsia 2023; 64 Suppl 3:S13-S24. [PMID: 37466948 DOI: 10.1111/epi.17721] [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] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 07/17/2023] [Accepted: 07/17/2023] [Indexed: 07/20/2023]
Abstract
Seizures beget seizures is a longstanding theory that proposed that seizure activity can impact the structural and functional properties of the brain circuits in ways that contribute to epilepsy progression and the future occurrence of seizures. Originally proposed by Gowers, this theory continues to be quoted in the pathophysiology of epilepsy. We critically review the existing data and observations on the consequences of recurrent seizures on brain networks and highlight a range of factors that speak for and against the theory. The existing literature demonstrates clearly that ictal activity, especially if recurrent, induces molecular, structural, and functional changes including cell loss, connectivity reorganization, changes in neuronal behavior, and metabolic alterations. These changes have the potential to modify the seizure threshold, contribute to disease progression, and recruit wider areas of the epileptic network into epileptic activity. Repeated seizure activity may, thus, act as a pathological positive-feedback mechanism that increases seizure likelihood. On the other hand, the time course of self-limited epilepsies and the presence of seizure remission in two thirds of epilepsy cases and various chronic epilepsy models oppose the theory. Experimental work showed that seizures could induce neural changes that increase the seizure threshold and decrease the risk of a subsequent seizure. Due to the complex nature of epilepsies, it is wrong to consider only seizures as the key factor responsible for disease progression. Epilepsy worsening can be attributed to the various forms of interictal epileptiform activity or underlying disease mechanisms. Although seizure activity can negatively impact brain structure and function, the "seizures beget seizures" theory should not be used dogmatically but with extreme caution.
Collapse
Affiliation(s)
- Premysl Jiruska
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | | | - Vadym Gnatkovsky
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Yujiang Wang
- Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- Interdisciplinary Computing and Complex BioSystems Group, School of Computing Science, Newcastle University, Newcastle upon Tyne, UK
| |
Collapse
|
11
|
Izumi M, Kobayashi K, Kajikawa S, Kanazawa K, Takayama Y, Iijima K, Iwasaki M, Okahara Y, Mine S, Iwadate Y, Ikeda A. Focal ictal direct current shifts by a time constant of 2 seconds were clinically useful for resective epilepsy surgery. Epilepsia 2023; 64:3294-3306. [PMID: 37905469 DOI: 10.1111/epi.17782] [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: 03/17/2023] [Revised: 09/26/2023] [Accepted: 09/26/2023] [Indexed: 11/02/2023]
Abstract
OBJECTIVE Ictal direct current shifts (icDCs) and ictal high-frequency oscillations (icHFOs) have been reported as surrogate markers for better surgical outcomes in epilepsy surgery. icDCs have been classified into two types: rapid and slow development. icDCs have been investigated with a time constant of 10 s (TC10s); however, many institutes use electroencephalography with a time constant of 2 s (TC2s). This study aimed to evaluate whether icDCs can be observed adequately with TC2s; moreover, it examined the relationship between the resected core area of icDCs or icHFOs and surgical outcomes, occurrence rate of each type of icDCs, and relationship between each type of icDCs and pathology. METHODS Twenty-five patients with intractable focal epilepsy were analyzed retrospectively. icDCs and icHFOs were defined according to common metrics. The amplitude of icDCs was defined at >200 μV and even <200 μV. The two electrodes producing the most prominent icDCs and icHFOs were defined as core electrodes. The correlation between the resected core electrode area and degree of seizure control after surgery was analyzed. icDCs were classified into two types based on a peak latency value cutoff of 8.9 s, and the occurrence rates of both patterns were investigated. RESULTS icDCs (142/147 seizures [96.6%]) and icHFOs (135/147 seizures [91.8%]) occurred in all patients (100%). Compared with the amplitude of icDCs with TC10s reported in previous studies, the amplitude of icDCs with TC2s was attenuated in the current study. A significant positive correlation was observed between the resected core electrode area and degree of seizure control in both icDCs and icHFOs. A rapid development pattern was observed in 202 of 264 electrodes (76.5%). SIGNIFICANCE Similar to icDCs with TC10s, those with TC2s were observed adequately. Furthermore, favorable outcomes are expected using TC2s, which is currently available worldwide.
Collapse
Grants
- JPMH20FC1039 Ministry of Health, Labour and Welfare
- JP15H05874 Japan Ministry of Education, Culture, Sports, Science and Technology
- JP20K21573 Japan Ministry of Education, Culture, Sports, Science and Technology
- JP19H03574 Japan Ministry of Education, Culture, Sports, Science and Technology
Collapse
Affiliation(s)
- Masaki Izumi
- Department of Neurosurgery, Chiba University Graduate School of Medicine, Chiba, Japan
- Department of Neurosurgery, Chiba Cerebral and Cardiovascular Center, Chiba, Japan
| | - Katsuya Kobayashi
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shunsuke Kajikawa
- Department of Neurology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
| | - Kyoko Kanazawa
- Department of Neurology, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Yutaro Takayama
- Department of Neurosurgery, Yokohama City University, Kanagawa, Japan
| | - Keiya Iijima
- Department of Neurosurgery, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Yoji Okahara
- Department of Neurosurgery, Chiba Cerebral and Cardiovascular Center, Chiba, Japan
| | - Seiichiro Mine
- Department of Neurosurgery, Gyotoku General Hospital, Chiba, Japan
| | - Yasuo Iwadate
- Department of Neurosurgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders, and Physiology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| |
Collapse
|
12
|
Wang S, Lévesque M, Fisher TAJ, Kennedy TE, Avoli M. CA3 principal cell activation triggers hypersynchronous-onset seizures in a mouse model of mesial temporal lobe epilepsy. J Neurophysiol 2023; 130:1041-1052. [PMID: 37703488 DOI: 10.1152/jn.00244.2023] [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: 06/20/2023] [Revised: 09/13/2023] [Accepted: 09/13/2023] [Indexed: 09/15/2023] Open
Abstract
Mesial temporal lobe epilepsy (MTLE) is the most common form of focal epilepsy and it is characterized by seizures that are often refractory to medications. Seizures in MTLE have two main patterns of onset that have been termed hypersynchronous (HYP) and low-voltage fast (LVF) and are believed to mainly depend on the activity of excitatory principal cells and inhibitory interneurons, respectively. In this study, we investigated whether unilateral open-loop optogenetic activation of CaMKII-positive principal cells in the hippocampus CA3 region favors the generation of spontaneous HYP seizures in kainic acid-treated (KA) CaMKII-ChR2 mice. Optogenetic activation of CA3 principal cells (1 Hz, 180 s ON, 220 s OFF) was implemented for 15 days after KA-induced status epilepticus. We found that both LVF and HYP seizures occurred in nonstimulated CaMKII-ChR2 (n = 6) and stimulated CaMKII-Cre (n = 5) mice. In contrast, optogenetic activation of principal cells in CaMKII-ChR2 mice (n = 5) triggered only HYP seizures that were characterized by high fast ripple (250-500 Hz) rates during the pre-ictal and ictal periods. These results provide firm evidence that in MTLE spontaneous seizures with different onset patterns depend on distinct neuronal network mechanisms of generation. They also demonstrate that HYP seizures occurring in vivo along with their associated fast ripples depend on the activity of principal cells in the CA3 region.NEW & NOTEWORTHY Previous evidence suggested that different seizure onset patterns rely on the activity of distinct neuronal populations. In this study, we show for the first time that in vivo optogenetic stimulation of CaMKII principal cells in kainic acid-treated mice triggers hypersynchronous-onset seizures that are associated with fast ripples. Our findings indicate that in patients with predominant HYP-onset seizures, anticonvulsant treatments should be aimed at limiting the firing of principal neurons in the seizure onset zone.
Collapse
Affiliation(s)
- Siyan Wang
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
| | - Maxime Lévesque
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
| | - Teddy A J Fisher
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
| | - Timothy E Kennedy
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
| | - Massimo Avoli
- Department of Neurology & Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montréal, Quebec, Canada
- Department of Physiology, McGill University, Montréal, Quebec, Canada
| |
Collapse
|
13
|
Jean G, Carton J, Haq K, Musto AE. The role of dendritic spines in epileptogenesis. Front Cell Neurosci 2023; 17:1173694. [PMID: 37601280 PMCID: PMC10433379 DOI: 10.3389/fncel.2023.1173694] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 07/06/2023] [Indexed: 08/22/2023] Open
Abstract
Epilepsy is a chronic central nervous system (CNS) disease associated with high morbidity. To date, there is no known disease-modifying therapy for epilepsy. A leading hypothesis for a mechanism of epileptogenesis is the generation of aberrant neuronal networks. Although the underlying biological mechanism is not clear, scientific evidence indicates that it is associated with a hyperexcitable synchronous neuronal network and active dendritic spine plasticity. Changes in dendritic spine morphology are related to altered expression of synaptic cytoskeletal proteins, inflammatory molecules, neurotrophic factors, and extracellular matrix signaling. However, it remains to be determined if these aberrant dendritic spine formations lead to neuronal hyperexcitability and abnormal synaptic connections or whether they constitute an underlying mechanism of seizure susceptibility. Focusing on dendritic spine machinery as a potential target for medications could limit or reverse the development of epilepsy.
Collapse
Affiliation(s)
- Gary Jean
- Medical Program, School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Joseph Carton
- Medical Program, School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Kaleem Haq
- Department of Pathology and Anatomy, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Alberto E. Musto
- Department of Pathology and Anatomy, Eastern Virginia Medical School, Norfolk, VA, United States
- Department of Neurology, Eastern Virginia Medical School, Norfolk, VA, United States
| |
Collapse
|
14
|
Johnson GW, Doss DJ, Morgan VL, Paulo DL, Cai LY, Shless JS, Negi AS, Gummadavelli A, Kang H, Reddy SB, Naftel RP, Bick SK, Williams Roberson S, Dawant BM, Wallace MT, Englot DJ. The Interictal Suppression Hypothesis in focal epilepsy: network-level supporting evidence. Brain 2023; 146:2828-2845. [PMID: 36722219 PMCID: PMC10316780 DOI: 10.1093/brain/awad016] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 12/24/2022] [Accepted: 01/08/2023] [Indexed: 02/02/2023] Open
Abstract
Why are people with focal epilepsy not continuously having seizures? Previous neuronal signalling work has implicated gamma-aminobutyric acid balance as integral to seizure generation and termination, but is a high-level distributed brain network involved in suppressing seizures? Recent intracranial electrographic evidence has suggested that seizure-onset zones have increased inward connectivity that could be associated with interictal suppression of seizure activity. Accordingly, we hypothesize that seizure-onset zones are actively suppressed by the rest of the brain network during interictal states. Full testing of this hypothesis would require collaboration across multiple domains of neuroscience. We focused on partially testing this hypothesis at the electrographic network level within 81 individuals with drug-resistant focal epilepsy undergoing presurgical evaluation. We used intracranial electrographic resting-state and neurostimulation recordings to evaluate the network connectivity of seizure onset, early propagation and non-involved zones. We then used diffusion imaging to acquire estimates of white-matter connectivity to evaluate structure-function coupling effects on connectivity findings. Finally, we generated a resting-state classification model to assist clinicians in detecting seizure-onset and propagation zones without the need for multiple ictal recordings. Our findings indicate that seizure onset and early propagation zones demonstrate markedly increased inwards connectivity and decreased outwards connectivity using both resting-state (one-way ANOVA, P-value = 3.13 × 10-13) and neurostimulation analyses to evaluate evoked responses (one-way ANOVA, P-value = 2.5 × 10-3). When controlling for the distance between regions, the difference between inwards and outwards connectivity remained stable up to 80 mm between brain connections (two-way repeated measures ANOVA, group effect P-value of 2.6 × 10-12). Structure-function coupling analyses revealed that seizure-onset zones exhibit abnormally enhanced coupling (hypercoupling) of surrounding regions compared to presumably healthy tissue (two-way repeated measures ANOVA, interaction effect P-value of 9.76 × 10-21). Using these observations, our support vector classification models achieved a maximum held-out testing set accuracy of 92.0 ± 2.2% to classify early propagation and seizure-onset zones. These results suggest that seizure-onset zones are actively segregated and suppressed by a widespread brain network. Furthermore, this electrographically observed functional suppression is disproportionate to any observed structural connectivity alterations of the seizure-onset zones. These findings have implications for the identification of seizure-onset zones using only brief electrographic recordings to reduce patient morbidity and augment the presurgical evaluation of drug-resistant epilepsy. Further testing of the interictal suppression hypothesis can provide insight into potential new resective, ablative and neuromodulation approaches to improve surgical success rates in those suffering from drug-resistant focal epilepsy.
Collapse
Affiliation(s)
- Graham W Johnson
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute for Surgery and Engineering (VISE), Vanderbilt University, Nashville, TN 37235, USA
| | - Derek J Doss
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute for Surgery and Engineering (VISE), Vanderbilt University, Nashville, TN 37235, USA
| | - Victoria L Morgan
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute for Surgery and Engineering (VISE), Vanderbilt University, Nashville, TN 37235, USA
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Danika L Paulo
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Leon Y Cai
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute for Surgery and Engineering (VISE), Vanderbilt University, Nashville, TN 37235, USA
| | - Jared S Shless
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute for Surgery and Engineering (VISE), Vanderbilt University, Nashville, TN 37235, USA
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Aarushi S Negi
- Department of Neuroscience, Vanderbilt University, Nashville, TN 37232, USA
| | - Abhijeet Gummadavelli
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Hakmook Kang
- Department of Biostatistics, Vanderbilt University, Nashville, TN 37232, USA
| | - Shilpa B Reddy
- Department of Pediatrics, Vanderbilt Children’s Hospital, Nashville, TN 37232, USA
| | - Robert P Naftel
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sarah K Bick
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | | | - Benoit M Dawant
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute for Surgery and Engineering (VISE), Vanderbilt University, Nashville, TN 37235, USA
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN 37235, USA
| | - Mark T Wallace
- Department of Hearing and Speech Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Psychology, Vanderbilt University, Nashville, TN 37232, USA
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Dario J Englot
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute for Surgery and Engineering (VISE), Vanderbilt University, Nashville, TN 37235, USA
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN 37235, USA
| |
Collapse
|
15
|
Fabo D, Bokodi V, Szabó JP, Tóth E, Salami P, Keller CJ, Hajnal B, Thesen T, Devinsky O, Doyle W, Mehta A, Madsen J, Eskandar E, Erőss L, Ulbert I, Halgren E, Cash SS. The role of superficial and deep layers in the generation of high frequency oscillations and interictal epileptiform discharges in the human cortex. Sci Rep 2023; 13:9620. [PMID: 37316509 DOI: 10.1038/s41598-022-22497-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023] Open
Abstract
Describing intracortical laminar organization of interictal epileptiform discharges (IED) and high frequency oscillations (HFOs), also known as ripples. Defining the frequency limits of slow and fast ripples. We recorded potential gradients with laminar multielectrode arrays (LME) for current source density (CSD) and multi-unit activity (MUA) analysis of interictal epileptiform discharges IEDs and HFOs in the neocortex and mesial temporal lobe of focal epilepsy patients. IEDs were observed in 20/29, while ripples only in 9/29 patients. Ripples were all detected within the seizure onset zone (SOZ). Compared to hippocampal HFOs, neocortical ripples proved to be longer, lower in frequency and amplitude, and presented non-uniform cycles. A subset of ripples (≈ 50%) co-occurred with IEDs, while IEDs were shown to contain variable high-frequency activity, even below HFO detection threshold. The limit between slow and fast ripples was defined at 150 Hz, while IEDs' high frequency components form clusters separated at 185 Hz. CSD analysis of IEDs and ripples revealed an alternating sink-source pair in the supragranular cortical layers, although fast ripple CSD appeared lower and engaged a wider cortical domain than slow ripples MUA analysis suggested a possible role of infragranularly located neural populations in ripple and IED generation. Laminar distribution of peak frequencies derived from HFOs and IEDs, respectively, showed that supragranular layers were dominated by slower (< 150 Hz) components. Our findings suggest that cortical slow ripples are generated primarily in upper layers while fast ripples and associated MUA in deeper layers. The dissociation of macro- and microdomains suggests that microelectrode recordings may be more selective for SOZ-linked ripples. We found a complex interplay between neural activity in the neocortical laminae during ripple and IED formation. We observed a potential leading role of cortical neurons in deeper layers, suggesting a refined utilization of LMEs in SOZ localization.
Collapse
Affiliation(s)
- Daniel Fabo
- Epilepsy Unit, Department of Neurology, National Institute of Mental Health, Neurology and Neurosurgery, Amerikai Út 57. 1145, Budapest, Hungary.
| | - Virag Bokodi
- Epilepsy Unit, Department of Neurology, National Institute of Mental Health, Neurology and Neurosurgery, Amerikai Út 57. 1145, Budapest, Hungary
- Roska Tamás Doctoral School of Sciences and Technologies, Budapest, Hungary
| | - Johanna-Petra Szabó
- Epilepsy Unit, Department of Neurology, National Institute of Mental Health, Neurology and Neurosurgery, Amerikai Út 57. 1145, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Budapest, Hungary
| | - Emilia Tóth
- Epilepsy Unit, Department of Neurology, National Institute of Mental Health, Neurology and Neurosurgery, Amerikai Út 57. 1145, Budapest, Hungary
- Department of Neurology, University of Texas, McGovern Medical School, Houston, TX, USA
| | - Pariya Salami
- Epilepsy Division, Department of Neurology, Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Corey J Keller
- Department of Psychiatry and Behavioral Sciences, Stanford University Medical Center, Stanford, CA, USA
- VA Palo Alto Health Care System, Palo Alto, CA, USA
| | - Boglárka Hajnal
- Epilepsy Unit, Department of Neurology, National Institute of Mental Health, Neurology and Neurosurgery, Amerikai Út 57. 1145, Budapest, Hungary
- János Szentágothai Doctoral School of Neurosciences, Budapest, Hungary
| | - Thomas Thesen
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, USA
- Department of Biomedical Sciences, College of Medicine, University of Houston, Houston, TX, USA
| | - Orrin Devinsky
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, USA
| | - Werner Doyle
- Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, USA
| | - Ashesh Mehta
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell and Feinstein Institute for Medical Research, Manhasset, NY, USA
| | | | - Emad Eskandar
- Massachusetts General Hospital Neurosurgery Research, Boston, MA, USA
| | - Lorand Erőss
- Department of Functional Neurosurgery, National Institute of Mental Health, Neurology and Neurosurgery, Budapest, Hungary
| | - István Ulbert
- Epilepsy Unit, Department of Neurology, National Institute of Mental Health, Neurology and Neurosurgery, Amerikai Út 57. 1145, Budapest, Hungary
- Institute of Psychology, Eötvös Loránd Research Network, Budapest, Hungary
| | - Eric Halgren
- Department of Radiology, Neurosciences and Psychiatry, University of California, San Diego, San Diego, CA, USA
| | - Sydney S Cash
- Epilepsy Division, Department of Neurology, Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
16
|
Firestone E, Sonoda M, Kuroda N, Sakakura K, Jeong JW, Lee MH, Wada K, Takayama Y, Iijima K, Iwasaki M, Miyazaki T, Asano E. Sevoflurane-induced high-frequency oscillations, effective connectivity and intraoperative classification of epileptic brain areas. Clin Neurophysiol 2023; 150:17-30. [PMID: 36989866 PMCID: PMC10192072 DOI: 10.1016/j.clinph.2023.03.004] [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: 10/24/2022] [Revised: 02/27/2023] [Accepted: 03/02/2023] [Indexed: 03/18/2023]
Abstract
OBJECTIVE To determine how sevoflurane anesthesia modulates intraoperative epilepsy biomarkers on electrocorticography, including high-frequency oscillation (HFO) effective connectivity (EC), and to investigate their relation to epileptogenicity and anatomical white matter. METHODS We studied eight pediatric drug-resistant focal epilepsy patients who achieved seizure control after invasive monitoring and resective surgery. We visualized spatial distributions of the electrocorticography biomarkers at an oxygen baseline, three time-points while sevoflurane was increasing, and at a plateau of 2 minimum alveolar concentration (MAC) sevoflurane. HFO EC was combined with diffusion-weighted imaging, in dynamic tractography. RESULTS Intraoperative HFO EC diffusely increased as a function of sevoflurane concentration, although most in epileptogenic sites (defined as those included in the resection); their ability to classify epileptogenicity was optimized at sevoflurane 2 MAC. HFO EC could be visualized on major white matter tracts, as a function of sevoflurane level. CONCLUSIONS The results strengthened the hypothesis that sevoflurane-activated HFO biomarkers may help intraoperatively localize the epileptogenic zone. SIGNIFICANCE Our results help characterize how HFOs at non-epileptogenic and epileptogenic networks respond to sevoflurane. It may be warranted to establish a normative HFO atlas incorporating the modifying effects of sevoflurane and major white matter pathways, as critical reference in epilepsy presurgical evaluation.
Collapse
Affiliation(s)
- Ethan Firestone
- Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center,Wayne State University, Detroit, MI 48201, USA; Department of Physiology, Wayne State University, Detroit, MI 48201, USA
| | - Masaki Sonoda
- Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center,Wayne State University, Detroit, MI 48201, USA; Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 2360004, Japan
| | - Naoto Kuroda
- Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center,Wayne State University, Detroit, MI 48201, USA; Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai 9808575, Japan
| | - Kazuki Sakakura
- Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center,Wayne State University, Detroit, MI 48201, USA; Department of Neurosurgery, University of Tsukuba, Tsukuba 3058575, Japan
| | - Jeong-Won Jeong
- Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center,Wayne State University, Detroit, MI 48201, USA; Department of Neurology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA
| | - Min-Hee Lee
- Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center,Wayne State University, Detroit, MI 48201, USA
| | - Keiko Wada
- Department of Anesthesiology, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 1878551, Japan; Department of Anesthesiology and Critical Care, Yokohama City University Graduate School of Medicine, Yokohama 2360004, Japan
| | - Yutaro Takayama
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 2360004, Japan; Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 1878551, Japan
| | - Keiya Iijima
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 1878551, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 1878551, Japan
| | - Tomoyuki Miyazaki
- Department of Anesthesiology, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 1878551, Japan; Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 2360004, Japan
| | - Eishi Asano
- Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center,Wayne State University, Detroit, MI 48201, USA; Department of Neurology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA.
| |
Collapse
|
17
|
Shen M, Zhang L, Gong Y, Li L, Liu X. Epileptic Tissue Localization through Skewness-Based Functional Connectivity in the High-Frequency Band of Intracranial EEG. Bioengineering (Basel) 2023; 10:bioengineering10040461. [PMID: 37106648 PMCID: PMC10136084 DOI: 10.3390/bioengineering10040461] [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: 03/17/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
Functional connectivity analysis of intracranial electroencephalography (iEEG) plays an important role in understanding the mechanism of epilepsy and seizure dynamics. However, existing connectivity analysis is only suitable for low-frequency bands below 80 Hz. High-frequency oscillations (HFOs) and high-frequency activity (HFA) in the high-frequency band (80-500 Hz) are thought to be specific biomarkers in epileptic tissue localization. However, the transience in duration and variability of occurrence time and amplitudes of these events pose a challenge for conducting effective connectivity analysis. To deal with this problem, we proposed skewness-based functional connectivity (SFC) in the high-frequency band and explored its utility in epileptic tissue localization and surgical outcome evaluation. SFC comprises three main steps. The first step is the quantitative measurement of amplitude distribution asymmetry between HFOs/HFA and baseline activity. The second step is functional network construction on the basis of rank correlation of asymmetry across time. The third step is connectivity strength extraction from the functional network. Experiments were conducted in two separate datasets which consist of iEEG recordings from 59 patients with drug-resistant epilepsy. Significant difference (p<0.001) in connectivity strength was found between epileptic and non-epileptic tissue. Results were quantified via the receiver operating characteristic curve and the area under the curve (AUC). Compared with low-frequency bands, SFC demonstrated superior performance. With respect to pooled and individual epileptic tissue localization for seizure-free patients, AUCs were 0.66 (95% confidence interval (CI): 0.63-0.69) and (0.63 95% CI 0.56-0.71), respectively. For surgical outcome classification, the AUC was 0.75 (95% CI 0.59-0.85). Therefore, SFC can act as a promising assessment tool in characterizing the epileptic network and potentially provide better treatment options for patients with drug-resistant epilepsy.
Collapse
Affiliation(s)
- Mu Shen
- School of Artificial Intelligence, Beijing University of Posts and Telecommunications, Beijing 100876, China
| | - Lin Zhang
- School of Artificial Intelligence, Beijing University of Posts and Telecommunications, Beijing 100876, China
| | - Yi Gong
- School of Information and Communication Engineering, Beijing Information Science and Technology University, Beijing 100096, China
| | - Lei Li
- School of Artificial Intelligence, Beijing University of Posts and Telecommunications, Beijing 100876, China
| | - Xianzeng Liu
- Department of Neurology, Peking University International Hospital, and Peking University Clinical Research Institute, Beijing 102206, China
| |
Collapse
|
18
|
Lévesque M, Wang S, Macey-Dare ADB, Salami P, Avoli M. Evolution of interictal activity in models of mesial temporal lobe epilepsy. Neurobiol Dis 2023; 180:106065. [PMID: 36907521 DOI: 10.1016/j.nbd.2023.106065] [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: 01/23/2023] [Revised: 02/22/2023] [Accepted: 03/02/2023] [Indexed: 03/12/2023] Open
Abstract
Interictal activity and seizures are the hallmarks of focal epileptic disorders (which include mesial temporal lobe epilepsy, MTLE) in humans and in animal models. Interictal activity, which is recorded with cortical and intracerebral EEG recordings, comprises spikes, sharp waves and high-frequency oscillations, and has been used in clinical practice to identify the epileptic zone. However, its relation with seizures remains debated. Moreover, it is unclear whether specific EEG changes in interictal activity occur during the time preceding the appearance of spontaneous seizures. This period, which is termed "latent", has been studied in rodent models of MTLE in which spontaneous seizures start to occur following an initial insult (most often a status epilepticus induced by convulsive drugs such as kainic acid or pilocarpine) and may mirror epileptogenesis, i.e., the process leading the brain to develop an enduring predisposition to seizure generation. Here, we will address this topic by reviewing experimental studies performed in MTLE models. Specifically, we will review data highlighting the dynamic changes in interictal spiking activity and high-frequency oscillations occurring during the latent period, and how optogenetic stimulation of specific cell populations can modulate them in the pilocarpine model. These findings indicate that interictal activity: (i) is heterogeneous in its EEG patterns and thus, presumably, in its underlying neuronal mechanisms; and (ii) can pinpoint to the epileptogenic processes occurring in focal epileptic disorders in animal models and, perhaps, in epileptic patients.
Collapse
Affiliation(s)
- Maxime Lévesque
- Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montreal, H3A 2B4, QC, Canada.
| | - Siyan Wang
- Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montreal, H3A 2B4, QC, Canada
| | - Anežka D B Macey-Dare
- Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montreal, H3A 2B4, QC, Canada; Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Pariya Salami
- Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montreal, H3A 2B4, QC, Canada; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA
| | - Massimo Avoli
- Montreal Neurological Institute-Hospital and Departments of Neurology & Neurosurgery, McGill University, 3801 Rue University, Montreal, H3A 2B4, QC, Canada; Department of Physiology, McGill University, 3655 Promenade Sir William Osler, Montreal, H3G 1Y6, QC, Canada
| |
Collapse
|
19
|
Insulin-Like Growth Factor-1 Promotes Synaptogenesis Signaling, a Major Dysregulated Pathway in Malformation of Cortical Development, in a Rat Model. Mol Neurobiol 2023; 60:3299-3310. [PMID: 36847937 DOI: 10.1007/s12035-023-03256-4] [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: 04/26/2022] [Accepted: 02/07/2023] [Indexed: 03/01/2023]
Abstract
Malformation of cortical development (MCD) is one of the main causes of intractable epilepsy in childhood. We explored a treatment based on molecular changes using an infant rat model of methylazoxymethanol (MAM)-induced MCD established by injecting MAM at gestational day 15. The offspring were sacrificed on postnatal day (P) 15 for proteomic analysis, which revealed significant downregulation in the synaptogenesis signaling pathway in the cortex of MCD rats. Recombinant human insulin-growth factor-1 (rhIGF-1) was injected from P12 to P14 twice daily and the effect of IGF1 on N-methyl-D-aspartate (NMDA)-induced spasms (15 mg/kg of NMDA, i.p.) was tested; the onset of P15 single spasm was significantly delayed (p = 0.002) and the number of spasms decreased (p < 0.001) in rhIGF1-pretreated rats (n = 17) compared to those in VEH-treated rats (n = 18). Electroencephalographic monitoring during spasms showed significantly reduced spectral entropy and event-related spectral dynamics of fast oscillation in rhIGF-1 treated rats. Magnetic resonance spectroscopy of the retrosplenial cortex showed decreased glutathione (GSH) (p = 0.039) and significant developmental changes in GSH, phosphocreatine (PCr), and total creatine (tCr) (p = 0.023, 0.042, 0.015, respectively) after rhIGF1 pretreatment. rhIGF1 pretreatment significantly upregulated expression of cortical synaptic proteins such as PSD95, AMPAR1, AMPAR4, NMDAR1, and NMDAR2A (p < 0.05). Thus, early rhIGF-1 treatment could promote synaptic protein expression, which was significantly downregulated by prenatal MAM exposure, and effectively suppress NMDA-induced spasms. Early IGF1 treatment should be further investigated as a therapeutic strategy in infants with MCD-related epilepsy.
Collapse
|
20
|
Lai N, Li Z, Xu C, Wang Y, Chen Z. Diverse nature of interictal oscillations: EEG-based biomarkers in epilepsy. Neurobiol Dis 2023; 177:105999. [PMID: 36638892 DOI: 10.1016/j.nbd.2023.105999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/07/2023] [Accepted: 01/09/2023] [Indexed: 01/11/2023] Open
Abstract
Interictal electroencephalogram (EEG) patterns, including high-frequency oscillations (HFOs), interictal spikes (ISs), and slow wave activities (SWAs), are defined as specific oscillations between seizure events. These interictal oscillations reflect specific dynamic changes in network excitability and play various roles in epilepsy. In this review, we briefly describe the electrographic characteristics of HFOs, ISs, and SWAs in the interictal state, and discuss the underlying cellular and network mechanisms. We also summarize representative evidence from experimental and clinical epilepsy to address their critical roles in ictogenesis and epileptogenesis, indicating their potential as electrophysiological biomarkers of epilepsy. Importantly, we put forwards some perspectives for further research in the field.
Collapse
Affiliation(s)
- Nanxi Lai
- Institute of Pharmacology & Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhisheng Li
- Institute of Pharmacology & Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology & Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, China; Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China; Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| |
Collapse
|
21
|
Nejedly P, Kremen V, Lepkova K, Mivalt F, Sladky V, Pridalova T, Plesinger F, Jurak P, Pail M, Brazdil M, Klimes P, Worrell G. Utilization of temporal autoencoder for semi-supervised intracranial EEG clustering and classification. Sci Rep 2023; 13:744. [PMID: 36639549 PMCID: PMC9839708 DOI: 10.1038/s41598-023-27978-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/11/2023] [Indexed: 01/14/2023] Open
Abstract
Manual visual review, annotation and categorization of electroencephalography (EEG) is a time-consuming task that is often associated with human bias and requires trained electrophysiology experts with specific domain knowledge. This challenge is now compounded by development of measurement technologies and devices allowing large-scale heterogeneous, multi-channel recordings spanning multiple brain regions over days, weeks. Currently, supervised deep-learning techniques were shown to be an effective tool for analyzing big data sets, including EEG. However, the most significant caveat in training the supervised deep-learning models in a clinical research setting is the lack of adequate gold-standard annotations created by electrophysiology experts. Here, we propose a semi-supervised machine learning technique that utilizes deep-learning methods with a minimal amount of gold-standard labels. The method utilizes a temporal autoencoder for dimensionality reduction and a small number of the expert-provided gold-standard labels used for kernel density estimating (KDE) maps. We used data from electrophysiological intracranial EEG (iEEG) recordings acquired in two hospitals with different recording systems across 39 patients to validate the method. The method achieved iEEG classification (Pathologic vs. Normal vs. Artifacts) results with an area under the receiver operating characteristic (AUROC) scores of 0.862 ± 0.037, 0.879 ± 0.042, and area under the precision-recall curve (AUPRC) scores of 0.740 ± 0.740, 0.714 ± 0.042. This demonstrates that semi-supervised methods can provide acceptable results while requiring only 100 gold-standard data samples in each classification category. Subsequently, we deployed the technique to 12 novel patients in a pseudo-prospective framework for detecting Interictal epileptiform discharges (IEDs). We show that the proposed temporal autoencoder was able to generalize to novel patients while achieving AUROC of 0.877 ± 0.067 and AUPRC of 0.705 ± 0.154.
Collapse
Affiliation(s)
- Petr Nejedly
- 1St Department of Neurology, Faculty of Medicine, Masaryk University, Brno, Czech Republic. .,Institute of Scientific Instruments, The Czech Academy of Sciences, Brno, Czech Republic. .,Department of Neurology, Mayo Clinic, Mayo Systems Electrophysiology Laboratory, Rochester, MN, USA.
| | - Vaclav Kremen
- Department of Neurology, Mayo Clinic, Mayo Systems Electrophysiology Laboratory, Rochester, MN, USA. .,Czech Institute of Informatics, Robotics, and Cybernetics, Czech Technical University in Prague, Prague, Czech Republic.
| | - Kamila Lepkova
- Department of Neurology, Mayo Clinic, Mayo Systems Electrophysiology Laboratory, Rochester, MN, USA.,Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic
| | - Filip Mivalt
- Department of Neurology, Mayo Clinic, Mayo Systems Electrophysiology Laboratory, Rochester, MN, USA.,Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czech Republic
| | - Vladimir Sladky
- Department of Neurology, Mayo Clinic, Mayo Systems Electrophysiology Laboratory, Rochester, MN, USA
| | - Tereza Pridalova
- Institute of Scientific Instruments, The Czech Academy of Sciences, Brno, Czech Republic.,Department of Neurology, Mayo Clinic, Mayo Systems Electrophysiology Laboratory, Rochester, MN, USA
| | - Filip Plesinger
- Institute of Scientific Instruments, The Czech Academy of Sciences, Brno, Czech Republic
| | - Pavel Jurak
- Institute of Scientific Instruments, The Czech Academy of Sciences, Brno, Czech Republic
| | - Martin Pail
- 1St Department of Neurology, Faculty of Medicine, Masaryk University, Brno, Czech Republic.,Institute of Scientific Instruments, The Czech Academy of Sciences, Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic
| | - Milan Brazdil
- 1St Department of Neurology, Faculty of Medicine, Masaryk University, Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic.,CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Petr Klimes
- Institute of Scientific Instruments, The Czech Academy of Sciences, Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic
| | - Gregory Worrell
- Department of Neurology, Mayo Clinic, Mayo Systems Electrophysiology Laboratory, Rochester, MN, USA.
| |
Collapse
|
22
|
Kuhnke N, Wusthoff CJ, Swarnalingam E, Yanoussi M, Jacobs J. Epileptic high-frequency oscillations occur in neonates with a high risk for seizures. Front Neurol 2023; 13:1048629. [PMID: 36686542 PMCID: PMC9848430 DOI: 10.3389/fneur.2022.1048629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/30/2022] [Indexed: 01/05/2023] Open
Abstract
Introduction Scalp high-frequency oscillations (HFOs, 80-250 Hz) are increasingly recognized as EEG markers of epileptic brain activity. It is, however, unclear what level of brain maturity is necessary to generate these oscillations. Many studies have reported the occurrence of scalp HFOs in children with a correlation between treatment success of epileptic seizures and the reduction of HFOs. More recent studies describe the reliable detection of HFOs on scalp EEG during the neonatal period. Methods In the present study, continuous EEGs of 38 neonates at risk for seizures were analyzed visually for the scalp HFOs using 30 min of quiet sleep EEG. EEGs of 14 patients were of acceptable quality to analyze HFOs. Results The average rate of HFOs was 0.34 ± 0.46/min. About 3.2% of HFOs occurred associated with epileptic spikes. HFOs were significantly more frequent in EEGs with abnormal vs. normal background activities (p = 0.005). Discussion Neonatal brains are capable of generating HFOs. HFO could be a viable biomarker for neonates at risk of developing seizures. Our preliminary data suggest that HFOs mainly occur in those neonates who have altered background activity. Larger data sets are needed to conclude whether HFO occurrence is linked to seizure generation and whether this might predict the development of epilepsy.
Collapse
Affiliation(s)
- Nicola Kuhnke
- Department of Pediatric Neurology and Muscular Disease, University Medical Center, Freiburg, Germany
| | | | - Eroshini Swarnalingam
- Department of Pediatrics, University of Calgary, Alberta Children's Hospital, Calgary, AB, Canada
| | - Mina Yanoussi
- Department of Pediatric Neurology and Muscular Disease, University Medical Center, Freiburg, Germany
| | - Julia Jacobs
- Department of Pediatrics, University of Calgary, Alberta Children's Hospital, Calgary, AB, Canada,*Correspondence: Julia Jacobs ✉
| |
Collapse
|
23
|
Zhu F, Wang H, Li L, Bragin A, Cao D, Cheng Y. Intracranial electrophysiological recordings on a swine model of mesial temporal lobe epilepsy. Front Neurol 2023; 14:1077702. [PMID: 37139062 PMCID: PMC10150775 DOI: 10.3389/fneur.2023.1077702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 03/20/2023] [Indexed: 05/05/2023] Open
Abstract
Objective To test the feasibility and reliability of intracranial electrophysiological recordings in an acute status epilepticus model on laboratory swine. Method Intrahippocampal injection of kainic acid (KA) was performed on 17 male Bama pigs (Sus scrofa domestica) weighing between 25 and 35 kg. Two stereoelectroencephalography (SEEG) electrodes with a total of 16 channels were implanted bilaterally along the sensorimotor cortex to the hippocampus. Brain electrical activity was recorded 2 h daily for 9-28 days. Three KA dosages were tested to evaluate the quantities capable of evoking status epilepticus. Local field potentials (LFPs) were recorded and compared before and after the KA injection. We quantified the epileptic patterns, including the interictal spikes, seizures, and high-frequency oscillations (HFOs), up to 4 weeks after the KA injection. Test-retest reliability using intraclass correlation coefficients (ICCs) were performed on interictal HFO rates to evaluate the recording stability of this model. Results The KA dosage test suggested that a 10 μl (1.0 μg/μl) intrahippocampal injection could successfully evoke status epilepticus lasting from 4 to 12 h. At this dosage, eight pigs (50% of total) had prolonged epileptic events (tonic-chronic seizures + interictal spikes n = 5, interictal spikes alone n = 3) in the later 4 weeks of the video-SEEG recording period. Four pigs (25% of total) had no epileptic activities, and another four (25%) had lost the cap or did not complete the experiments. Animals that showed epileptiform events were grouped as E + (n = 8) and the four animals showing no signs of epileptic events were grouped as E- (n = 4). A total of 46 electrophysiological seizures were captured in the 4-week post-KA period from 4 E + animals, with the earliest onset on day 9. The seizure durations ranged from 12 to 45 s. A significant increase of hippocampal HFOs rate (num/min) was observed in the E+ group during the post-KA period (weeks 1, 2,4, p < 0.05) compared to the baseline. But the E-showed no change or a decrease (in week 2, p = 0.43) compared to their baseline rate. The between-group comparison showed much higher HFO rates in E + vs. E - (F = 35, p < 0.01). The high ICC value [ICC (1, k) = 0.81, p < 0.05] quantified from the HFO rate suggested that this model had a stable measurement of HFOs during the four-week post-KA periods. Significance This study measured intracranial electrophysiological activity in a swine model of KA-induced mesial temporal lobe epilepsy (mTLE). Using the clinical SEEG electrode, we distinguished abnormal EEG patterns in the swine brain. The high test-retest reliability of HFO rates in the post-KA period suggests the utility of this model for studying mechanisms of epileptogenesis. The use of swine may provide satisfactory translational value for clinical epilepsy research.
Collapse
Affiliation(s)
- Fengjun Zhu
- Department of Neurosurgery, Shenzhen Children’s Hospital, Shenzhen, Guangdong, China
- Department of Neurosurgery, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, United States
| | - Hanwen Wang
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, United States
| | - Lin Li
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, United States
- Department of Biomedical Engineering, University of North Texas, Denton, TX, United States
| | - Anatol Bragin
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, United States
| | - Dezhi Cao
- Department of Neurosurgery, Shenzhen Children’s Hospital, Shenzhen, Guangdong, China
- *Correspondence: Dezhi Cao,
| | - Yuan Cheng
- Department of Neurosurgery, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Yuan Cheng,
| |
Collapse
|
24
|
Urriola J, Bollmann S, Tremayne F, Burianová H, Marstaller L, Reutens D. Spikes with and without concurrent high-frequency oscillations: Topographic relationship and neural correlates using EEG-fMRI. Epilepsy Res 2022; 188:107039. [DOI: 10.1016/j.eplepsyres.2022.107039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 09/11/2022] [Accepted: 10/17/2022] [Indexed: 11/03/2022]
|
25
|
Lippmann K, Klaft ZJ, Salar S, Hollnagel JO, Valero M, Maslarova A. Status epilepticus induces chronic silencing of burster and dominance of regular firing neurons during sharp wave-ripples in the mouse subiculum. Neurobiol Dis 2022; 175:105929. [DOI: 10.1016/j.nbd.2022.105929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/08/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
|
26
|
Recruitment of interictal- and ictal-like discharges in posterior piriform cortex by delta-rate (1–4 Hz) focal bursts in anterior piriform cortex in vivo. Epilepsy Res 2022; 187:107032. [DOI: 10.1016/j.eplepsyres.2022.107032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/10/2022] [Accepted: 10/06/2022] [Indexed: 11/23/2022]
|
27
|
Avoli M, de Curtis M, Lévesque M, Librizzi L, Uva L, Wang S. GABAA signaling, focal epileptiform synchronization and epileptogenesis. Front Neural Circuits 2022; 16:984802. [PMID: 36275847 PMCID: PMC9581276 DOI: 10.3389/fncir.2022.984802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 09/13/2022] [Indexed: 12/04/2022] Open
Abstract
Under physiological conditions, neuronal network synchronization leads to different oscillatory EEG patterns that are associated with specific behavioral and cognitive functions. Excessive synchronization can, however, lead to focal or generalized epileptiform activities. It is indeed well established that in both epileptic patients and animal models, focal epileptiform EEG patterns are characterized by interictal and ictal (seizure) discharges. Over the last three decades, employing in vitro and in vivo recording techniques, several experimental studies have firmly identified a paradoxical role of GABAA signaling in generating interictal discharges, and in initiating—and perhaps sustaining—focal seizures. Here, we will review these experiments and we will extend our appraisal to evidence suggesting that GABAA signaling may also contribute to epileptogenesis, i.e., the development of plastic changes in brain excitability that leads to the chronic epileptic condition. Overall, we anticipate that this information should provide the rationale for developing new specific pharmacological treatments for patients presenting with focal epileptic disorders such as mesial temporal lobe epilepsy (MTLE).
Collapse
Affiliation(s)
- Massimo Avoli
- Montreal Neurological Institute-Hospital, Montreal, QC, Canada
- Departments of Neurology and Neurosurgery, Montreal, QC, Canada
- Department of Physiology, McGill University, Montreal, QC, Canada
- *Correspondence: Massimo Avoli,
| | - Marco de Curtis
- Epilepsy Unit, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Istituto Neurologico Carlo Besta, Milan, Italy
| | - Maxime Lévesque
- Montreal Neurological Institute-Hospital, Montreal, QC, Canada
- Departments of Neurology and Neurosurgery, Montreal, QC, Canada
| | - Laura Librizzi
- Epilepsy Unit, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Istituto Neurologico Carlo Besta, Milan, Italy
| | - Laura Uva
- Epilepsy Unit, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Istituto Neurologico Carlo Besta, Milan, Italy
| | - Siyan Wang
- Montreal Neurological Institute-Hospital, Montreal, QC, Canada
- Departments of Neurology and Neurosurgery, Montreal, QC, Canada
| |
Collapse
|
28
|
Zhou Y, You J, Kumar U, Weiss SA, Bragin A, Engel J, Papadelis C, Li L. An approach for reliably identifying high-frequency oscillations and reducing false-positive detections. Epilepsia Open 2022; 7:674-686. [PMID: 36053171 PMCID: PMC9712470 DOI: 10.1002/epi4.12647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 08/31/2022] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE Aiming to improve the feasibility and reliability of using high-frequency oscillations (HFOs) for translational studies of epilepsy, we present a pipeline with features specifically designed to reject false positives for HFOs to improve the automatic HFO detector. METHODS We presented an integrated, multi-layered procedure capable of automatically rejecting HFOs from a variety of common false positives, such as motion, background signals, and sharp transients. This method utilizes a time-frequency contour approach that embeds three different layers including peak constraints, power thresholds, and morphological identification to discard false positives. Four experts were involved in rating detected HFO events that were randomly selected from different posttraumatic epilepsy (PTE) animals for a comprehensive evaluation. RESULTS The algorithm was run on 768-h recordings of intracranial electrodes in 48 PTE animals. A total of 453 917 HFOs were identified by initial HFO detection, of which 450 917 were implemented for HFO refinement and 203 531 events were retained. Random sampling was used to evaluate the performance of the detector. The HFO detection yielded an overall accuracy of 0.95 ± 0.03 , with precision, recall, and F1 scores of 0.92 ± 0.05 , 0.99 ± 0.01 , and 0.94 ± 0.03 , respectively. For the HFO classification, our algorithm obtained an accuracy of 0.97 ± 0.02 . For the inter-rater reliability of algorithm evaluation, the agreement among four experts was 0.94 ± 0.03 for HFO detection and 0.85 ± 0.04 for HFO classification. SIGNIFICANCE Our approach shows that a segregated pipeline design with a focus on false-positive rejection can improve the detection efficiency and provide reliable results. This pipeline does not require customization and uses fixed parameters, making it highly feasible and translatable for basic and clinical applications of epilepsy.
Collapse
Affiliation(s)
- Yufeng Zhou
- Department of Biomedical EngineeringUniversity of North TexasTexasUSA
| | - Jing You
- Department of Biomedical EngineeringUniversity of North TexasTexasUSA
| | - Udaya Kumar
- Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaUSA
| | - Shennan A Weiss
- Departments of Neurology, Department of Physiology and PharmacologyState University of New York DownstateBrooklynNew YorkUSA,Department of NeurologyNew York City Health + Hospitals/Kings CountyBrooklynNew YorkUSA
| | - Anatol Bragin
- Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaUSA,Brain Research InstituteUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - Jerome Engel
- Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaUSA,Brain Research InstituteUniversity of CaliforniaLos AngelesCaliforniaUSA,Department of NeurobiologyDavid Geffen School of Medicine at UCLALos AngelesCaliforniaUSA,Department of Psychiatry and Biobehavioral SciencesDavid Geffen School of Medicine at UCLACaliforniaUSA
| | - Christos Papadelis
- Jane and John Justin Neurosciences CenterCook Children's Health Care SystemFort WorthTexasUSA,School of MedicineTexas Christian UniversityFort WorthTexasUSA,Department of BioengineeringUniversity of Texas at ArlingtonArlingtonTexasUSA
| | - Lin Li
- Department of Biomedical EngineeringUniversity of North TexasTexasUSA,Department of NeurologyUniversity of California Los AngelesLos AngelesCaliforniaUSA
| |
Collapse
|
29
|
Granado M, Collavini S, Baravalle R, Martinez N, Montemurro MA, Rosso OA, Montani F. High-frequency oscillations in the ripple bands and amplitude information coding: Toward a biomarker of maximum entropy in the preictal signals. CHAOS (WOODBURY, N.Y.) 2022; 32:093151. [PMID: 36182366 DOI: 10.1063/5.0101220] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/29/2022] [Indexed: 06/16/2023]
Abstract
Intracranial electroencephalography (iEEG) can directly record local field potentials (LFPs) from a large set of neurons in the vicinity of the electrode. To search for possible epileptic biomarkers and to determine the epileptogenic zone that gives rise to seizures, we investigated the dynamics of basal and preictal signals. For this purpose, we explored the dynamics of the recorded time series for different frequency bands considering high-frequency oscillations (HFO) up to 240 Hz. We apply a Hilbert transform to study the amplitude and phase of the signals. The dynamics of the different frequency bands in the time causal entropy-complexity plane, H × C, is characterized by comparing the dynamical evolution of the basal and preictal time series. As the preictal states evolve closer to the time in which the epileptic seizure starts, the, H × C, dynamics changes for the higher frequency bands. The complexity evolves to very low values and the entropy becomes nearer to its maximal value. These quasi-stable states converge to equiprobable states when the entropy is maximal, and the complexity is zero. We could, therefore, speculate that in this case, it corresponds to the minimization of Gibbs free energy. In this case, the maximum entropy is equivalent to the principle of minimum consumption of resources in the system. We can interpret this as the nature of the system evolving temporally in the preictal state in such a way that the consumption of resources by the system is minimal for the amplitude in frequencies between 220-230 and 230-240 Hz.
Collapse
Affiliation(s)
- Mauro Granado
- Instituto de Física de La Plata (IFLP), Universidad Nacional de La Plata, CONICET CCT-La Plata, Diagonal 113 entre 63 y 64, La Plata 1900, Buenos Aires, Argentina
| | - Santiago Collavini
- Instituto de Electrónica Industrial, Control y Procesamiento de Se nales (LEICI), Facultad de Ingeniería, Universidad Nacional de La Plata (UNLP-CONICET), La Plata 1900, Buenos Aires, Argentina
| | - Roman Baravalle
- Instituto de Física de La Plata (IFLP), Universidad Nacional de La Plata, CONICET CCT-La Plata, Diagonal 113 entre 63 y 64, La Plata 1900, Buenos Aires, Argentina
| | - Nataniel Martinez
- Instituto de Física de Mar del Plata, Universidad Nacional de Mar del Plata & CONICET, Mar del Plata 7600, Buenos Aires, Argentina
| | - Marcelo A Montemurro
- School of Mathematics & Statistics, Faculty of Science, Technology, Engineering & Mathematics, The Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom
| | - Osvaldo A Rosso
- Instituto de Física de La Plata (IFLP), Universidad Nacional de La Plata, CONICET CCT-La Plata, Diagonal 113 entre 63 y 64, La Plata 1900, Buenos Aires, Argentina
| | - Fernando Montani
- Instituto de Física de La Plata (IFLP), Universidad Nacional de La Plata, CONICET CCT-La Plata, Diagonal 113 entre 63 y 64, La Plata 1900, Buenos Aires, Argentina
| |
Collapse
|
30
|
Kalogeropoulos K, Kleidonas D, Psarropoulou C. Timing differences between HFOs and interictal epileptiform discharges generated in vitro by different mechanisms in rat hippocampal slices: A novel approach. Epilepsia Open 2022; 7:608-615. [PMID: 35908206 PMCID: PMC9712485 DOI: 10.1002/epi4.12633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 07/28/2022] [Indexed: 12/30/2022] Open
Abstract
OBJECTIVE To investigate the effect of generating mechanism on the relationship between interictal-like epileptiform discharges (IEDs) and the underlying High Frequency Oscillations (HFOs; Ripples, R, and Fast Ripples, FR). METHODS Synchronous spontaneous IEDs were recorded from the CA1 area of hippocampal slices from adult rats, perfused by Mg2+ -free ACSF (n = 41slices/14 animals) or 4-aminopyridine (50 μM, n = 37slices/16 animals); IED filtering revealed Rs and FRs and several metrics were calculated and compared (amplitude, duration, relative onset, time lag, % overlap, peak frequency, peak power, FR/R). RESULTS Longer IEDs and higher 1st Population Spike (PS) amplitude in Mg2+ -free ACSF (vs 4-AP; P < .001, P < .001) correlated with longer duration and higher amplitude Rs (P < .0001, P = .001) and longer duration FRs (P < .001). In both media, Rs and FRs appeared before IED onset with Rs preceding FRs; R- and FR-IED lag (P = .008, P = .01) as well as R-FR lag (P = .04) were significantly longer in Mg2+ -free ACSF vs in 4-AP. R peak frequency and power were higher in Mg2+ -free ACSF, while no such differences were observed in FRs. Inter-model differences were mostly reflected in Rs, not FRs, suggesting that mechanisms unique to R generation are more active in Mg2+ -free ACSF vs in 4-AP. FRs appeared to contribute equally to IEDs irrespective of generating mechanism. SIGNIFICANCE Several of the metrics used, particularly those regarding the timing between HFOs and IEDs, appear to correlate with the synchronizing mechanism and we propose that they may be useful when investigating antiepileptic substance effects on neuronal network activity.
Collapse
Affiliation(s)
- Konstantinos Kalogeropoulos
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health SciencesUniversity of IoanninaIoanninaGreece
| | - Dimitrios Kleidonas
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health SciencesUniversity of IoanninaIoanninaGreece,Department of Neuroanatomy, Faculty of MedicineInstitute of Anatomy and Cell Biology, University of FreiburgFreiburgGermany
| | - Caterina Psarropoulou
- Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health SciencesUniversity of IoanninaIoanninaGreece,Department of Biological Applications & TechnologiesUniversity of IoanninaIoanninaGreece
| |
Collapse
|
31
|
Chen Z, Maturana MI, Burkitt AN, Cook MJ, Grayden DB. Seizure Forecasting by High-Frequency Activity (80-170 Hz) in Long-term Continuous Intracranial EEG Recordings. Neurology 2022; 99:e364-e375. [PMID: 35523589 DOI: 10.1212/wnl.0000000000200348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 02/21/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Reliable seizure forecasting has important implications in epilepsy treatment and improving the quality of lives for people with epilepsy. High-frequency activity (HFA) is a biomarker that has received significant attention over the past 2 decades, but its predictive value in seizure forecasting remains uncertain. This work aimed to determine the utility of HFA in seizure forecasting. METHODS We used seizure data and HFA (80-170 Hz) data obtained from long-term, continuous intracranial EEG recordings of patients with drug-resistant epilepsy. Instantaneous rates and phases of HFA cycles were used as features for seizure forecasting. Seizure forecasts based on each individual HFA feature, and with the use of a combined approach, were generated pseudo-prospectively (causally). To compute the instantaneous phases for pseudo-prospective forecasting, real-time phase estimation based on an autoregressive model was used. Features were combined with a weighted average approach. The performance of seizure forecasting was primarily evaluated by the area under the curve (AUC). RESULTS Of 15 studied patients (median recording duration 557 days, median seizures 151), 12 patients with >10 seizures after 100 recording days were included in the pseudo-prospective analysis. The presented real-time phase estimation is feasible and can causally estimate the instantaneous phases of HFA cycles with high accuracy. Pseudo-prospective seizure forecasting based on HFA rates and phases performed significantly better than chance in 11 of 12 patients, although there were patient-specific differences. Combining rate and phase information improved forecasting performance compared to using either feature alone. The combined forecast using the best-performing channel yielded a median AUC of 0.70, a median sensitivity of 0.57, and a median specificity of 0.77. DISCUSSION These findings show that HFA could be useful for seizure forecasting and represent proof of concept for using prior information of patient-specific relationships between HFA and seizures in pseudo-prospective forecasting. Future seizure forecasting algorithms might benefit from the inclusion of HFA, and the real-time phase estimation approach can be extended to other biomarkers. CLASSIFICATION OF EVIDENCE This study provides Class IV evidence that HFA (80-170 Hz) in long-term continuous intracranial EEG can be useful to forecast seizures in patients with refractory epilepsy.
Collapse
Affiliation(s)
- Zhuying Chen
- From the Department of Biomedical Engineering (Z.C., A.N.B., M.J.C., D.B.G.) and Graeme Clark Institute for Biomedical Engineering (M.J.C., D.B.G.), University of Melbourne, Parkville; Department of Medicine (Z.C., M.I.M., M.J.C., D.B.G.), St Vincent's Hospital; and Seer Medical (M.I.M.), Melbourne, VIC, Australia.
| | - Matias I Maturana
- From the Department of Biomedical Engineering (Z.C., A.N.B., M.J.C., D.B.G.) and Graeme Clark Institute for Biomedical Engineering (M.J.C., D.B.G.), University of Melbourne, Parkville; Department of Medicine (Z.C., M.I.M., M.J.C., D.B.G.), St Vincent's Hospital; and Seer Medical (M.I.M.), Melbourne, VIC, Australia
| | - Anthony N Burkitt
- From the Department of Biomedical Engineering (Z.C., A.N.B., M.J.C., D.B.G.) and Graeme Clark Institute for Biomedical Engineering (M.J.C., D.B.G.), University of Melbourne, Parkville; Department of Medicine (Z.C., M.I.M., M.J.C., D.B.G.), St Vincent's Hospital; and Seer Medical (M.I.M.), Melbourne, VIC, Australia
| | - Mark J Cook
- From the Department of Biomedical Engineering (Z.C., A.N.B., M.J.C., D.B.G.) and Graeme Clark Institute for Biomedical Engineering (M.J.C., D.B.G.), University of Melbourne, Parkville; Department of Medicine (Z.C., M.I.M., M.J.C., D.B.G.), St Vincent's Hospital; and Seer Medical (M.I.M.), Melbourne, VIC, Australia
| | - David B Grayden
- From the Department of Biomedical Engineering (Z.C., A.N.B., M.J.C., D.B.G.) and Graeme Clark Institute for Biomedical Engineering (M.J.C., D.B.G.), University of Melbourne, Parkville; Department of Medicine (Z.C., M.I.M., M.J.C., D.B.G.), St Vincent's Hospital; and Seer Medical (M.I.M.), Melbourne, VIC, Australia
| |
Collapse
|
32
|
Shukralla AA, Dolan E, Delanty N. Acetazolamide: Old drug, new evidence? Epilepsia Open 2022; 7:378-392. [PMID: 35673961 PMCID: PMC9436286 DOI: 10.1002/epi4.12619] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 06/05/2022] [Indexed: 11/24/2022] Open
Abstract
Acetazolamide is an old drug used as an antiepileptic agent, amongst other indications. The drug is seldom used, primarily due to perceived poor efficacy and adverse events. Acetazolamide acts as a noncompetitive inhibitor of carbonic anhydrase, of which there are several subtypes in humans. Acetazolamide causes an acidification of the intracellular and extracellular environments activating acid‐sensing ion channels, and these may account for the anti‐seizure effects of acetazolamide. Other potential mechanisms are modulation of neuroinflammation and attenuation of high‐frequency oscillations. The overall effect increases the seizure threshold in critical structures such as the hippocampus. The evidence for its clinical efficacy was from 12 observational studies of 941 patients. The 50% responder rate was 49%, 20% of patients were rendered seizure‐free, and 30% were noted to have had at least one adverse event. We conclude that the evidence from several observational studies may overestimate efficacy because they lack a comparator; hence, this drug would need further randomized placebo‐controlled trials to assess effectiveness and harm.
Collapse
Affiliation(s)
| | - Emma Dolan
- The National Epilepsy Programme, Beaumont Hospital, Dublin, Ireland
| | - Norman Delanty
- The National Epilepsy Programme, Beaumont Hospital, Dublin, Ireland.,FutureNeuro, The SFI Research Centre for Chronic and Rare Neurological Disease, Dublin, Ireland.,Royal College of Surgeons in Ireland, Dublin, Ireland
| |
Collapse
|
33
|
Burelo K, Sharifshazileh M, Indiveri G, Sarnthein J. Automatic Detection of High-Frequency Oscillations With Neuromorphic Spiking Neural Networks. Front Neurosci 2022; 16:861480. [PMID: 35720714 PMCID: PMC9205405 DOI: 10.3389/fnins.2022.861480] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
Interictal high-frequency oscillations (HFO) detected in electroencephalography recordings have been proposed as biomarkers of epileptogenesis, seizure propensity, disease severity, and treatment response. Automatic HFO detectors typically analyze the data offline using complex time-consuming algorithms, which limits their clinical application. Neuromorphic circuits offer the possibility of building compact and low-power processing systems that can analyze data on-line and in real time. In this review, we describe a fully automated detection pipeline for HFO that uses, for the first time, spiking neural networks and neuromorphic technology. We demonstrated that our HFO detection pipeline can be applied to recordings from different modalities (intracranial electroencephalography, electrocorticography, and scalp electroencephalography) and validated its operation in a custom-designed neuromorphic processor. Our HFO detection approach resulted in high accuracy and specificity in the prediction of seizure outcome in patients implanted with intracranial electroencephalography and electrocorticography, and in the prediction of epilepsy severity in patients recorded with scalp electroencephalography. Our research provides a further step toward the real-time detection of HFO using compact and low-power neuromorphic devices. The real-time detection of HFO in the operation room may improve the seizure outcome of epilepsy surgery, while the use of our neuromorphic processor for non-invasive therapy monitoring might allow for more effective medication strategies to achieve seizure control. Therefore, this work has the potential to improve the quality of life in patients with epilepsy by improving epilepsy diagnostics and treatment.
Collapse
Affiliation(s)
- Karla Burelo
- Klinik für Neurochirurgie, UniversitätsSpital Zürich, Universität Zürich, Zurich, Switzerland
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Zurich, Switzerland
| | | | - Giacomo Indiveri
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Zurich, Switzerland
- Zentrum für Neurowissenschaften Zurich, ETH und Universität Zürich, Zurich, Switzerland
| | - Johannes Sarnthein
- Klinik für Neurochirurgie, UniversitätsSpital Zürich, Universität Zürich, Zurich, Switzerland
- Zentrum für Neurowissenschaften Zurich, ETH und Universität Zürich, Zurich, Switzerland
- *Correspondence: Johannes Sarnthein,
| |
Collapse
|
34
|
Loss of neuronal heterogeneity in epileptogenic human tissue impairs network resilience to sudden changes in synchrony. Cell Rep 2022; 39:110863. [PMID: 35613586 DOI: 10.1016/j.celrep.2022.110863] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/16/2022] [Accepted: 05/03/2022] [Indexed: 12/25/2022] Open
Abstract
A myriad of pathological changes associated with epilepsy can be recast as decreases in cell and circuit heterogeneity. We thus propose recontextualizing epileptogenesis as a process where reduction in cellular heterogeneity, in part, renders neural circuits less resilient to seizure. By comparing patch clamp recordings from human layer 5 (L5) cortical pyramidal neurons from epileptogenic and non-epileptogenic tissue, we demonstrate significantly decreased biophysical heterogeneity in seizure-generating areas. Implemented computationally, this renders model neural circuits prone to sudden transitions into synchronous states with increased firing activity, paralleling ictogenesis. This computational work also explains the surprising finding of significantly decreased excitability in the population-activation functions of neurons from epileptogenic tissue. Finally, mathematical analyses reveal a bifurcation structure arising only with low heterogeneity and associated with seizure-like dynamics. Taken together, this work provides experimental, computational, and mathematical support for the theory that ictogenic dynamics accompany a reduction in biophysical heterogeneity.
Collapse
|
35
|
Liu B, Ran X, Yi Y, Zhang X, Chen H, Hu Y. Anticonvulsant Effect of Carbenoxolone on Chronic Epileptic Rats and Its Mechanism Related to Connexin and High-Frequency Oscillations. Front Mol Neurosci 2022; 15:870947. [PMID: 35615064 PMCID: PMC9125185 DOI: 10.3389/fnmol.2022.870947] [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: 02/07/2022] [Accepted: 04/04/2022] [Indexed: 12/03/2022] Open
Abstract
Objective This study was designed to investigate the influence and mechanism of gap junction carbenoxolone (CBX) on dynamic changes in the spectral power of ripples and fast ripples (FRs) in the hippocampus of chronic epileptic rats. Methods The lithium-pilocarpine (PILO) status epilepticus (SE) model (PILO group) and the CBX pretreatment model (CBX + PILO group) were established to analyze dynamic changes in the spectral power of ripples and FRs, and the dynamic expression of connexin (CX)26, CX32, CX36, and CX43 in the hippocampus of chronic epileptic rats. Results Within 28 days after SE, the number of spontaneous recurrent seizures (SRSs) in the PILO group was significantly higher than that in the CBX + PILO group. The average spectral power of FRs in the PILO group was significantly higher than the baseline level at 1 and 7 days after SE. The average spectral power of FRs in the PILO group was significantly higher than that in the CBX + PILO group at 1, 7, and 14 days after SE. Seizures induced an increase in CX43 expression at 1 and 7 days after SE, but had no significant effect on CX26, CX36, or CX32. CBX pretreatment did not affect the expression of CXs in the hippocampus of normal rats, but it inhibited the expression of CX43 in epileptic rats. The number of SRSs at 2 and 4 weeks after SE had the highest correlation with the average spectral power of FRs; the average spectral power of FRs was moderately correlated with the expression of CX43. Conclusion The results of this study indicate that the energy of FRs may be regulated by its interference with the expression of CX43, and thus, affect seizures. Blocking the expression of CX43 thereby reduces the formation of pathological high-frequency oscillations (HFOs), making it a promising strategy for the treatment of chronic epilepsy.
Collapse
Affiliation(s)
- Benke Liu
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
- Shenzhen Baoan Women’s and Children’s Hospital, Jinan University, Shenzhen, China
| | - Xiao Ran
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
| | - Yanjun Yi
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
| | - Xinyu Zhang
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
| | - Hengsheng Chen
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
| | - Yue Hu
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, China
- *Correspondence: Yue Hu,
| |
Collapse
|
36
|
Validity of intraoperative ECoG in the parahippocampal gyrus as an indicator of hippocampal epileptogenicity. Epilepsy Res 2022; 184:106950. [DOI: 10.1016/j.eplepsyres.2022.106950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 05/01/2022] [Accepted: 05/25/2022] [Indexed: 11/20/2022]
|
37
|
Kajikawa S, Matsuhashi M, Kobayashi K, Hitomi T, Daifu-Kobayashi M, Kobayashi T, Yamao Y, Kikuchi T, Yoshida K, Kunieda T, Matsumoto R, Kakita A, Namiki T, Tsuda I, Miyamoto S, Takahashi R, Ikeda A. Two types of clinical ictal direct current shifts in invasive EEG of intractable focal epilepsy identified by waveform cluster analysis. Clin Neurophysiol 2022; 137:113-121. [PMID: 35305495 DOI: 10.1016/j.clinph.2022.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/07/2022] [Accepted: 02/25/2022] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To determine clinically ictal direct current (DC) shifts that can be identified by a time constant (TC) of 2 s and to delineate different types of DC shifts by different attenuation patterns between TC of 10 s and 2 s. METHODS Twenty-one patients who underwent subdural electrode implantation for epilepsy surgery were investigated. For habitual seizures, we compared (1) the peak amplitude and (2) peak latency of the earliest ictal DC shifts between TC of 10 s and 2 s. Cluster and logistic regression analyses were performed based on the attenuation rate of amplitude and peak latency with TC 10 s. RESULTS Ictal DC shifts in 120 seizures were analyzed; 89.1% of which were appropriately depicted even by a TC of 2 s. Cluster and logistic regression analyses revealed two types of ictal DC shift. Namely, a rapid development pattern was defined as the ictal DC shifts with a shorter peak latency and they also showed smaller attenuation rate of amplitude (73/120 seizures). Slow development pattern was defined as the ictal DC shifts with crosscurrent of a rapid development pattern, i.e., a longer peak latency and larger attenuation rate of amplitude (47/120 seizures). Focal cortical dysplasia (FCD) 1A tended to show a rapid development pattern (22/29 seizures) and FCD2A tended to show a slow development pattern (13 /18 seizures), indicating there might be some correlations between two types of ictal DC shift and certain pathologies. CONCLUSIONS Ictal DC shifts, especially rapid development pattern, can be recorded and identified by the AC amplifiers of TC of 2 s which is widely used in many institutes compared to that of TC of 10 s. Two types of ictal DC shifts were identified with possibility of corresponding pathology. SIGNIFICANCE Ictal DC shifts can be distinguished by their attenuation patterns.
Collapse
Affiliation(s)
- Shunsuke Kajikawa
- Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Masao Matsuhashi
- Department of Epilepsy, Movement Disorders and Physiology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Katsuya Kobayashi
- Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Takefumi Hitomi
- Department of Clinical Laboratory, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Masako Daifu-Kobayashi
- Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Tamaki Kobayashi
- Department of Neurosurgery, Otsu City Hospital, 2 Motomiya, Otsu-shi, Shiga 520-0804, Japan; Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Yukihiro Yamao
- Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Takayuki Kikuchi
- Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Kazumichi Yoshida
- Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Takeharu Kunieda
- Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan; Department of Neurosurgery, Ehime University Graduate School of Medicine, 454 Shitsukawa, Touon-shi, Ehime 791-0295, Japan.
| | - Riki Matsumoto
- Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan; Division of Neurology, Kobe University Graduate School of Medicine, 7 Kusunoki-cho, Chuou-ku, Kobe-shi, Hyougo 650-0017, Japan.
| | - Akiyoshi Kakita
- Department of Pathology, Brain Research Institute, Niigata University, 757 Asahi-cho 1, Chuou-ku, Niigata-shi, Niigata 951-8585, Japan.
| | - Takao Namiki
- Department of Mathematics, Faculty of Science, Hokkaido University, 8 West, 10 North, Kita-ku, Sapporo-shi, Hokkaido 060-0810, Japan.
| | - Ichiro Tsuda
- Chubu University Academy of Emerging Sciences, Chubu University, 1200 Matsumoto-cho, Kasugai-shi, Aichi 487-8501, Japan.
| | - Susumu Miyamoto
- Department of Neurosurgery, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Ryosuke Takahashi
- Department of Neurology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders and Physiology, Kyoto University Graduate School of Medicine, 54 Shogoin-Kawaharacho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507, Japan.
| |
Collapse
|
38
|
Differential Electrographic Signatures Generated by Mechanistically-Diverse Seizurogenic Compounds in the Larval Zebrafish Brain. eNeuro 2022; 9:ENEURO.0337-21.2022. [PMID: 35228313 PMCID: PMC8970338 DOI: 10.1523/eneuro.0337-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 01/13/2022] [Accepted: 01/21/2022] [Indexed: 11/21/2022] Open
Abstract
We assessed similarities and differences in the electrographic signatures of local field potentials (LFPs) evoked by different pharmacological agents in zebrafish larvae. We then compared and contrasted these characteristics with what is known from electrophysiological studies of seizures and epilepsy in mammals, including humans. Ultimately, our aim was to phenotype neurophysiological features of drug-induced seizures in larval zebrafish for expanding knowledge on the translational potential of this valuable alternative to mammalian models. LFPs were recorded from the midbrain of 4-d-old zebrafish larvae exposed to a pharmacologically diverse panel of seizurogenic compounds, and the outputs of these recordings were assessed using frequency domain analysis. This included analysis of changes occurring within various spectral frequency bands of relevance to mammalian CNS circuit pathophysiology. From these analyses, there were clear differences in the frequency spectra of drug-exposed LFPs, relative to controls, many of which shared notable similarities with the signatures exhibited by mammalian CNS circuits. These similarities included the presence of specific frequency components comparable to those observed in mammalian studies of seizures and epilepsy. Collectively, the data presented provide important information to support the value of larval zebrafish as an alternative model for the study of seizures and epilepsy. These data also provide further insight into the electrophysiological characteristics of seizures generated in nonmammalian species by the action of neuroactive drugs.
Collapse
|
39
|
Godoy LD, Prizon T, Rossignoli MT, Leite JP, Liberato JL. Parvalbumin Role in Epilepsy and Psychiatric Comorbidities: From Mechanism to Intervention. Front Integr Neurosci 2022; 16:765324. [PMID: 35250498 PMCID: PMC8891758 DOI: 10.3389/fnint.2022.765324] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 01/24/2022] [Indexed: 12/22/2022] Open
Abstract
Parvalbumin is a calcium-binding protein present in inhibitory interneurons that play an essential role in regulating many physiological processes, such as intracellular signaling and synaptic transmission. Changes in parvalbumin expression are deeply related to epilepsy, which is considered one of the most disabling neuropathologies. Epilepsy is a complex multi-factor group of disorders characterized by periods of hypersynchronous activity and hyperexcitability within brain networks. In this scenario, inhibitory neurotransmission dysfunction in modulating excitatory transmission related to the loss of subsets of parvalbumin-expressing inhibitory interneuron may have a prominent role in disrupted excitability. Some studies also reported that parvalbumin-positive interneurons altered function might contribute to psychiatric comorbidities associated with epilepsy, such as depression, anxiety, and psychosis. Understanding the epileptogenic process and comorbidities associated with epilepsy have significantly advanced through preclinical and clinical investigation. In this review, evidence from parvalbumin altered function in epilepsy and associated psychiatric comorbidities were explored with a translational perspective. Some advances in potential therapeutic interventions are highlighted, from current antiepileptic and neuroprotective drugs to cutting edge modulation of parvalbumin subpopulations using optogenetics, designer receptors exclusively activated by designer drugs (DREADD) techniques, transcranial magnetic stimulation, genome engineering, and cell grafting. Creating new perspectives on mechanisms and therapeutic strategies is valuable for understanding the pathophysiology of epilepsy and its psychiatric comorbidities and improving efficiency in clinical intervention.
Collapse
Affiliation(s)
- Lívea Dornela Godoy
- Department of Psychology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Tamiris Prizon
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Matheus Teixeira Rossignoli
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - João Pereira Leite
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- João Pereira Leite,
| | - José Luiz Liberato
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- *Correspondence: José Luiz Liberato,
| |
Collapse
|
40
|
Cai F, Wang K, Zhao T, Wang H, Zhou W, Hong B. BrainQuake: An Open-Source Python Toolbox for the Stereoelectroencephalography Spatiotemporal Analysis. Front Neuroinform 2022; 15:773890. [PMID: 35069168 PMCID: PMC8782204 DOI: 10.3389/fninf.2021.773890] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/26/2021] [Indexed: 11/13/2022] Open
Abstract
Intracranial stereoelectroencephalography (SEEG) is broadly used in the presurgical evaluation of intractable epilepsy, due to its high temporal resolution in neural activity recording and high spatial resolution within suspected epileptogenic zones. Neurosurgeons or technicians face the challenge of conducting a workflow of post-processing operations with the multimodal data (e.g., MRI, CT, and EEG) after the implantation surgery, such as brain surface reconstruction, electrode contact localization, and SEEG data analysis. Several software or toolboxes have been developed to take one or more steps in the workflow but without an end-to-end solution. In this study, we introduced BrainQuake, an open-source Python software for the SEEG spatiotemporal analysis, integrating modules and pipelines in surface reconstruction, electrode localization, seizure onset zone (SOZ) prediction based on ictal and interictal SEEG analysis, and final visualizations, each of which is highly automated with a user-friendly graphical user interface (GUI). BrainQuake also supports remote communications with a public server, which is facilitated with automated and standardized preprocessing pipelines, high-performance computing power, and data curation management to provide a time-saving and compatible platform for neurosurgeons and researchers.
Collapse
Affiliation(s)
- Fang Cai
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Kang Wang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Tong Zhao
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - Haixiang Wang
- Epilepsy Center, Yuquan Hospital, Tsinghua University, Beijing, China
| | - Wenjing Zhou
- Epilepsy Center, Yuquan Hospital, Tsinghua University, Beijing, China
| | - Bo Hong
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| |
Collapse
|
41
|
Simon MV, Nuwer MR, Szelényi A. Electroencephalography, electrocorticography, and cortical stimulation techniques. HANDBOOK OF CLINICAL NEUROLOGY 2022; 186:11-38. [PMID: 35772881 DOI: 10.1016/b978-0-12-819826-1.00001-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Electroencephalography (EEG) and electrocorticography (ECoG) are two important neurophysiologic techniques used in the operating room for monitoring and mapping electrical brain activity. In this chapter, we detail their principle, recording methodology, and address specifics of their interpretation in the intraoperative setting (e.g., effect of anesthetics), as well as their clinical applications in epilepsy and non-epilepsy surgeries. In addition, we address differences between scalp, surface, and deep cortical recordings that will help towards a more reliable interpretation of the significance of electrophysiologic parameters such as amplitude and morphology as well as in differentiation between abnormal and normal patterns of electrical brain activity. Electrical stimulation is used for intraoperative mapping of different cortical functions such as language, parietal, and motor. Stimulation paradigms used in clinical practice vary with regard to stimulation frequencies and probes being used. Parameters, such as the number of phases per pulse, pulse/phase duration, pulse frequency, organization, and polarity, define their characteristics, including their safety, propensity to trigger seizures, efficiency and reliability of stimulation, and the mapping thresholds. Specifically, in this chapter, we will address differences between monopolar and bipolar stimulation; anodal and cathodal polarity; monophasic and biphasic pulses; constant voltage, and constant current paradigms.
Collapse
Affiliation(s)
- Mirela V Simon
- Department of Neurology, Massachusetts General Hospital, Boston, MA, United States.
| | - Marc R Nuwer
- Departments of Neurology and Clinical Neurophysiology, David Geffen School of Medicine, University of California Los Angeles, and Ronald Reagan UCLA Medical Center, Los Angeles, CA, United States
| | - Andrea Szelényi
- Department of Neurosurgery, University Hospital, Ludwig-Maximilians-University (LMU), Munich, Germany
| |
Collapse
|
42
|
Frazzini V, Cousyn L, Navarro V. Semiology, EEG, and neuroimaging findings in temporal lobe epilepsies. HANDBOOK OF CLINICAL NEUROLOGY 2022; 187:489-518. [PMID: 35964989 DOI: 10.1016/b978-0-12-823493-8.00021-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Temporal lobe epilepsy (TLE) is the most common type of focal epilepsy. First descriptions of TLE date back in time and detailed portraits of epileptic seizures of temporal origin can be found in early medical reports as well as in the works of various artists and dramatists. Depending on the seizure onset zone, several subtypes of TLE have been identified, each one associated with peculiar ictal semiology. TLE can result from multiple etiological causes, ranging from genetic to lesional ones. While the diagnosis of TLE relies on detailed analysis of clinical as well as electroencephalographic (EEG) features, the lesions responsible for seizure generation can be highlighted by multiple brain imaging modalities or, in selected cases, by genetic investigations. TLE is the most common cause of refractory epilepsy and despite the great advances in diagnostic tools, no lesion is found in around one-third of patients. Surgical treatment is a safe and effective option, requiring presurgical investigations to accurately identify the seizure onset zone (SOZ). In selected cases, presurgical investigations need intracerebral investigations (such as stereoelectroencephalography) or dedicated metabolic imaging techniques (interictal PET and ictal SPECT) to correctly identify the brain structures to be removed.
Collapse
Affiliation(s)
- Valerio Frazzini
- AP-HP, Department of Neurology and Department of Clinical Neurophysiology, Epilepsy and EEG Unit, Reference Center for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, Paris Brain Institute, Team "Dynamics of Neuronal Networks and Neuronal Excitability", Paris, France
| | - Louis Cousyn
- AP-HP, Department of Neurology and Department of Clinical Neurophysiology, Epilepsy and EEG Unit, Reference Center for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, Paris Brain Institute, Team "Dynamics of Neuronal Networks and Neuronal Excitability", Paris, France
| | - Vincent Navarro
- AP-HP, Department of Neurology and Department of Clinical Neurophysiology, Epilepsy and EEG Unit, Reference Center for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, Paris Brain Institute, Team "Dynamics of Neuronal Networks and Neuronal Excitability", Paris, France.
| |
Collapse
|
43
|
Mokhothu TM, Tanaka KZ. Characterizing Hippocampal Oscillatory Signatures Underlying Seizures in Temporal Lobe Epilepsy. Front Behav Neurosci 2021; 15:785328. [PMID: 34899205 PMCID: PMC8656355 DOI: 10.3389/fnbeh.2021.785328] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/29/2021] [Indexed: 01/01/2023] Open
Abstract
Temporal Lobe Epilepsy (TLE) is a neurological condition characterized by focal brain hyperexcitability, resulting in abnormal neuronal discharge and uncontrollable seizures. The hippocampus, with its inherently highly synchronized firing patterns and relatively high excitability, is prone to epileptic seizures, and it is usually the focus of TLE. Researchers have identified hippocampal high-frequency oscillations (HFOs) as a salient feature in people with TLE and animal models of this disease, arising before or at the onset of the epileptic event. To a certain extent, these pathological HFOs have served as a marker and a potential target for seizure attenuation using electrical or optogenetic interventions. However, many questions remain about whether we can reliably distinguish pathological from non-pathological HFOs and whether they can tell us about the development of the disease. While this would be an arduous task to perform in humans, animal models of TLE provide an excellent opportunity to study the characteristics of HFOs in predicting how epilepsy evolves. This minireview will (1) summarize what we know about the oscillatory disruption in TLE, (2) summarize knowledge about oscillatory changes in the latent period and their role in predicting seizures, and (3) propose future studies essential to uncovering potential treatments based on early detection of pathological HFOs.
Collapse
Affiliation(s)
- Thato Mary Mokhothu
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Kazumasa Zen Tanaka
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| |
Collapse
|
44
|
Guth TA, Kunz L, Brandt A, Dümpelmann M, Klotz KA, Reinacher PC, Schulze-Bonhage A, Jacobs J, Schönberger J. Interictal spikes with and without high-frequency oscillation have different single-neuron correlates. Brain 2021; 144:3078-3088. [PMID: 34343264 PMCID: PMC8634126 DOI: 10.1093/brain/awab288] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 06/07/2021] [Accepted: 07/06/2021] [Indexed: 11/13/2022] Open
Abstract
Interictal epileptiform discharges (IEDs) are a widely used biomarker in patients with epilepsy but lack specificity. It has been proposed that there are truly epileptogenic and less pathological or even protective IEDs. Recent studies suggest that highly pathological IEDs are characterized by high-frequency oscillations (HFOs). Here, we aimed to dissect these 'HFO-IEDs' at the single-neuron level, hypothesizing that the underlying mechanisms are distinct from 'non-HFO-IEDs'. Analysing hybrid depth electrode recordings from patients with temporal lobe epilepsy, we found that single-unit firing rates were higher in HFO- than in non-HFO-IEDs. HFO-IEDs were characterized by a pronounced pre-peak increase in firing, which coincided with the preferential occurrence of HFOs, whereas in non-HFO-IEDs, there was only a mild pre-peak increase followed by a post-peak suppression. Comparing each unit's firing during HFO-IEDs to its baseline activity, we found many neurons with a significant increase during the HFO component or ascending part, but almost none with a decrease. No such imbalance was observed during non-HFO-IEDs. Finally, comparing each unit's firing directly between HFO- and non-HFO-IEDs, we found that most cells had higher rates during HFO-IEDs and, moreover, identified a distinct subset of neurons with a significant preference for this IED subtype. In summary, our study reveals that HFO- and non-HFO-IEDs have different single-unit correlates. In HFO-IEDs, many neurons are moderately activated, and some participate selectively, suggesting that both types of increased firing contribute to highly pathological IEDs.
Collapse
Affiliation(s)
- Tim A Guth
- Epilepsy Center, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neuropediatrics and Muscle Disorders, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lukas Kunz
- Epilepsy Center, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Armin Brandt
- Epilepsy Center, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthias Dümpelmann
- Epilepsy Center, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Kerstin A Klotz
- Epilepsy Center, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neuropediatrics and Muscle Disorders, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Berta-Ottenstein-Programme, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Peter C Reinacher
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Stereotactic and Functional Neurosurgery, Medical Center—University of Freiburg, Freiburg, Germany
- Fraunhofer Institute for Laser Technology, Aachen, Germany
| | - Andreas Schulze-Bonhage
- Epilepsy Center, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Julia Jacobs
- Department of Neuropediatrics and Muscle Disorders, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Paediatrics and Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Jan Schönberger
- Epilepsy Center, Medical Center, University of Freiburg, Freiburg, Germany
- Department of Neuropediatrics and Muscle Disorders, Medical Center, University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Berta-Ottenstein-Programme, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
45
|
High frequency oscillations associate with neuroinflammation in low-grade epilepsy associated tumors. Clin Neurophysiol 2021; 133:165-174. [PMID: 34774442 DOI: 10.1016/j.clinph.2021.08.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/03/2021] [Accepted: 08/29/2021] [Indexed: 01/26/2023]
Abstract
OBJECTIVE High frequency oscillations (HFOs) in intraoperative electrocorticography (ioECoG) are thought to be generated by hyperexcitable neurons. Inflammation may promote neuronal hyperexcitability. We investigated the relation between HFOs and inflammation in tumor-related epilepsy. METHODS We identified HFOs (ripples 80-250 Hz, fast ripples 250-500 Hz) in the preresection ioECoG of 32 patients with low-grade tumors. Localization of recorded HFOs was classified based on magnetic resonance imaging reconstructions: in tumor, in resected non-tumorous area and outside the resected area. We tested if the following inflammatory markers in the tumor or peritumoral tissue were related to HFOs: activated microglia, cluster of differentiation 3 (CD3)-positive T-cells, interleukin 1-beta (IL1β), toll-like receptor 4 (TLR4) and high mobility group box 1 protein (HMGB1). RESULTS Tumors that generated ripples were infiltrated by more CD3-positive cells than tumors without ripples. Ripple rate outside the resected area was positively correlated with IL1β/TLR4/HMGB1 pathway activity in peritumoral area. These two areas did not directly overlap. CONCLUSIONS Ripple rates may be associated with inflammatory processes. SIGNIFICANCE Our findings support that ripple generation and spread might be associated with synchronized fast firing of hyperexcitable neurons due to certain inflammatory processes. This pilot study provides arguments for further investigations in HFOs and inflammation.
Collapse
|
46
|
Yang Y, Wang W, Wang J, Wang M, Li X, Yan Z, Deng Q, Feng X, Luan G, Yang X, Li T. Scalp-HFO indexes are biomarkers for the lateralization and localization of the epileptogenic zone in preoperative assessment. J Neurophysiol 2021; 126:1148-1158. [PMID: 34495792 DOI: 10.1152/jn.00212.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During the noninvasive evaluation phase for refractory epilepsy, the localization of the epileptogenic zone (EZ) is essential for the surgical protocols. Confirmation of laterality is required when the preoperative evaluation limits the EZ to bilateral anterior temporal lobes or bilateral frontal lobes. High-frequency oscillations (HFOs) are considered to be promising biological markers for the EZ. However, a large number of studies on HFOs stem from intracranial research. There were few quantitative measures for scalp HFOs, so we proposed a new method to quantify and analyze scalp HFOs. This method was called the "scalp-HFO index" (HI) and calculated in both the EZ and non-EZ. The calculation was based on the numbers and spectral power of scalp HFOs automatically detected. We labeled the brain lobes involved in the EZ as regions of interest (ROIs). The HIs based on the ripple numbers (n-HI) and spectral power (s-HI) were significantly higher in the ROI than in the contra-ROI (P = 0.012, P = 0.003), indicating that HIs contributed to the lateralization of EZ. The sensitivity and specificity of n-HI for the localization of the EZ were 90% and 79.58%, respectively, suggesting that n-HI was valuable in localizing the EZ. HI may contribute to the implantation strategy of invasive electrodes. However, few scalp HFOs were recorded when the EZ was located in the medial cortex region.NEW & NOTEWORTHY We proposed the scalp-high-frequency oscillation (HFO) index (HI) as a quantitative assessment method for scalp HFOs to locate the epileptogenic zone (EZ). Our results showed that the HI in regions of interest (ROIs) was significantly higher than in contra-ROIs. Sensitivity and specificity of HI based on ripple rates (n-HI) for EZ localization were 90% and 79.58%, respectively. If the n-HI of the brain region was >1.35, it was more likely to be an epileptogenic region. Clinical application of HIs as an indicator may facilitate localization of the EZ.
Collapse
Affiliation(s)
- Yujiao Yang
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Wei Wang
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China.,Bioland Laboratory, Guangzhou Regenerative Medicine and Health, Guangdong Laboratory, Guangzhou, China
| | - Jing Wang
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Mengyang Wang
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Xiaonan Li
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China.,Bioland Laboratory, Guangzhou Regenerative Medicine and Health, Guangdong Laboratory, Guangzhou, China
| | - Zhaofen Yan
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Qinqin Deng
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Xing Feng
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing, China
| | - Guoming Luan
- Department of Functional Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Epilepsy, Sanbo Brain Hospital, Capital Medical University, Beijing, China.,Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Xiaofeng Yang
- Bioland Laboratory, Guangzhou Regenerative Medicine and Health, Guangdong Laboratory, Guangzhou, China
| | - Tianfu Li
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Epilepsy, Sanbo Brain Hospital, Capital Medical University, Beijing, China.,Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| |
Collapse
|
47
|
Lee CH, Le JT, Swann JW. Brain state-dependent high-frequency activity as a biomarker for abnormal neocortical networks in an epileptic spasms animal model. Epilepsia 2021; 62:2263-2273. [PMID: 34258765 DOI: 10.1111/epi.17008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Epileptic spasms are a hallmark of a severe epileptic state. A previous study showed neocortical up and down states defined by unit activity play a role in the generation of spasms. However, recording unit activity is challenging in clinical settings, and more accessible neurophysiological signals are needed for the analysis of these brain states. METHODS In the tetrodotoxin model, we used 16-channel microarrays to record electrophysiological activity in the neocortex during interictal periods and spasms. High-frequency activity (HFA) in the frequency range of fast ripples (200-500 Hz) was analyzed, as were slow wave oscillations (1-8 Hz), and correlated with the neocortical up and down states defined by multiunit activity (MUA). RESULTS HFA and MUA had high temporal correlation during interictal and ictal periods. Both increased strikingly during interictal up states and ictal events but were silenced during interictal down states and preictal pauses, and their distributions were clustered at the peak of slow oscillations in local field potential recordings. In addition, both HFA power and MUA firing rates were increased to a greater extent during spasms than interictal up states. During non-rapid eye movement sleep, the HFA rhythmicity faithfully followed the MUA up and down states, but during rapid eye movement sleep when MUA up and down states disappeared the HFA rhythmicity was largely absent. We also observed an increase in the number of HFA down state minutes prior to ictal onset, consistent with the results from analyses of MUA down states. SIGNIFICANCE This study provides evidence that HFA may serve as a biomarker for the pathological up states of epileptic spasms. The availability of HFA recordings makes this a clinically practical technique. These findings will likely provide a novel approach for localizing and studying epileptogenic neocortical networks not only in spasms patients but also in other types of epilepsy.
Collapse
Affiliation(s)
- Chih-Hong Lee
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
- Department of Neurology, Chang Gung Memorial Hospital Linkou Medical Center and Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - John T Le
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - John W Swann
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
- Cain Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| |
Collapse
|
48
|
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.
Collapse
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.
| |
Collapse
|
49
|
Moraes MFD, de Castro Medeiros D, Mourao FAG, Cancado SAV, Cota VR. Epilepsy as a dynamical system, a most needed paradigm shift in epileptology. Epilepsy Behav 2021; 121:106838. [PMID: 31859231 DOI: 10.1016/j.yebeh.2019.106838] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/22/2019] [Accepted: 12/01/2019] [Indexed: 01/08/2023]
Abstract
The idea of the epileptic brain being highly excitable and facilitated to synchronic activity has guided pharmacological treatment since the early twentieth century. Although tackling epilepsy's seizure-prone feature, by tonically modifying overall circuit excitability and/or connectivity, the last 50 years of drug development has not seen a substantial improvement in seizure suppression of refractory epilepsies. This review presents a new conceptual framework for epilepsy in which the temporal dynamics of the disease plays a more critical role in both its understanding and therapeutic strategies. The repetitive epileptiform pattern (characteristic during ictal activity) and other well-defined electrographic signatures (i.e., present during the interictal period) are discussed in terms of the sequential activation of the circuit motifs. Lessons learned from the physiological activation of neural circuitry are used to further corroborate the argument and explore the transition from proper function to a state of instability. Furthermore, the review explores how interfering in the temporally dependent abnormal connectivity between circuits may work as a therapeutic approach. We also review the use of probing stimulation to access network connectivity and evaluate its power to determine transitional states of the dynamical system as it moves towards regions of instability, especially when conventional electrographic monitoring is proven inefficient. Unorthodox cases, with little or no scalp electrographic correlate, in which ictogenic circuitry and/or seizure spread is temporally restricted to neurovegetative, cognitive, and motivational areas are shown as possible explanations for sudden death in epilepsy (SUDEP) and other psychiatric comorbidities. In short, this review presents a paradigm shift in the way that we address the disease and is aimed to encourage debate rather than narrow the rationale epilepsy is currently engaged in. This article is part of the Special Issue "NEWroscience 2018".
Collapse
Affiliation(s)
- Márcio Flávio Dutra Moraes
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Centro de Tecnologia e Pesquisa em Magneto Ressonância, Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
| | - Daniel de Castro Medeiros
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Flávio Afonso Gonçalves Mourao
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Centro de Tecnologia e Pesquisa em Magneto Ressonância, Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Vinicius Rosa Cota
- Laboratório Interdisciplinar de Neuroengenharia e Neurociências, Departamento de Engenharia Elétrica, Universidade Federal de São João Del-Rei, São João Del-Rei, Brazil
| |
Collapse
|
50
|
Chvojka J, Kudlacek J, Chang WC, Novak O, Tomaska F, Otahal J, Jefferys JGR, Jiruska P. The role of interictal discharges in ictogenesis - A dynamical perspective. Epilepsy Behav 2021; 121:106591. [PMID: 31806490 DOI: 10.1016/j.yebeh.2019.106591] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/23/2019] [Accepted: 09/23/2019] [Indexed: 10/25/2022]
Abstract
Interictal epileptiform discharge (IED) is a traditional hallmark of epileptic tissue that is generated by the synchronous activity of a population of neurons. Interictal epileptiform discharges represent a heterogeneous group of pathological activities that differ in shape, duration, spatiotemporal distribution, underlying cellular and network mechanisms, and their relationship to seizure genesis. The exact role of IEDs in epilepsy is still not well understood, and there remains a persistent dichotomy about the impact on IEDs on seizures. Proseizure, antiseizure, and no impact on ictogenesis have all been described in previous studies. In this article, we review the existing knowledge on the role of interictal discharges in seizure genesis, and we discuss how dynamical approaches to ictogenesis can explain the existing dichotomy about the multifaceted role of IEDs in ictogenesis. This article is part of the Special Issue "NEWroscience 2018".
Collapse
Affiliation(s)
- Jan Chvojka
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic; Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic; Department of Circuit Theory, Faculty of Electrical Engineering, Czech Technical University in Prague, Prague, Czech Republic
| | - Jan Kudlacek
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic; Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic; Department of Circuit Theory, Faculty of Electrical Engineering, Czech Technical University in Prague, Prague, Czech Republic
| | - Wei-Chih Chang
- Faculty of Veterinary Medicine and Neuroscience Center, University of Helsinki, Helsinki 00014, Finland
| | - Ondrej Novak
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Filip Tomaska
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jakub Otahal
- Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, 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, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Premysl Jiruska
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic; Department of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
| |
Collapse
|