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Yu S, Chen X, Yang T, Cheng J, Liu E, Jiang L, Song M, Shu H, Ma Y. Revealing the mechanisms of blood-brain barrier in chronic neurodegenerative disease: an opportunity for therapeutic intervention. Rev Neurosci 2024; 0:revneuro-2024-0040. [PMID: 38967133 DOI: 10.1515/revneuro-2024-0040] [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: 03/16/2024] [Accepted: 05/30/2024] [Indexed: 07/06/2024]
Abstract
The brain microenvironment is tightly regulated, and the blood-brain barrier (BBB) plays a pivotal role in maintaining the homeostasis of the central nervous system. It effectively safeguards brain tissue from harmful substances in peripheral blood. However, both acute pathological factors and age-related biodegradation have the potential to compromise the integrity of the BBB and are associated with chronic neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD), as well as Epilepsy (EP). This association arises due to infiltration of peripheral foreign bodies including microorganisms, immune-inflammatory mediators, and plasma proteins into the central nervous system when the BBB is compromised. Nevertheless, these partial and generalized understandings do not prompt a shift from passive to active treatment approaches. Therefore, it is imperative to acquire a comprehensive and in-depth understanding of the intricate molecular mechanisms underlying vascular disease alterations associated with the onset and progression of chronic neurodegenerative disorders, as well as the subsequent homeostatic changes triggered by BBB impairment. The present article aims to systematically summarize and review recent scientific work with a specific focus on elucidating the fundamental mechanisms underlying BBB damage in AD, PD, and EP as well as their consequential impact on disease progression. These findings not only offer guidance for optimizing the physiological function of the BBB, but also provide valuable insights for developing intervention strategies aimed at early restoration of BBB structural integrity, thereby laying a solid foundation for designing drug delivery strategies centered around the BBB.
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Affiliation(s)
- Sixun Yu
- Department of Neurosurgery, Western Theater General Hospital, Chengdu, Sichuan Province, China
- College of Medicine, Southwest Jiaotong University, Chengdu, Sichuan Province, China
| | - Xin Chen
- Department of Neurosurgery, Western Theater General Hospital, Chengdu, Sichuan Province, China
| | - Tao Yang
- Department of Neurosurgery, Western Theater General Hospital, Chengdu, Sichuan Province, China
| | - Jingmin Cheng
- Department of Neurosurgery, Western Theater General Hospital, Chengdu, Sichuan Province, China
| | - Enyu Liu
- Department of Neurosurgery, Western Theater General Hospital, Chengdu, Sichuan Province, China
| | - Lingli Jiang
- Department of Neurosurgery, Western Theater General Hospital, Chengdu, Sichuan Province, China
| | - Min Song
- Department of Neurosurgery, Western Theater General Hospital, Chengdu, Sichuan Province, China
| | - Haifeng Shu
- Department of Neurosurgery, Western Theater General Hospital, Chengdu, Sichuan Province, China
- College of Medicine, Southwest Jiaotong University, Chengdu, Sichuan Province, China
| | - Yuan Ma
- Department of Neurosurgery, Western Theater General Hospital, Chengdu, Sichuan Province, China
- Department of Neurosurgery, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province, China
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Chen H, Mirg S, Gaddale P, Agrawal S, Li M, Nguyen V, Xu T, Li Q, Liu J, Tu W, Liu X, Drew PJ, Zhang N, Gluckman BJ, Kothapalli SR. Multiparametric Brain Hemodynamics Imaging Using a Combined Ultrafast Ultrasound and Photoacoustic System. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2401467. [PMID: 38884161 DOI: 10.1002/advs.202401467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/25/2024] [Indexed: 06/18/2024]
Abstract
Studying brain-wide hemodynamic responses to different stimuli at high spatiotemporal resolutions can help gain new insights into the mechanisms of neuro- diseases and -disorders. Nonetheless, this task is challenging, primarily due to the complexity of neurovascular coupling, which encompasses interdependent hemodynamic parameters including cerebral blood volume (CBV), cerebral blood flow (CBF), and cerebral oxygen saturation (SO2). The current brain imaging technologies exhibit inherent limitations in resolution, sensitivity, and imaging depth, restricting their capacity to comprehensively capture the intricacies of cerebral functions. To address this, a multimodal functional ultrasound and photoacoustic (fUSPA) imaging platform is reported, which integrates ultrafast ultrasound and multispectral photoacoustic imaging methods in a compact head-mountable device, to quantitatively map individual dynamics of CBV, CBF, and SO2 as well as contrast agent enhanced brain imaging at high spatiotemporal resolutions. Following systematic characterization, the fUSPA system is applied to study brain-wide cerebrovascular reactivity (CVR) at single-vessel resolution via relative changes in CBV, CBF, and SO2 in response to hypercapnia stimulation. These results show that cortical veins and arteries exhibit differences in CVR in the stimulated state and consistent anti-correlation in CBV oscillations during the resting state, demonstrating the multiparametric fUSPA system's unique capabilities in investigating complex mechanisms of brain functions.
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Affiliation(s)
- Haoyang Chen
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Shubham Mirg
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Prameth Gaddale
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Sumit Agrawal
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Menghan Li
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Van Nguyen
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Tianbao Xu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Qiong Li
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Jinyun Liu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Wenyu Tu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Xiao Liu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Institute for Computational and Data Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Patrick J Drew
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Nanyin Zhang
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Bruce J Gluckman
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Sri-Rajasekhar Kothapalli
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Penn State Cancer Institute, The Pennsylvania State University, Hershey, PA, 17033, USA
- Graduate Program in Acoustics, The Pennsylvania State University, University Park, PA, 16802, USA
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Lucas A, Vadali C, Mouchtaris S, Arnold TC, Gugger JJ, Kulick-Soper C, Josyula M, Petillo N, Das S, Dubroff J, Detre JA, Stein JM, Davis KA. Enhancing the Diagnostic Utility of ASL Imaging in Temporal Lobe Epilepsy through FlowGAN: An ASL to PET Image Translation Framework. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.28.24308027. [PMID: 38853910 PMCID: PMC11160820 DOI: 10.1101/2024.05.28.24308027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Background and Significance Positron Emission Tomography (PET) using fluorodeoxyglucose (FDG-PET) is a standard imaging modality for detecting areas of hypometabolism associated with the seizure onset zone (SOZ) in temporal lobe epilepsy (TLE). However, FDG-PET is costly and involves the use of a radioactive tracer. Arterial Spin Labeling (ASL) offers an MRI-based quantification of cerebral blood flow (CBF) that could also help localize the SOZ, but its performance in doing so, relative to FDG-PET, is limited. In this study, we seek to improve ASL's diagnostic performance by developing a deep learning framework for synthesizing FDG-PET-like images from ASL and structural MRI inputs. Methods We included 68 epilepsy patients, out of which 36 had well lateralized TLE. We compared the coupling between FDG-PET and ASL CBF values in different brain regions, as well as the asymmetry of these values across the brain. We additionally assessed each modality's ability to lateralize the SOZ across brain regions. Using our paired PET-ASL data, we developed FlowGAN, a generative adversarial neural network (GAN) that synthesizes PET-like images from ASL and T1-weighted MRI inputs. We tested our synthetic PET images against the actual PET images of subjects to assess their ability to reproduce clinically meaningful hypometabolism and asymmetries in TLE. Results We found variable coupling between PET and ASL CBF values across brain regions. PET and ASL had high coupling in neocortical temporal and frontal brain regions (Spearman's r > 0.30, p < 0.05) but low coupling in mesial temporal structures (Spearman's r < 0.30, p > 0.05). Both whole brain PET and ASL CBF asymmetry values provided good separability between left and right TLE subjects, but PET (AUC = 0.96, 95% CI: [0.88, 1.00]) outperformed ASL (AUC = 0.81; 95% CI: [0.65, 0.96]). FlowGAN-generated images demonstrated high structural similarity to actual PET images (SSIM = 0.85). Globally, asymmetry values were better correlated between synthetic PET and original PET than between ASL CBF and original PET, with a mean correlation increase of 0.15 (95% CI: [0.07, 0.24], p<0.001, Cohen's d = 0.91). Furthermore, regions that had poor ASL-PET correlation (e.g. mesial temporal structures) showed the greatest improvement with synthetic PET images. Conclusions FlowGAN improves ASL's diagnostic performance, generating synthetic PET images that closely mimic actual FDG-PET in depicting hypometabolism associated with TLE. This approach could improve non-invasive SOZ localization, offering a promising tool for epilepsy presurgical assessment. It potentially broadens the applicability of ASL in clinical practice and could reduce reliance on FDG-PET for epilepsy and other neurological disorders.
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Affiliation(s)
- Alfredo Lucas
- Perelman School of Medicine, University of Pennsylvania
- Department of Bioengineering, University of Pennsylvania
| | - Chetan Vadali
- Department of Bioengineering, University of Pennsylvania
| | | | | | | | | | | | - Nina Petillo
- Department of Neurology, University of Pennsylvania
| | | | | | - John A Detre
- Department of Neurology, University of Pennsylvania
| | - Joel M Stein
- Department of Radiology, University of Pennsylvania
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Tada Y, Fujihara T, Yamaguchi I, Korai M, Sogabe S, Azumi M, Shikata E, Bando K, Nakajima K, Shimada K, Yamamoto N, Yamazaki H, Izumi Y, Harada M, Kanematsu Y, Takagi Y. Nonconvulsive status epilepticus in patients with acute subarachnoid hemorrhage is associated with negative arterial spin labeling on peri-ictal magnetic resonance images. Heliyon 2024; 10:e24754. [PMID: 38298648 PMCID: PMC10828066 DOI: 10.1016/j.heliyon.2024.e24754] [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: 04/28/2023] [Revised: 12/16/2023] [Accepted: 01/12/2024] [Indexed: 02/02/2024] Open
Abstract
Purpose Non-convulsive status epilepticus (NCSE) is characterized by repetitive or continuous seizures without convulsions. Arterial spin labeling (ASL) is useful for assessing hyperperfusion due to neurovascular unit coupling in patients with NCSE; subarachnoid hemorrhage (SAH) impairs the neurovascular unit. We hypothesized that the sensitivity of ASL in detecting NCSE is low in patients with SAH during the acute phase. Methods Based on ASL findings obtained within 48 h after the clinical suspicion of focal-onset NCSE, we divided 34 patients into ASL-negative (no hyperperfusion; n = 10) and ASL-positive (confirmed hyperperfusion; n = 24) groups. We further divided the two groups according to the NCSE etiology: patients who were diagnosed with NCSE within 14 days after SAH onset (acute SAH, n = 11) and patients with NCSE due to factors other acute SAH (n = 23) and compared their characteristics. Results In 10 of the 34 patients (29.4 %) the ASL findings were normal. The rate of acute SAH was significantly higher in ASL-negative- (n = 8, 80.0 %) than ASL-positive patients (n = 3, 12.5 %). The rate of patients in aphasic status was significantly lower in ASL-negative patients (n = 1, 10 %) than in ASL-positive patients (n = 12, 50.0 %). Conclusion Normal ASL findings alone should not be used to exclude a diagnosis of NCSE particularly in patients in the acute phase of SAH with deterioration or no improvement in consciousness.
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Affiliation(s)
- Yoshiteru Tada
- Epilepsy Center, Tokushima University Hospital, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Toshitaka Fujihara
- Epilepsy Center, Tokushima University Hospital, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Izumi Yamaguchi
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Masaaki Korai
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Shu Sogabe
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Mai Azumi
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Eiji Shikata
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Koji Bando
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Kohei Nakajima
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Kenji Shimada
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Nobuaki Yamamoto
- Department of Neurology, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Hiroki Yamazaki
- Epilepsy Center, Tokushima University Hospital, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
- Department of Neurology, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Yuishin Izumi
- Epilepsy Center, Tokushima University Hospital, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
- Department of Neurology, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Masafumi Harada
- Department of Radiology, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Yasuhisa Kanematsu
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
| | - Yasushi Takagi
- Department of Neurosurgery, Graduate School of Biomedical Sciences, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima, Tokushima, 770-8503, Japan
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Qing K, Alkhachroum A, Claassen J, Forgacs P, Schiff N. The Electrographic Effects of Ketamine on Patients With Refractory Status Epilepticus After Cardiac Arrest: A Single-Center Retrospective Cohort. J Clin Neurophysiol 2024:00004691-990000000-00119. [PMID: 38194637 PMCID: PMC11231056 DOI: 10.1097/wnp.0000000000001065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024] Open
Abstract
PURPOSE To investigate the effects of ketamine on patients with refractory status epilepticus after cardiac arrest. METHODS In this retrospective cohort, selected EEG segments from patients after cardiac arrest were classified into different EEG patterns (based on background continuity and burden of epileptiform discharges) and spectral profiles (based on the presence of frequency components). For patients who received ketamine, EEG data were compared before, during, and after ketamine infusion; for the no-ketamine group, EEG data were compared at three separated time points during recording. Ketamine usage was determined by clinical providers. Electrographic improvement in epileptiform activity was scored, and the odds ratio was calculated using the Fisher exact test. Functional outcome measures at time of discharge were also examined. RESULTS Of a total of 38 patients with postcardiac arrest refractory status epilepticus, 13 received ketamine and 25 did not. All patients were on ≥2 antiseizure medications including at least one sedative infusion (midazolam). For the ketamine group, eight patients had electrographic improvement, compared with only two patients in the no-ketamine group, with an odds ratio of 7.19 (95% confidence interval 1.16-44.65, P value of 0.0341) for ketamine versus no ketamine. Most of the patients who received ketamine had myoclonic status epilepticus, and overall neurologic outcomes were poor with no patients having a favorable outcome. CONCLUSIONS For postarrest refractory status epilepticus, ketamine use was associated with electrographic improvement, but with the available data, it is unclear whether ketamine use or EEG improvement can be linked to better functional recovery.
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Affiliation(s)
- Kurt Qing
- Department of Neurology, New York-Presbyterian Hospital Weill Cornell, New York, New York, U.S.A
| | - Ayham Alkhachroum
- Department of Neurology, University of Miami, Miami, Florida, U.S.A.; and
| | - Jan Claassen
- Department of Neurology, Columbia University Medical Center, New York, New York, U.S.A
| | - Peter Forgacs
- Department of Neurology, New York-Presbyterian Hospital Weill Cornell, New York, New York, U.S.A
| | - Nicholas Schiff
- Department of Neurology, New York-Presbyterian Hospital Weill Cornell, New York, New York, U.S.A
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Chen H, Mirg S, Gaddale P, Agrawal S, Li M, Nguyen V, Xu T, Li Q, Liu J, Tu W, Liu X, Drew PJ, Zhang N, Gluckman BJ, Kothapalli SR. Dissecting Multiparametric Cerebral Hemodynamics using Integrated Ultrafast Ultrasound and Multispectral Photoacoustic Imaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.07.566048. [PMID: 37986863 PMCID: PMC10659547 DOI: 10.1101/2023.11.07.566048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Understanding brain-wide hemodynamic responses to different stimuli at high spatiotemporal resolutions can help study neuro-disorders and brain functions. However, the existing brain imaging technologies have limited resolution, sensitivity, imaging depth and provide information about only one or two hemodynamic parameters. To address this, we propose a multimodal functional ultrasound and photoacoustic (fUSPA) imaging platform, which integrates ultrafast ultrasound and multispectral photoacoustic imaging methods in a compact head-mountable device, to quantitatively map cerebral blood volume (CBV), cerebral blood flow (CBF), oxygen saturation (SO2) dynamics as well as contrast agent enhanced brain imaging with high spatiotemporal resolutions. After systematic characterization, the fUSPA system was applied to quantitatively study the changes in brain hemodynamics and vascular reactivity at single vessel resolution in response to hypercapnia stimulation. Our results show an overall increase in brain-wide CBV, CBF, and SO2, but regional differences in singular cortical veins and arteries and a reproducible anti-correlation pattern between venous and cortical hemodynamics, demonstrating the capabilities of the fUSPA system for providing multiparametric cerebrovascular information at high-resolution and sensitivity, that can bring insights into the complex mechanisms of neurodiseases.
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Affiliation(s)
- Haoyang Chen
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Shubham Mirg
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Prameth Gaddale
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Sumit Agrawal
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Menghan Li
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Van Nguyen
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Tianbao Xu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Qiong Li
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jinyun Liu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Wenyu Tu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Xiao Liu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Institute for Computational and Data Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Patrick J. Drew
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA 16802, USA
| | - Nanyin Zhang
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Bruce J. Gluckman
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Neurosurgery, The Pennsylvania State University, University Park, PA 16802, USA
| | - Sri-Rajasekhar Kothapalli
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Neural Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Penn State Cancer Institute, The Pennsylvania State University, Hershey, PA 17033, USA
- Graduate Program in Acoustics, The Pennsylvania State University, University Park, PA 16802, USA
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Sanicola HW, Stewart CE, Luther P, Yabut K, Guthikonda B, Jordan JD, Alexander JS. Pathophysiology, Management, and Therapeutics in Subarachnoid Hemorrhage and Delayed Cerebral Ischemia: An Overview. PATHOPHYSIOLOGY 2023; 30:420-442. [PMID: 37755398 PMCID: PMC10536590 DOI: 10.3390/pathophysiology30030032] [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: 07/20/2023] [Revised: 08/21/2023] [Accepted: 09/07/2023] [Indexed: 09/28/2023] Open
Abstract
Subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke resulting from the rupture of an arterial vessel within the brain. Unlike other stroke types, SAH affects both young adults (mid-40s) and the geriatric population. Patients with SAH often experience significant neurological deficits, leading to a substantial societal burden in terms of lost potential years of life. This review provides a comprehensive overview of SAH, examining its development across different stages (early, intermediate, and late) and highlighting the pathophysiological and pathohistological processes specific to each phase. The clinical management of SAH is also explored, focusing on tailored treatments and interventions to address the unique pathological changes that occur during each stage. Additionally, the paper reviews current treatment modalities and pharmacological interventions based on the evolving guidelines provided by the American Heart Association (AHA). Recent advances in our understanding of SAH will facilitate clinicians' improved management of SAH to reduce the incidence of delayed cerebral ischemia in patients.
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Affiliation(s)
- Henry W. Sanicola
- Department of Neurology, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA;
| | - Caleb E. Stewart
- Department of Neurosurgery, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA;
| | - Patrick Luther
- School of Medicine, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA; (P.L.); (K.Y.)
| | - Kevin Yabut
- School of Medicine, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA; (P.L.); (K.Y.)
| | - Bharat Guthikonda
- Department of Neurosurgery, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA;
| | - J. Dedrick Jordan
- Department of Neurology, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA;
| | - J. Steven Alexander
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center in Shreveport, Shreveport, LA 71103, USA
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Nourhashemi M, Mahmoudzadeh M, Heberle C, Wallois F. Preictal neuronal and vascular activity precedes the onset of childhood absence seizure: direct current potential shifts and their correlation with hemodynamic activity. NEUROPHOTONICS 2023; 10:025005. [PMID: 37114185 PMCID: PMC10128878 DOI: 10.1117/1.nph.10.2.025005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 03/20/2023] [Indexed: 06/19/2023]
Abstract
SIGNIFICANCE AIMS The neurovascular mechanisms underlying the initiation of absence seizures and their dynamics are still not well understood. The objective of this study was to better noninvasively characterize the dynamics of the neuronal and vascular network at the transition from the interictal state to the ictal state of absence seizures and back to the interictal state using a combined electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), and diffuse correlation spectroscopy (DCS) approach. The second objective was to develop hypotheses about the neuronal and vascular mechanisms that propel the networks to the 3-Hz spikes and wave discharges (SWDs) observed during absence seizures. APPROACHES We evaluated the simultaneous changes in electrical (neuronal) and optical dynamics [hemodynamic, with changes in (Hb) and cerebral blood flow] of 8 pediatric patients experiencing 25 typical childhood absence seizures during the transition from the interictal state to the absence seizure by simultaneously performing EEG, fNIRS, and DCS. RESULTS Starting from ∼ 20 s before the onset of the SWD, we observed a transient direct current potential shift that correlated with alterations in functional fNIRS and DCS measurements of the cerebral hemodynamics detecting the preictal changes. DISCUSSION Our noninvasive multimodal approach highlights the dynamic interactions between the neuronal and vascular compartments that take place in the neuronal network near the time of the onset of absence seizures in a very specific cerebral hemodynamic environment. These noninvasive approaches contribute to a better understanding of the electrical hemodynamic environment prior to seizure onset. Whether this may ultimately be relevant for diagnostic and therapeutic approaches requires further evaluation.
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Affiliation(s)
- Mina Nourhashemi
- Université de Picardie Jules Verne, Inserm U1105, GRAMFC, CURS, Amiens, France
| | - Mahdi Mahmoudzadeh
- Université de Picardie Jules Verne, Inserm U1105, GRAMFC, CURS, Amiens, France
- Amiens University Hospital, Pediatric Neurophysiology Unit, Amiens, France
| | - Claire Heberle
- Amiens University Hospital, Pediatric Neurophysiology Unit, Amiens, France
| | - Fabrice Wallois
- Université de Picardie Jules Verne, Inserm U1105, GRAMFC, CURS, Amiens, France
- Amiens University Hospital, Pediatric Neurophysiology Unit, Amiens, France
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9
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Zhao J, Wang C, Sun W, Li C. Tailoring Materials for Epilepsy Imaging: From Biomarkers to Imaging Probes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2203667. [PMID: 35735191 DOI: 10.1002/adma.202203667] [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] [Received: 04/24/2022] [Revised: 06/11/2022] [Indexed: 06/15/2023]
Abstract
Excising epileptic foci (EF) is the most efficient approach for treating drug-resistant epilepsy (DRE). However, owing to the vast heterogeneity of epilepsies, EF in one-third of patients cannot be accurately located, even after exhausting all current diagnostic strategies. Therefore, identifying biomarkers that truly represent the status of epilepsy and fabricating probes with high targeting specificity are prerequisites for identifying the "concealed" EF. However, no systematic summary of this topic has been published. Herein, the potential biomarkers of EF are first summarized and classified into three categories: functional, molecular, and structural aberrances during epileptogenesis, a procedure of nonepileptic brain biasing toward epileptic tissue. The materials used to fabricate these imaging probes and their performance in defining the EF in preclinical and clinical studies are highlighted. Finally, perspectives for developing the next generation of probes and their challenges in clinical translation are discussed. In general, this review can be helpful in guiding the development of imaging probes defining EF with improved accuracy and holds promise for increasing the number of DRE patients who are eligible for surgical intervention.
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Affiliation(s)
- Jing Zhao
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Zhangheng Road 826, Shanghai, 201203, China
| | - Cong Wang
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Zhangheng Road 826, Shanghai, 201203, China
- Academy for Engineering and Technology, Fudan University, 20 Handan Road, Yangpu District, Shanghai, 200433, China
- Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai, 200031, China
| | - Wanbing Sun
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Cong Li
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Zhangheng Road 826, Shanghai, 201203, China
- State Key Laboratory of Medical Neurobiology, School of Pharmacy, Fudan University, Shanghai, 201203, China
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10
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Lee YJ, Bae H, Byun JC, Kwon S, Oh SS, Kim S. Clinical Usefulness of Simultaneous Electroencephalography and Functional Magnetic Resonance Imaging in Children With Focal Epilepsy. J Clin Neurol 2022; 18:535-546. [PMID: 36062771 PMCID: PMC9444567 DOI: 10.3988/jcn.2022.18.5.535] [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: 01/19/2022] [Revised: 04/04/2022] [Accepted: 04/04/2022] [Indexed: 11/17/2022] Open
Abstract
Background and Purpose The current study analyzed the interictal epileptiform discharge (IED)-related hemodynamic response and aimed to determine the clinical usefulness of simultaneous electroencephalography and functional magnetic resonance imaging (EEG-fMRI) in defining the epileptogenic zone (EZ) in children with focal epilepsy. Methods Patients with focal epilepsy showing IEDs on conventional EEG were evaluated using EEG-fMRI. Statistical analyses were performed using the times of spike as events modeled with multiple hemodynamic response functions. The area showing the most significant t-value for blood-oxygen-level-dependent (BOLD) changes was compared with the presumed EZ. Moreover, BOLD responses between -9 and +9 s around the spike times were analyzed to track the hemodynamic response patterns over time. Results Half (n=13) of 26 EEG-fMRI investigations of 19 patients were successful. Two patients showed 2 different types of spikes, resulting in 15 analyses. The maximum BOLD response was concordant with the EZ in 11 (73.3%) of the 15 analyses. In 10 (66.7%) analyses, the BOLD response localized the EZs more specifically. Focal BOLD responses in the EZs occurred before IEDs in 11 analyses and were often widespread after IEDs. Hemodynamic response patterns were consistent in the same epilepsy syndrome or when repeating the investigation in the same patients. Conclusions EEG-fMRI can provide additional information for localizing the EZ in children with focal epilepsy, and also reveal the pathogenesis of pediatric epilepsy by evaluating the patterns in the hemodynamic response across time windows of IEDs.
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Affiliation(s)
- Yun Jeong Lee
- Department of Pediatrics, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea
| | - Hyunwoo Bae
- Department of Pediatrics, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea
| | - Jun Chul Byun
- Department of Pediatrics, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, Korea
| | - Soonhak Kwon
- Department of Pediatrics, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, Korea
| | - Sung Suk Oh
- Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation (K-MEDI hub), Daegu, Korea.
| | - Saeyoon Kim
- Department of Pediatrics, Yeungnam University Medical Center, Yeungnam University College of Medicine, Daegu, Korea.
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11
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Tada Y, Fujihara T, Shimada K, Yamamoto N, Yamazaki H, Izumi Y, Harada M, Kanematsu Y, Takagi Y. Seizure types associated with negative arterial spin labeling and positive diffusion-weighted imaging on peri-ictal magnetic resonance imaging. J Neurol Sci 2022; 436:120223. [DOI: 10.1016/j.jns.2022.120223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/23/2022] [Accepted: 03/03/2022] [Indexed: 11/15/2022]
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12
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Yin L, Gao DS, Hu JM, Zhong C, Xi W. Long-term development of dynamic changes in neurovascular coupling after acute temporal lobe epilepsy. Brain Res 2022; 1784:147858. [PMID: 35245486 DOI: 10.1016/j.brainres.2022.147858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/23/2022] [Accepted: 02/27/2022] [Indexed: 12/25/2022]
Abstract
Epilepsy is an abnormal brain state that may be induced by synchronous neuronal activation and also abnormalities in energy metabolism or the oxygen supply vascular system. Neurovascular coupling (NVC), the relationship between neuron, capillary, and penetrating artery, remains unexplored on a fine-scale with respect to the pathology process after acute temporal lobe epilepsy (TLE). Here we use two-photon microscopy (TPM) to provide high temporal-spatial resolution imaging to identify changes in NVC during spontaneous and electro-stimulated (ES) states in awake mice. Implantation of a long-term craniotomy window allowed TPM recording of the pathological development after the acute Kainic Acid temporal lobe epilepsy model. Our results provide direct evidence that the capillary and penetrating artery are not correlated to rhythmic neuronal activity during acute epilepsy. During the CSD period, NVC shows a strong correlation. We demonstrate that NVC exhibits nonlinear dynamics after status epilepticus. Furthermore, the vascular correlation to neuronal signals in spontaneous and ES states shows dynamic changes which correlate to the evolution after acute TLE. Understanding NVC in all TLE stages, from the acute through the TLE pathological development, may provide new therapeutic pathways.
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Affiliation(s)
- Liu Yin
- Interdisciplinary Institute of Neuroscience and Technology, Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Kaixuan Road 258th, Hangzhou, 310020, PR China
| | - Dave Schwinn Gao
- Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou, 310016, PR China
| | - Jia Ming Hu
- Interdisciplinary Institute of Neuroscience and Technology, Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Kaixuan Road 258th, Hangzhou, 310020, PR China
| | - Chen Zhong
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China. Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China. Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| | - Wang Xi
- Interdisciplinary Institute of Neuroscience and Technology, Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Kaixuan Road 258th, Hangzhou, 310020, PR China; Key Laboratory of Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and instrument Science, Zhejiang University, Hangzhou 310027, PR China.
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13
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Sasaoka K, Ohta H, Ishizuka T, Kojima K, Sasaki N, Takiguchi M. Transcranial Doppler ultrasonography detects the elevation of cerebral blood flow during ictal-phase of pentetrazol-induced seizures in dogs. Am J Vet Res 2022; 83:331-338. [DOI: 10.2460/ajvr.21.06.0085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
OBJECTIVE
To investigate the association between changes in cerebral blood flow and electrographic epileptic seizure in dogs using transcranial Doppler ultrasonography (TCD).
ANIMALS
6 healthy Beagle dogs.
PROCEDURES
Each dog was administered pentetrazol (1.5 mg/kg/min) or saline (0.9% NaCl) solution under general anesthesia with continuous infusion of propofol. Both pentetrazol and saline solution were administered to all 6 dogs, with at least 28 days interval between the experiments. Blood flow waveforms in the middle cerebral artery and the basilar artery were obtained using TCD at baseline, after pentetrazol administration, and after diazepam administration. TCD velocities, including peak systolic velocity, end-diastolic velocity, and mean velocity and resistance variables, were determined from the Doppler waveforms.
RESULTS
During ictal-phase of pentetrazol-induced seizures, the TCD velocities significantly increased in the basilar and middle cerebral arteries while TCD vascular resistance variables did not change in either artery. The TCD velocities significantly decreased after diazepam administration. Systemic parameters, such as the heart rate, mean arterial pressure, systemic vascular resistance, cardiac index, end-tidal carbon dioxide, oxygen saturation, and body temperature, did not change significantly during seizures.
CLINICAL RELEVANCE
This study showed that cerebral blood flow, as obtained from TCD velocities, increased by 130% during ictal-phase of pentetrazol-induced seizures in dogs. The elevated velocities returned to baseline after seizure suppression. Thus, TCD may be used to detect electrographic seizures during the treatment of status epilepticus in dogs, and further clinical studies clarifying the association between changes in cerebral blood flow and non-convulsive seizure cases are needed.
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Affiliation(s)
- Kazuyoshi Sasaoka
- 1Veterinary Teaching Hospital, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
| | - Hiroshi Ohta
- 2Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
| | - Tomohito Ishizuka
- 1Veterinary Teaching Hospital, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
| | - Kazuki Kojima
- 2Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
| | - Noboru Sasaki
- 2Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
| | - Mitsuyoshi Takiguchi
- 2Laboratory of Veterinary Internal Medicine, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan
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14
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Othman AS, Abd-Allah F. Non-Convulsive Status Epilepticus (NCSE) in ICU: Bedside Usefulness of TCD in Comatose Patient Diagnosis. When the EEG Is Too Far. NEUROSONOLOGY IN CRITICAL CARE 2022:753-762. [DOI: 10.1007/978-3-030-81419-9_46] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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15
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Truong ND, Yang Y, Maher C, Kuhlmann L, McEwan A, Nikpour A, Kavehei O. Seizure Susceptibility Prediction in Uncontrolled Epilepsy. Front Neurol 2021; 12:721491. [PMID: 34589049 PMCID: PMC8474878 DOI: 10.3389/fneur.2021.721491] [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: 06/07/2021] [Accepted: 07/28/2021] [Indexed: 12/01/2022] Open
Abstract
Epileptic seizure forecasting, combined with the delivery of preventative therapies, holds the potential to greatly improve the quality of life for epilepsy patients and their caregivers. Forecasting seizures could prevent some potentially catastrophic consequences such as injury and death in addition to several potential clinical benefits it may provide for patient care in hospitals. The challenge of seizure forecasting lies within the seemingly unpredictable transitions of brain dynamics into the ictal state. The main body of computational research on determining seizure risk has been focused solely on prediction algorithms, which involves a challenging issue of balancing sensitivity and false alarms. There have been some studies on identifying potential biomarkers for seizure forecasting; however, the questions of “What are the true biomarkers for seizure prediction” or even “Is there a valid biomarker for seizure prediction?” are yet to be fully answered. In this paper, we introduce a tool to facilitate the exploration of the potential biomarkers. We confirm using our tool that interictal slowing activities are a promising biomarker for epileptic seizure susceptibility prediction.
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Affiliation(s)
- Nhan Duy Truong
- Australian Research Council Training Centre for Innovative BioEngineering, School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia.,The University of Sydney Nano Institute, Sydney, NSW, Australia
| | - Yikai Yang
- Australian Research Council Training Centre for Innovative BioEngineering, School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Christina Maher
- Australian Research Council Training Centre for Innovative BioEngineering, School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Levin Kuhlmann
- Faculty of Information Technology, Monash University, Melbourne, VIC, Australia.,Department of Medicine - St. Vincent's Hospital Melbourne, The University of Melbourne, Fitzroy, VIC, Australia
| | - Alistair McEwan
- Australian Research Council Training Centre for Innovative BioEngineering, School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Armin Nikpour
- Comprehensive Epilepsy Service and Department of Neurology at the Royal Prince Alfred Hospital, Sydney, NSW, Australia.,Faculty of Medicine and Health, Central Clinical School, The University of Sydney, Sydney, NSW, Australia
| | - Omid Kavehei
- Australian Research Council Training Centre for Innovative BioEngineering, School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia.,The University of Sydney Nano Institute, Sydney, NSW, Australia
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16
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Nicolas-Jilwan M, Wintermark M. Automated Brain Perfusion Imaging in Acute Ischemic Stroke: Interpretation Pearls and Pitfalls. Stroke 2021; 52:3728-3738. [PMID: 34565174 DOI: 10.1161/strokeaha.121.035049] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent advancements in computed tomography technology, including improved brain coverage and automated processing of the perfusion data, have reinforced the use of perfusion computed tomography imaging in the routine evaluation of patients with acute ischemic stroke. The DAWN (Diffusion Weighted Imaging or Computerized Tomography Perfusion Assessment With Clinical Mismatch in the Triage of Wake Up and Late Presenting Strokes Undergoing Neurointervention) and DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) trials have established the benefit of endovascular thrombectomy in patients with acute ischemic stroke with anterior circulation large vessel occlusion up to 24 hours of last seen normal, using perfusion imaging-based patient selection. The compelling data has prompted stroke centers to increasingly introduce automated perfusion computed tomography imaging in the routine evaluation of patients with acute ischemic stroke. We present a comprehensive overview of the acquisition and interpretation of automated perfusion imaging in patients with acute ischemic stroke with a special emphasis on the interpretation pearls, pitfalls, and stroke mimicking conditions.
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Affiliation(s)
- Manal Nicolas-Jilwan
- Division of Neuroradiology, Department of Radiology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia (M.N.-J.)
| | - Max Wintermark
- Division of Neuroimaging and Neurointervention, Department of Radiology, Stanford Healthcare, CA (M.W.)
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17
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Chen SF, Pan HY, Huang CR, Huang JB, Tan TY, Chen NC, Hsu CY, Chuang YC. Autonomic Dysfunction Contributes to Impairment of Cerebral Autoregulation in Patients with Epilepsy. J Pers Med 2021; 11:jpm11040313. [PMID: 33920691 PMCID: PMC8073240 DOI: 10.3390/jpm11040313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/16/2021] [Accepted: 04/16/2021] [Indexed: 12/26/2022] Open
Abstract
Patients with epilepsy frequently experience autonomic dysfunction and impaired cerebral autoregulation. The present study investigates autonomic function and cerebral autoregulation in patients with epilepsy to determine whether these factors contribute to impaired autoregulation. A total of 81 patients with epilepsy and 45 healthy controls were evaluated, assessing their sudomotor, cardiovagal, and adrenergic functions using a battery of autonomic nervous system (ANS) function tests, including the deep breathing, Valsalva maneuver, head-up tilting, and Q-sweat tests. Cerebral autoregulation was measured by transcranial Doppler examination during the breath-holding test, the Valsalva maneuver, and the head-up tilting test. Autonomic functions were impaired during the interictal period in patients with epilepsy compared to healthy controls. The three indices of cerebral autoregulation—the breath-holding index (BHI), an autoregulation index calculated in phase II of the Valsalva maneuver (ASI), and cerebrovascular resistance measured in the second minute during the head-up tilting test (CVR2-min)—all decreased in patients with epilepsy. ANS dysfunction correlated significantly with impairment of cerebral autoregulation (measured by BHI, ASI, and CVR2-min), suggesting that the increased autonomic dysfunction in patients with epilepsy may augment the dysregulation of cerebral blood flow. Long-term epilepsy, a high frequency of seizures, and refractory epilepsy, particularly temporal lobe epilepsy, may contribute to advanced autonomic dysfunction and impaired cerebral autoregulation. These results have implications for therapeutic interventions that aim to correct central autonomic dysfunction and impairment of cerebral autoregulation, particularly in patients at high risk for sudden, unexplained death in epilepsy.
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Affiliation(s)
- Shu-Fang Chen
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan; (S.-F.C.); (H.-Y.P.); (C.-R.H.); (J.-B.H.); (T.-Y.T.); (N.-C.C.)
- College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Hsiu-Yung Pan
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan; (S.-F.C.); (H.-Y.P.); (C.-R.H.); (J.-B.H.); (T.-Y.T.); (N.-C.C.)
- Department of Emergency Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan
| | - Chi-Ren Huang
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan; (S.-F.C.); (H.-Y.P.); (C.-R.H.); (J.-B.H.); (T.-Y.T.); (N.-C.C.)
- College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Jyun-Bin Huang
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan; (S.-F.C.); (H.-Y.P.); (C.-R.H.); (J.-B.H.); (T.-Y.T.); (N.-C.C.)
- Department of Emergency Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan
| | - Teng-Yeow Tan
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan; (S.-F.C.); (H.-Y.P.); (C.-R.H.); (J.-B.H.); (T.-Y.T.); (N.-C.C.)
- College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Nai-Ching Chen
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan; (S.-F.C.); (H.-Y.P.); (C.-R.H.); (J.-B.H.); (T.-Y.T.); (N.-C.C.)
- College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Chung-Yao Hsu
- Department of Neurology, School of Medicine, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Yao-Chung Chuang
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan; (S.-F.C.); (H.-Y.P.); (C.-R.H.); (J.-B.H.); (T.-Y.T.); (N.-C.C.)
- College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Neurology, School of Medicine, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
- Institute for Translation Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 83301, Taiwan
- Department of Biological Science, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
- Correspondence:
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18
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Nagendran A, McConnell JF, De Risio L, José-López R, Quintana RG, Robinson K, Platt SR, Masian DS, Maddox T, Gonçalves R. Peri-ictal magnetic resonance imaging characteristics in dogs with suspected idiopathic epilepsy. J Vet Intern Med 2021; 35:1008-1017. [PMID: 33559928 PMCID: PMC7995424 DOI: 10.1111/jvim.16058] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 01/09/2023] Open
Abstract
Background The pathophysiology of changes in magnetic resonance imaging (MRI) detected after a seizure is not fully understood. Objective To characterize and describe seizure‐induced changes detected by MRI. Animals Eighty‐one client‐owned dogs diagnosed with idiopathic epilepsy. Methods Data collected retrospectively from medical records and included anatomical areas affected, T1‐, T2‐weighted and T2‐FLAIR (fluid‐attenuated inversion recovery) appearance, whether changes were unilateral or bilateral, symmetry, contrast enhancement, mass effect, and, gray and white matter distribution. Diffusion‐ and perfusion weighted maps were evaluated, if available. Results Seizure‐induced changes were T2‐hyperintense with no suppression of signal on FLAIR. Lesions were T1‐isointense (55/81) or hypointense (26/81), local mass effect (23/81) and contrast enhancement (12/81). The majority of changes were bilateral (71/81) and symmetrical (69/71). The most common areas affected were the hippocampus (39/81) cingulate gyrus (33/81), hippocampus and piriform lobes (32/81). Distribution analysis suggested concurrence between cingulate gyrus and pulvinar thalamic nuclei, the cingulate gyrus and parahippocampal gyrus, hippocampus and piriform lobe, and, hippocampus and parahippocampal gyrus. Diffusion (DWI) characteristics were a mixed‐pattern of restricted, facilitated, and normal diffusion. Perfusion (PWI) showed either hypoperfusion (6/9) or hyperperfusion (3/9). Conclusions and Clinical Importance More areas, than previously reported, have been identified that could incur seizure‐induced changes. Similar to human literature, DWI and PWI changes have been identified that could reflect the underlying metabolic and vascular changes.
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Affiliation(s)
- Aran Nagendran
- Department of Veterinary Science, Small Animal Teaching Hospital, University of Liverpool, Cheshire, United Kingdom
| | - James Fraser McConnell
- Department of Veterinary Science, Small Animal Teaching Hospital, University of Liverpool, Cheshire, United Kingdom
| | - Luisa De Risio
- Neurology/Neurosurgery Service, Centre for Small Animal Studies, Animal Health Trust, Newmarket, United Kingdom
| | - Roberto José-López
- School of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | | | - Kelsey Robinson
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Simon R Platt
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Daniel Sanchez Masian
- Department of Veterinary Science, Small Animal Teaching Hospital, University of Liverpool, Cheshire, United Kingdom
| | - Thomas Maddox
- Department of Veterinary Science, Small Animal Teaching Hospital, University of Liverpool, Cheshire, United Kingdom
| | - Rita Gonçalves
- Department of Veterinary Science, Small Animal Teaching Hospital, University of Liverpool, Cheshire, United Kingdom
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19
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Hannan S, Aristovich K, Faulkner M, Avery J, Walker MC, Holder DS. Imaging slow brain activity during neocortical and hippocampal epileptiform events with electrical impedance tomography. Physiol Meas 2021; 42:014001. [PMID: 33361567 DOI: 10.1088/1361-6579/abd67a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Electrical impedance tomography (EIT) is an imaging technique that produces tomographic images of internal impedance changes within an object using surface electrodes. It can be used to image the slow increase in cerebral tissue impedance that occurs over seconds during epileptic seizures, which is attributed to cell swelling due to disturbances in ion homeostasis following hypersynchronous neuronal firing and its associated metabolic demands. In this study, we characterised and imaged this slow impedance response during neocortical and hippocampal epileptiform events in the rat brain and evaluated its relationship to the underlying neural activity. APPROACH Neocortical or hippocampal seizures, comprising repeatable series of high-amplitude ictal spikes, were induced by electrically stimulating the sensorimotor cortex or perforant path of rats anaesthetised with fentanyl-isoflurane. Transfer impedances were measured during ≥30 consecutive seizures, by applying a sinusoidal current through independent electrode pairs on an epicortical array, and combined to generate an EIT image of slow activity. MAIN RESULTS The slow impedance responses were consistently time-matched to the end of seizures and EIT images of this activity were reconstructed reproducibly in all animals (p < 0.03125, N = 5). These displayed foci of activity that were spatially confined to the facial somatosensory cortex and dentate gyrus for neocortical and hippocampal seizures, respectively, and encompassed a larger volume as the seizure progressed. Centre-of-mass analysis of reconstructions revealed that this activity corresponded to the true location of the epileptogenic zone, as determined by EEG recordings and fast neural EIT measurements which were obtained simultaneously. SIGNIFICANCE These findings suggest that the slow impedance response presents a reliable marker of hypersynchronous neuronal activity during epileptic seizures and can thus be utilised for investigating the mechanisms of epileptogenesis in vivo and for aiding localisation of the epileptogenic zone during presurgical evaluation of patients with refractory epilepsies.
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Affiliation(s)
- Sana Hannan
- Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
| | - Kirill Aristovich
- Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
| | - Mayo Faulkner
- Wolfson Institute for Biomedical Research, University College London, United Kingdom
| | - James Avery
- Department of Surgery and Cancer, Imperial College London, United Kingdom
| | - Matthew C Walker
- UCL Queen Square Institute of Neurology, University College London, United Kingdom
| | - David S Holder
- Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
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20
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Van Eyndhoven S, Dupont P, Tousseyn S, Vervliet N, Van Paesschen W, Van Huffel S, Hunyadi B. Augmenting interictal mapping with neurovascular coupling biomarkers by structured factorization of epileptic EEG and fMRI data. Neuroimage 2020; 228:117652. [PMID: 33359347 PMCID: PMC7903163 DOI: 10.1016/j.neuroimage.2020.117652] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 11/28/2020] [Accepted: 12/04/2020] [Indexed: 12/20/2022] Open
Abstract
EEG-correlated fMRI analysis is widely used to detect regional BOLD fluctuations that are synchronized to interictal epileptic discharges, which can provide evidence for localizing the ictal onset zone. However, the typical, asymmetrical and mass-univariate approach cannot capture the inherent, higher order structure in the EEG data, nor multivariate relations in the fMRI data, and it is nontrivial to accurately handle varying neurovascular coupling over patients and brain regions. We aim to overcome these drawbacks in a data-driven manner by means of a novel structured matrix-tensor factorization: the single-subject EEG data (represented as a third-order spectrogram tensor) and fMRI data (represented as a spatiotemporal BOLD signal matrix) are jointly decomposed into a superposition of several sources, characterized by space-time-frequency profiles. In the shared temporal mode, Toeplitz-structured factors account for a spatially specific, neurovascular 'bridge' between the EEG and fMRI temporal fluctuations, capturing the hemodynamic response's variability over brain regions. By analyzing interictal data from twelve patients, we show that the extracted source signatures provide a sensitive localization of the ictal onset zone (10/12). Moreover, complementary parts of the IOZ can be uncovered by inspecting those regions with the most deviant neurovascular coupling, as quantified by two entropy-like metrics of the hemodynamic response function waveforms (9/12). Hence, this multivariate, multimodal factorization provides two useful sets of EEG-fMRI biomarkers, which can assist the presurgical evaluation of epilepsy. We make all code required to perform the computations available at https://github.com/svaneynd/structured-cmtf.
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Affiliation(s)
- Simon Van Eyndhoven
- Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, KU Leuven, Belgium.
| | - Patrick Dupont
- Laboratory for Cognitive Neurology, Department of Neurosciences, KU Leuven, Leuven, Belgium; Leuven Brain Institute, Leuven, Belgium
| | - Simon Tousseyn
- Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, the Netherlands
| | - Nico Vervliet
- Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, KU Leuven, Belgium
| | - Wim Van Paesschen
- Laboratory for Epilepsy Research, KU Leuven, Leuven, Belgium; Department of Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Sabine Van Huffel
- Department of Electrical Engineering (ESAT), STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, KU Leuven, Belgium
| | - Borbála Hunyadi
- Circuits and Systems Group (CAS), Department of Microelectronics, Delft University of Technology, Delft, the Netherlands
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In Vitro and In Vivo Study of the Short-Term Vasomotor Response during Epileptic Seizures. Brain Sci 2020; 10:brainsci10120942. [PMID: 33297329 PMCID: PMC7762235 DOI: 10.3390/brainsci10120942] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/29/2020] [Accepted: 11/30/2020] [Indexed: 02/07/2023] Open
Abstract
Epilepsy remains one of the most common brain disorders, and the different types of epilepsy encompass a wide variety of physiological manifestations. Clinical and preclinical findings indicate that cerebral blood flow is usually focally increased at seizure onset, shortly after the beginning of ictal events. Nevertheless, many questions remain about the relationship between vasomotor changes in the epileptic foci and the epileptic behavior of neurons and astrocytes. To study this relationship, we performed a series of in vitro and in vivo experiments using the 4-aminopyridine model of epileptic seizures. It was found that in vitro pathological synchronization of neurons and the depolarization of astrocytes is accompanied by rapid short-term vasoconstriction, while in vivo vasodilation during the seizure prevails. We suggest that vasomotor activity during epileptic seizures is a correlate of the complex, self-sustained response that includes neuronal and astrocytic oscillations, and that underlies the clinical presentation of epilepsy.
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Winslow N, George M, Michalos A, Wang H, Ergene E, Xu M. Hemodynamic Changes Associated with Lateralized Periodic Discharges: A Near-Infrared Spectroscopy and Continuous EEG Study. Neurocrit Care 2020; 35:153-161. [PMID: 33263144 DOI: 10.1007/s12028-020-01154-4] [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: 07/14/2020] [Accepted: 11/12/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Lateral periodic discharges (LPDs) have been recognized as a common electroencephalographic (EEG) pattern in critically ill patients. However, management decisions in these patients are still a challenge for clinicians. This study investigates hemodynamic changes associated with LPDs and evaluates if this pattern is likely to represent an ictal, interictal, or ictal-interictal continuum phenomenon via non-invasive near infra-red spectroscopy (NIRS) with concurrent with continuous EEG. METHODS Seventeen patients admitted to the intensive care unit with LPDs on continuous electroencephalogram (EEG) were included. Participants engaged in NIRS recording-with scalp probes on right and left frontal regions simultaneously. Associations between LPDs laterality, primary frequency, NIRS a of cerebral oxygen saturation (SO2), total hemoglobin concentration (tHb), oxygenated hemoglobin concentration (O2Hb), de-oxygenated hemoglobin concentration (HHb), and variables in participant medical history were studied. RESULTS Hemispheres with LPDs showed higher overall SO2 when compared to non-LPDs hemispheres (57% vs 52%, p = 0.03). Additionally, mildly increased tHb, O2Hb, and mildly decreased HHb concentrations were detected in the hemisphere showing LPDs, but changes were not statistically significant. A higher primary frequency of LPDs was associated with lower cerebral SO2 (Pearson correlation r = - 0.55, p = 0.022) and O2Hb (Pearson correlation r = - 0.52, p = 0.033). In patients with seizure during their EEG recording (64.7%), lower tHb (28.2 μmol/L vs 37.8 μmol/L, p = 0.049) and O2Hb (15.5 μmol/L vs 24.2 μmol/L, p = 0.033) were recorded in the LPDs hemisphere. CONCLUSIONS This study demonstrates an increased cerebral SO2 in the hemisphere with LPDs, and decreased SO2 and O2Hb when the frequency of LPDs increases. The findings indicate that LPDs increase oxygen demand on the ipsilateral hemisphere. We infer that a threshold of LPDs frequency might exit, when the cerebral oxygen demand begins to supersede the ability of delivery, and saturation decreases.
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Affiliation(s)
- Nolan Winslow
- Department of Neurosurgery, OSF Illinois Neurological Institute, 200 E Pennsylvania Ave, Peoria, IL, 61603, USA
| | - Mebin George
- Department of Engineering, University of Illinois Urbana-Champaign, 1206 W. Clark Street, Urbana, IL, 61801, USA
| | - Antonios Michalos
- Health Care Engineering Systems Center, University of Illinois Urbana-Champaign, 1206 W. Clark Street, Urbana, IL, 61801, USA
| | - Huaping Wang
- University of Illinois College of Medicine, One Illini Drive, Peoria, IL, 61656, USA
| | - Erhan Ergene
- Department of Neurology, OSF Illinois Neurological Institute, 200 E Pennsylvania Ave, Peoria, IL, 61603, USA
| | - Michael Xu
- Department of Neurology, OSF Illinois Neurological Institute, 200 E Pennsylvania Ave, Peoria, IL, 61603, USA.
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Verhoog QP, Holtman L, Aronica E, van Vliet EA. Astrocytes as Guardians of Neuronal Excitability: Mechanisms Underlying Epileptogenesis. Front Neurol 2020; 11:591690. [PMID: 33324329 PMCID: PMC7726323 DOI: 10.3389/fneur.2020.591690] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are key homeostatic regulators in the central nervous system and play important roles in physiology. After brain damage caused by e.g., status epilepticus, traumatic brain injury, or stroke, astrocytes may adopt a reactive phenotype. This process of reactive astrogliosis is important to restore brain homeostasis. However, persistent reactive astrogliosis can be detrimental for the brain and contributes to the development of epilepsy. In this review, we will focus on physiological functions of astrocytes in the normal brain as well as pathophysiological functions in the epileptogenic brain, with a focus on acquired epilepsy. We will discuss the role of astrocyte-related processes in epileptogenesis, including reactive astrogliosis, disturbances in energy supply and metabolism, gliotransmission, and extracellular ion concentrations, as well as blood-brain barrier dysfunction and dysregulation of blood flow. Since dysfunction of astrocytes can contribute to epilepsy, we will also discuss their role as potential targets for new therapeutic strategies.
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Affiliation(s)
- Quirijn P. Verhoog
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Linda Holtman
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Erwin A. van Vliet
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
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24
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Soldozy S, Galindo J, Snyder H, Ali Y, Norat P, Yağmurlu K, Sokolowski JD, Sharifi K, Tvrdik P, Park MS, Kalani MYS. Clinical utility of arterial spin labeling imaging in disorders of the nervous system. Neurosurg Focus 2020; 47:E5. [PMID: 31786550 DOI: 10.3171/2019.9.focus19567] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 09/16/2019] [Indexed: 11/06/2022]
Abstract
Neuroimaging is an indispensable tool in the workup and management of patients with neurological disorders. Arterial spin labeling (ASL) is an imaging modality that permits the examination of blood flow and perfusion without the need for contrast injection. Noninvasive in nature, ASL provides a feasible alternative to existing vascular imaging techniques, including angiography and perfusion imaging. While promising, ASL has yet to be fully incorporated into the diagnosis and management of neurological disorders. This article presents a review of the most recent literature on ASL, with a special focus on its use in moyamoya disease, brain neoplasms, seizures, and migraines and a commentary on recent advances in ASL that make the imaging technique more attractive as a clinically useful tool.
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Multimodal Detection for Cryptogenic Epileptic Seizures Based on Combined Micro Sensors. BIOMED RESEARCH INTERNATIONAL 2020; 2020:5734932. [PMID: 32964037 PMCID: PMC7492941 DOI: 10.1155/2020/5734932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/24/2020] [Accepted: 08/17/2020] [Indexed: 12/02/2022]
Abstract
The cryptogenic epilepsy of the neocortex is a disease in which the seizure is accompanied by intense cerebral nerve electrical activities but the lesions are not observed. It is difficult to locate disease foci. Electrocorticography (ECoG) is one of the gold standards in seizure focus localization. This method detects electrical signals, and its limitations are inadequate resolution which is only 10 mm and lack of depth information. In order to solve these problems, our new method with implantable micro ultrasound transducer (MUT) and photoplethysmogram (PPG) device detects blood changes to achieve higher resolution and provide depth information. The basis of this method is the neurovascular coupling mechanism, which shows that intense neural activity leads to sufficient cerebral blood volume (CBV). The neurovascular coupling mechanism established the relationship between epileptic electrical signals and CBV. The existence of mechanism enables us to apply our new methods on the basis of ECoG. Phantom experiments and in vivo experiments were designed to verify the proposed method. The first phantom experiments designed a phantom with two channels at different depths, and the MUT was used to detect the depth where the blood concentration changed. The results showed that the MUT detected the blood concentration change at the depth of 12 mm, which is the position of the second channel. In the second phantom experiments where a PPG device and MUT were used to monitor the change of blood concentration in a thick tube, the results showed that the trend of superficial blood concentration change provided by the PPG device is the same as that provided by the MUT within the depth of 2.5 mm. Finally, in the verification of in vivo experiments, the blood concentration changes on the surface recorded by the PPG device and the changes at a certain depth recorded by the MUT all matched the seizure status shown by ECoG. These results confirmed the effectiveness of the combined micro sensors.
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26
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Bandyopadhyay A, Sharma G, Roy Chowdhury S. Computational analysis of NIRS and BOLD signal from neurovascular coupling with three neuron-system feedforward inhibition network. J Theor Biol 2020; 498:110297. [PMID: 32371007 DOI: 10.1016/j.jtbi.2020.110297] [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: 01/26/2020] [Revised: 03/29/2020] [Accepted: 04/26/2020] [Indexed: 10/24/2022]
Abstract
Several neurological disorders occur due to hypoxic condition in brain arising from impairment of cerebral functionality, which can be controlled by neural stimulation driven vasoactive response mediated through biological response in astrocyte, a phenomenon known as neurovascular coupling. Brain can adjust with the problem of hypoxic condition by causing vasodilation with the help of this mechanism. To deduce the mechanism behind vasodilation of blood vessel caused by neuronal stimulus, current study articulates a mathematical model involving neuronal system feedforward inhibition network model (FFI) with two other functional components of neurovascular coupling, i.e. astrocyte and smooth muscle cell lining blood vessel. This study includes the neural inhibition network system where glutamatergic pyramidal neuron and GABAergic interneuron act antagonistically with each other. The proposed model successfully includes the implication of the inhibition system to design mathematical model for neurovascular coupling. Result of the proposed model shows that the increase in neuronal stimulus from 20 to 60 µA/cm2 has the ability to increase the vasodilatory activity of blood tissue vasculature. Oxygenation level and hemodynamic response due to input synaptic stimulation has been calculated by regional cerebral oxygenation level (rS02) and blood oxygen level dependent (BOLD) imaging signal which supports vasodilation of blood vessel with increase in synaptic input stimulus.
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Affiliation(s)
- Anirban Bandyopadhyay
- Biomedical Systems Laboratory, Multimedia Analytics, Networks and Systems Group, Indian Institute of Technology Mandi, India.
| | - Gaurav Sharma
- Biomedical Systems Laboratory, Multimedia Analytics, Networks and Systems Group, Indian Institute of Technology Mandi, India.
| | - Shubhajit Roy Chowdhury
- Biomedical Systems Laboratory, Multimedia Analytics, Networks and Systems Group, Indian Institute of Technology Mandi, India.
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27
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Source-Detector Spectral Pairing-Related Inaccuracies in Pulse Oximetry: Evaluation of the Wavelength Shift. SENSORS 2020; 20:s20113302. [PMID: 32532116 PMCID: PMC7309008 DOI: 10.3390/s20113302] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 01/19/2023]
Abstract
Pulse oximetry enables oxygen saturation estimation (SpO2) non-invasively in real time with few components and modest processing power. With the advent of affordable development kits dedicated to the monitoring of biosignals, capabilities once reserved to hospitals and high-end research laboratories are becoming accessible for rapid prototyping. While one may think that medical-grade equipment differs greatly in quality, surprisingly, we found that the performance requirements are not widely different from available consumer-grade components, especially regarding the photodetection module in pulse oximetry. This study investigates how the use of candidate light sources and photodetectors for the development of a custom SpO2 monitoring system can lead to inaccuracies when using the standard computational model for oxygen saturation without calibration. Following the optical characterization of selected light sources, we compare the extracted parameters to the key features in their respective datasheet. We then quantify the wavelength shift caused by spectral pairing of light sources in association with photodetectors. Finally, using the widely used approximation, we report the resulting absolute error in SpO2 estimation and show that it can lead up to 8% of the critical 90–100% saturation window.
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28
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Khoo CS, Kim SE, Lee BI, Shin KJ, Ha SY, Park J, Park KM, Bae SY, Lee D, Kim BJ, Bae MJ, Kim SE. Characteristics of Perfusion Computed Tomography Imaging in Patients with Seizures Mimicking Acute Stroke. Eur Neurol 2020; 83:56-64. [DOI: 10.1159/000506591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 02/15/2020] [Indexed: 11/19/2022]
Abstract
Introduction: Seizures as acute stroke mimics are a diagnostic challenge. Objective: The aim of the study was to characterize the perfusion patterns on perfusion computed tomography (PCT) in patients with seizures masquerading as acute stroke. Methods: We conducted a study on patients with acute seizures as stroke mimics. The inclusion criteria for this study were patients (1) initially presenting with stroke-like symptoms but finally diagnosed to have seizures and (2) with PCT performed within 72 h of seizures. The PCT of seizure patients (n = 27) was compared with that of revascularized stroke patients (n = 20) as the control group. Results: Among the 27 patients with seizures as stroke mimics, 70.4% (n = 19) showed characteristic PCT findings compared with the revascularized stroke patients, which were as follows: (1) multi-territorial cortical hyperperfusion {(73.7% [14/19] vs. 0% [0/20], p = 0.002), sensitivity of 73.7%, negative predictive value (NPV) of 80%}, (2) involvement of the ipsilateral thalamus {(57.9% [11/19] vs. 0% [0/20], p = 0.007), sensitivity of 57.9%, NPV of 71.4%}, and (3) reduced perfusion time {(84.2% [16/19] vs. 0% [0/20], p = 0.001), sensitivity of 84.2%, NPV of 87%}. These 3 findings had 100% specificity and positive predictive value in predicting patients with acute seizures in comparison with reperfused stroke patients. Older age was strongly associated with abnormal perfusion changes (p = 0.038), with a mean age of 66.8 ± 14.5 years versus 49.2 ± 27.4 years (in seizure patients with normal perfusion scan). Conclusions: PCT is a reliable tool to differentiate acute seizures from acute stroke in the emergency setting.
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29
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Montgomery MK, Kim SH, Dovas A, Zhao HT, Goldberg AR, Xu W, Yagielski AJ, Cambareri MK, Patel KB, Mela A, Humala N, Thibodeaux DN, Shaik MA, Ma Y, Grinband J, Chow DS, Schevon C, Canoll P, Hillman EMC. Glioma-Induced Alterations in Neuronal Activity and Neurovascular Coupling during Disease Progression. Cell Rep 2020; 31:107500. [PMID: 32294436 PMCID: PMC7443283 DOI: 10.1016/j.celrep.2020.03.064] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 02/10/2020] [Accepted: 03/18/2020] [Indexed: 12/14/2022] Open
Abstract
Diffusely infiltrating gliomas are known to cause alterations in cortical function, vascular disruption, and seizures. These neurological complications present major clinical challenges, yet their underlying mechanisms and causal relationships to disease progression are poorly characterized. Here, we follow glioma progression in awake Thy1-GCaMP6f mice using in vivo wide-field optical mapping to monitor alterations in both neuronal activity and functional hemodynamics. The bilateral synchrony of spontaneous neuronal activity gradually decreases in glioma-infiltrated cortical regions, while neurovascular coupling becomes progressively disrupted compared to uninvolved cortex. Over time, mice develop diverse patterns of high amplitude discharges and eventually generalized seizures that appear to originate at the tumors' infiltrative margins. Interictal and seizure events exhibit positive neurovascular coupling in uninfiltrated cortex; however, glioma-infiltrated regions exhibit disrupted hemodynamic responses driving seizure-evoked hypoxia. These results reveal a landscape of complex physiological interactions occurring during glioma progression and present new opportunities for exploring novel biomarkers and therapeutic targets.
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Affiliation(s)
- Mary Katherine Montgomery
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Sharon H Kim
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Athanassios Dovas
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Hanzhi T Zhao
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Alexander R Goldberg
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Weihao Xu
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Alexis J Yagielski
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Morgan K Cambareri
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Kripa B Patel
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Angeliki Mela
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Nelson Humala
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - David N Thibodeaux
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Mohammed A Shaik
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Ying Ma
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA
| | - Jack Grinband
- Department of Psychiatry, New York State Psychiatric Institute, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Daniel S Chow
- Department of Radiological Sciences, University of California, Irvine, Orange, CA 92868, USA
| | - Catherine Schevon
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Peter Canoll
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA.
| | - Elizabeth M C Hillman
- Laboratory for Functional Optical Imaging, Zuckerman Mind Brain Behavior Institute, Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027, USA.
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Sharma G, Chowdhury SR. Statistical Analysis to Find out the Optimal Locations for Non Invasive Brain Stimulation. J Med Syst 2020; 44:85. [PMID: 32166505 DOI: 10.1007/s10916-020-1535-7] [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: 04/19/2019] [Accepted: 01/29/2020] [Indexed: 10/24/2022]
Abstract
Non-invasive brain electrical stimulation (NIBES) techniques are progressively used for modulation of neuronal membrane potentials, which alters cortical excitability. The neuronal activity depends on position of channel locations for electrodes and the amount and direction of injected weak current through the target neurons area. In the present paper hybrid near infrared spectroscopy and electroencephalogram (NIRS-EEG) open access dataset for brain computer interface (BCI) has been used to find the best locations for NIBES. The percentage oxygen saturation has been calculated with the help of provided NIRS experimental dataset of changes in concentration of oxy-hemoglobin (HbO2) and deoxy-hemoglobin (Hb) in thirty-six scalp site locations of twenty-eight healthy subjects. The variation in standard deviation have been calculated for given pre-processed EEG signals of thirty locations for same twenty-eight healthy subjects. The statistical one-way ANOVA method has been used to find out the best channels and locations which are having less variation in all motion artifacts. In this method, F value is calculated for these locations and those locations are selected which are significant at 99% confidence interval (P < 0.01). In this study, out of sixty-six locations sixteen best locations have been selected for non-invasive brain electrical stimulation. This pilot study has been used to find out the appropriate locations on the scalp sites to place the electrodes to provide weak direct current stimulation which are less affected by motion artifacts.
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Affiliation(s)
- Gaurav Sharma
- Biomedical Systems Laboratory, Multimedia, Analytics, Networks and Systems Group, School of Computing and Electrical Engineering, Indian Institute of Technology Mandi, Mandi, India.
| | - Shubhajit Roy Chowdhury
- Biomedical Systems Laboratory, Multimedia, Analytics, Networks and Systems Group, School of Computing and Electrical Engineering, Indian Institute of Technology Mandi, Mandi, India
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Baruah J, Vasudevan A, Köhling R. Vascular Integrity and Signaling Determining Brain Development, Network Excitability, and Epileptogenesis. Front Physiol 2020; 10:1583. [PMID: 32038280 PMCID: PMC6987412 DOI: 10.3389/fphys.2019.01583] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 12/17/2019] [Indexed: 01/27/2023] Open
Abstract
Our understanding of the etiological mechanisms leading up to epilepsy has undergone radical changes over time due to more insights into the complexity of the disease. The traditional hypothesis emphasized network hyperexcitability and an imbalance of inhibition and excitation, eventually leading to seizures. In this context, the contribution of the vascular system, and particularly the interactions between blood vessels and neuronal tissue, came into focus only recently. Thus, one highly exciting causative or contributing factor of epileptogenesis is the disruption of the blood-brain barrier (BBB) in the context of not only posttraumatic epilepsy, but also other etiologies. This hypothesis is now recognized as a synergistic mechanism that can give rise to epilepsy, and BBB repair for restoration of cerebrovascular integrity is considered a therapeutic alternative. Endothelial cells lining the inner surface of blood vessels are an integral component of the BBB system. Sealed by tight junctions, they are crucial in maintaining homeostatic activities of the brain, as well as acting as an interface in the neurovascular unit. Additional potential vascular mechanisms such as inflammation, altered neurovascular coupling, or changes in blood flow that can modulate neuronal circuit activity have been implicated in epilepsy. Our own work has shown how intrinsic defects within endothelial cells from the earliest developmental time points, which preclude neuronal changes, can lead to vascular abnormalities and autonomously support the development of hyperexcitability and epileptiform activity. In this article, we review the importance of vascular integrity and signaling for network excitability and epilepsy by highlighting complementary basic and clinical research studies and by outlining possible novel therapeutic strategies.
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Affiliation(s)
- Jugajyoti Baruah
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States.,Angiogenesis and Brain Development Laboratory, Division of Basic Neuroscience, McLean Hospital, Belmont, MA, United States
| | - Anju Vasudevan
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States.,Angiogenesis and Brain Development Laboratory, Division of Basic Neuroscience, McLean Hospital, Belmont, MA, United States
| | - Rüdiger Köhling
- Oscar-Langendorff-Institute of Physiology, Rostock University Medical Center, Rostock, Germany
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32
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Ye H, Kaszuba S. Neuromodulation with electromagnetic stimulation for seizure suppression: From electrode to magnetic coil. IBRO Rep 2019; 7:26-33. [PMID: 31360792 PMCID: PMC6639724 DOI: 10.1016/j.ibror.2019.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/25/2019] [Indexed: 12/31/2022] Open
Abstract
Non-invasive brain tissue stimulation with a magnetic coil provides several irreplaceable advantages over that with an implanted electrode, in altering neural activities under pathological situations. We reviewed clinical cases that utilized time-varying magnetic fields for the treatment of epilepsy, and the safety issues related to this practice. Animal models have been developed to foster understanding of the cellular/molecular mechanisms underlying magnetic control of epileptic activity. These mechanisms include (but are not limited to) (1) direct membrane polarization by the magnetic field, (2) depolarization blockade by the deactivation of ion channels, (3) alteration in synaptic transmission, and (4) interruption of ephaptic interaction and cellular synchronization. Clinical translation of this technology could be improved through the advancement of magnetic design, optimization of stimulation protocols, and evaluation of the long-term safety. Cellular and molecular studies focusing on the mechanisms of magnetic stimulation are of great value in facilitating this translation.
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Key Words
- 4-AP, 4-aminopyridine
- Animal models
- CD50, convulsant dose
- Cellular mechanisms
- DBS, deep brain stimulation
- EEG, electroencephalography
- ELF-MF, extremely low frequency magnetic fields
- EcoG, electrocorticography
- Epilepsy
- GABA, gamma-aminobutyric acid
- HFS, high frequency stimulation
- KA, kainic acid
- LD50, lethal dose
- LTD, long-term depression
- LTP, long-term potential
- MEG, magnetoencephalography
- MRI, magnetic resonance imaging
- Magnetic stimulation
- NMDAR, N-methyl-d-aspartate receptor
- PTZ, pentylenetetrazol
- REM, rapid eye movement
- SMF, static magnetic field
- TES, transcranial electrical stimulation
- TLE, temporal lobe epilepsy
- TMS, transcranial magnetic stimulation
- rTMS, repetitive transcranial magnetic stimulation
- tDCS, transcranial direct-current stimulation
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Affiliation(s)
- Hui Ye
- Department of Biology, Loyola University Chicago, Chicago, 1032 W. Sheridan Rd., IL, 60660, United States
| | - Stephanie Kaszuba
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Rd., North Chicago, IL, 60064, United States
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González‐Cuevas M, Coscojuela P, Santamarina E, Pareto D, Quintana M, Sueiras M, Guzman L, Sarria S, Salas‐Puig X, Toledo M, Rovira À. Usefulness of brain perfusion CT in focal‐onset status epilepticus. Epilepsia 2019; 60:1317-1324. [DOI: 10.1111/epi.16063] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 05/14/2019] [Accepted: 05/15/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Montserrat González‐Cuevas
- Epilepsy Unit Neurology Department Hospital Universitari Vall d'Hebron Barcelona Spain
- Department of Medicine Universitat Autonoma de Barcelona Barcelona Spain
| | - Pilar Coscojuela
- Neuroradiology Section Radiology Department Hospital Universitari Vall d'Hebron Barcelona Spain
| | - Estevo Santamarina
- Epilepsy Unit Neurology Department Hospital Universitari Vall d'Hebron Barcelona Spain
- Department of Medicine Universitat Autonoma de Barcelona Barcelona Spain
| | - Deborah Pareto
- Neuroradiology Section Radiology Department Hospital Universitari Vall d'Hebron Barcelona Spain
| | - Manuel Quintana
- Epilepsy Unit Neurology Department Hospital Universitari Vall d'Hebron Barcelona Spain
- Department of Medicine Universitat Autonoma de Barcelona Barcelona Spain
| | - María Sueiras
- Neurophysiology Unit Hospital Universitari Vall d'Hebron Barcelona Spain
| | - Lorena Guzman
- Neurophysiology Unit Hospital Universitari Vall d'Hebron Barcelona Spain
| | - Silvana Sarria
- Neuroradiology Section Radiology Department Hospital Universitari Vall d'Hebron Barcelona Spain
| | - Xavier Salas‐Puig
- Epilepsy Unit Neurology Department Hospital Universitari Vall d'Hebron Barcelona Spain
- Department of Medicine Universitat Autonoma de Barcelona Barcelona Spain
| | - Manuel Toledo
- Epilepsy Unit Neurology Department Hospital Universitari Vall d'Hebron Barcelona Spain
- Department of Medicine Universitat Autonoma de Barcelona Barcelona Spain
| | - Àlex Rovira
- Neuroradiology Section Radiology Department Hospital Universitari Vall d'Hebron Barcelona Spain
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Evaluation of cerebral blood flow in older patients with status epilepticus using arterial spin labeling. eNeurologicalSci 2019; 14:56-59. [PMID: 30619954 PMCID: PMC6313842 DOI: 10.1016/j.ensci.2018.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 09/06/2018] [Accepted: 12/16/2018] [Indexed: 11/23/2022] Open
Abstract
Introduction Although older patients with status epilepticus (SE) have a high mortality rate and poor outcome, it is difficult to perform emergent electroencephalography (EEG) to diagnose SE in community hospitals. Arterial spin labeling (ASL) is a non-invasive magnetic resonance imaging (MRI) technique that can rapidly assess cerebral blood flow (CBF). Further, ASL can detect increased CBF in the ictal period. Therefore, ASL may be a useful tool for diagnosing SE in older patients. However, its effectiveness in this population is unknown. Methods We retrospectively investigated differences in CBF abnormalities between older patients (≥70 years) and non-older patients (<70 years) with SE using ASL. Participants were diagnosed with convulsive status epilepticus (CSE) or non-convulsive status epilepticus (NCSE) based on symptoms, brain MRI, and EEG. Results ASL detected CBF abnormalities in 40% of older patients with CSE or NCSE. Rates of CBF abnormalities in older patients were not significantly different compared with that in non-older patients. Conclusions ASL did not detect a higher rate of CBF abnormalities in older patients, but may help physicians diagnose SE in older patients in a community hospital setting if emergent EEG cannot be immediately performed. ASL is a non-invasive MRI technique. ASL can assess CBF in a short time. ASL showed abnormality in CBF in 40% of older patients with SE. ASL detected CBF abnormality more often in older patients with NCSE than with CSE. ASL may be an aid to diagnosing SE in older patients.
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Hendrikx D, Smits A, Lavanga M, De Wel O, Thewissen L, Jansen K, Caicedo A, Van Huffel S, Naulaers G. Measurement of Neurovascular Coupling in Neonates. Front Physiol 2019; 10:65. [PMID: 30833901 PMCID: PMC6387909 DOI: 10.3389/fphys.2019.00065] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 01/21/2019] [Indexed: 01/01/2023] Open
Abstract
Neurovascular coupling refers to the mechanism that links the transient neural activity to the subsequent change in cerebral blood flow, which is regulated by both chemical signals and mechanical effects. Recent studies suggest that neurovascular coupling in neonates and preterm born infants is different compared to adults. The hemodynamic response after a stimulus is later and less pronounced and the stimulus might even result in a negative (hypoxic) signal. In addition, studies both in animals and neonates confirm the presence of a short hypoxic period after a stimulus in preterm infants. In clinical practice, different methodologies exist to study neurovascular coupling. The combination of functional magnetic resonance imaging or functional near-infrared spectroscopy (brain hemodynamics) with EEG (brain function) is most commonly used in neonates. Especially near-infrared spectroscopy is of interest, since it is a non-invasive method that can be integrated easily in clinical care and is able to provide results concerning longer periods of time. Therefore, near-infrared spectroscopy can be used to develop a continuous non-invasive measurement system, that could be used to study neonates in different clinical settings, or neonates with different pathologies. The main challenge for the development of a continuous marker for neurovascular coupling is how the coupling between the signals can be described. In practice, a wide range of signal interaction measures exist. Moreover, biomedical signals often operate on different time scales. In a more general setting, other variables also have to be taken into account, such as oxygen saturation, carbon dioxide and blood pressure in order to describe neurovascular coupling in a concise manner. Recently, new mathematical techniques were developed to give an answer to these questions. This review discusses these recent developments.
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Affiliation(s)
- Dries Hendrikx
- Department of Electrical Engineering, KU Leuven, Leuven, Belgium
- imec, Leuven, Belgium
| | - Anne Smits
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
| | - Mario Lavanga
- Department of Electrical Engineering, KU Leuven, Leuven, Belgium
- imec, Leuven, Belgium
| | - Ofelie De Wel
- Department of Electrical Engineering, KU Leuven, Leuven, Belgium
- imec, Leuven, Belgium
| | - Liesbeth Thewissen
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
| | - Katrien Jansen
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
- Child Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Alexander Caicedo
- Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Sabine Van Huffel
- Department of Electrical Engineering, KU Leuven, Leuven, Belgium
- imec, Leuven, Belgium
| | - Gunnar Naulaers
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
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Schertz M, Benzakoun J, Pyatigorskaya N, Belkacem S, Sahli-Amor M, Navarro V, Cholet C, Leclercq D, Dormont D, Law-Ye B. Specificities of arterial spin labeling (ASL) abnormalities in acute seizure. J Neuroradiol 2018; 47:20-26. [PMID: 30500358 DOI: 10.1016/j.neurad.2018.11.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/10/2018] [Accepted: 11/19/2018] [Indexed: 11/18/2022]
Abstract
PURPOSE Arterial spin labeling (ASL) is a non-invasive tool measuring cerebral blood flow (CBF) and is useful to assess acute neurological deficit. While acute stroke presents as hypoperfused vascular territory, epileptic activity causes cortical hyperperfusion. Other neurological conditions exhibit hyperperfusion, like migraine or secondary "luxury perfusion" in strokes. Our objectives were to evaluate the usefulness and potential specificities of ASL in acute seizure and correlate it with electroencephalogram. MATERIALS AND METHODS Amongst a cohort of patients with neurological deficit, addressed for suspicion of stroke, we retrospectively reviewed 25 consecutive patients with seizures who underwent magnetic resonance imaging (MRI) with ASL and electroencephalography (EEG). We compared them with a control group of patients with migraine and stroke secondary re-perfusion, exhibiting ASL hyperperfusion. RESULTS Lateralized cortical hyperperfusion (high relative CBF) was observed in all patients. Good topographic correlation with EEG was found in 18 patients (72%). Eight (32%) had hyperperfusion of ipsilateral pulvinar, 5 (20%) had hyperperfused contralateral cerebellar hemisphere, 16 (64%) presented diffusion abnormalities and 20 (80%) had underlying epileptogenic lesions. Pulvinar hyperperfusion was not observed in the control group, nor were diffusion abnormalities in migrainous patients. Contralateral cerebellar hyperperfusion was observed in two migrainous patient, without associated pulvinar activation, whereas all patients with cerebellar hyperperfusion in the study group had associated pulvinar activation. CONCLUSIONS Elevated CBF can be observed in the epileptogenic zone, ipsilateral pulvinar and contralateral cerebellum (diaschisis) in seizure. These abnormalities seem specific when compared with other causes of hyperperfusion. Arterial spin labeling can be highly effective in the differential diagnosis of strokes.
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Affiliation(s)
- Mathieu Schertz
- AP-HP, groupe hospitalier Pitié-Salpêtrière, neuroradiology department, 75013 Paris, France
| | - Joseph Benzakoun
- AP-HP, groupe hospitalier Pitié-Salpêtrière, neuroradiology department, 75013 Paris, France
| | - Nadya Pyatigorskaya
- AP-HP, groupe hospitalier Pitié-Salpêtrière, neuroradiology department, 75013 Paris, France; Sorbonne universités, Pierre and Marie-Curie faculty of medicine, 75013 Paris, France
| | - Samia Belkacem
- AP-HP, groupe hospitalier Pitié-Salpêtrière, neuroradiology department, 75013 Paris, France
| | - Melika Sahli-Amor
- AP-HP, groupe hospitalier Pitié-Salpêtrière, neuroradiology department, 75013 Paris, France
| | - Vincent Navarro
- AP-HP, groupe hospitalier Pitié-Salpêtrière, epileptology department, 75013 Paris, France
| | - Clément Cholet
- AP-HP, groupe hospitalier Pitié-Salpêtrière, neuroradiology department, 75013 Paris, France
| | - Delphine Leclercq
- AP-HP, groupe hospitalier Pitié-Salpêtrière, neuroradiology department, 75013 Paris, France
| | - Didier Dormont
- AP-HP, groupe hospitalier Pitié-Salpêtrière, neuroradiology department, 75013 Paris, France; Sorbonne universités, Pierre and Marie-Curie faculty of medicine, 75013 Paris, France
| | - Bruno Law-Ye
- AP-HP, groupe hospitalier Pitié-Salpêtrière, neuroradiology department, 75013 Paris, France.
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Shang K, Wang J, Fan X, Cui B, Ma J, Yang H, Zhou Y, Zhao G, Lu J. Clinical Value of Hybrid TOF-PET/MR Imaging-Based Multiparametric Imaging in Localizing Seizure Focus in Patients with MRI-Negative Temporal Lobe Epilepsy. AJNR Am J Neuroradiol 2018; 39:1791-1798. [PMID: 30237304 DOI: 10.3174/ajnr.a5814] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/18/2018] [Indexed: 01/06/2023]
Abstract
BACKGROUND AND PURPOSE Temporal lobe epilepsy is the most common type of epilepsy. Early surgical treatment is superior to prolonged medical therapy in refractory temporal lobe epilepsy. Successful surgical operations depend on the correct localization of the epileptogenic zone. This study aimed to evaluate the clinical value of hybrid TOF-PET/MR imaging-based multiparametric imaging in localizing the epileptogenic zone in patients with MR imaging-negative for temporal lobe epilepsy. MATERIALS AND METHODS Twenty patients with MR imaging-negative temporal lobe epilepsy who underwent preoperative evaluation and 10 healthy controls were scanned using PET/MR imaging with simultaneous acquisition of PET and arterial spin-labeling. On the basis of the standardized uptake value and cerebral blood flow, receiver operating characteristic analysis and a logistic regression model were used to evaluate the predictive value for the localization. Statistical analyses were performed using statistical parametric mapping. The values of the standardized uptake value and cerebral blood flow, as well as the asymmetries of metabolism and perfusion, were compared between the 2 groups. Histopathologic findings were used as the criterion standard. RESULTS Complete concordance was noted in lateralization and localization among the PET, arterial spin-labeling, and histopathologic findings in 12/20 patients based on visual assessment. Concordance with histopathologic findings was also obtained for the remaining 8 patients based on the complementary PET and arterial spin-labeling information. Receiver operating characteristic analysis showed that the sensitivity and specificity of PET, arterial spin-labeling, and combined PET and arterial spin-labeling were 100% and 81.8%, 83.3% and 54.5%, and 100% and 90.9%, respectively. When we compared the metabolic abnormalities in patients with those in healthy controls, hypometabolism was detected in the middle temporal gyrus (P < .001). Metabolism and perfusion asymmetries were also located in the temporal lobe (P < .001). CONCLUSIONS PET/MR imaging-based multiparametric imaging involving arterial spin-labeling may increase the clinical value of localizing the epileptogenic zone by providing concordant and complementary information in patients with MR imaging-negative temporal lobe epilepsy.
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Affiliation(s)
- K Shang
- From the Departments of Nuclear Medicine (K.S., J.W., B.C., J.M., H.Y., J.L.)
| | - J Wang
- From the Departments of Nuclear Medicine (K.S., J.W., B.C., J.M., H.Y., J.L.)
| | - X Fan
- Neurosurgery (X.F., G.Z.)
| | - B Cui
- From the Departments of Nuclear Medicine (K.S., J.W., B.C., J.M., H.Y., J.L.)
| | - J Ma
- From the Departments of Nuclear Medicine (K.S., J.W., B.C., J.M., H.Y., J.L.)
| | - H Yang
- From the Departments of Nuclear Medicine (K.S., J.W., B.C., J.M., H.Y., J.L.)
| | - Y Zhou
- Department of Radiology (Y.Z.), Johns Hopkins University, Baltimore, Maryland
| | - G Zhao
- Neurosurgery (X.F., G.Z.)
| | - J Lu
- From the Departments of Nuclear Medicine (K.S., J.W., B.C., J.M., H.Y., J.L.) .,Radiology (J.L.), Xuanwu Hospital, Capital Medical University, Beijing, China
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Yuan Y, Wang Z, Wang X, Yan J, Liu M, Li X. Low-Intensity Pulsed Ultrasound Stimulation Induces Coupling Between Ripple Neural Activity and Hemodynamics in the Mouse Visual Cortex. Cereb Cortex 2018; 29:3220-3223. [DOI: 10.1093/cercor/bhy187] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Indexed: 12/19/2022] Open
Abstract
Abstract
Several studies have separately investigated neural activities and hemodynamic responses induced by low-intensity pulsed ultrasound stimulation (LIPUS), less is known about their coupling under LIPUS. This study aims to investigate the neurovascular coupling with LIPUS by measuring neural activity and hemodynamics. We found that the relative power and sample entropy of local field potential at the ripple band have a significant correlation to relative cerebral blood flow over time (correlation coefficients: 0.66 ± 0.13 [P < 0.01] and −0.58 ± 0.11 [P < 0.05]). These results demonstrate that LIPUS can induce neurovascular coupling in the mouse visual cortex.
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Affiliation(s)
- Yi Yuan
- Institute of Electrical Engineering, Yanshan University, Qinhuangdao, China
| | - Zhijie Wang
- Institute of Electrical Engineering, Yanshan University, Qinhuangdao, China
| | - Xingran Wang
- Institute of Electrical Engineering, Yanshan University, Qinhuangdao, China
| | - Jiaqing Yan
- College of Electrical and Control Engineering, North China University of Technology, Beijing, China
| | - Mengyang Liu
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna , Austria
| | - Xiaoli Li
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
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Presurgical electromagnetic functional brain mapping in refractory focal epilepsy. ZEITSCHRIFT FUR EPILEPTOLOGIE 2018. [DOI: 10.1007/s10309-018-0189-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Compromised Dynamic Cerebral Autoregulation in Patients with Epilepsy. BIOMED RESEARCH INTERNATIONAL 2018; 2018:6958476. [PMID: 29568762 PMCID: PMC5820585 DOI: 10.1155/2018/6958476] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 12/18/2017] [Accepted: 12/26/2017] [Indexed: 12/17/2022]
Abstract
Objective The aim of this study is to analyze dynamic cerebral autoregulation (dCA) in patients with epilepsy. Methods One hundred patients with epilepsy and 100 age- and sex-matched healthy controls were recruited. Noninvasive continuous cerebral blood flow velocity of the bilateral middle artery and arterial blood pressure were recorded. Transfer function analyses were used to analyze the autoregulatory parameters (phase difference and gain). Results The overall phase difference of patients with epilepsy was significantly lower than that of the healthy control group (p = 0.046). Furthermore, patients with interictal slow wave had significant lower phase difference than the slow-wave-free patients (p = 0.012). There was no difference in overall phase between focal discharges and multifocal discharges in patients with epilepsy. Simultaneously, there was no difference in mean phase between the affected and unaffected hemispheres in patients with unilateral discharges. In particular, interictal slow wave was an independent factor that influenced phase difference in patients with epilepsy (p = 0.016). Conclusions Our study documented that dCA is impaired in patients with epilepsy, especially in those with interictal slow wave. The impairment of dCA occurs irrespective of the discharge location and type. Interictal slow wave is an independent factor to predict impaired dCA in patients with epilepsy. Clinical Trial Identifier This trial is registered with NCT02775682.
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Identification of cerebral perfusion using arterial spin labeling in patients with seizures in acute settings. PLoS One 2017; 12:e0173538. [PMID: 28291816 PMCID: PMC5349669 DOI: 10.1371/journal.pone.0173538] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 02/21/2017] [Indexed: 11/28/2022] Open
Abstract
This study aimed to explore the utility of arterial spin labeling perfusion-weighted imaging (ASL-PWI) in patients with suspected seizures in acute settings. A total of 164 patients who underwent ASL-PWI for suspected seizures in acute settings (with final diagnoses of seizure [n = 129], poststroke seizure [n = 18], and seizure mimickers [n = 17]), were included in this retrospective study. Perfusion abnormality was analyzed for: (1) pattern, (2) multifocality, and (3) atypical distribution against vascular territories. Perfusion abnormality was detected in 39% (50/129) of the seizure patients, most (94%, 47/50) being the hyperperfusion pattern. Of the patients with perfusion abnormality, multifocality or hemispheric involvement and atypical distribution against vascular territory were revealed in 46% (23/50) and 98% (49/50), respectively. In addition, seizures showed characteristic features including hyperperfusion (with or without non-territorial distribution) on ASL-PWI, thus differentiating them from poststroke seizures or seizure mimickers. In patients in whom seizure focus could be localized on both EEG and ASL-PWI, the concordance rate was 77%. The present study demonstrates that ASL-PWI can provide information regarding cerebral perfusion status in patients with seizures in acute settings and has the potential to be used as a non-invasive imaging tool to identify the cerebral perfusion in patients with seizures.
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Pichette J, Laurence A, Angulo L, Lesage F, Bouthillier A, Nguyen DK, Leblond F. Intraoperative video-rate hemodynamic response assessment in human cortex using snapshot hyperspectral optical imaging. NEUROPHOTONICS 2016; 3:045003. [PMID: 27752519 PMCID: PMC5061108 DOI: 10.1117/1.nph.3.4.045003] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/19/2016] [Indexed: 05/21/2023]
Abstract
Using light, we are able to visualize the hemodynamic behavior of the brain to better understand neurovascular coupling and cerebral metabolism. In vivo optical imaging of tissue using endogenous chromophores necessitates spectroscopic detection to ensure molecular specificity as well as sufficiently high imaging speed and signal-to-noise ratio, to allow dynamic physiological changes to be captured, isolated, and used as surrogate of pathophysiological processes. An optical imaging system is introduced using a 16-bands on-chip hyperspectral camera. Using this system, we show that up to three dyes can be imaged and quantified in a tissue phantom at video-rate through the optics of a surgical microscope. In vivo human patient data are presented demonstrating brain hemodynamic response can be measured intraoperatively with molecular specificity at high speed.
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Affiliation(s)
- Julien Pichette
- Polytechnique Montreal, Department of Engineering Physics, C.P. 6079, Succ. Centre-Ville, Montréal H3C3A7, Canada
| | - Audrey Laurence
- Polytechnique Montreal, Department of Engineering Physics, C.P. 6079, Succ. Centre-Ville, Montréal H3C3A7, Canada
| | - Leticia Angulo
- Polytechnique Montreal, Department of Engineering Physics, C.P. 6079, Succ. Centre-Ville, Montréal H3C3A7, Canada
| | - Frederic Lesage
- Polytechnique Montreal, Department of Electrical Engineering, C.P. 6079, Succ. Centre-Ville, Montréal H3C3A7, Canada
| | - Alain Bouthillier
- Centre Hospitalier de l’Université de Montréal, Notre-Dame Hospital, Division of Neurosurgery, 1560 Sherbrooke Street East, Montréal H2L4M1, Canada
| | - Dang Khoa Nguyen
- Centre Hospitalier de l’Université de Montréal, Notre-Dame Hospital, Division of Neurology, 1560 Sherbrooke Street East, Montréal H2L4M1, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, 900 Saint-Denis, Montréal H2X0A9, Canada
| | - Frederic Leblond
- Polytechnique Montreal, Department of Engineering Physics, C.P. 6079, Succ. Centre-Ville, Montréal H3C3A7, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, 900 Saint-Denis, Montréal H2X0A9, Canada
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Sigal I, Koletar MM, Ringuette D, Gad R, Jeffrey M, Carlen PL, Stefanovic B, Levi O. Imaging brain activity during seizures in freely behaving rats using a miniature multi-modal imaging system. BIOMEDICAL OPTICS EXPRESS 2016; 7:3596-3609. [PMID: 27699123 PMCID: PMC5030035 DOI: 10.1364/boe.7.003596] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 08/11/2016] [Accepted: 08/11/2016] [Indexed: 05/20/2023]
Abstract
We report on a miniature label-free imaging system for monitoring brain blood flow and blood oxygenation changes in awake, freely behaving rats. The device, weighing 15 grams, enables imaging in a ∼ 2 × 2 mm field of view with 4.4 μm lateral resolution and 1 - 8 Hz temporal sampling rate. The imaging is performed through a chronically-implanted cranial window that remains optically clear between 2 to > 6 weeks after the craniotomy. This imaging method is well suited for longitudinal studies of chronic models of brain diseases and disorders. In this work, it is applied to monitoring neurovascular coupling during drug-induced absence-like seizures 6 weeks following the craniotomy.
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Affiliation(s)
- Iliya Sigal
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON M5S 3G9,
Canada
- The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, 10 King’s College Road, Toronto, ON M5S 3G4,
Canada
| | - Margaret M. Koletar
- Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5,
Canada
| | - Dene Ringuette
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON M5S 3G9,
Canada
| | - Raanan Gad
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON M5S 3G9,
Canada
- The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, 10 King’s College Road, Toronto, ON M5S 3G4,
Canada
| | - Melanie Jeffrey
- Krembil Research Institute, 60 Leonard Avenue, Toronto, ON M5T 2S1,
Canada
| | - Peter L. Carlen
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON M5S 3G9,
Canada
- Krembil Research Institute, 60 Leonard Avenue, Toronto, ON M5T 2S1,
Canada
| | - Bojana Stefanovic
- Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5,
Canada
- Department of Medical Biophysics, University of Toronto, 2075 Bayview Avenue, Toronto, ON M4N 3M5,
Canada
| | - Ofer Levi
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON M5S 3G9,
Canada
- The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, 10 King’s College Road, Toronto, ON M5S 3G4,
Canada
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Kim BS, Lee ST, Yun TJ, Lee SK, Paeng JC, Jun J, Kang KM, Choi SH, Kim JH, Sohn CH. Capability of arterial spin labeling MR imaging in localizing seizure focus in clinical seizure activity. Eur J Radiol 2016; 85:1295-303. [PMID: 27235877 DOI: 10.1016/j.ejrad.2016.04.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/15/2016] [Accepted: 04/28/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE The purpose of this study was to evaluate cerebral blood flow using arterial spin labeling (ASL) perfusion magnetic resonance (MR) imaging in patients with clinical seizure activity and determine its diagnostic performance in identifying seizure focus. MATERIALS AND METHODS Institutional Review Board of our hospital approved this retrospective study. Informed consent was waived. Clinical seizure focus was determined by a neurologist based on seizure semiology, electroencephalography, and conventional imaging modalities. The diagnostic performance of ASL perfusion MR imaging to identifying seizure focus compared to clinical seizure focus was analyzed. RESULTS Clinical seizure focus was localized in 95% (42/44) of patients. The sensitivity and specificity of ASL perfusion MR imaging for identifying seizure focus were 74% (95% CI: 58%, 86%) (clinical seizure focus was localizable in 31 of 42 patients, including complete concordance in 10 patients and partial concordance in 21 patients) and 0% (95% CI: 0%, 84%) (for the two patients whose clinical seizure foci were not localizable, they were identified by ASL perfusion MR imaging), respectively. Thus, the overall accuracy of ASL perfusion MR imaging for localizing seizure focus was 70% (33/44). For 4 patients who had abnormal perfusion on ASL, their seizure foci based on ASL perfusion MR imaging were discordant with clinical seizure foci. CONCLUSION ASL perfusion MR imaging can provide information about perfusion status and important diagnostic clue in localizing seizure focus in patients with clinical seizure activity. It has the potential as a non-invasive complementary diagnostic tool for patients with clinical seizure activity.
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Affiliation(s)
- Beom Su Kim
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea; Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Soon-Tae Lee
- Department of Neurology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Tae Jin Yun
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea; Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea.
| | - Sang Kun Lee
- Department of Neurology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jin Chul Paeng
- Department of Nuclear Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jinsun Jun
- Department of Neurology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Koung Mi Kang
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea; Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Seung Hong Choi
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea; Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Ji-Hoon Kim
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea; Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Chul-Ho Sohn
- Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea; Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea
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Chhabria K, Chakravarthy VS. Low-Dimensional Models of "Neuro-Glio-Vascular Unit" for Describing Neural Dynamics under Normal and Energy-Starved Conditions. Front Neurol 2016; 7:24. [PMID: 27014179 PMCID: PMC4783418 DOI: 10.3389/fneur.2016.00024] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 02/18/2016] [Indexed: 01/08/2023] Open
Abstract
The motivation of developing simple minimal models for neuro-glio-vascular (NGV) system arises from a recent modeling study elucidating the bidirectional information flow within the NGV system having 89 dynamic equations (1). While this was one of the first attempts at formulating a comprehensive model for neuro-glio-vascular system, it poses severe restrictions in scaling up to network levels. On the contrary, low-dimensional models are convenient devices in simulating large networks that also provide an intuitive understanding of the complex interactions occurring within the NGV system. The key idea underlying the proposed models is to describe the glio-vascular system as a lumped system, which takes neural firing rate as input and returns an “energy” variable (analogous to ATP) as output. To this end, we present two models: biophysical neuro-energy (Model 1 with five variables), comprising KATP channel activity governed by neuronal ATP dynamics, and the dynamic threshold (Model 2 with three variables), depicting the dependence of neural firing threshold on the ATP dynamics. Both the models show different firing regimes, such as continuous spiking, phasic, and tonic bursting depending on the ATP production coefficient, ɛp, and external current. We then demonstrate that in a network comprising such energy-dependent neuron units, ɛp could modulate the local field potential (LFP) frequency and amplitude. Interestingly, low-frequency LFP dominates under low ɛp conditions, which is thought to be reminiscent of seizure-like activity observed in epilepsy. The proposed “neuron-energy” unit may be implemented in building models of NGV networks to simulate data obtained from multimodal neuroimaging systems, such as functional near infrared spectroscopy coupled to electroencephalogram and functional magnetic resonance imaging coupled to electroencephalogram. Such models could also provide a theoretical basis for devising optimal neurorehabilitation strategies, such as non-invasive brain stimulation for stroke patients.
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Affiliation(s)
- Karishma Chhabria
- Computational Biophysics and Neurosciences Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai , India
| | - V Srinivasa Chakravarthy
- Computational Biophysics and Neurosciences Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras , Chennai , India
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Nagaraj V, Lee S, Krook-Magnuson E, Soltesz I, Benquet P, Irazoqui P, Netoff T. Future of seizure prediction and intervention: closing the loop. J Clin Neurophysiol 2015; 32:194-206. [PMID: 26035672 PMCID: PMC4455045 DOI: 10.1097/wnp.0000000000000139] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The ultimate goal of epilepsy therapies is to provide seizure control for all patients while eliminating side effects. Improved specificity of intervention through on-demand approaches may overcome many of the limitations of current intervention strategies. This article reviews the progress in seizure prediction and detection, potential new therapies to provide improved specificity, and devices to achieve these ends. Specifically, we discuss (1) potential signal modalities and algorithms for seizure detection and prediction, (2) closed-loop intervention approaches, and (3) hardware for implementing these algorithms and interventions. Seizure prediction and therapies maximize efficacy, whereas minimizing side effects through improved specificity may represent the future of epilepsy treatments.
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Affiliation(s)
- Vivek Nagaraj
- Graduate Program in Neuroscience, University of Minnesota
| | - Steven Lee
- Weldon School of Biomedical Engineering, Purdue University
| | | | - Ivan Soltesz
- Department of Anatomy & Neurobiology, University of California, Irvine
| | | | - Pedro Irazoqui
- Weldon School of Biomedical Engineering, Purdue University
| | - Theoden Netoff
- Graduate Program in Neuroscience, University of Minnesota
- Department of Biomedical Engineering, University of Minnesota
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Pashaie R, Baumgartner R, Richner TJ, Brodnick SK, Azimipour M, Eliceiri KW, Williams JC. Closed-Loop Optogenetic Brain Interface. IEEE Trans Biomed Eng 2015; 62:2327-37. [PMID: 26011877 DOI: 10.1109/tbme.2015.2436817] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This paper presents a new approach for implementation of closed-loop brain-machine interface algorithms by combining optogenetic neural stimulation with electrocorticography and fluorescence microscopy. We used a new generation of microfabricated electrocorticography (micro-ECoG) devices in which electrode arrays are embedded within an optically transparent biocompatible substrate that provides optical access to the brain tissue during electrophysiology recording. An optical setup was designed capable of projecting arbitrary patterns of light for optogenetic stimulation and performing fluorescence microscopy through the implant. For realization of a closed-loop system using this platform, the feedback can be taken from electrophysiology data or fluorescence imaging. In the closed-loop systems discussed in this paper, the feedback signal was taken from the micro-ECoG. In these algorithms, the electrophysiology data are continuously transferred to a computer and compared with some predefined spatial-temporal patterns of neural activity. The computer which processes the data also readjusts the duration and distribution of optogenetic stimulating pulses to minimize the difference between the recorded activity and the predefined set points so that after a limited period of transient response the recorded activity follows the set points. Details of the system design and implementation of typical closed-loop paradigms are discussed in this paper.
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Nugent AC, Martinez A, D'Alfonso A, Zarate CA, Theodore WH. The relationship between glucose metabolism, resting-state fMRI BOLD signal, and GABAA-binding potential: a preliminary study in healthy subjects and those with temporal lobe epilepsy. J Cereb Blood Flow Metab 2015; 35:583-91. [PMID: 25564232 PMCID: PMC4420874 DOI: 10.1038/jcbfm.2014.228] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 10/29/2014] [Accepted: 11/13/2014] [Indexed: 12/22/2022]
Abstract
Glucose metabolism has been associated with magnitude of blood oxygen level-dependent (BOLD) signal and connectivity across subjects within the default mode and dorsal attention networks. Similar correlations within subjects across the entire brain remain unexplored. [(18)F]-fluorodeoxyglucose positron emission tomography ([(18)F]-FDG PET), [(11)C]-flumazenil PET, and resting-state functional magnetic resonance imaging (fMRI) scans were acquired in eight healthy individuals and nine with temporal lobe epilepsy (TLE). Regional metabolic rate of glucose (rMRGlu) was correlated with amplitude of low frequency fluctuations (ALFFs) in the fMRI signal, global fMRI connectivity (GC), regional homogeneity (ReHo), and gamma-aminobutyric acid A-binding potential (GABAA BP(ND)) across the brain. Partial correlations for ALFFs, GC, and ReHo with GABAA BP(ND) were calculated, controlling for rMRGlu. In healthy subjects, significant positive correlations were observed across the brain between rMRGlu and ALFF, ReHo and GABAA BP(ND), and between ALFFs and GABAA BP(ND), controlling for rMRGlu. Brain-wide correlations between rMRGlu and ALFFs were significantly lower in TLE patients, and correlations between rMRGlu and GC were significantly greater in TLE than healthy subjects. These results indicate that the glutamatergic and GABAergic systems are coupled across the healthy human brain, and that ALFF is related to glutamate use throughout the healthy human brain. TLE may be a disorder of altered long-range connectivity in association with glutamate function.
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Affiliation(s)
- Allison C Nugent
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
| | - Ashley Martinez
- Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Alana D'Alfonso
- Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Carlos A Zarate
- Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
| | - William H Theodore
- Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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Wang B, Zhou J, Carney P, Jiang H. A novel detachable head-mounted device for simultaneous EEG and photoacoustic monitoring of epilepsy in freely moving rats. Neurosci Res 2015; 91:57-62. [DOI: 10.1016/j.neures.2014.08.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 07/25/2014] [Accepted: 08/13/2014] [Indexed: 02/01/2023]
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Murta T, Leite M, Carmichael DW, Figueiredo P, Lemieux L. Electrophysiological correlates of the BOLD signal for EEG-informed fMRI. Hum Brain Mapp 2015; 36:391-414. [PMID: 25277370 PMCID: PMC4280889 DOI: 10.1002/hbm.22623] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/04/2014] [Accepted: 08/20/2014] [Indexed: 12/11/2022] Open
Abstract
Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) are important tools in cognitive and clinical neuroscience. Combined EEG-fMRI has been shown to help to characterise brain networks involved in epileptic activity, as well as in different sensory, motor and cognitive functions. A good understanding of the electrophysiological correlates of the blood oxygen level-dependent (BOLD) signal is necessary to interpret fMRI maps, particularly when obtained in combination with EEG. We review the current understanding of electrophysiological-haemodynamic correlates, during different types of brain activity. We start by describing the basic mechanisms underlying EEG and BOLD signals and proceed by reviewing EEG-informed fMRI studies using fMRI to map specific EEG phenomena over the entire brain (EEG-fMRI mapping), or exploring a range of EEG-derived quantities to determine which best explain colocalised BOLD fluctuations (local EEG-fMRI coupling). While reviewing studies of different forms of brain activity (epileptic and nonepileptic spontaneous activity; cognitive, sensory and motor functions), a significant attention is given to epilepsy because the investigation of its haemodynamic correlates is the most common application of EEG-informed fMRI. Our review is focused on EEG-informed fMRI, an asymmetric approach of data integration. We give special attention to the invasiveness of electrophysiological measurements and the simultaneity of multimodal acquisitions because these methodological aspects determine the nature of the conclusions that can be drawn from EEG-informed fMRI studies. We emphasise the advantages of, and need for, simultaneous intracranial EEG-fMRI studies in humans, which recently became available and hold great potential to improve our understanding of the electrophysiological correlates of BOLD fluctuations.
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Affiliation(s)
- Teresa Murta
- Department of Clinical and Experimental EpilepsyUCL Institute of Neurology, Queen SquareLondonUnited Kingdom
- Department of BioengineeringInstitute for systems and robotics, Instituto Superior Técnico, Universidade de LisboaLisbonPortugal
| | - Marco Leite
- Department of Clinical and Experimental EpilepsyUCL Institute of Neurology, Queen SquareLondonUnited Kingdom
- Department of BioengineeringInstitute for systems and robotics, Instituto Superior Técnico, Universidade de LisboaLisbonPortugal
| | - David W. Carmichael
- Imaging and Biophysics UnitUCL Institute of Child HealthLondonUnited Kingdom
| | - Patrícia Figueiredo
- Department of BioengineeringInstitute for systems and robotics, Instituto Superior Técnico, Universidade de LisboaLisbonPortugal
| | - Louis Lemieux
- Department of Clinical and Experimental EpilepsyUCL Institute of Neurology, Queen SquareLondonUnited Kingdom
- MRI Unit, Epilepsy SocietyChalfont St. PeterUnited Kingdom
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