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Traub-Weidinger T, Arbizu J, Barthel H, Boellaard R, Borgwardt L, Brendel M, Cecchin D, Chassoux F, Fraioli F, Garibotto V, Guedj E, Hammers A, Law I, Morbelli S, Tolboom N, Van Weehaeghe D, Verger A, Van Paesschen W, von Oertzen TJ, Zucchetta P, Semah F. EANM practice guidelines for an appropriate use of PET and SPECT for patients with epilepsy. Eur J Nucl Med Mol Imaging 2024; 51:1891-1908. [PMID: 38393374 PMCID: PMC11139752 DOI: 10.1007/s00259-024-06656-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 02/13/2024] [Indexed: 02/25/2024]
Abstract
Epilepsy is one of the most frequent neurological conditions with an estimated prevalence of more than 50 million people worldwide and an annual incidence of two million. Although pharmacotherapy with anti-seizure medication (ASM) is the treatment of choice, ~30% of patients with epilepsy do not respond to ASM and become drug resistant. Focal epilepsy is the most frequent form of epilepsy. In patients with drug-resistant focal epilepsy, epilepsy surgery is a treatment option depending on the localisation of the seizure focus for seizure relief or seizure freedom with consecutive improvement in quality of life. Beside examinations such as scalp video/electroencephalography (EEG) telemetry, structural, and functional magnetic resonance imaging (MRI), which are primary standard tools for the diagnostic work-up and therapy management of epilepsy patients, molecular neuroimaging using different radiopharmaceuticals with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) influences and impacts on therapy decisions. To date, there are no literature-based praxis recommendations for the use of Nuclear Medicine (NM) imaging procedures in epilepsy. The aims of these guidelines are to assist in understanding the role and challenges of radiotracer imaging for epilepsy; to provide practical information for performing different molecular imaging procedures for epilepsy; and to provide an algorithm for selecting the most appropriate imaging procedures in specific clinical situations based on current literature. These guidelines are written and authorized by the European Association of Nuclear Medicine (EANM) to promote optimal epilepsy imaging, especially in the presurgical setting in children, adolescents, and adults with focal epilepsy. They will assist NM healthcare professionals and also specialists such as Neurologists, Neurophysiologists, Neurosurgeons, Psychiatrists, Psychologists, and others involved in epilepsy management in the detection and interpretation of epileptic seizure onset zone (SOZ) for further treatment decision. The information provided should be applied according to local laws and regulations as well as the availability of various radiopharmaceuticals and imaging modalities.
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Affiliation(s)
- Tatjana Traub-Weidinger
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Javier Arbizu
- Department of Nuclear Medicine, University of Navarra Clinic, Pamplona, Spain
| | - Henryk Barthel
- Department of Nuclear Medicine, Leipzig University Medical Centre, Leipzig, Germany
| | - Ronald Boellaard
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Location VUmc, Amsterdam, The Netherlands
| | - Lise Borgwardt
- Department of Clinical Physiology and Nuclear Medicine, University of Copenhagen, Blegdamsvej 9, DK-2100, RigshospitaletCopenhagen, Denmark
| | - Matthias Brendel
- Department of Nuclear Medicine, Ludwig Maximilian-University of Munich, Munich, Germany
- DZNE-German Center for Neurodegenerative Diseases, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Diego Cecchin
- Nuclear Medicine Unit, Department of Medicine-DIMED, University-Hospital of Padova, Padova, Italy
| | - Francine Chassoux
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, 91401, Orsay, France
| | - Francesco Fraioli
- Institute of Nuclear Medicine, University College London (UCL), London, UK
| | - Valentina Garibotto
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospitals, Geneva, Switzerland
- NIMTLab, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Center for Biomedical Imaging (CIBM), Geneva, Switzerland
| | - Eric Guedj
- APHM, CNRS, Centrale Marseille, Institut Fresnel, Timone Hospital, CERIMED, Nuclear Medicine Department, Aix Marseille Univ, Marseille, France
| | - Alexander Hammers
- School of Biomedical Engineering and Imaging Sciences, Faculty of Life Sciences and Medicine, King's College London & Guy's and St Thomas' PET Centre, King's College London, London, UK
| | - Ian Law
- Department of Clinical Physiology and Nuclear Medicine, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, DK-2100, Copenhagen, Denmark
| | - Silvia Morbelli
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
| | - Nelleke Tolboom
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | - Antoine Verger
- Department of Nuclear Medicine and Nancyclotep Imaging Platform, CHRU Nancy, Université de Lorraine, IADI, INSERM U1254, Nancy, France
| | - Wim Van Paesschen
- Laboratory for Epilepsy Research, KU Leuven and Department of Neurology, University Hospitals, Leuven, Belgium
| | - Tim J von Oertzen
- Depts of Neurology 1&2, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Pietro Zucchetta
- Nuclear Medicine Unit, Department of Medicine-DIMED, University-Hospital of Padova, Padova, Italy
| | - Franck Semah
- Nuclear Medicine Department, University Hospital, Inserm, CHU Lille, U1172-LilNCog-Lille, F-59000, Lille, France.
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Song C, Xie S, Zhang X, Han S, Lian Y, Ma K, Mao X, Zhang Y, Cheng J. Similarities and differences of dynamic and static spontaneous brain activity between left and right temporal lobe epilepsy. Brain Imaging Behav 2024; 18:352-367. [PMID: 38087148 DOI: 10.1007/s11682-023-00835-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2023] [Indexed: 06/07/2024]
Abstract
To comprehensively investigate the potential temporal dynamic and static abnormalities of spontaneous brain activity (SBA) in left temporal lobe epilepsy (LTLE) and right temporal lobe epilepsy (RTLE) and to detect whether these alterations correlate with cognition. Twelve SBA metrics, including ALFF, dALFF, fALFF, dfALFF, ReHo, dReHo, DC, dDC, GSCorr, dGSCorr, VMHC, and dVMHC, in 46 LTLE patients, 43 RTLE patients, and 53 healthy volunteers were compared in the voxel-wise analysis. Correlation analyses between metrics in regions showing statistic differences and epilepsy duration, epilepsy severity, and cognition scores were also performed. Compared with the healthy volunteers, the alteration of SBA was identified both in LTLE and RTLE patients. The ALFF, fALFF, and dALFF values in LTLE, as well as the fALFF values in RTLE, increased in the bilateral thalamus, basal ganglia, mesial temporal lobe, cerebellum, and vermis. Increased dfALFF in the bilateral basal ganglia, increased ReHo and dReHo in the bilateral thalamus in the LTLE group, increased ALFF and dALFF in the pons, and increased ReHo and dReHo in the right hippocampus in the RTLE group were also detected. However, the majority of deactivation clusters were in the ipsilateral lateral temporal lobe. For LTLE, the fALFF, DC, dDC, and GSCorr values in the left lateral temporal lobe and the ReHo and VMHC values in the bilateral lateral temporal lobe all decreased. For RTLE, the ALFF, fALFF, dfALFF, ReHo, dReHo, and DC values in the right lateral temporal lobe and the VMHC values in the bilateral lateral temporal lobe all decreased. Moreover, for both the LTLE and RTLE groups, the dVMHC values decreased in the calcarine cortex. The most significant difference between LTLE and RTLE was the higher activation in the cerebellum of the LTLE group. The alterations of many SBA metrics were correlated with cognition and epilepsy duration. The patterns of change in SBA abnormalities in the LTLE and RTLE patients were generally similar. The integrated application of temporal dynamic and static SBA metrics might aid in the investigation of the propagation and suppression pathways of seizure activity as well as the cognitive impairment mechanisms in TLE.
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Affiliation(s)
- Chengru Song
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Dong Road, Zhengzhou, 450052, China
| | - Shanshan Xie
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Dong Road, Zhengzhou, 450052, China
| | - Xiaonan Zhang
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Dong Road, Zhengzhou, 450052, China
| | - Shaoqiang Han
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Dong Road, Zhengzhou, 450052, China
| | - Yajun Lian
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Keran Ma
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Dong Road, Zhengzhou, 450052, China
| | - Xinyue Mao
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Dong Road, Zhengzhou, 450052, China
| | - Yong Zhang
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Dong Road, Zhengzhou, 450052, China.
| | - Jingliang Cheng
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe Dong Road, Zhengzhou, 450052, China.
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Rogeau A, Lilburn DML, Kaplar Z, Anderson C, Scott CJ, Chowdhury FA, Fraioli F, Bomanji JB. Identifying and troubleshooting the pitfalls of ictal/interictal brain perfusion SPECT studies. Nucl Med Commun 2023; 44:1053-1058. [PMID: 37661779 DOI: 10.1097/mnm.0000000000001755] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Epilepsy is a prevalent condition, and surgical intervention can benefit patients with refractory seizures. Single photon emission computed tomography (SPECT) using 99mTc-HMPAO or 99mTc-ECD provides assessment of regional cerebral blood flow and is the primary non-invasive approach for imaging brain perfusion in ictal and interictal states. Ictal/interictal SPECT is valuable in localising epileptogenic foci, particularly when MRI and electroencephalography are negative. However, to obtain accurate images reflecting brain perfusion in both states, meticulous preparation of the patient, timely radiotracer injection and close coordination between neurology and nuclear medicine teams are essential. Tracers also have inherent limitations, and patients may present with coexisting brain pathologies for which coregistration of SPECT images with MRI is recommended to improve diagnostic accuracy. Inconclusive SPECT findings may require repeating the exam or considering additional investigations. A comprehensive approach, considering various factors, is crucial for accurate interpretation of SPECT studies in presurgical epilepsy evaluations. This article provides a summary of the organisation and key challenges involved in conducting ictal/interictal SPECT studies, covering the entire process from a patient's hospital arrival to the integration of results within their presurgical pathway and using our experience of 182 patients over 10 years.
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Affiliation(s)
- Antoine Rogeau
- Institute of Nuclear Medicine, University College London Hospitals NHS Foundation Trust, London, UK
- Department of Nuclear Medicine, Lille University Hospitals, Lille, France
| | - David M L Lilburn
- Institute of Nuclear Medicine, University College London Hospitals NHS Foundation Trust, London, UK
- Department of Imaging, School of Medicine, University College London
| | - Zoltan Kaplar
- Institute of Nuclear Medicine, University College London Hospitals NHS Foundation Trust, London, UK
| | - Cameron Anderson
- Institute of Nuclear Medicine, University College London Hospitals NHS Foundation Trust, London, UK
| | - Catherine J Scott
- Institute of Nuclear Medicine, University College London Hospitals NHS Foundation Trust, London, UK
| | - Fahmida A Chowdhury
- Department of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
| | - Francesco Fraioli
- Institute of Nuclear Medicine, University College London Hospitals NHS Foundation Trust, London, UK
- Department of Imaging, School of Medicine, University College London
| | - Jamshed B Bomanji
- Institute of Nuclear Medicine, University College London Hospitals NHS Foundation Trust, London, UK
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Cosentino C, Al Maawali S, Wittayacharoenpong T, Tan T, Au Yong HM, Shakhatreh L, Chen Z, Beech P, Foster E, O'Brien TJ, Kwan P, Neal A. Ex-SPECTing success: Predictors of successful SPECT radiotracer injection during presurgical video-EEG admissions. Epilepsia Open 2023. [PMID: 37469231 DOI: 10.1002/epi4.12795] [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: 01/29/2023] [Accepted: 07/17/2023] [Indexed: 07/21/2023] Open
Abstract
OBJECTIVES To determine predictors of successful ictal single photon emission computed tomography (SPECT) injections during Epilepsy Monitoring Unit (EMU) admissions for patients undergoing presurgical evaluation for drug-resistant focal epilepsy. METHODS In this retrospective study, consecutive EMU admissions were analyzed at a single center between 2019 and 2021. All seizures that occurred during the admission were reviewed. "Injectable seizures" occurred during hours when the radiotracer was available. EMU-level data were analyzed to identify factors predictive of an EMU admission with a successful SPECT injection (successful admission). Seizure-level data were analyzed to identify factors predictive of an injectable seizure receiving a SPECT injection during the ictal phase (successful injection). A multivariate generalized linear model was used to identify predictive variables. RESULTS 125 EMU admissions involving 103 patients (median 37 years, IQR 27.0-45.5) were analyzed. 38.8% of seizures that were eligible for SPECT (n = 134) were successfully injected; this represented 17.4% of all seizures (n = 298) that occurred during admission. Unsuccessful admissions were most commonly due to a lack of seizures during EMU-SPECT (19.3%) or no injectable seizures (62.3%). Successful EMU-SPECT was associated with baseline seizure frequency >1 per week (95% CI 2.1-3.0, P < 0.001) and focal PET hypometabolism (95% CI 2.0-3.7, P < 0.001). On multivariate analysis, the only factor associated with successful injection was patients being able to indicate they were having a seizure to staff (95% CI 1.0-4.4, P = 0.038). SIGNIFICANCE Completing a successful ictal SPECT study remains challenging. A baseline seizure frequency of >1 per week, a PET hypometabolic focus, and a patient's ability to indicate seizure onset were identified as predictors of success. These findings may assist EMUs in optimizing their SPECT protocols, patient selection, and resource allocation.
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Affiliation(s)
- Carmela Cosentino
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - Said Al Maawali
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | | | - Tracie Tan
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - Hue Mun Au Yong
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - Lubna Shakhatreh
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - Zhibin Chen
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Paul Beech
- Department of Radiology, Alfred Health, Melbourne, Victoria, Australia
| | - Emma Foster
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Terence J O'Brien
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Patrick Kwan
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Andrew Neal
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
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Streng ML, Froula JM, Krook-Magnuson E. The cerebellum's understated role and influences in the epilepsies. Neurobiol Dis 2023; 183:106160. [PMID: 37209926 DOI: 10.1016/j.nbd.2023.106160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/03/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023] Open
Abstract
Approximately 1 in 26 people will develop epilepsy in their lifetime, but current treatment options leave as many as half of all epilepsy patients with uncontrolled seizures. In addition to the burden of the seizures themselves, chronic epilepsy can be associated with cognitive deficits, structural changes, and devastating negative outcomes such as sudden unexpected death in epilepsy (SUDEP). Thus, major challenges in epilepsy research surround the need to both develop new therapeutic targets for intervention as well as shed light on the mechanisms by which chronic epilepsy can lead to comorbidities and negative outcomes. Despite not being traditionally associated with epilepsy or seizures, the cerebellum has emerged as not only a brain region that can serve as an important target for seizure control, but one that may also be profoundly impacted by chronic epilepsy. Here, we discuss targeting the cerebellum for potential therapeutic intervention and discuss pathway insights gained from recent optogenetic studies. We then review observations of cerebellar alterations during seizures and in chronic epilepsy, as well as the potential for the cerebellum to be a seizure focus. Cerebellar alterations in epilepsy may be critical to patient outcomes, highlighting the need for a more comprehensive understanding and appreciation of the cerebellum in the epilepsies.
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Affiliation(s)
- Martha L Streng
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA.
| | - Jessica M Froula
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
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Krishnan B, Tousseyn S, Wang ZI, Murakami H, Wu G, Burgess R, Iasemidis L, Najm I, Alexopoulos AV. Novel noninvasive identification of patient-specific epileptic networks in focal epilepsies: Linking single-photon emission computed tomography perfusion during seizures with resting-state magnetoencephalography dynamics. Hum Brain Mapp 2023; 44:1695-1710. [PMID: 36480260 PMCID: PMC9921232 DOI: 10.1002/hbm.26168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 08/31/2022] [Accepted: 11/18/2022] [Indexed: 12/13/2022] Open
Abstract
Single-photon emission computed tomography (SPECT) during seizures and magnetoencephalography (MEG) during the interictal state are noninvasive modalities employed in the localization of the epileptogenic zone in patients with drug-resistant focal epilepsy (DRFE). The present study aims to investigate whether there exists a preferentially high MEG functional connectivity (FC) among those regions of the brain that exhibit hyperperfusion or hypoperfusion during seizures. We studied MEG and SPECT data in 30 consecutive DRFE patients who had resective epilepsy surgery. We parcellated each ictal perfusion map into 200 regions of interest (ROIs) and generated ROI time series using source modeling of MEG data. FC between ROIs was quantified using coherence and phase-locking value. We defined a generalized linear model to relate the connectivity of each ROI, ictal perfusion z score, and distance between ROIs. We compared the coefficients relating perfusion z score to FC of each ROI and estimated the connectivity within and between resected and unresected ROIs. We found that perfusion z scores were strongly correlated with the FC of hyper-, and separately, hypoperfused ROIs across patients. High interictal connectivity was observed between hyperperfused brain regions inside and outside the resected area. High connectivity was also observed between regions of ictal hypoperfusion. Importantly, the ictally hypoperfused regions had a low interictal connectivity to regions that became hyperperfused during seizures. We conclude that brain regions exhibiting hyperperfusion during seizures highlight a preferentially connected interictal network, whereas regions of ictal hypoperfusion highlight a separate, discrete and interconnected, interictal network.
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Affiliation(s)
- Balu Krishnan
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Simon Tousseyn
- Academic Center for EpileptologyKempenhaeghe and Maastricht UMC+HeezeThe Netherlands
| | - Zhong Irene Wang
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Hiroatsu Murakami
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Guiyun Wu
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Richard Burgess
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
| | - Leonidas Iasemidis
- Department of Translational NeuroscienceBarrow Neurological InstituteScottsdaleArizonaUSA
- Department of NeurologyBarrow Neurological InstituteScottsdaleArizonaUSA
| | - Imad Najm
- Neurological InstituteEpilepsy Center, Cleveland ClinicClevelandOhioUSA
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Mao L, Zheng G, Cai Y, Luo W, Zhang Q, Peng W, Ding J, Wang X. Frontotemporal phase lag index correlates with seizure severity in patients with temporal lobe epilepsy. Front Neurol 2022; 13:855842. [DOI: 10.3389/fneur.2022.855842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 10/18/2022] [Indexed: 12/05/2022] Open
Abstract
ObjectivesTo find the brain network indicators correlated with the seizure severity in temporal lobe epilepsy (TLE) by graph theory analysis.MethodsWe enrolled 151 patients with TLE and 36 age- and sex-matched controls with video-EEG monitoring. The 90-s interictal EEG data were acquired. We adopted a network analyzing pipeline based on graph theory to quantify and localize their functional networks, including weighted classical network, minimum spanning tree, community structure, and LORETA. The seizure severities were evaluated using the seizure frequency, drug-resistant epilepsy (DRE), and VA-2 scores.ResultsOur network analysis pipeline showed ipsilateral frontotemporal activation in patients with TLE. The frontotemporal phase lag index (PLI) values increased in the theta band (4–7 Hz), which were elevated in patients with higher seizure severities (P < 0.05). Multivariate linear regression analysis showed that the VA-2 scores were independently correlated with frontotemporal PLI values in the theta band (β = 0.259, P = 0.001) and age of onset (β = −0.215, P = 0.007).SignificanceThis study illustrated that the frontotemporal PLI in the theta band independently correlated with seizure severity in patients with TLE. Our network analysis provided an accessible approach to guide the treatment strategy in routine clinical practice.
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Song C, Zhang X, Han S, Ma K, Wang K, Mao X, Lian Y, Zhang X, Zhu J, Zhang Y, Cheng J. More than just statics: Static and temporal dynamic changes in intrinsic brain activity in unilateral temporal lobe epilepsy. Front Hum Neurosci 2022; 16:971062. [PMID: 36118964 PMCID: PMC9471141 DOI: 10.3389/fnhum.2022.971062] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/01/2022] [Indexed: 11/17/2022] Open
Abstract
Background Temporal lobe epilepsy (TLE) is the most prevalent refractory focal epilepsy and is more likely accompanied by cognitive impairment. The fully understanding of the neuronal activity underlying TLE is of great significance. Objective This study aimed to comprehensively explore the potential brain activity abnormalities affected by TLE and detect whether the changes were associated with cognition. Methods Six static intrinsic brain activity (IBA) indicators [amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), regional homogeneity (ReHo), degree centrality (DC), global signal correlation (GSCorr), and voxel-mirrored homotopic connectivity (VMHC)] and their corresponding dynamic indicators, such as dynamic ALFF (dALFF), dynamic fALFF (dfALFF), dynamic ReHo (dReHo), dynamic DC (dDC), dynamic VMHC (dVMHC), and dynamic GSCorr (dGSCorr), in 57 patients with unilateral TLE and 42 healthy volunteers were compared. Correlation analyses were also performed between these indicators in areas displaying group differences and cognitive function, epilepsy duration, and severity. Results Marked overlap was present among the abnormal brain regions detected using various static and dynamic indicators, primarily including increased ALFF/dALFF/fALFF in the bilateral medial temporal lobe and thalamus, decreased ALFF/dALFF/fALFF in the frontal lobe contralateral to the epileptogenic side, decreased fALFF, ReHo, dReHo, DC, dDC, GSCorr, dGSCorr, and VMHC in the temporal neocortex ipsilateral to the epileptogenic foci, decreased dReHo, dDC, dGSCorr, and dVMHC in the occipital lobe, and increased ALFF, fALFF, dfALFF, ReHo, and DC in the supplementary motor area ipsilateral to the epileptogenic foci. Furthermore, most IBA indicators in the abnormal brain region significantly correlated with the duration of epilepsy and several cognitive scale scores (P < 0.05). Conclusion The combined application of static and dynamic IBA indicators could comprehensively reveal more real abnormal neuronal activity and the impairment and compensatory mechanisms of cognitive function in TLE. Moreover, it might help in the lateralization of epileptogenic foci and exploration of the transmission and inhibition pathways of epileptic activity.
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Affiliation(s)
- Chengru Song
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, Zhengzhou, China
- Engineering Technology Research Center for Detection and Application of Brain Function of Henan Province, Zhengzhou, China
- Engineering Research Center of Medical Imaging Intelligent Diagnosis and Treatment of Henan Province, Zhengzhou, China
- Key Laboratory of Magnetic Resonance and Brain Function of Henan Province, Zhengzhou, China
- Key Laboratory of Brain Function and Cognitive Magnetic Resonance Imaging of Zhengzhou, Zhengzhou, China
- Key Laboratory of Imaging Intelligence Research Medicine of Henan Province, Zhengzhou, China
| | - Xiaonan Zhang
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, Zhengzhou, China
- Engineering Technology Research Center for Detection and Application of Brain Function of Henan Province, Zhengzhou, China
- Engineering Research Center of Medical Imaging Intelligent Diagnosis and Treatment of Henan Province, Zhengzhou, China
- Key Laboratory of Magnetic Resonance and Brain Function of Henan Province, Zhengzhou, China
- Key Laboratory of Brain Function and Cognitive Magnetic Resonance Imaging of Zhengzhou, Zhengzhou, China
- Key Laboratory of Imaging Intelligence Research Medicine of Henan Province, Zhengzhou, China
| | - Shaoqiang Han
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, Zhengzhou, China
- Engineering Technology Research Center for Detection and Application of Brain Function of Henan Province, Zhengzhou, China
- Engineering Research Center of Medical Imaging Intelligent Diagnosis and Treatment of Henan Province, Zhengzhou, China
- Key Laboratory of Magnetic Resonance and Brain Function of Henan Province, Zhengzhou, China
- Key Laboratory of Brain Function and Cognitive Magnetic Resonance Imaging of Zhengzhou, Zhengzhou, China
- Key Laboratory of Imaging Intelligence Research Medicine of Henan Province, Zhengzhou, China
| | - Keran Ma
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, Zhengzhou, China
- Engineering Technology Research Center for Detection and Application of Brain Function of Henan Province, Zhengzhou, China
- Engineering Research Center of Medical Imaging Intelligent Diagnosis and Treatment of Henan Province, Zhengzhou, China
- Key Laboratory of Magnetic Resonance and Brain Function of Henan Province, Zhengzhou, China
- Key Laboratory of Brain Function and Cognitive Magnetic Resonance Imaging of Zhengzhou, Zhengzhou, China
- Key Laboratory of Imaging Intelligence Research Medicine of Henan Province, Zhengzhou, China
| | - Kefan Wang
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, Zhengzhou, China
- Engineering Technology Research Center for Detection and Application of Brain Function of Henan Province, Zhengzhou, China
- Engineering Research Center of Medical Imaging Intelligent Diagnosis and Treatment of Henan Province, Zhengzhou, China
- Key Laboratory of Magnetic Resonance and Brain Function of Henan Province, Zhengzhou, China
- Key Laboratory of Brain Function and Cognitive Magnetic Resonance Imaging of Zhengzhou, Zhengzhou, China
- Key Laboratory of Imaging Intelligence Research Medicine of Henan Province, Zhengzhou, China
| | - Xinyue Mao
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, Zhengzhou, China
- Engineering Technology Research Center for Detection and Application of Brain Function of Henan Province, Zhengzhou, China
- Engineering Research Center of Medical Imaging Intelligent Diagnosis and Treatment of Henan Province, Zhengzhou, China
- Key Laboratory of Magnetic Resonance and Brain Function of Henan Province, Zhengzhou, China
- Key Laboratory of Brain Function and Cognitive Magnetic Resonance Imaging of Zhengzhou, Zhengzhou, China
- Key Laboratory of Imaging Intelligence Research Medicine of Henan Province, Zhengzhou, China
| | - Yajun Lian
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | | | - Jinxia Zhu
- MR Collaboration, Siemens Healthcare Ltd., Beijing, China
| | - Yong Zhang
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, Zhengzhou, China
- Engineering Technology Research Center for Detection and Application of Brain Function of Henan Province, Zhengzhou, China
- Engineering Research Center of Medical Imaging Intelligent Diagnosis and Treatment of Henan Province, Zhengzhou, China
- Key Laboratory of Magnetic Resonance and Brain Function of Henan Province, Zhengzhou, China
- Key Laboratory of Brain Function and Cognitive Magnetic Resonance Imaging of Zhengzhou, Zhengzhou, China
- Key Laboratory of Imaging Intelligence Research Medicine of Henan Province, Zhengzhou, China
| | - Jingliang Cheng
- Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, Zhengzhou, China
- Engineering Technology Research Center for Detection and Application of Brain Function of Henan Province, Zhengzhou, China
- Engineering Research Center of Medical Imaging Intelligent Diagnosis and Treatment of Henan Province, Zhengzhou, China
- Key Laboratory of Magnetic Resonance and Brain Function of Henan Province, Zhengzhou, China
- Key Laboratory of Brain Function and Cognitive Magnetic Resonance Imaging of Zhengzhou, Zhengzhou, China
- Key Laboratory of Imaging Intelligence Research Medicine of Henan Province, Zhengzhou, China
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9
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Haemels M, Van Weehaeghe D, Cleeren E, Dupont P, van Loon J, Theys T, Van Laere K, Van Paesschen W, Goffin K. Predictive value of metabolic and perfusion changes outside the seizure onset zone for postoperative outcome in patients with refractory focal epilepsy. Acta Neurol Belg 2022; 122:325-335. [PMID: 33544336 DOI: 10.1007/s13760-020-01569-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 12/08/2020] [Indexed: 01/30/2023]
Abstract
The value of functional molecular changes outside the seizure onset zone as independent predictive factors of surgical outcome has been scarcely evaluated. The aim of this retrospective study was to evaluate relative metabolic and perfusion changes outside the seizure onset zone as predictors of postoperative outcome in patients with unifocal refractory focal epilepsy. Eighty-six unifocal epilepsy patients who underwent 18F-FDG PET prior to surgery were included. Ictal and interictal perfusion SPECT was available in 65 patients. Good postoperative outcome was defined as the International League against Epilepsy class 1. Using univariate statistical analysis, the predictive ability of volume-of-interest based relative metabolism/perfusion for outcome classification was quantified by AUC ROC-curve, using composite, unilateral cortical (frontal, orbitofrontal, temporal, parietal, occipital) and central volumes-of-interest. The results were cross-validated, and a false discovery rate (FDR) correction was applied. As a secondary objective, a subgroup analysis was performed on temporal lobe epilepsy patients (N = 64). Increased relative ictal perfusion in the contralateral central volume-of-interest was significantly associated with the good surgical outcome both in the total population (AUC 0.79, pFDR = 0.009) and the temporal lobe epilepsy subgroup (AUC 0.80, pFDR = 0.028). No other significant associations between functional molecular changes and postoperative outcome were found. Increased relative ictal perfusion in the contralateral central region significantly predicted outcome after epilepsy surgery in patients with refractory focal epilepsy. We postulate that these relative perfusion changes could be an expression of better preoperative neuronal network integration and centralization in the contralateral central structures, which is suggested to be associated with better postoperative outcome.
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10
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Frazzini V, Cousyn L, Navarro V. Semiology, EEG, and neuroimaging findings in temporal lobe epilepsies. HANDBOOK OF CLINICAL NEUROLOGY 2022; 187:489-518. [PMID: 35964989 DOI: 10.1016/b978-0-12-823493-8.00021-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Temporal lobe epilepsy (TLE) is the most common type of focal epilepsy. First descriptions of TLE date back in time and detailed portraits of epileptic seizures of temporal origin can be found in early medical reports as well as in the works of various artists and dramatists. Depending on the seizure onset zone, several subtypes of TLE have been identified, each one associated with peculiar ictal semiology. TLE can result from multiple etiological causes, ranging from genetic to lesional ones. While the diagnosis of TLE relies on detailed analysis of clinical as well as electroencephalographic (EEG) features, the lesions responsible for seizure generation can be highlighted by multiple brain imaging modalities or, in selected cases, by genetic investigations. TLE is the most common cause of refractory epilepsy and despite the great advances in diagnostic tools, no lesion is found in around one-third of patients. Surgical treatment is a safe and effective option, requiring presurgical investigations to accurately identify the seizure onset zone (SOZ). In selected cases, presurgical investigations need intracerebral investigations (such as stereoelectroencephalography) or dedicated metabolic imaging techniques (interictal PET and ictal SPECT) to correctly identify the brain structures to be removed.
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Affiliation(s)
- Valerio Frazzini
- AP-HP, Department of Neurology and Department of Clinical Neurophysiology, Epilepsy and EEG Unit, Reference Center for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, Paris Brain Institute, Team "Dynamics of Neuronal Networks and Neuronal Excitability", Paris, France
| | - Louis Cousyn
- AP-HP, Department of Neurology and Department of Clinical Neurophysiology, Epilepsy and EEG Unit, Reference Center for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, Paris Brain Institute, Team "Dynamics of Neuronal Networks and Neuronal Excitability", Paris, France
| | - Vincent Navarro
- AP-HP, Department of Neurology and Department of Clinical Neurophysiology, Epilepsy and EEG Unit, Reference Center for Rare Epilepsies, Pitié-Salpêtrière Hospital, Paris, France; Sorbonne Université, Paris Brain Institute, Team "Dynamics of Neuronal Networks and Neuronal Excitability", Paris, France.
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11
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Elisevich K, Davoodi-Bojd E, Heredia JG, Soltanian-Zadeh H. Prospective Quantitative Neuroimaging Analysis of Putative Temporal Lobe Epilepsy. Front Neurol 2021; 12:747580. [PMID: 34803885 PMCID: PMC8602195 DOI: 10.3389/fneur.2021.747580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 09/20/2021] [Indexed: 11/22/2022] Open
Abstract
Purpose: A prospective study of individual and combined quantitative imaging applications for lateralizing epileptogenicity was performed in a cohort of consecutive patients with a putative diagnosis of mesial temporal lobe epilepsy (mTLE). Methods: Quantitative metrics were applied to MRI and nuclear medicine imaging studies as part of a comprehensive presurgical investigation. The neuroimaging analytics were conducted remotely to remove bias. All quantitative lateralizing tools were trained using a separate dataset. Outcomes were determined after 2 years. Of those treated, some underwent resection, and others were implanted with a responsive neurostimulation (RNS) device. Results: Forty-eight consecutive cases underwent evaluation using nine attributes of individual or combinations of neuroimaging modalities: 1) hippocampal volume, 2) FLAIR signal, 3) PET profile, 4) multistructural analysis (MSA), 5) multimodal model analysis (MMM), 6) DTI uncertainty analysis, 7) DTI connectivity, and 9) fMRI connectivity. Of the 24 patients undergoing resection, MSA, MMM, and PET proved most effective in predicting an Engel class 1 outcome (>80% accuracy). Both hippocampal volume and FLAIR signal analysis showed 76% and 69% concordance with an Engel class 1 outcome, respectively. Conclusion: Quantitative multimodal neuroimaging in the context of a putative mTLE aids in declaring laterality. The degree to which there is disagreement among the various quantitative neuroimaging metrics will judge whether epileptogenicity can be confined sufficiently to a particular temporal lobe to warrant further study and choice of therapy. Prediction models will improve with continued exploration of combined optimal neuroimaging metrics.
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Affiliation(s)
- Kost Elisevich
- Department of Clinical Neurosciences, Spectrum Health, Grand Rapids, MI, United States
- Department of Surgery, College of Human Medicine, Michigan State University, Grand Rapids, MI, United States
| | - Esmaeil Davoodi-Bojd
- Radiology and Research Administration, Henry Ford Health System, Detroit, MI, United States
| | - John G. Heredia
- Imaging Physics, Department of Radiology, Spectrum Health, Grand Rapids, MI, United States
| | - Hamid Soltanian-Zadeh
- Radiology and Research Administration, Henry Ford Health System, Detroit, MI, United States
- Control and Intelligent Processing Center of Excellence (CIPCE), School of Electrical and Computer Engineering, University of Tehran, Tehran, Iran
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12
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Taherpour J, Jaber M, Voges B, Apostolova I, Sauvigny T, House PM, Lanz M, Lindenau M, Klutmann S, Martens T, Stodieck S, Buchert R. Predicting the outcome of epilepsy surgery by covariance pattern analysis of ictal perfusion SPECT. J Nucl Med 2021; 63:925-930. [PMID: 34593599 DOI: 10.2967/jnumed.121.262702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 09/09/2021] [Indexed: 11/16/2022] Open
Abstract
Previous studies on the utility of specific perfusion patterns in ictal brain perfusion SPECT for predicting the outcome of temporal lobe epilepsy surgery used qualitative visual pattern classification, semi-quantitative region-of-interest analysis or conventional univariate voxel-based testing, which are limited by intra- and inter-rater variability and/or low sensitivity to capture functional interactions among brain regions. The present study performed covariance pattern analysis of ictal perfusion SPECT using the Scaled Subprofile Model for unbiased identification of predictive covariance patterns. Methods: The study retrospectively included 18 responders to temporal lobe epilepsy surgery (Engel I-A at 12 months follow-up) and 18 non-responders (≥ Engel I-B). Ictal SPECT images were analyzed with the Scaled Subprofile Model blinded to group membership for unbiased identification of the 16 covariance patterns explaining the highest proportion of variance in the whole data set. Individual expression scores of the covariance patterns were evaluated for predicting seizure freedom after temporal lobe surgery by ROC analysis. Kaplan-Meier analysis including all available follow-up data (up to 60 months after surgery) was also performed. Results: Amongst the 16 covariance patterns only one showed a different expression between responders and non-responders (P = 0.03). This 'favorable ictal perfusion pattern' resembled the typical ictal perfusion pattern in temporomesial epilepsy. The expression score of the pattern provided an area of 0.744 (95%-confidence interval 0.577-0.911, P = 0.004) under the ROC curve. Kaplan-Meier analysis revealed a statistical trend towards longer seizure freedom in patients with positive expression score (P = 0.06). The median estimated seizure free time was 48 months in patients with positive expression score versus 6 months in patients with negative expression score. Conclusion: The expression of the 'favorable ictal perfusion pattern' identified by covariance analysis of ictal brain perfusion SPECT provides independent (from demographical and clinical variables) information for the prediction of seizure freedom after temporal lobe epilepsy surgery. The expression of this pattern is easily computed for new ictal SPECT images and, therefore, might be used to support the decision for or against temporal lobe surgery in clinical patient care.
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Affiliation(s)
| | - Marian Jaber
- University Medical Center Hamburg-Eppendorf, Germany
| | | | | | | | | | | | | | | | | | | | - Ralph Buchert
- University Medical Center Hamburg-Eppendorf, Germany
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13
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Zhou X, Zhang Z, Yu L, Fan B, Wang M, Jiang B, Su Y, Li P, Zheng J. Disturbance of functional and effective connectivity of the salience network involved in attention deficits in right temporal lobe epilepsy. Epilepsy Behav 2021; 124:108308. [PMID: 34536737 DOI: 10.1016/j.yebeh.2021.108308] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/04/2021] [Accepted: 08/23/2021] [Indexed: 12/23/2022]
Abstract
The salience network (SN) acts as a switch that generates transient control signals to regulate the executive control network (ECN) and the default mode network (DMN) and has been implicated in cognitive processes. Temporal lobe epilepsy (TLE) is usually accompanied by different types of cognitive deficits, but whether it is associated with dysfunctional connectivity of the SN remains unknown. To address this, thirty-six patients with right TLE (rTLE) and thirty-six healthy controls (HCs) were recruited for the present study. All of the participants were subjected to attention network test (ANT) and resting-state functional resonance imaging (rs-fMRI) scanning. The patient group showed deficits in attention performance. Moreover, the functional connectivity (FC) and effective connectivity (EC) were analyzed based on key SN hubs (the anterior cingulate cortex (ACC) and the bilateral anterior insula (AI)). When compared with those in the HC group, the ACC showed increased FC with the left middle frontal gyrus and the left precentral gyrus, and the right AI showed decreased FC with the right precuneus and the right superior occipital gyrus in the patient group. The EC analysis revealed an increased inflow of information from the left middle temporal gyrus to the ACC and the right AI and an increased outflow of information from the bilateral AI to the left middle frontal gyrus. Furthermore, in the correlation analysis, the abnormal EC from the right AI to the left middle temporal gyrus was positively correlated with the executive control effect. These findings demonstrated aberrant modulation of the SN in rTLE, which was particularly characterized by dysfunctional connectivity between the SN and key brain regions in the DMN and ECN. Elucidation of this effect may further contribute to the comprehensive understanding of the neural mechanisms of the SN in regard to attention deficits in patients with TLE.
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Affiliation(s)
- Xia Zhou
- Department of Neurology, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, China
| | - Zhao Zhang
- Department of Neurology, the Fifth Affiliated Hospital of Guangxi Medical University, Nanning 530021, China
| | - Lu Yu
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China
| | - Binglin Fan
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China
| | - Minli Wang
- Department of Neurology, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, China
| | - Binjian Jiang
- Department of Neurology, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, China
| | - Yuying Su
- Department of Neurology, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, China
| | - Peihu Li
- Department of Neurology, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, China
| | - Jinou Zheng
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China.
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14
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Goldman-Yassen AE, Straka M, Uhouse M, Dehkharghani S. Normative distribution of posterior circulation tissue time-to-maximum: Effects of anatomic variation, tracer kinetics, and implications for patient selection in posterior circulation ischemic stroke. J Cereb Blood Flow Metab 2021; 41:1912-1923. [PMID: 33444095 PMCID: PMC8327115 DOI: 10.1177/0271678x20982395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The generalization of perfusion-based, anterior circulation large vessel occlusion selection criteria to posterior circulation stroke is not straightforward due to physiologic delay, which we posit produces physiologic prolongation of the posterior circulation perfusion time-to-maximum (Tmax). To assess normative Tmax distributions, patients undergoing CTA/CTP for suspected ischemic stroke between 1/2018-3/2019 were retrospectively identified. Subjects with any cerebrovascular stenoses, or with follow-up MRI or final clinical diagnosis of stroke were excluded. Posterior circulation anatomic variations were identified. CTP were processed in RAPID and segmented in a custom pipeline permitting manually-enforced arterial input function (AIF) and perfusion estimations constrained to pre-specified vascular territories. Seventy-one subjects (mean 64 ± 19 years) met inclusion. Median Tmax was significantly greater in the cerebellar hemispheres (right: 3.0 s, left: 2.9 s) and PCA territories (right: 2.9 s; left: 3.3 s) than in the anterior circulation (right: 2.4 s; left: 2.3 s, p < 0.001). Fetal PCA disposition eliminated ipsilateral PCA Tmax delays (p = 0.012). Median territorial Tmax was significantly lower with basilar versus any anterior circulation AIF for all vascular territories (p < 0.001). Significant baseline delays in posterior circulation Tmax are observed even without steno-occlusive disease and vary with anatomic variation and AIF selection. The potential for overestimation of at-risk volumes in the posterior circulation merits caution in future trials.
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Affiliation(s)
- Adam E Goldman-Yassen
- Department of Radiology, New York University Langone Medical Center, New York, NY, USA.,Department of Radiology, Children's Healthcare of Atlanta, Atlanta, GA, USA
| | | | - Michael Uhouse
- Department of Radiology, George Washington University, Washington, DC, USA
| | - Seena Dehkharghani
- Department of Radiology, New York University Langone Medical Center, New York, NY, USA.,Department of Neurology, New York University Langone Medical Center, New York, NY, USA
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15
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El-Wahsh S, Dunkerton S, Ang T, Winters HS, Delcourt C. Current perspectives on neuroimaging techniques used to identify stroke mimics in clinical practice. Expert Rev Neurother 2021; 21:517-531. [PMID: 33787426 DOI: 10.1080/14737175.2021.1911650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Urgent clinical assessment and brain imaging are essential for differentiating stroke mimics from stroke and to avoid unnecessary initiation of reperfusion and other therapies in stroke mimic patients. AREAS COVERED In this article, the authors will review acute stroke imaging and then the imaging patterns of the most common stroke mimics. The authors have focused our review on brain CT scan, and more specifically CT perfusion, as this is the most commonly available and emerging tool in emergency settings. The authors also provide information on acute brain MRI and MR perfusion. EXPERT OPINION Imaging can contribute to the detection and diagnosis of acute stroke mimics. Knowledge of imaging findings in different stroke mimics can help distinguish these from patients with stroke who require timely reperfusion therapy. CT and MRI perfusion and diffusion-weighted imaging (DWI) MRI are useful imaging modalities for the assessment of acute stroke patients as they provide more accurate information than plain CT scan. Some of these modalities should be available in the emergency setting. The authors recommended CT perfusion as a useful tool for stroke management and differentiation with stroke mimics.
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Affiliation(s)
- Shadi El-Wahsh
- Neurology Department, Royal Prince Alfred Hospital, the University of Sydney, Sydney, New South Wales, Australia.,South Western Sydney Clinical School, University of New South Wales, Sydney, Australia
| | - Sophie Dunkerton
- Neurology Department, Royal Prince Alfred Hospital, the University of Sydney, Sydney, New South Wales, Australia
| | - Timothy Ang
- Neurology Department, Royal Prince Alfred Hospital, the University of Sydney, Sydney, New South Wales, Australia
| | - Hugh Stephen Winters
- Neurology Department, Royal Prince Alfred Hospital, the University of Sydney, Sydney, New South Wales, Australia
| | - Candice Delcourt
- The George Institute for Global Health, The University of New South Wales, Sydney, Australia.,Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie University, Macquarie Park, New South Wales, Australia
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16
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De Vito A, Mankad K, Pujar S, Chari A, Ippolito D, D’Arco F. Narrative review of epilepsy: getting the most out of your neuroimaging. Transl Pediatr 2021; 10:1078-1099. [PMID: 34012857 PMCID: PMC8107872 DOI: 10.21037/tp-20-261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Neuroimaging represents an important step in the evaluation of pediatric epilepsy. The crucial role of brain imaging in the diagnosis, follow-up and presurgical assessment of patients with epilepsy is noted and has to be familiar to all neuroradiologists and trainees approaching pediatric brain imaging. Morphological qualitative imaging shows the majority of cerebral lesions/alterations underlying focal epilepsy and can highlight some features which are useful in the differential diagnosis of the different types of epilepsy. Recent advances in MRI acquisitions including diffusion-weighted imaging (DWI), post-acquisition image processing techniques, and quantification of imaging data are increasing the accuracy of lesion detection during the last decades. Functional MRI (fMRI) can be really useful and helps to identify cortical eloquent areas that are essential for language, motor function, and memory, and diffusion tensor imaging (DTI) can reveal white matter tracts that are vital for these functions, thus reducing the risk of epilepsy surgery causing new morbidities. Also positron emission tomography (PET), single photon emission computed tomography (SPECT), simultaneous electroencephalogram (EEG) and fMRI, and electrical and magnetic source imaging can be used to assess the exact localization of epileptic foci and help in the design of intracranial EEG recording strategies. The main role of these "hybrid" techniques is to obtain quantitative and qualitative informations, a necessary step to evaluate and demonstrate the complex relationship between abnormal structural and functional data and to manage a "patient-tailored" surgical approach in epileptic patients.
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Affiliation(s)
- Andrea De Vito
- Department of Neuroradiology, H. S. Gerardo Monza, Monza, Italy
| | - Kshitij Mankad
- Department of Radiology, Great Ormond Street Hospital, London, UK
| | - Suresh Pujar
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - Aswin Chari
- Department of Neurosurgery, Great Ormond Street Hospital, London, UK
| | | | - Felice D’Arco
- Department of Radiology, Great Ormond Street Hospital, London, UK
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17
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Krishnan B, Tousseyn S, Nayak CS, Aung T, Kheder A, Wang ZI, Wu G, Gonzalez-Martinez J, Nair D, Burgess R, Iasemidis L, Najm I, Bulacio J, Alexopoulos AV. Neurovascular networks in epilepsy: Correlating ictal blood perfusion with intracranial electrophysiology. Neuroimage 2021; 231:117838. [PMID: 33577938 DOI: 10.1016/j.neuroimage.2021.117838] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 12/21/2020] [Accepted: 02/01/2021] [Indexed: 11/25/2022] Open
Abstract
Perfusion patterns observed in Subtraction Ictal SPECT Co-registered to MRI (SISCOM) assist in focus localization and surgical planning for patients with medically intractable focal epilepsy. While the localizing value of SISCOM has been widely investigated, its relationship to the underlying electrophysiology has not been extensively studied and is therefore not well understood. In the present study, we set to investigate this relationship in a cohort of 70 consecutive patients who underwent ictal and interictal SPECT studies and subsequent stereo-electroencephalography (SEEG) monitoring for localization of the epileptogenic focus and surgical intervention. Seizures recorded during SEEG evaluation (SEEG seizures) were matched to semiologically-similar seizures during the preoperative ictal SPECT evaluation (SPECT seizures) by comparing the semiological changes in the course of each seizure. The spectral changes of the ictal SEEG with respect to interictal ones over 7 traditional frequency bands (0.1 to 150Hz) were analyzed at each SEEG site. Neurovascular (SEEG/SPECT) relations were assessed by comparing the estimated spectral power density changes of the SEEG at each site with the perfusion changes (SISCOM z-scores) estimated from the acquired SISCOM map at that site. Across patients, a significant correlation (p<0.05) was observed between spectral changes during the SEEG seizure and SISCOM perfusion z-scores. Brain sites with high perfusion z-score exhibited higher increased SEEG power in theta to ripple frequency bands with concurrent suppression in delta and theta frequency bands compared to regions with lower perfusion z-score. The dynamics of the correlation of SISCOM perfusion and SEEG spectral power from ictal onset to seizure end and immediate postictal period were also derived. Forty-six (46) of the 70 patients underwent resective epilepsy surgery. SISCOM z-score and power increase in beta to ripple frequency bands were significantly higher in resected than non-resected sites in the patients who were seizure-free following surgery. This study provides for the first time concrete evidence that both hyper-perfusion and hypo-perfusion patterns observed in SISCOM maps have strong electrophysiological underpinnings, and that integration of the information from SISCOM and SEEG can shed light on the location and dynamics of the underlying epileptic brain networks, and thus advance our anatomo-electro-clinical understanding and approaches to targeted diagnostic and therapeutic interventions.
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Affiliation(s)
- Balu Krishnan
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA.
| | - Simon Tousseyn
- Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands
| | - Chetan Sateesh Nayak
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Thandar Aung
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Ammar Kheder
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Z Irene Wang
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Guiyun Wu
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Jorge Gonzalez-Martinez
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Dileep Nair
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Richard Burgess
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Leonidas Iasemidis
- Center for Biomedical Engineering and Rehabilitation Science, Louisiana Tech University, Ruston, LA, USA
| | - Imad Najm
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Juan Bulacio
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
| | - Andreas V Alexopoulos
- Neurological Institute, Cleveland Clinic Foundation, 9500 Euclid Ave, S51, Cleveland, OH 44195, USA
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18
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Fei Y, Shi R, Song Z, Wu J. Metabolic Control of Epilepsy: A Promising Therapeutic Target for Epilepsy. Front Neurol 2020; 11:592514. [PMID: 33363507 PMCID: PMC7753014 DOI: 10.3389/fneur.2020.592514] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/20/2020] [Indexed: 12/16/2022] Open
Abstract
Epilepsy is a common neurological disease that is not always controlled, and the ketogenic diet shows good antiepileptic effects drug-resistant epilepsy or seizures caused by specific metabolic defects via regulating the metabolism. The brain is a vital organ with high metabolic demands, and epileptic foci tend to exhibit high metabolic characteristics. Accordingly, there has been growing interest in the relationship between brain metabolism and epilepsy in recent years. To date, several new antiepileptic therapies targeting metabolic pathways have been proposed (i.e., inhibiting glycolysis, targeting lactate dehydrogenase, and dietary therapy). Promising strategies to treat epilepsy via modulating the brain's metabolism could be expected, while a lack of thorough understanding of the role of brain metabolism in the control of epilepsy remains. Herein, this review aims to provide insight into the state of the art concerning the brain's metabolic patterns and their association with epilepsy. Regulation of neuronal excitation via metabolic pathways and antiepileptic therapies targeting metabolic pathways are emphasized, which could provide a better understanding of the role of metabolism in epilepsy and could reveal potential therapeutic targets.
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Affiliation(s)
- Yanqing Fei
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Ruting Shi
- Department of Rehabilitation, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi Song
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Jinze Wu
- Department of Neurology, The Third Xiangya Hospital, Central South University, Changsha, China
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19
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Kundu B, Lucke-Wold B, Foster C, Englot DJ, Urhie O, Nwafor D, Rolston JD. Fornicotomy for the Treatment of Epilepsy: An Examination of Historical Literature in the Setting of Modern Operative Techniques. Neurosurgery 2020; 87:157-165. [PMID: 31885037 PMCID: PMC8101091 DOI: 10.1093/neuros/nyz554] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 11/07/2019] [Indexed: 02/05/2023] Open
Abstract
Fornicotomy has been used to treat intractable temporal lobe epilepsy with mixed success historically; however, modern advances in stereotactic, neurosurgical, and imaging techniques offer new opportunities to target the fornix with greater precision and safety. In this review, we discuss the historical uses and quantify the outcomes of fornicotomy for the treatment of temporal lobe epilepsy, highlight the potential mechanisms of benefit, and address what is known about the side effects of the procedure. We find that fornicotomy, with or without anterior commissurotomy, resulted in 61% (83/136) of patients having some seizure control benefit. We discuss the potential operative approaches for targeting the fornix, including laser ablation and the use of focused ultrasound ablation. More work is needed to address the true efficacy of fornicotomy in the modern surgical setting. This review is intended to serve as a framework for developing this approach.
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Affiliation(s)
- Bornali Kundu
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah School of Medicine, Salt Lake City, Utah
| | | | - Chase Foster
- Department of Neurosurgery, George Washington University, Washington, District of Columbia
| | - Dario J Englot
- Department of Neurosurgery, Vanderbilt University, Nashville, Tennessee
| | - Ogaga Urhie
- Department of Neurosurgery, West Virginia University, Morgantown, West Virginia
| | - Divine Nwafor
- Department of Neurosurgery, West Virginia University, Morgantown, West Virginia
| | - John D Rolston
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah School of Medicine, Salt Lake City, Utah
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Anwar H, Khan QU, Nadeem N, Pervaiz I, Ali M, Cheema FF. Epileptic seizures. Discoveries (Craiova) 2020; 8:e110. [PMID: 32577498 PMCID: PMC7305811 DOI: 10.15190/d.2020.7] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/02/2020] [Accepted: 06/02/2020] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is a condition marked by abnormal neuronal discharges or hyperexcitability of neurons with synchronicity and is recognized as a major public health concern. The pathology is categorized into three subgroups: acquired, idiopathic, and epilepsy of genetic or developmental origin. There are approximately 1000 associated genes and the role of γ-aminobutyric acid (GABA) mediated inhibition, as well as glutamate mediated excitation, forms the basis of pathology. Epilepsy is further classified as being of focal, general or unknown onset. Genetic predisposition, comorbidities and novel biomarkers are useful for prediction. Prevalent postictal symptoms are postictal headache and migraine, postictal psychosis and delirium, postictal Todd's paresis and postictal automatisms. Diagnostic methods include electroencephalography (EEG), computed tomography scan, magnetic resonance imaging (MRI), positron emission tomography, single photon emission computed tomography and genetic testing; EEG and MRI are the two main techniques. Clinical history and witness testimonies combined with a knowledge of seizure semiology helps in distinguishing between seizures. Clinical information and patient history do not always lead to a clear diagnosis, in which case EEG and 24-hour EEG monitoring with video recording (video-EEG/vEEG) help in seizure differentiation. Treatment includes first aid, therapeutics such as anti-epileptic drugs, surgery, ketogenic diet and gene therapy. In this review, we are focusing on summarizing published literature on epilepsy and epileptic seizures, and concisely apprise the reader of the latest cutting-edge advances and knowledge on epileptic seizures.
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Affiliation(s)
- Haleema Anwar
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
| | | | - Natasha Nadeem
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
| | - Iqra Pervaiz
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
| | - Muhammad Ali
- CMH Lahore Medical College & Institute of Dentistry, Lahore, Pakistan
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21
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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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Yue Z, Freedman IG, Vincent P, Andrews JP, Micek C, Aksen M, Martin R, Zuckerman D, Perrenoud Q, Neske GT, Sieu LA, Bo X, Cardin JA, Blumenfeld H. Up and Down States of Cortical Neurons in Focal Limbic Seizures. Cereb Cortex 2019; 30:3074-3086. [PMID: 31800015 DOI: 10.1093/cercor/bhz295] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 08/18/2019] [Accepted: 08/20/2019] [Indexed: 12/31/2022] Open
Abstract
Recent work suggests an important role for cortical-subcortical networks in seizure-related loss of consciousness. Temporal lobe seizures disrupt subcortical arousal systems, which may lead to depressed cortical function and loss of consciousness. Extracellular recordings show ictal neocortical slow waves at about 1 Hz, but it is not known whether these simply represent seizure propagation or alternatively deep sleep-like activity, which should include cortical neuronal Up and Down states. In this study, using in vivo whole-cell recordings in a rat model of focal limbic seizures, we directly examine the electrophysiological properties of cortical neurons during seizures and deep anesthesia. We found that during seizures, the membrane potential of frontal cortical secondary motor cortex layer 5 neurons fluctuates between Up and Down states, with decreased input resistance and increased firing rate in Up states when compared to Down states. Importantly, Up and Down states in seizures are not significantly different from those in deep anesthesia, in terms of membrane potential, oscillation frequency, firing rate, and input resistance. By demonstrating these fundamental similarities in cortical electrophysiology between deep anesthesia and seizures, our results support the idea that a state of decreased cortical arousal may contribute to mechanisms of loss of consciousness during seizures.
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Affiliation(s)
- Zongwei Yue
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China.,Department of Neurology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510120, China
| | - Isaac G Freedman
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Peter Vincent
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - John P Andrews
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Christopher Micek
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Mark Aksen
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Reese Martin
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - David Zuckerman
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Quentin Perrenoud
- Department of Neuroscience Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Garrett T Neske
- Department of Neuroscience Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Lim-Anna Sieu
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Xiao Bo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jessica A Cardin
- Department of Neuroscience Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
| | - Hal Blumenfeld
- Department of Neurology Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.,Department of Neuroscience Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.,Department of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA
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Abstract
Purpose of review Functional neuroimaging with PET and SPECT is a commonly used tool in presurgical evaluation. The following article reviews the literature of PET and SPECT in presurgical assessment of epilepsies published in the last year. Recent findings FDG-PET adds concomitant information in temporal and extratemporal lobe epilepsy in adults and children. The pattern of hypometabolism in FDG-PET is a good additional predictor or seizure outcome in TLE with mesial temporal sclerosis or negative MRI. There is growing evidence that diagnostic value of FDG-PET increases with postprocessing. Although several methods were applied in the reviewed literature, all of them seem to outperform the visual analysis. Imaging of the epileptic focus with ictal SPECT is depending on short injection latencies. It is particularly useful in patients with nonlesional MRI and mostly of extratemporal localization. Areas of hyperperfusion remote of SOZ are reflecting the epileptic network. Combining more concordant investigations including PET and SPECT in MRI-negative evaluation adds to better presurgical stratification and therefore, better postsurgical outcome. FET-PET shows increased uptake in status epilepticus. Summary PET and SPECT are important investigations to localize the epileptic focus in temporal lobe and nonlesional extratemporal epilepsies. Postprocessing for both modalities is important to increase diagnostic value.
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Subcortical SISCOM hyperperfusion: Should we pay more attention to it? Seizure 2018; 62:43-48. [PMID: 30278347 DOI: 10.1016/j.seizure.2018.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 09/19/2018] [Accepted: 09/21/2018] [Indexed: 11/20/2022] Open
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Cleeren E, Casteels C, Goffin K, Koole M, Van Laere K, Janssen P, Van Paesschen W. Positron emission tomography imaging of cerebral glucose metabolism and type 1 cannabinoid receptor availability during temporal lobe epileptogenesis in the amygdala kindling model in rhesus monkeys. Epilepsia 2018; 59:959-970. [DOI: 10.1111/epi.14059] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2018] [Indexed: 01/31/2023]
Affiliation(s)
- Evy Cleeren
- Laboratory for Neuro‐ and Psychophysiology KU Leuven Leuven Belgium
- Laboratory for Epilepsy Research KU Leuven Leuven Belgium
| | - Cindy Casteels
- Nuclear Medicine & Molecular Imaging Department of Imaging and Pathology KU Leuven Leuven Belgium
- Molecular Small Animal Imaging Center (MoSAIC) KU Leuven Leuven Belgium
| | - Karolien Goffin
- Nuclear Medicine & Molecular Imaging Department of Imaging and Pathology KU Leuven Leuven Belgium
- Molecular Small Animal Imaging Center (MoSAIC) KU Leuven Leuven Belgium
| | - Michel Koole
- Nuclear Medicine & Molecular Imaging Department of Imaging and Pathology KU Leuven Leuven Belgium
- Molecular Small Animal Imaging Center (MoSAIC) KU Leuven Leuven Belgium
| | - Koen Van Laere
- Nuclear Medicine & Molecular Imaging Department of Imaging and Pathology KU Leuven Leuven Belgium
- Molecular Small Animal Imaging Center (MoSAIC) KU Leuven Leuven Belgium
| | - Peter Janssen
- Laboratory for Neuro‐ and Psychophysiology KU Leuven Leuven Belgium
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Park HR, Seong MJ, Shon YM, Joo EY, Seo DW, Hong SB. SPECT perfusion changes during ictal automatisms with preserved responsiveness in patients with right temporal lobe epilepsy. Epilepsy Behav 2018; 80:11-14. [PMID: 29396356 DOI: 10.1016/j.yebeh.2017.12.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 12/23/2017] [Accepted: 12/24/2017] [Indexed: 10/18/2022]
Abstract
Ictal automatism with preserved responsiveness (APR) has been reported, particularly in nondominant temporal lobe epilepsy (TLE), but its pathophysiology remains poorly understood. This study sought to investigate the relationship between APRs and increased cerebral blood flow (CBF) using ictal single photon emission computed tomography (SPECT) in TLE. Forty-seven subjects with right mesial TLE (15 with and 32 without APR) were enrolled. Patients with APR (APR+) were subdivided into four groups according to degree of responsiveness during seizures. Cerebral blood flow changes during these seizures were semiquantitatively assessed by subtraction ictal SPECT coregistered to MRI (SISCOM). Hyperperfusion in temporal regions did not vary significantly between the APR+ and APR- groups. Cerebral blood flow changes in the frontal area, insula, cingulum, and occipital area were also nonsignificant. However, hyperperfusion in the ipsilateral parietal areas was more frequent in the APR- group than in the APR+ group. Furthermore, hyperperfusion of the contralateral basal ganglia showed an inclination to be more common in the APR- group, but without statistical significance. The study suggested that the involvement of the parietal association cortex during seizure may play an important role in ictal loss of consciousness in TLE. Further studies will be needed to elucidate the pathophysiology of changes in consciousness during temporal lobe seizures.
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Affiliation(s)
- Hea Ree Park
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Republic of Korea; Neuroscience Center, Samsung Medical Center, Republic of Korea
| | - Min Jae Seong
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Republic of Korea; Neuroscience Center, Samsung Medical Center, Republic of Korea
| | - Young-Min Shon
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Republic of Korea; Neuroscience Center, Samsung Medical Center, Republic of Korea.
| | - Eun Yeon Joo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Republic of Korea; Neuroscience Center, Samsung Medical Center, Republic of Korea
| | - Dae-Won Seo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Republic of Korea; Neuroscience Center, Samsung Medical Center, Republic of Korea
| | - Seung Bong Hong
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Republic of Korea; Neuroscience Center, Samsung Medical Center, Republic of Korea
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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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28
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Sheng J, Liu S, Qin H, Li B, Zhang X. Drug-Resistant Epilepsy and Surgery. Curr Neuropharmacol 2018; 16:17-28. [PMID: 28474565 PMCID: PMC5771378 DOI: 10.2174/1570159x15666170504123316] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/23/2017] [Accepted: 04/25/2017] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Epilepsy is a chronic brain disease that is caused by various factors and characterized by recurrent, episodic and temporary central nervous system dysfunction which results due to excessive discharge of brain neurons. In the past decades, despite the continuous development of antiepileptic drugs, there are still many patients with epilepsy progressing to drugresistant epilepsy. Currently, surgical treatment is one of important way to cure drug-resistant epilepsy. METHODS Data were collected from Web of Science, Medline, Pubmed, through searching of these keywords: "surgery" and "drug-resistant epilepsy". RESULTS An increasing number of studies have shown that surgery plays an important role in the treatment of drug-resistant epilepsy. Moreover, the comprehensive treatment mainly based on surgery can achieve the remission and even cure of drug-resistant epilepsy. CONCLUSION In this review, we discuss the pathogenesis of drug-resistant epilepsy and the comprehensive treatment mainly based on surgery; this review may provide a reference for the clinical treatment of drug-resistant epilepsy.
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Affiliation(s)
- Jiyao Sheng
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, Second Hospital of Jilin University, Changchun130041, P.R. China
| | - Shui Liu
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, Second Hospital of Jilin University, Changchun130041, P.R. China
| | - Hanjiao Qin
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, Second Hospital of Jilin University, Changchun130041, P.R. China
| | - Bingjin Li
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, Second Hospital of Jilin University, Changchun130041, P.R. China
| | - Xuewen Zhang
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, Second Hospital of Jilin University, Changchun130041, P.R. China
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29
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Tousseyn S, Krishnan B, Wang ZI, Wongwiangjunt S, Nayak CS, Mosher JC, Wu G, Van Paesschen W, Leahy RM, Gonzalez-Martinez JA, Bulacio J, Najm IM, Alexopoulos AV, Nair DR. Connectivity in ictal single photon emission computed tomography perfusion: a cortico-cortical evoked potential study. Brain 2017; 140:1872-1884. [PMID: 28582473 DOI: 10.1093/brain/awx123] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 04/14/2017] [Indexed: 11/13/2022] Open
Abstract
Subtraction ictal and interictal single photon emission computed tomography can demonstrate complex ictal perfusion patterns. Regions with ictal hyperperfusion are suggested to reflect seizure onset and propagation pathways. The significance of ictal hypoperfusion is not well understood. The aim of this study was to verify whether ictal perfusion changes, both hyper- and hypoperfusion, correspond to electrically connected brain networks. A total of 36 subtraction ictal and interictal perfusion studies were analysed in 31 consecutive medically refractory focal epilepsy patients, evaluated by stereo-electroencephalography that demonstrated a single focal onset. Cortico-cortical evoked potential studies were performed after repetitive electrical stimulation of the ictal onset zone. Evoked responses at electrode contacts outside the stimulation site were used as a measure of connectivity. The evoked responses at these electrodes were compared to ictal perfusion values noted at these locations. In 67% of studies, evoked responses were significantly larger in hyperperfused compared to baseline-perfused areas. The majority of hyperperfused contacts also had significantly increased evoked responses relative to pre-stimulus electroencephalogram. In contrast, baseline-perfused and hypoperfused contacts mainly demonstrated non-significant evoked responses. Finally, positive significant correlations (P < 0.05) were found between perfusion scores and evoked responses in 61% of studies. When the stimulated ictal onset area was hyperperfused, 82% of studies demonstrated positive significant correlations. Following stimulation of hyperperfused areas outside seizure onset, positive significant correlations between perfusion changes and evoked responses could be seen, suggesting bidirectional connectivity. We conclude that strong connectivity was demonstrated between the ictal onset zone and hyperperfused regions, while connectivity was weaker in the direction of baseline-perfused or hypoperfused areas. In trying to understand a patient's epilepsy, one should consider the contribution of all hyperperfused regions, as these are likely not random, but represent an electrically connected epileptic network.
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Affiliation(s)
- Simon Tousseyn
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH, USA.,Academic Center for Epileptology, Kempenhaeghe and Maastricht UMC+, Heeze, The Netherlands
| | - Balu Krishnan
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Zhong I Wang
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH, USA
| | | | - Chetan S Nayak
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - John C Mosher
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Guiyun Wu
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH, USA
| | | | | | | | - Juan Bulacio
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Imad M Najm
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH, USA
| | | | - Dileep R Nair
- Epilepsy Center, Cleveland Clinic Foundation, Cleveland, OH, USA
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30
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Maccotta L, Lopez MA, Adeyemo B, Ances BM, Day BK, Eisenman LN, Dowling JL, Leuthardt EC, Schlaggar BL, Hogan RE. Postoperative seizure freedom does not normalize altered connectivity in temporal lobe epilepsy. Epilepsia 2017; 58:1842-1851. [PMID: 28776646 DOI: 10.1111/epi.13867] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Specific changes in the functional connectivity of brain networks occur in patients with epilepsy. Yet whether such changes reflect a stable disease effect or one that is a function of active seizure burden remains unclear. Here, we longitudinally assessed the connectivity of canonical cognitive functional networks in patients with intractable temporal lobe epilepsy (TLE), both before and after patients underwent epilepsy surgery and achieved seizure freedom. METHODS Seventeen patients with intractable TLE who underwent epilepsy surgery with Engel class I outcome and 17 matched healthy controls took part in the study. The functional connectivity of a set of cognitive functional networks derived from typical cognitive tasks was assessed in patients, preoperatively and postoperatively, as well as in controls, using stringent methods of artifact reduction. RESULTS Preoperatively, functional networks in TLE patients differed significantly from healthy controls, with differences that largely, but not exclusively, involved the default mode and temporal/auditory subnetworks. However, undergoing epilepsy surgery and achieving seizure freedom did not lead to significant changes in network connectivity, with postoperative functional network abnormalities closely mirroring the preoperative state. SIGNIFICANCE This result argues for a stable chronic effect of the disease on brain connectivity, with changes that are largely "burned in" by the time a patient with intractable TLE undergoes epilepsy surgery, which typically occurs years after the initial diagnosis. The result has potential implications for the treatment of intractable epilepsy, suggesting that delaying surgical intervention that may achieve seizure freedom may lead to functional network changes that are no longer reversible by the time of epilepsy surgery.
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Affiliation(s)
- Luigi Maccotta
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Mayra A Lopez
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Babatunde Adeyemo
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Beau M Ances
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Brian K Day
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Lawrence N Eisenman
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Joshua L Dowling
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Eric C Leuthardt
- Department of Neurological Surgery, Washington University School of Medicine, St. Louis, Missouri, U.S.A.,Department of Biomedical Engineering, Washington University School of Medicine, St. Louis, Missouri, U.S.A.,Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Bradley L Schlaggar
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, U.S.A.,Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri, U.S.A.,Department of Radiology, Washington University School of Medicine, St. Louis, Missouri, U.S.A.,Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, U.S.A.,Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, U.S.A
| | - Robert Edward Hogan
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, U.S.A
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Peng K, Pouliot P, Lesage F, Nguyen DK. Multichannel continuous electroencephalography-functional near-infrared spectroscopy recording of focal seizures and interictal epileptiform discharges in human epilepsy: a review. NEUROPHOTONICS 2016; 3:031402. [PMID: 26958576 PMCID: PMC4750425 DOI: 10.1117/1.nph.3.3.031402] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 12/08/2015] [Indexed: 05/11/2023]
Abstract
Functional near-infrared spectroscopy (fNIRS) has emerged as a promising neuroimaging technique as it allows noninvasive and long-term monitoring of cortical hemodynamics. Recent work by our group and others has revealed the potential of fNIRS, combined with electroencephalography (EEG), in the context of human epilepsy. Hemodynamic brain responses attributed to epileptic events, such as seizures and interictal epileptiform discharges (IEDs), are routinely observed with a good degree of statistical significance and in concordance with clinical presentation. Recording done with over 100 channels allows sufficiently large coverage of the epileptic focus and other areas. Three types of seizures have been documented: frontal lobe seizures, temporal lobe seizures, and posterior seizures. Increased oxygenation was observed in the epileptic focus in most cases, while rapid but similar hemodynamic variations were identified in the contralateral homologous region. While investigating IEDs, it was shown that their hemodynamic effect is observable with fNIRS, that their response is associated with significant (inhibitive) nonlinearities, and that the sensitivity and specificity of fNIRS to localize the epileptic focus can be estimated in a sample of 40 patients. This paper first reviews recent EEG-fNIRS developments in epilepsy research and then describes applications to the study of focal seizures and IEDs.
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Affiliation(s)
- Ke Peng
- École Polytechnique de Montréal, Département de génie électrique and Institut de génie biomédical, C.P. 6079, Succursale Centre-ville, Montréal, Quebec H3C3A7, Canada
| | - Philippe Pouliot
- École Polytechnique de Montréal, Département de génie électrique and Institut de génie biomédical, C.P. 6079, Succursale Centre-ville, Montréal, Quebec H3C3A7, Canada
- Institut de Cardiologie de Montréal, Centre de recherche, 5000 rue Bélanger est, Montréal, Quebec H1T1C8, Canada
| | - Frédéric Lesage
- École Polytechnique de Montréal, Département de génie électrique and Institut de génie biomédical, C.P. 6079, Succursale Centre-ville, Montréal, Quebec H3C3A7, Canada
- Institut de Cardiologie de Montréal, Centre de recherche, 5000 rue Bélanger est, Montréal, Quebec H1T1C8, Canada
| | - Dang Khoa Nguyen
- Centre Hospitalier de l’Université de Montréal, Hôpital Notre-Dame, Service de neurologie, 1560 rue Sherbrooke est, Montréal, Quebec H2L4M1, Canada
- Address all correspondence to: Dang Khoa Nguyen, E-mail:
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Watson CG, Dehaes M, Gagoski BA, Grant PE, Rivkin MJ. Arterial Spin Labeling Perfusion Magnetic Resonance Imaging Performed in Acute Perinatal Stroke Reveals Hyperperfusion Associated With Ischemic Injury. Stroke 2016; 47:1514-9. [DOI: 10.1161/strokeaha.115.011936] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 03/14/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Christopher G. Watson
- From the Departments of Neurology (C.G.W., M.J.R.), Psychiatry (M.J.R.), Radiology (P.E.G., M.J.R.), and Newborn Medicine (M.D., B.A.G., P.E.G.), Boston Children’s Hospital, MA; Graduate Program for Neuroscience, Boston University, MA (C.G.W.); Department of Radiology, University of Montreal, Montreal, Quebec, Canada (M.D.); and Department of Radiology, Centre Hospitalier Universitaire Saint-Justine, Montreal, Quebec, Canada (M.D.)
| | - Mathieu Dehaes
- From the Departments of Neurology (C.G.W., M.J.R.), Psychiatry (M.J.R.), Radiology (P.E.G., M.J.R.), and Newborn Medicine (M.D., B.A.G., P.E.G.), Boston Children’s Hospital, MA; Graduate Program for Neuroscience, Boston University, MA (C.G.W.); Department of Radiology, University of Montreal, Montreal, Quebec, Canada (M.D.); and Department of Radiology, Centre Hospitalier Universitaire Saint-Justine, Montreal, Quebec, Canada (M.D.)
| | - Borjan A. Gagoski
- From the Departments of Neurology (C.G.W., M.J.R.), Psychiatry (M.J.R.), Radiology (P.E.G., M.J.R.), and Newborn Medicine (M.D., B.A.G., P.E.G.), Boston Children’s Hospital, MA; Graduate Program for Neuroscience, Boston University, MA (C.G.W.); Department of Radiology, University of Montreal, Montreal, Quebec, Canada (M.D.); and Department of Radiology, Centre Hospitalier Universitaire Saint-Justine, Montreal, Quebec, Canada (M.D.)
| | - P. Ellen Grant
- From the Departments of Neurology (C.G.W., M.J.R.), Psychiatry (M.J.R.), Radiology (P.E.G., M.J.R.), and Newborn Medicine (M.D., B.A.G., P.E.G.), Boston Children’s Hospital, MA; Graduate Program for Neuroscience, Boston University, MA (C.G.W.); Department of Radiology, University of Montreal, Montreal, Quebec, Canada (M.D.); and Department of Radiology, Centre Hospitalier Universitaire Saint-Justine, Montreal, Quebec, Canada (M.D.)
| | - Michael J. Rivkin
- From the Departments of Neurology (C.G.W., M.J.R.), Psychiatry (M.J.R.), Radiology (P.E.G., M.J.R.), and Newborn Medicine (M.D., B.A.G., P.E.G.), Boston Children’s Hospital, MA; Graduate Program for Neuroscience, Boston University, MA (C.G.W.); Department of Radiology, University of Montreal, Montreal, Quebec, Canada (M.D.); and Department of Radiology, Centre Hospitalier Universitaire Saint-Justine, Montreal, Quebec, Canada (M.D.)
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Cleeren E, Premereur E, Casteels C, Goffin K, Janssen P, Van Paesschen W. The effective connectivity of the seizure onset zone and ictal perfusion changes in amygdala kindled rhesus monkeys. NEUROIMAGE-CLINICAL 2016; 12:252-61. [PMID: 27489773 PMCID: PMC4959940 DOI: 10.1016/j.nicl.2016.05.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/04/2016] [Accepted: 05/31/2016] [Indexed: 12/22/2022]
Abstract
Epileptic seizures are network-level phenomena. Hence, epilepsy may be regarded as a circuit-level disorder that cannot be understood outside this context. Better insight into the effective connectivity of the seizure onset zone and the manner in which seizure activity spreads could lead to specifically-tailored therapies for epilepsy. We applied the electrical amygdala kindling model in two rhesus monkeys until these animals displayed consistent stage IV seizures. At this stage, we investigated the effective connectivity of the amygdala by means of electrical microstimulation during fMRI (EM-fMRI). In addition, we imaged changes in perfusion during a seizure using ictal SPECT perfusion imaging. The spatial overlap between the connectivity network and the ictal perfusion network was assessed both at the regional level, by calculating Dice coefficients using anatomically defined regions of interest, and at the voxel level. The kindled amygdala was extensively connected to bilateral cortical and subcortical structures, which in many cases were connected multisynaptically to the amygdala. At the regional level, the spatial extents of many of these fMRI activations and deactivations corresponded to the respective increases and decreases in perfusion imaged during a stage IV seizure. At the voxel level, however, some regions showed residual seizure-specific activity (not overlapping with the EM-fMRI activations) or fMRI-specific activation (not overlapping with the ictal SPECT activations), indicating that frequently, only a part of a region anatomically connected to the seizure onset zone participated in seizure propagation. Thus, EM-fMRI in the amygdala of electrically-kindled monkeys reveals widespread areas that are often connected multisynaptically to the seizure focus. Seizure activity appears to spread, to a large extent, via these connected areas.
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Affiliation(s)
- Evy Cleeren
- Laboratory for Neuro- and Psychophysiology, KU Leuven, O&N II Herestraat 49 - bus 1021, 3000 Leuven, Belgium; Laboratory for Epilepsy Research, KU Leuven, UZ Herestraat 49 - bus 7003 48, 3000 Leuven, Belgium
| | - Elsie Premereur
- Laboratory for Neuro- and Psychophysiology, KU Leuven, O&N II Herestraat 49 - bus 1021, 3000 Leuven, Belgium
| | - Cindy Casteels
- Nuclear Medicine & Molecular Imaging, Department of Imaging and Pathology, UZ Herestraat 49 - bus 7003 59, 3000 Leuven, Belgium; Molecular Small Animal Imaging Center (MoSAIC), O&N I Herestraat 49 - bus 505, 3000 Leuven, Belgium
| | - Karolien Goffin
- Nuclear Medicine & Molecular Imaging, Department of Imaging and Pathology, UZ Herestraat 49 - bus 7003 59, 3000 Leuven, Belgium
| | - Peter Janssen
- Laboratory for Neuro- and Psychophysiology, KU Leuven, O&N II Herestraat 49 - bus 1021, 3000 Leuven, Belgium
| | - Wim Van Paesschen
- Laboratory for Epilepsy Research, KU Leuven, UZ Herestraat 49 - bus 7003 48, 3000 Leuven, Belgium
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Seizures and brain regulatory systems: consciousness, sleep, and autonomic systems. J Clin Neurophysiol 2016; 32:188-93. [PMID: 25233249 DOI: 10.1097/wnp.0000000000000133] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Research into the physiologic underpinnings of epilepsy has revealed reciprocal relationships between seizures and the activity of several regulatory systems in the brain. This review highlights recent progress in understanding and using the relationships between seizures and the arousal or consciousness system, the sleep-wake and associated circadian system, and the central autonomic network.
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Duncan JS, Winston GP, Koepp MJ, Ourselin S. Brain imaging in the assessment for epilepsy surgery. Lancet Neurol 2016; 15:420-33. [PMID: 26925532 DOI: 10.1016/s1474-4422(15)00383-x] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/22/2015] [Accepted: 12/02/2015] [Indexed: 01/14/2023]
Abstract
Brain imaging has a crucial role in the presurgical assessment of patients with epilepsy. Structural imaging reveals most cerebral lesions underlying focal epilepsy. Advances in MRI acquisitions including diffusion-weighted imaging, post-acquisition image processing techniques, and quantification of imaging data are increasing the accuracy of lesion detection. Functional MRI can be used to identify areas of the cortex that are essential for language, motor function, and memory, and tractography can reveal white matter tracts that are vital for these functions, thus reducing the risk of epilepsy surgery causing new morbidities. PET, SPECT, simultaneous EEG and functional MRI, and electrical and magnetic source imaging can be used to infer the localisation of epileptic foci and assist in the design of intracranial EEG recording strategies. Progress in semi-automated methods to register imaging data into a common space is enabling the creation of multimodal three-dimensional patient-specific datasets. These techniques show promise for the demonstration of the complex relations between normal and abnormal structural and functional data and could be used to direct precise intracranial navigation and surgery for individual patients.
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Affiliation(s)
- John S Duncan
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK; Chalfont Centre for Epilepsy, Chalfont St Peter, Gerrards Cross, UK.
| | - Gavin P Winston
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK; Chalfont Centre for Epilepsy, Chalfont St Peter, Gerrards Cross, UK
| | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK; Chalfont Centre for Epilepsy, Chalfont St Peter, Gerrards Cross, UK
| | - Sebastien Ourselin
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; Translational Imaging Group, Centre for Medical Image Computing, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK
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Abstract
Single-photon emission computed tomography (SPECT) is a functional nuclear imaging technique that allows visualization and quantification of different in vivo physiologic and pathologic features of brain neurobiology. It has been used for many years in diagnosis of several neurologic and psychiatric disorders. In this chapter, we discuss the current state-of-the-art of SPECT imaging of brain perfusion and dopamine transporter (DAT) imaging. Brain perfusion SPECT imaging plays an important role in the localization of the seizure onset zone in patients with refractory epilepsy. In cerebrovascular disease, it can be useful in determining the cerebrovascular reserve. After traumatic brain injury, SPECT has shown perfusion abnormalities despite normal morphology. In the context of organ donation, the diagnosis of brain death can be made with high accuracy. In neurodegeneration, while amyloid or (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) are the nuclear diagnostic tools of preference for early and differential diagnosis of dementia, perfusion SPECT imaging can be useful, albeit with slightly lower accuracy. SPECT imaging of the dopamine transporter system is widely available in Europe and Asia, but since recently also in the USA, and has been accepted as an important diagnostic tool in the early and differential diagnosis of parkinsonism in patients with unclear clinical features. The combination of perfusion SPECT (or FDG-PET) and DAT imaging provides differential diagnosis between idiopathic Parkinson's disease, Parkinson-plus syndromes, dementia with Lewy bodies, and essential tremor.
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Affiliation(s)
- Karolien Goffin
- Division of Nuclear Medicine, University Hospital Leuven and KU Leuven, Leuven, Belgium
| | - Koen van Laere
- Division of Nuclear Medicine, University Hospital Leuven and KU Leuven, Leuven, Belgium.
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Stylianou P, Kimchi G, Hoffmann C, Blat I, Harnof S. Neuroimaging for patient selection for medial temporal lobe epilepsy surgery: Part 2 functional neuroimaging. J Clin Neurosci 2016; 23:23-33. [DOI: 10.1016/j.jocn.2015.04.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/11/2015] [Accepted: 04/18/2015] [Indexed: 11/17/2022]
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Perfusion SPECT, SISCOM and PET 18F-FDG in the assessment of drug-refractory epilepsy patients candidates for epilepsy surgery. Rev Esp Med Nucl Imagen Mol 2015. [DOI: 10.1016/j.remnie.2015.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Doucet GE, He X, Sperling M, Sharan A, Tracy JI. Frontal gray matter abnormalities predict seizure outcome in refractory temporal lobe epilepsy patients. NEUROIMAGE-CLINICAL 2015; 9:458-66. [PMID: 26594628 PMCID: PMC4596924 DOI: 10.1016/j.nicl.2015.09.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 09/04/2015] [Accepted: 09/08/2015] [Indexed: 12/20/2022]
Abstract
Developing more reliable predictors of seizure outcome following temporal lobe surgery for intractable epilepsy is an important clinical goal. In this context, we investigated patients with refractory temporal lobe epilepsy (TLE) before and after temporal resection. In detail, we explored gray matter (GM) volume change in relation with seizure outcome, using a voxel-based morphometry (VBM) approach. To do so, this study was divided into two parts. The first one involved group analysis of differences in regional GM volume between the groups (good outcome (GO), e.g., no seizures after surgery; poor outcome (PO), e.g., persistent postoperative seizures; and controls, N = 24 in each group), pre- and post-surgery. The second part of the study focused on pre-surgical data only (N = 61), determining whether the degree of GM abnormalities can predict surgical outcomes. For this second step, GM abnormalities were identified, within each lobe, in each patient when compared with an ad hoc sample of age-matched controls. For the first analysis, the results showed larger GM atrophy, mostly in the frontal lobe, in PO patients, relative to both GO patients and controls, pre-surgery. When comparing pre-to-post changes, we found relative GM gains in the GO but not in the PO patients, mostly in the non-resected hemisphere. For the second analysis, only the frontal lobe displayed reliable prediction of seizure outcome. 81% of the patients showing pre-surgical increased GM volume in the frontal lobe became seizure free, post-surgery; while 77% of the patients with pre-surgical reduced frontal GM volume had refractory seizures, post-surgery. A regression analysis revealed that the proportion of voxels with reduced frontal GM volume was a significant predictor of seizure outcome (p = 0.014). Importantly, having less than 1% of the frontal voxels with GM atrophy increased the likelihood of being seizure-free, post-surgery, by seven times. Overall, our results suggest that using pre-surgical GM abnormalities within the frontal lobe is a reliable predictor of seizure outcome post-surgery in TLE. We believe that this frontal GM atrophy captures seizure burden outside the pre-existing ictal temporal lobe, reflecting either the development of epileptogenesis or the loss of a protective, adaptive force helping to control or limit seizures. This study provides evidence of the potential of VBM-based approaches to predict surgical outcomes in refractory TLE candidates. Gray matter abnormalities within the frontal lobe predicts seizure outcome in TLE. Poor outcome patients suffer from GM atrophy in the frontal lobe, pre-surgery. Good outcome patients show gain of GM in the non-resected hemisphere, post-surgery. Frontal GM atrophy captures seizure burden outside the ictal temporal lobe.
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Affiliation(s)
- Gaelle E Doucet
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Xiaosong He
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Michael Sperling
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Ashwini Sharan
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Joseph I Tracy
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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He X, Doucet GE, Sperling M, Sharan A, Tracy JI. Reduced thalamocortical functional connectivity in temporal lobe epilepsy. Epilepsia 2015; 56:1571-9. [PMID: 26193910 DOI: 10.1111/epi.13085] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/19/2015] [Indexed: 01/06/2023]
Abstract
OBJECTIVE In temporal lobe epilepsy (TLE), the thalamus is well known for its role in the propagation and spread of epileptiform activity. However, the integrity of thalamocortical functional connectivity (FC) in TLE and its relation to specific seizure patterns have not yet been determined. We address these issues with resting-state functional magnetic resonance imaging (fMRI). METHODS Resting-state fMRI was performed on two groups of unilateral TLE patients: those with focal seizures only (16 left TLE, 16 right TLE) and those with additional generalized seizures (16 left TLE, 10 right TLE), and 16 matched controls. A thalamic parcellation based on FC between five nonoverlapping cortical seeds (prefrontal, motor, somatosensory, parietal-occipital, and temporal) and the ipsilateral thalamus was carried out to parcel each thalamus into five corresponding segments. FCs between each segment and its ipsilateral cortical seed were extracted and compared across groups using analyses of variance (ANOVAs). RESULTS Compared to healthy controls, patients with TLE displayed decreased thalamocortical FC in multiple posterior and ventromedial thalamic segments of both the ictal and nonictal hemispheres. Our parcellation analysis revealed that these thalamic regions were functionally connected to the parietal/occipital and temporal lobes. In patients with TLE with focal seizures these regional thalamocortical FC decreases were limited to the ictal hemisphere. In contrast, TLE patients with both focal and generalized epileptiform activity displayed FC decreases in both the ictal and nonictal thalamus involving the dorsolateral pulvinar, a region preferentially connected to the parietal and occipital lobes. SIGNIFICANCE Our data provide the first evidence of regional specific thalamocortical FC decreases in patients with unilateral TLE. Furthermore, our results demonstrate that patients with different seizure types present different thalamoparietal/occipital FC decrease patterns. While patients with focal seizures present thalamocortical FC decreases in the ictal hemisphere only, patients with additional generalized seizure activity also show thalamocortical FC decreases involving the thalamus in the nonictal hemisphere.
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Affiliation(s)
- Xiaosong He
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Gaelle E Doucet
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Michael Sperling
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Ashwini Sharan
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
| | - Joseph I Tracy
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, U.S.A
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Cleeren E, Casteels C, Goffin K, Janssen P, Van Paesschen W. Ictal perfusion changes associated with seizure progression in the amygdala kindling model in the rhesus monkey. Epilepsia 2015; 56:1366-75. [PMID: 26174547 DOI: 10.1111/epi.13077] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2015] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Amygdala kindling is a widely used animal model for studying mesial temporal lobe epileptogenesis. In the macaque monkey, electrical amygdala kindling develops slowly and provides an opportunity for investigating ictal perfusion changes during epileptogenesis. METHODS Two rhesus monkeys were electrically kindled through chronically implanted electrodes in the right amygdala over a period of 16 and 17 months. Ictal perfusion single photon emission computed tomography (SPECT) imaging was performed during each of the four predefined clinical stages. RESULTS Afterdischarge duration increased slowly over 477 days for monkey K and 515 days for monkey S (18 ± 8 s in stage I; 52 ± 13 s in stage IV). During this time, the animals progressed through four clinical stages ranging from interrupting ongoing behavior to bilateral convulsions. Ictal SPECT perfusion imaging showed well-localized but widely distributed regions of hyperperfusion and hypoperfusion, in both cortical and subcortical structures, at every seizure stage. A large portion of the ictal network was involved in the early stages of epileptogenesis and subsequently expanded over time as seizure severity evolved. SIGNIFICANCE Our data indicate that the different mesial temporal lobe seizure types occur within a common network affecting several parts of the brain, and that seizure severity may be determined by seizure-induced epileptogenesis within a bihemispheric network that is implicated from the start of the process.
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Affiliation(s)
- Evy Cleeren
- Laboratory for Neuro- and Psychophysiology, KU Leuven, Leuven, Belgium.,Laboratory for Epilepsy Research, KU Leuven, Leuven, Belgium
| | - Cindy Casteels
- Nuclear Medicine & Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium.,Molecular Small Animal Imaging Center (MoSAIC), KU Leuven, Leuven, Belgium
| | - Karolien Goffin
- Nuclear Medicine & Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Peter Janssen
- Laboratory for Neuro- and Psychophysiology, KU Leuven, Leuven, Belgium
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Suárez-Piñera M, Mestre-Fusco A, Ley M, González S, Medrano S, Principe A, Mojal S, Conesa G, Rocamora R. Perfusion SPECT, SISCOM and PET (18)F-FDG in the assessment of drug- refractory epilepsy patients candidates for epilepsy surgery. Rev Esp Med Nucl Imagen Mol 2015; 34:350-7. [PMID: 26118354 DOI: 10.1016/j.remn.2015.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/13/2015] [Accepted: 05/14/2015] [Indexed: 11/30/2022]
Abstract
AIMS Brain perfusion SPECT (ictal-interictal), SPECT images and subtraction ictal SPECT coregistered to MRI (SISCOM) and (18)F-FDG-PET (interictal), play an important role in the pre-surgical diagnosis of patients with medically refractory epilepsy. This study aimed to establish: the reproducibility of visual ictal-interictal SPECT and SISCOM analysis altogether with the capacity of SPECT, SISCOM and PET to determine the epileptogenic zone. MATERIAL AND METHODS (99m)Tc-HMPAO SPECT ictal-interictal and SISCOM (Analyze 7.0) were performed on 47 refractory epilepsy patients (24 F, 19-60 yrs). In 13 patients, SISCOM was also performed using a new program (Focus DET). Ictal-interictal SPECT and SISCOM images were analysed independently by two nuclear medicine physicians (observer 1 and 2). Kappa concordance coefficient was used to evaluate the reproducibility. In sixteen patients, SPECT, SISCOM and PET findings were compared with the resected area during the surgery, and surgical outcome using Engel scale or with the stereo EEG-(SEEG). RESULTS The ictal-interictal SPECT interobserver agreement was 91%, Kappa index 0.86, SISCOM (Analyze 7.0) interobserver agreement percentage was 82%, Kappa index 0.80, Analyze 7.0 showed a higher inconclusive results than visual SPECT analysis. SISCOM FocusDET interobserver agreement was 92%, Kappa index 0.87, with lower inconclusive results than Analyze 7.0. SPECT, SISCOM and PET combined findings identified 87% seizure onset zone: 79% temporal, 26% parieto-temporal and 7% frontal. CONCLUSIONS Ictal-interictal SPECT and SISCOM showed a high reproducibility in this sample of patients with drug-refractory epilepsy. SPECT,SISCOM and PET combined findings improved detection of epileptogenic zone in comparison with the individual assessment.
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Affiliation(s)
- M Suárez-Piñera
- Servicio de Medicina Nuclear, Hospital del Mar, Parc de Salut Mar, Barcelona, España.
| | - A Mestre-Fusco
- Servicio de Medicina Nuclear, Hospital del Mar, Parc de Salut Mar, Barcelona, España
| | - M Ley
- Unidad de Epilepsia, Servicio de Neurología, Hospital del Mar, Parc de Salut Mar, Barcelona, España
| | - S González
- Servicio de Radiología, Hospital del Mar, Parc de Salut Mar, Barcelona, España
| | - S Medrano
- Servicio de Radiología, Hospital del Mar, Parc de Salut Mar, Barcelona, España
| | - A Principe
- Unidad de Epilepsia, Servicio de Neurología, Hospital del Mar, Parc de Salut Mar, Barcelona, España
| | - S Mojal
- Departamento de Estadística en Investigación Biomédica, Instituto Mar de Investigaciones Médicas (IMIM), Barcelona, España
| | - G Conesa
- Servicio de Neurocirugía, Hospital del Mar, Parc de Salut Mar, Barcelona, España
| | - R Rocamora
- Unidad de Epilepsia, Servicio de Neurología, Hospital del Mar, Parc de Salut Mar, Barcelona, España
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Memarian N, Madsen SK, Macey PM, Fried I, Engel J, Thompson PM, Staba RJ. Ictal depth EEG and MRI structural evidence for two different epileptogenic networks in mesial temporal lobe epilepsy. PLoS One 2015; 10:e0123588. [PMID: 25849340 PMCID: PMC4388829 DOI: 10.1371/journal.pone.0123588] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 03/05/2015] [Indexed: 11/18/2022] Open
Abstract
Hypersynchronous (HYP) and low voltage fast (LVF) activity are two separate ictal depth EEG onsets patterns often recorded in presurgical patients with MTLE. Evidence suggests the mechanisms generating HYP and LVF onset seizures are distinct, including differential involvement of hippocampal and extra-hippocampal sites. Yet the extent of extra-hippocampal structural alterations, which could support these two common seizures, is not known. In the current study, preoperative MRI from 24 patients with HYP or LVF onset seizures were analyzed to determine changes in cortical thickness and relate structural changes to spatiotemporal properties of the ictal EEG. Overall, onset and initial ipsilateral spread of HYP onset seizures involved mesial temporal structures, whereas LVF onset seizures involved mesial and lateral temporal as well as orbitofrontal cortex. MRI analysis found reduced cortical thickness correlated with longer duration of epilepsy. However, in patients with HYP onsets, the most affected areas were on the medial surface of each hemisphere, including parahippocampal regions and cingulate gyrus, whereas in patients with LVF onsets, the lateral surface of the anterior temporal lobe and orbitofrontal cortex showed the greatest effect. Most patients with HYP onset seizures were seizure-free after resective surgery, while a higher proportion of patients with LVF onset seizures had only worthwhile improvement. Our findings confirm the view that recurrent seizures cause progressive changes in cortical thickness, and provide information concerning the structural basis of two different epileptogenic networks responsible for MTLE. One, identified by HYP ictal onsets, chiefly involves hippocampus and is associated with excellent outcome after standardized anteromedial temporal resection, while the other also involves lateral temporal and orbitofrontal cortex and a seizure-free surgical outcome occurs less after this procedure. These results suggest that a more extensive tailored resection may be required for patients with the second type of MTLE.
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Affiliation(s)
- Negar Memarian
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
| | - Sarah K. Madsen
- Department of Neurology, Imaging Genetics Center, Institute for Neuroimaging and Informatics, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States of America
| | - Paul M. Macey
- UCLA School of Nursing, University of California Los Angeles, Los Angeles, CA, United States of America
| | - Itzhak Fried
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
| | - Jerome Engel
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
- Department of Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
| | - Paul M. Thompson
- Department of Neurology, Imaging Genetics Center, Institute for Neuroimaging and Informatics, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States of America
| | - Richard J. Staba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
- * E-mail:
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Vinette SA, Dunn JF, Slone E, Federico P. Artifact reduction in long-term monitoring of cerebral hemodynamics using near-infrared spectroscopy. NEUROPHOTONICS 2015; 2:025004. [PMID: 26158008 PMCID: PMC4478783 DOI: 10.1117/1.nph.2.2.025004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 05/01/2015] [Indexed: 05/09/2023]
Abstract
Near-infrared spectroscopy (NIRS) is a noninvasive neuroimaging technique used to assess cerebral hemodynamics. Its portability, ease of use, and relatively low operational cost lend itself well to the long-term monitoring of hemodynamic changes, such as those in epilepsy, where events are unpredictable. Long-term monitoring is associated with challenges including alterations in behaviors and motion that can result in artifacts. Five patients with epilepsy were assessed for interictal hemodynamic changes and alterations in behavior or motion. Based on this work, visual inspection was used to identify NIRS artifacts during a period of interest, specifically prior to seizures, in four patients. A motion artifact reduction algorithm (MARA, also known as the spline interpolation method) was tested on these data. Alterations in the NIRS measurements often occurred simultaneously with changes in motion and behavior. Occasionally, sharp shift artifacts were observed in the data. When artifacts appeared as sustained baseline shifts in the data, MARA reduced the standard deviation of the data and the appearance improved. We discussed motion and artifacts as challenges associated with long-term monitoring of cerebral hemodynamics in patients with epilepsy and our group's approach to circumvent these challenges and improve the quality of the data collected.
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Affiliation(s)
- Sarah A. Vinette
- University of Calgary, Faculty of Graduate Studies, Department of Neuroscience, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
- Hotchkiss Brain Institute, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Jeff F. Dunn
- Hotchkiss Brain Institute, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
- University of Calgary, Cumming School of Medicine, Department of Physiology and Pharmacology, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
- University of Calgary, Cumming School of Medicine, Department of Radiology, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
- University of Calgary, Cumming School of Medicine, Department of Clinical Neurosciences, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Edward Slone
- University of Calgary, Faculty of Graduate Studies, Department of Neuroscience, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
- Hotchkiss Brain Institute, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Paolo Federico
- Hotchkiss Brain Institute, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
- University of Calgary, Cumming School of Medicine, Department of Radiology, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
- University of Calgary, Cumming School of Medicine, Department of Clinical Neurosciences, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
- Address all correspondence to: Paolo Federico, E-mail:
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Tousseyn S, Dupont P, Goffin K, Sunaert S, Van Paesschen W. Correspondence between large-scale ictal and interictal epileptic networks revealed by single photon emission computed tomography (SPECT) and electroencephalography (EEG)-functional magnetic resonance imaging (fMRI). Epilepsia 2015; 56:382-92. [DOI: 10.1111/epi.12910] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Simon Tousseyn
- Laboratory for Epilepsy Research; UZ Leuven & KU Leuven; Leuven Belgium
- Medical Imaging Research Center; UZ Leuven & KU Leuven; Leuven Belgium
| | - Patrick Dupont
- Laboratory for Epilepsy Research; UZ Leuven & KU Leuven; Leuven Belgium
- Medical Imaging Research Center; UZ Leuven & KU Leuven; Leuven Belgium
- Laboratory for Cognitive Neurology; UZ Leuven & KU Leuven; Leuven Belgium
| | - Karolien Goffin
- Department of Nuclear Medicine; UZ Leuven & KU Leuven; Leuven Belgium
| | - Stefan Sunaert
- Medical Imaging Research Center; UZ Leuven & KU Leuven; Leuven Belgium
- Department of Radiology; UZ Leuven & KU Leuven; Leuven Belgium
| | - Wim Van Paesschen
- Laboratory for Epilepsy Research; UZ Leuven & KU Leuven; Leuven Belgium
- Medical Imaging Research Center; UZ Leuven & KU Leuven; Leuven Belgium
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Laufs H, Rodionov R, Thornton R, Duncan JS, Lemieux L, Tagliazucchi E. Altered FMRI connectivity dynamics in temporal lobe epilepsy might explain seizure semiology. Front Neurol 2014; 5:175. [PMID: 25309503 PMCID: PMC4160997 DOI: 10.3389/fneur.2014.00175] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 08/28/2014] [Indexed: 01/15/2023] Open
Abstract
Temporal lobe epilepsy (TLE) can be conceptualized as a network disease. The network can be characterized by inter-regional functional connectivity, i.e., blood oxygen level-dependent (BOLD) signal correlations between any two regions. However, functional connectivity is not constant over time, thus computing correlation at a given time and then at some later time could give different results (non-stationarity). We hypothesized (1) that non-stationarities can be induced by epilepsy (e.g., interictal epileptic activity) increasing local signal variance and that (2) these transient events contribute to fluctuations in connectivity leading to pathological functioning, i.e., TLE semiology. We analyzed fMRI data from 27 patients with TLE and 22 healthy controls focusing on EEG-confirmed wake epochs only to protect against sleep-induced connectivity changes. Testing hypothesis (1), we identified brain regions where the BOLD signal variance was significantly greater in TLE than in controls: the temporal pole – including the hippocampus. Taking the latter as the seed region and testing hypothesis (2), we calculated the time-varying inter-regional correlation values (dynamic functional connectivity) to other brain regions and found greater connectivity variance in the TLE than the control group mainly in the precuneus, the supplementary and sensorimotor, and the frontal cortices. We conclude that the highest BOLD signal variance in the hippocampi is highly suggestive of a specific epilepsy-related effect. The altered connectivity dynamics in TLE patients might help to explain the hallmark semiological features of dyscognitive seizures including impaired consciousness (precuneus, frontal cortex), sensory disturbance, and motor automatisms (sensorimotor cortices, supplementary motor cortex). Accounting for the non-stationarity and state-dependence of functional connectivity are a prerequisite in the search for potential connectivity-derived biomarkers in TLE.
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Affiliation(s)
- Helmut Laufs
- Department of Neurology and Brain Imaging Center, Goethe-University Frankfurt am Main , Frankfurt am Main , Germany ; Department of Neurology, University Hospital Schleswig-Holstein, Christian-Albrechts-University Kiel , Kiel , Germany ; National Hospital for Neurology and Neurosurgery, University College London , London , UK ; The Epilepsy Society , Chalfont St. Peter , UK
| | - Roman Rodionov
- National Hospital for Neurology and Neurosurgery, University College London , London , UK ; The Epilepsy Society , Chalfont St. Peter , UK
| | - Rachel Thornton
- National Hospital for Neurology and Neurosurgery, University College London , London , UK ; The Epilepsy Society , Chalfont St. Peter , UK
| | - John Sydney Duncan
- National Hospital for Neurology and Neurosurgery, University College London , London , UK ; The Epilepsy Society , Chalfont St. Peter , UK
| | - Louis Lemieux
- National Hospital for Neurology and Neurosurgery, University College London , London , UK ; The Epilepsy Society , Chalfont St. Peter , UK
| | - Enzo Tagliazucchi
- Department of Neurology and Brain Imaging Center, Goethe-University Frankfurt am Main , Frankfurt am Main , Germany
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Alteration of interictal brain activity in patients with temporal lobe epilepsy in the left dominant hemisphere: a resting-state MEG study. BIOMED RESEARCH INTERNATIONAL 2014; 2014:171487. [PMID: 25136558 PMCID: PMC4127284 DOI: 10.1155/2014/171487] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 07/03/2014] [Accepted: 07/05/2014] [Indexed: 12/26/2022]
Abstract
Resting MEG activities were compared between patients with left temporal lobe epilepsy (LTLE) and normal controls. Using SAMg2, the activities of MEG data were reconstructed and normalized. Significantly elevated SAMg2 signals were found in LTLE patients in the left temporal lobe and medial structures. Marked decreases of SAMg2 signals were found in the wide extratemporal lobe regions, such as the bilateral visual cortex. The study also demonstrated a positive correlation between the seizure frequency and brain activities of the abnormal regions after the multiple linear regression analysis. These results suggested that the aberrant brain activities not only were related to the epileptogenic zones, but also existed in other extratemporal regions in patients with LTLE. The activities of the aberrant regions could be further damaged with the increase of the seizure frequency. Our findings indicated that LTLE could be a multifocal disease, including complex epileptic networks and brain dysfunction networks.
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Harris S, Boorman L, Bruyns-Haylett M, Kennerley A, Ma H, Zhao M, Overton PG, Schwartz TH, Berwick J. Contralateral dissociation between neural activity and cerebral blood volume during recurrent acute focal neocortical seizures. Epilepsia 2014; 55:1423-30. [PMID: 25053117 PMCID: PMC4336552 DOI: 10.1111/epi.12726] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2014] [Indexed: 11/30/2022]
Abstract
Objective Whether epileptic events disrupt normal neurovascular coupling mechanisms locally or remotely is unclear. We sought to investigate neurovascular coupling in an acute model of focal neocortical epilepsy, both within the seizure onset zone and in contralateral homotopic cortex. Methods Neurovascular coupling in both ipsilateral and contralateral vibrissal cortices of the urethane-anesthetized rat were examined during recurrent 4-aminopyridine (4-AP, 15 mm, 1 μl) induced focal seizures. Local field potential (LFP) and multiunit spiking activity (MUA) were recorded via two bilaterally implanted 16-channel microelectrodes. Concurrent two-dimensional optical imaging spectroscopy was used to produce spatiotemporal maps of cerebral blood volume (CBV). Results Recurrent acute seizures in right vibrissal cortex (RVC) produced robust ipsilateral increases in LFP and MUA activity, most prominently in layer 5, that were nonlinearly correlated to local increases in CBV. In contrast, contralateral left vibrissal cortex (LVC) exhibited relatively smaller nonlaminar specific increases in neural activity coupled with a decrease in CBV, suggestive of dissociation between neural and hemodynamic responses. Significance These findings provide insights into the impact of epileptic events on the neurovascular unit, and have important implications both for the interpretation of perfusion-based imaging signals in the disorder and understanding the widespread effects of epilepsy.
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Affiliation(s)
- Sam Harris
- Department of Psychology, University of Sheffield, Sheffield, United Kingdom; Department of Neurological Surgery, Brain and Mind Research Institute, Brain and Spine Center, Weill Cornell Medical College, New York Presbyterian Hospital, New York, New York, U.S.A
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Coan AC, Campos BM, Yasuda CL, Kubota BY, Bergo FPG, Guerreiro CAM, Cendes F. Frequent seizures are associated with a network of gray matter atrophy in temporal lobe epilepsy with or without hippocampal sclerosis. PLoS One 2014; 9:e85843. [PMID: 24475055 PMCID: PMC3903486 DOI: 10.1371/journal.pone.0085843] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 12/02/2013] [Indexed: 11/23/2022] Open
Abstract
Objective Patients with temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) have diffuse subtle gray matter (GM) atrophy detectable by MRI quantification analyses. However, it is not clear whether the etiology and seizure frequency are associated with this atrophy. We aimed to evaluate the occurrence of GM atrophy and the influence of seizure frequency in patients with TLE and either normal MRI (TLE-NL) or MRI signs of HS (TLE-HS). Methods We evaluated a group of 172 consecutive patients with unilateral TLE-HS or TLE-NL as defined by hippocampal volumetry and signal quantification (122 TLE-HS and 50 TLE-NL) plus a group of 82 healthy individuals. Voxel-based morphometry was performed with VBM8/SPM8 in 3T MRIs. Patients with up to three complex partial seizures and no generalized tonic-clonic seizures in the previous year were considered to have infrequent seizures. Those who did not fulfill these criteria were considered to have frequent seizures. Results Patients with TLE-HS had more pronounced GM atrophy, including the ipsilateral mesial temporal structures, temporal lobe, bilateral thalami and pre/post-central gyri. Patients with TLE-NL had more subtle GM atrophy, including the ipsilateral orbitofrontal cortex, bilateral thalami and pre/post-central gyri. Both TLE-HS and TLE-NL showed increased GM volume in the contralateral pons. TLE-HS patients with frequent seizures had more pronounced GM atrophy in extra-temporal regions than TLE-HS with infrequent seizures. Patients with TLE-NL and infrequent seizures had no detectable GM atrophy. In both TLE-HS and TLE-NL, the duration of epilepsy correlated with GM atrophy in extra-hippocampal regions. Conclusion Although a diffuse network GM atrophy occurs in both TLE-HS and TLE-NL, this is strikingly more evident in TLE-HS and in patients with frequent seizures. These findings suggest that neocortical atrophy in TLE is related to the ongoing seizures and epilepsy duration, while thalamic atrophy is more probably related to the original epileptogenic process.
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Affiliation(s)
- Ana C. Coan
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Brunno M. Campos
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Clarissa L. Yasuda
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Bruno Y. Kubota
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Felipe PG. Bergo
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Carlos AM. Guerreiro
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Fernando Cendes
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
- * E-mail:
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Blumenfeld H. What is a seizure network? Long-range network consequences of focal seizures. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 813:63-70. [PMID: 25012367 PMCID: PMC6287499 DOI: 10.1007/978-94-017-8914-1_5] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
What defines the spatial and temporal boundaries of seizure activity in brain networks? To fully answer this question a precise and quantitative definition of seizures is needed, which unfortunately remains elusive. Nevertheless, it is possible to ask under conditions where clearly divergent patterns of activity occur in large-scale brain networks whether certain activity patterns are part of the seizure while others are not. Here we examine brain network activity during focal limbic seizures, including diverse regions such as the hippocampus, subcortical arousal systems and fronto-parietal association cortex. Based on work from patients and from animal models we describe a characteristic pattern of intense increases in neuronal firing, cerebral blood flow, cerebral blood volume, blood oxygen level dependent functional magnetic resonance imaging (BOLD fMRI) signals and cerebral metabolic rate of oxygen consumption in the hippocampus during focal limbic seizures. Similar increases are seen in certain closely linked subcortical structures such as the lateral septal nuclei and anterior hypothalamus, which contain inhibitory neurons. In marked contrast, decreases in all of these parameters are seen in the subcortical arousal systems of the upper brainstem and intralaminar thalamus, as well as in the fronto-parietal association cortex. We propose that the seizure proper can be defined as regions showing intense increases, while those areas showing opposite changes are inhibited by the seizure network and constitute long-range network consequences beyond the seizure itself. Importantly, the fronto-parietal cortex shows sleep-like slow wave activity and depressed metabolism under these conditions, associated with impaired consciousness. Understanding which brain networks are directly involved in seizures versus which sustain secondary consequences can provide new insights into the mechanisms of brain dysfunction in epilepsy, hopefully leading to innovative treatment approaches.
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Affiliation(s)
- Hal Blumenfeld
- Department of Neurology, Neurobiology and Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA,
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