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Wang X, Wang T, Fan X, Zhang Z, Wang Y, Li Z. A Molecular Toolbox of Positron Emission Tomography Tracers for General Anesthesia Mechanism Research. J Med Chem 2023; 66:6463-6497. [PMID: 37145921 DOI: 10.1021/acs.jmedchem.2c01965] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
With appropriate radiotracers, positron emission tomography (PET) allows direct or indirect monitoring of the spatial and temporal distribution of anesthetics, neurotransmitters, and biomarkers, making it an indispensable tool for studying the general anesthesia mechanism. In this Perspective, PET tracers that have been recruited in general anesthesia research are introduced in the following order: 1) 11C/18F-labeled anesthetics, i.e., PET tracers made from inhaled and intravenous anesthetics; 2) PET tracers targeting anesthesia-related receptors, e.g., neurotransmitters and voltage-gated ion channels; and 3) PET tracers for studying anesthesia-related neurophysiological effects and neurotoxicity. The radiosynthesis, pharmacodynamics, and pharmacokinetics of the above PET tracers are mainly discussed to provide a practical molecular toolbox for radiochemists, anesthesiologists, and those who are interested in general anesthesia.
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Affiliation(s)
- Xiaoxiao Wang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Tao Wang
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaowei Fan
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhao Zhang
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Yingwei Wang
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Zijing Li
- Center for Molecular Imaging and Translational Medicine, State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
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2
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Nwabufo CK, Aigbogun OP. Diagnostic and therapeutic agents that target alpha-synuclein in Parkinson's disease. J Neurol 2022; 269:5762-5786. [PMID: 35831620 PMCID: PMC9281355 DOI: 10.1007/s00415-022-11267-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 12/14/2022]
Abstract
The development of disease-modifying drugs and differential diagnostic agents is an urgent medical need in Parkinson’s disease. Despite the complex pathophysiological pathway, the misfolding of alpha-synuclein has been identified as a putative biomarker for detecting the onset and progression of the neurodegeneration associated with Parkinson’s disease. Identifying the most appropriate alpha-synuclein-based diagnostic modality with clinical translation will revolutionize the diagnosis of Parkinson’s. Likewise, molecules that target alpha-synuclein could alter the disease pathway that leads to Parkinson’s and may serve as first-in class therapeutics compared to existing treatment options such as levodopa and dopamine agonist that do not necessarily modify the disease pathway. Notwithstanding the promising benefits that alpha-synuclein presents to therapeutics and diagnostics development for Parkinson’s disease, finding ways to address potential challenges such as inadequate preclinical models, safety and efficacy will be paramount to achieving clinical translation. In this comprehensive review paper, we described the role of alpha-synuclein in the pathogenesis of Parkinson’s disease, as well as how its structure and function relationship delineate disease onset and progression. We further discussed different alpha-synuclein-based diagnostic modalities including biomolecular assays and molecular imaging. Finally, we presented current small molecules and biologics that are being developed as disease-modifying drugs or positron emission tomography imaging probes for Parkinson’s disease.
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Affiliation(s)
- Chukwunonso K Nwabufo
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada. .,Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, M5S 3M2, Canada.
| | - Omozojie P Aigbogun
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada.,Department of Chemistry, University of Saskatchewan, Saskatoon, Canada
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Kumar A, Shandal V, Juhász C, Chugani HT. PET imaging in epilepsy. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00049-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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4
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Exploiting Feature Selection and Neural Network Techniques for Identification of Focal and Nonfocal EEG Signals in TQWT Domain. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:6283900. [PMID: 34659691 PMCID: PMC8418932 DOI: 10.1155/2021/6283900] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 07/22/2021] [Accepted: 08/04/2021] [Indexed: 11/17/2022]
Abstract
For drug resistance patients, removal of a portion of the brain as a cause of epileptic seizures is a surgical remedy. However, before surgery, the detailed analysis of the epilepsy localization area is an essential and logical step. The Electroencephalogram (EEG) signals from these areas are distinct and are referred to as focal, while the EEG signals from other normal areas are known as nonfocal. The visual inspection of multiple channels for detecting the focal EEG signal is time-consuming and prone to human error. To address this challenge, we propose a novel method based on differential operator and Tunable Q-factor wavelet transform (TQWT) to distinguish the focal and nonfocal signals. For this purpose, first, the EEG signal was differenced and then decomposed by TQWT. Second, several entropy-based features were derived from the TQWT subbands. Third, the efficacy of the six binary feature selection algorithms, binary bat algorithm (BBA), binary differential evolution (BDE) algorithm, firefly algorithm (FA), genetic algorithm (GA), grey wolf optimization (GWO), and particle swarm optimization (PSO), was evaluated. In the end, the selected features were fed to several machine learning and neural network classifiers. We observed that the PSO with neural networks provides an effective solution for the application of focal EEG signal detection. The proposed framework resulted in an average classification accuracy of 97.68%, a sensitivity of 97.26%, and a specificity of 98.11% in a tenfold cross-validation strategy, which is higher than the state of the art used in the public Bern-Barcelona EEG database.
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Janisch J, Mitoyen C, Perinot E, Spezie G, Fusani L, Quigley C. Video Recording and Analysis of Avian Movements and Behavior: Insights from Courtship Case Studies. Integr Comp Biol 2021; 61:1378-1393. [PMID: 34037219 PMCID: PMC8516111 DOI: 10.1093/icb/icab095] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Video recordings are useful tools for advancing our understanding of animal movements and behavior. Over the past decades, a burgeoning area of behavioral research has put forward innovative methods to investigate animal movement using video analysis, which includes motion capture and machine learning algorithms. These tools are particularly valuable for the study of elaborate and complex motor behaviors, but can be challenging to use. We focus in particular on elaborate courtship displays, which commonly involve rapid and/or subtle motor patterns. Here, we review currently available tools and provide hands-on guidelines for implementing these techniques in the study of avian model species. First, we suggest a set of possible strategies and solutions for video acquisition based on different model systems, environmental conditions, and time or financial budget. We then outline the available options for video analysis and illustrate how different analytical tools can be chosen to draw inference about animal motor performance. Finally, a detailed case study describes how these guidelines have been implemented to study courtship behavior in golden-collared manakins (Manacus vitellinus).
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Affiliation(s)
- Judith Janisch
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, 1160 Vienna, Austria
| | - Clementine Mitoyen
- Department of Cognitive Biology, University of Vienna, 1090 Vienna, Austria
| | - Elisa Perinot
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, 1160 Vienna, Austria
| | - Giovanni Spezie
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, 1160 Vienna, Austria
| | - Leonida Fusani
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, 1160 Vienna, Austria
- Department of Cognitive Biology, University of Vienna, 1090 Vienna, Austria
| | - Cliodhna Quigley
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, 1160 Vienna, Austria
- Department of Cognitive Biology, University of Vienna, 1090 Vienna, Austria
- Vienna Cognitive Science Hub, University of Vienna, 1090 Vienna, Austria
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Abstract
OBJECTIVE. The purpose of this article is to summarize the role of molecular imaging of the brain by use of SPECT, FDG PET, and non-FDG PET radiotracers in epilepsy. CONCLUSION. Quantitative image analysis with PET and SPECT has increased the diagnostic utility of these modalities in localizing epileptogenic onset zones. A multi-modal platform approach integrating the functional imaging of PET and SPECT with the morphologic information from MRI in presurgical evaluation of epilepsy can greatly improve outcomes.
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Juhász C, John F. Utility of MRI, PET, and ictal SPECT in presurgical evaluation of non-lesional pediatric epilepsy. Seizure 2019; 77:15-28. [PMID: 31122814 DOI: 10.1016/j.seizure.2019.05.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 02/12/2019] [Accepted: 05/10/2019] [Indexed: 12/12/2022] Open
Abstract
Children with epilepsy and normal structural MRI pose a particular challenge in localization of epileptic foci for surgical resection. Many of these patients have subtle structural lesions such as mild cortical dysplasia that can be missed by conventional MRI but may become detectable by optimized and advanced MRI acquisitions and post-processing. Specificity of objective analytic techniques such as voxel-based morphometry remains an issue. Combination of MRI with functional imaging approaches can improve the accuracy of detecting epileptogenic brain regions. Analysis of glucose positron emission tomography (PET) combined with high-resolution MRI can optimize detection of hypometabolic cortex associated with subtle cortical malformations and can also enhance presurgical evaluation in children with epileptic spasms. Additional PET tracers may detect subtle epileptogenic lesions and cortex with enhanced specificity in carefully selected subgroups with various etiologies; e.g., increased tryptophan uptake can identify epileptogenic cortical dysplasia in the interictal state. Subtraction ictal SPECT can be also useful to delineate ictal foci in those with non-localizing PET or after failed surgical resection. Presurgical delineation of language and motor cortex and the corresponding white matter tracts is increasingly reliable by functional MRI and DTI techniques; with careful preparation, these can be useful even in young and sedated children. While evidence-based pediatric guidelines are still lacking, the data accumulated in the last decade strongly indicate that multimodal imaging with combined analysis of MRI, PET, and/or ictal SPECT data can optimize the detection of subtle epileptogenic lesions and facilitate seizure-free outcome while minimizing the postsurgical functional deficit in children with normal conventional MRI.
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Affiliation(s)
- Csaba Juhász
- Department of Pediatrics, Wayne State University, PET Center and Translational Imaging Laboratory, Children's Hospital of Michigan, 3901 Beaubien St., Detroit, Michigan, 48201, USA; Departments of Neurology and Neurosurgery, Wayne State University, 4201 St. Antoine St., Detroit, Michigan, 48201, USA.
| | - Flóra John
- Department of Pediatrics, Wayne State University, PET Center and Translational Imaging Laboratory, Children's Hospital of Michigan, 3901 Beaubien St., Detroit, Michigan, 48201, USA; Department of Neurology, University of Pécs, H-7623, Rét u. 2., Pécs, Hungary.
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SHARMA RAHUL, SIRCAR PRADIP, PACHORI RAMBILAS. A NEW TECHNIQUE FOR CLASSIFICATION OF FOCAL AND NONFOCAL EEG SIGNALS USING HIGHER-ORDER SPECTRA. J MECH MED BIOL 2019. [DOI: 10.1142/s0219519419400104] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Epilepsy is a neurological disorder characterized by epileptic seizures inside the human brain. An authentic localization of epileptogenic area will help the clinicians for a successful epilepsy surgery. The epileptogenic area can be characterized by the focal electroencephalogram (EEG) signals. Hence, in this article, a bispectrum-based approach is implemented to characterize the focal EEG signals. The highest twenty-five magnitudes of bispectrum from the principal domain are used as features. The locality sensitive discriminant analysis (LSDA), data reduction technique, is implemented to reduce the number of attributes. The ranked LSDA attributes are input to the support vector machine (SVM) classifier yielding 96.2% classification accuracy using the entire Bern Barcelona EEG database. Hence, the proposed technique can be employed to confirm the epileptogenic area for successful epilepsy surgery and can be employed in the community health care centers and hospitals.
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Affiliation(s)
- RAHUL SHARMA
- Department of Electrical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - PRADIP SIRCAR
- Department of Electrical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - RAM BILAS PACHORI
- Discipline of Electrical Engineering, Indian Institute of Technology Indore, Indore 453552, India
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Kumar A, Chugani HT. The Role of Radionuclide Imaging in Epilepsy, Part 1: Sporadic Temporal and Extratemporal Lobe Epilepsy. J Nucl Med Technol 2017; 45:14-21. [PMID: 28258205 DOI: 10.2967/jnumed.112.114397] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 08/06/2013] [Indexed: 11/16/2022] Open
Abstract
Epilepsy is one of the most common yet diverse neurologic disorders, affecting almost 1%-2% of the population. Presently, radionuclide imaging such as PET and SPECT is not used in the primary diagnosis or evaluation of recent-onset epilepsy. However, it can play a unique and important role in certain specific situations, such as in noninvasive presurgical localization of epileptogenic brain regions in intractable-seizure patients being considered for epilepsy surgery. Radionuclide imaging can be particularly useful if MR imaging is either negative for lesions or shows several lesions of which only 1 or 2 are suspected to be epileptogenic and if electroencephalogram changes are equivocal or discordant with the structural imaging. Similarly, PET and SPECT can also be useful for evaluating the functional integrity of the rest of the brain and may provide useful information on the possible pathogenesis of the neurocognitive and behavioral abnormalities frequently observed in these patients.
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Affiliation(s)
- Ajay Kumar
- PET Center, Department of Pediatrics, Neurology, and Radiology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University School of Medicine, Detroit, Michigan
| | - Harry T Chugani
- PET Center, Department of Pediatrics, Neurology, and Radiology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University School of Medicine, Detroit, Michigan
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Tunable-Q Wavelet Transform Based Multivariate Sub-Band Fuzzy Entropy with Application to Focal EEG Signal Analysis. ENTROPY 2017. [DOI: 10.3390/e19030099] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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A novel approach for automated detection of focal EEG signals using empirical wavelet transform. Neural Comput Appl 2016. [DOI: 10.1007/s00521-016-2646-4] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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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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Routine production of [(18)f]flumazenil from iodonium tosylate using a sample pretreatment method: a 2.5-year production report. Mol Imaging Biol 2015; 16:619-25. [PMID: 24788440 DOI: 10.1007/s11307-014-0738-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE [(18)F]Flumazenil, which has the advantage of a longer half-life than [(11)C]flumazenil, is well known for determining of the central benzodiazepine receptor concentrations. However, [(18)F]flumazenil has not been widely used because fluctuating and relatively low yields render automatic production insufficient for routine and multicenter clinical trials. Here, we describe the results of a 2.5-year production study of [(18)F]flumazenil using an iodonium tosylate precursor, which allowed us to overcome the limitations of low and fluctuating radiochemical yields. PROCEDURES We developed a clinically applicable production system by modifying a commercial synthesizer for the reliable and reproducible production of [(18)F]flumazenil for routine clinical studies. [(18)F]Flumazenil was prepared at 150 °C for 5 min in the presence of 4-methylphenyl-mazenil iodonium tosylate (4 mg), a radical scavenger (TEMPO, 1 mg), and [(18)F]KF/kryptofix 2.2.2 complex in N,N-dimethylformamide (1 ml). In the purification step, the final mixture was pretreated using different cartridges before performing high-performance liquid chromatography (HPLC) separation. Finally, we measured the radiochemical yield and performed quality-control assays on 94 batches. RESULTS After carrying out additional purification before HPLC separation using a C18 plus Sep-Pak cartridge, the radiochemical yield of [(18)F]flumazenil increased from 34.4 ± 9.7 % (without the pretreatment, n = 24) to 53.4 ± 9.0 % (n = 94), and the lifetime of the semi-preparative column was five times that of the column without the C18 plus Sep-Pak cartridge. The mean-specific activity of [(18)F]flumazenil was 572 ± 116 GBq/μmol at the end of synthesis, and the radiochemical purity was more than 99 %, as determined by analytical HPLC and radio-TLC. [(18)F]Flumazenil prepared using this method satisfied all quality-control test standards and was highly stable for up to 6 h after preparation. CONCLUSIONS The results of the 2.5-year production study using an iodonium tosylate precursor indicate that [(18)F]flumazenil has commercial and routine clinical applicability.
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Lu FM, Yuan Z. PET/SPECT molecular imaging in clinical neuroscience: recent advances in the investigation of CNS diseases. Quant Imaging Med Surg 2015; 5:433-47. [PMID: 26029646 PMCID: PMC4426104 DOI: 10.3978/j.issn.2223-4292.2015.03.16] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 03/23/2015] [Indexed: 01/10/2023]
Abstract
Molecular imaging is an attractive technology widely used in clinical practice that greatly enhances our understanding of the pathophysiology and treatment in central nervous system (CNS) diseases. It is a novel multidisciplinary technique that can be defined as real-time visualization, in vivo characterization and qualification of biological processes at the molecular and cellular level. It involves the imaging modalities and the corresponding imaging agents. Nowadays, molecular imaging in neuroscience has provided tremendous insights into disturbed human brain function. Among all of the molecular imaging modalities, positron emission tomography (PET) and single photon emission computed tomography (SPECT) have occupied a particular position that visualize and measure the physiological processes using high-affinity and high-specificity molecular radioactive tracers as imaging probes in intact living brain. In this review, we will put emphasis on the PET/SPECT applications in Alzheimer's disease (AD) and Parkinson's disease (PD) as major CNS disorders. We will first give an overview of the main classical molecular neuroimaging modalities. Then, the major clinical applications of PET and SPECT along with molecular probes in the fields of psychiatry and neurology will be discussed.
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Affiliation(s)
- Feng-Mei Lu
- Bioimaging Core, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Zhen Yuan
- Bioimaging Core, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
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Application of Entropy Measures on Intrinsic Mode Functions for the Automated Identification of Focal Electroencephalogram Signals. ENTROPY 2015. [DOI: 10.3390/e17020669] [Citation(s) in RCA: 234] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Rheims S, Jung J, Ryvlin P. Combination of PET and Magnetoencephalography in the Presurgical Assessment of MRI-Negative Epilepsy. Front Neurol 2013; 4:188. [PMID: 24312076 PMCID: PMC3836027 DOI: 10.3389/fneur.2013.00188] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/04/2013] [Indexed: 11/13/2022] Open
Abstract
Despite major advances in neuroimaging, no lesion is visualized on MRI in up to a quarter of patients with drug-resistant focal epilepsy presenting for presurgical evaluation. These patients demonstrate poorer surgical outcomes than those with lesion seen on MRI. Accurate localization of the seizure onset zone (SOZ) is more difficult in MRI-negative patients and often requires invasive EEG recordings. Positron emission tomography (PET) and magnetoencephalography (MEG) have been proposed as clinically relevant tools to localize the SOZ prior to intracranial EEG recordings. However, there is no consensus regarding the optimal gold standard that should be used for assessing the performance of these presurgical investigations. Here, we review the current knowledge concerning the usefulness of PET and MEG for presurgical assessment of MRI-negative epilepsy. Beyond the individual diagnostic performance of MEG and of different PET tracers, including [(18)F]-fluorodeoxyglucose, [(11)C]flumazenil, and markers of 5-HT1A receptors, recent data suggest that the combination of PET and MEG might provide greater sensitivity and specificity than that of each of the two individual tests in patients with normal MRI.
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Affiliation(s)
- Sylvain Rheims
- Department of Functional Neurology and Epileptology, Institute of Epilepsies (IDEE), Hospices Civils de Lyon , Lyon , France ; INSERM U1028/CNRS UMR5292, Lyon Neuroscience Research Center , Lyon , France
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Vivash L, Gregoire MC, Lau EW, Ware RE, Binns D, Roselt P, Bouilleret V, Myers DE, Cook MJ, Hicks RJ, O'Brien TJ. 18F-flumazenil: a γ-aminobutyric acid A-specific PET radiotracer for the localization of drug-resistant temporal lobe epilepsy. J Nucl Med 2013; 54:1270-7. [PMID: 23857513 DOI: 10.2967/jnumed.112.107359] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Studies report that (11)C-flumazenil (FMZ) PET more specifically localizes the epileptogenic zone in patients with medically refractory focal epilepsy than (18)F-FDG PET. However, practical aspects of (11)C use limit clinical application. We report a phase I/IIa study assessing the clinical use of (18)F-FMZ PET for the localization of the epileptogenic zone in patients with drug-resistant temporal lobe epilepsy (TLE). Receptor binding was quantified using kinetic modeling that did not require arterial sampling. METHODS Dynamic (18)F-FMZ PET and static interictal (18)F-FDG PET scans were compared in healthy controls (n = 17 for (18)F-FMZ and n = 20 for (18)F-FDG) and TLE patients with mesial temporal sclerosis on MR imaging (MTS, n = 12) and with normal MR imaging (NL TLE, n = 19). Masked visual assessment of images was undertaken. Parametric images of (18)F-FMZ binding potential (BPND) were generated using the simplified reference tissue model. Region-of-interest analysis on coregistered MR images and statistical parametric mapping were used to quantify (18)F-FMZ BPND and (18)F-FDG uptake in the temporal lobe. RESULTS The visual assessment of static standardized uptake value images showed (18)F-FMZ PET to have high specificity (16/17 [94%]) and moderate sensitivity (21/31 [68%]) for the localization of the epileptogenic zone, with a more restricted abnormality than (18)F-FDG PET. However, the (18)F-FMZ standardized uptake value images were falsely localizing in 3 of 31 patients (10%). Region-of-interest analysis demonstrated reductions in ipsilateral hippocampal (18)F-FMZ BPND in patients with either MTS or NL TLE, compared with controls subjects. Ipsilateral hippocampal (18)F-FMZ BPND was independent of both hippocampal volume and (18)F-FDG uptake, whereas ipsilateral hippocampal volume was correlated with (18)F-FDG uptake (r(2) = 0.69, P < 0.0001). Statistical parametric mapping analysis demonstrated decreased uptake in 14 of 31 (45%) cases with (18)F-FMZ PET and 18 of 29 (62%) with (18)F-FDG PET. Cluster size was significantly smaller on (18)F-FMZ than (18)F-FDG images (37 vs. 160 voxels, P < 0.01). CONCLUSION (18)F-FMZ PET has potential as a clinical tool for the localization of the epileptogenic zone in the presurgical evaluation of drug-resistant TLE, providing information complementary to (18)F-FDG PET, with a more restricted region of abnormality.
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Affiliation(s)
- Lucy Vivash
- Departments of Medicine and Neurology, Melbourne Brain Centre, The Royal Melbourne Hospital, University of Melbourne, Royal Parade, Parkville, Victoria, Australia
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Neuner I, Arrubla J, Felder J, Shah NJ. Simultaneous EEG-fMRI acquisition at low, high and ultra-high magnetic fields up to 9.4 T: perspectives and challenges. Neuroimage 2013; 102 Pt 1:71-9. [PMID: 23796544 DOI: 10.1016/j.neuroimage.2013.06.048] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 01/25/2023] Open
Abstract
In this perspectives article we highlight the advantages of simultaneous acquisition of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). As MRI moves towards using ultra-high magnetic fields in the quest for increased signal-to-noise, the question arises whether combined EEG-fMRI measurements are feasible at magnetic fields of 7 T and higher. We describe the challenges of MRI-EEG at 1.5, 3, 7 and 9.4 T and review the proposed solutions. In an outlook, we discuss further developments such as simultaneous trimodal imaging using MR, positron emission tomography (PET) and EEG under the same physiological conditions in the same subject.
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Affiliation(s)
- Irene Neuner
- Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Germany; Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Germany; JARA - BRAIN - Translational Medicine, Germany.
| | - Jorge Arrubla
- Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Germany
| | - Jörg Felder
- Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Germany
| | - N Jon Shah
- Institute of Neuroscience and Medicine 4, INM 4, Forschungszentrum Jülich, Germany; Department of Neurology, RWTH Aachen University, Germany; JARA - BRAIN - Translational Medicine, Germany
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Juhász C. The impact of positron emission tomography imaging on the clinical management of patients with epilepsy. Expert Rev Neurother 2013; 12:719-32. [PMID: 22650174 DOI: 10.1586/ern.12.48] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Clinical positron emission tomography (PET) imaging of human epilepsy has a 30-year history, but it is still searching for its exact role among rapidly advancing neuroimaging techniques. The vast majority of epilepsy PET studies used this technique to improve detection of epileptic foci for surgical resection. Here, we review the main trends emerging from three decades of PET research in epilepsy, with a particular emphasis on how PET imaging has impacted on the clinical management of patients with intractable epilepsy. While reviewing the latest studies, we also present an argument for a changing role of PET and molecular imaging in the future, with an increasing focus on epileptogenesis and newly discovered molecular mechanisms of epilepsy. These new applications will be facilitated by technological advances, such as the use of integrated PET/MRI systems and utilization of novel radiotracers, which may also enhance phenotype-genotype correlations and assist rational, individualized treatment strategies.
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Affiliation(s)
- Csaba Juhász
- Department of Pediatrics, Wayne State University School of Medicine, PET Center, Children's Hospital of Michigan, Detroit, MI 48201, USA.
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Abstract
Among various neuroimaging techniques used for the evaluation of children with intractable epilepsy, positron emission tomography (PET) employing various PET tracers plays a very important role, especially in localizing areas of focal cortical dysplasia. This is particularly important in infants, where incomplete myelination may limit the structural information provided by MRI. In children with tuberous sclerosis, PET can differentiate between epileptogenic and nonepileptogenic tubers, previously not thought to be possible with neuroimaging. PET may reveal cortical or subcortical abnormalities in various epilepsy syndromes, such as infantile spasms and Landau-Kleffner syndrome. Various other applications of PET have included the investigation of epileptic networks, secondary epileptic foci, dual pathology, and neuroinflammation. Finally, PET can also be used to evaluate various cognitive processes and their underlying neurological substrates and can help in addressing the issue of brain plasticity and reorganization, related to epilepsy.
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Affiliation(s)
- Ajay Kumar
- Departments of Pediatrics and Neurology, School of Medicine, Wayne State University, and PET Center, Children's Hospital of Michigan, Detroit, MI, USA
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Laymon CM, Narendran R, Mason NS, Carney JP, Lopresti BJ, Mathis CA, Mountz JM, Sashin D, Frankle WG. Human biodistribution and dosimetry of the PET radioligand [¹¹C]flumazenil (FMZ). Mol Imaging Biol 2012; 14:115-22. [PMID: 21365327 DOI: 10.1007/s11307-011-0478-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE We measure the whole-body distribution of IV injected [¹¹C]Flumazenil (FMZ) as a function of time in adult subjects and determine the absorbed radiation doses. PROCEDURES After injection with 770 MBq of [¹¹C]FMZ (nominal), each of six subjects underwent nine consecutive whole body PET scans. Twelve source organs were identified using PET attenuation and emission images. Activity within each organ as a function of time was determined from the sequence of the nine PET scans. Source organ time activity curves were integrated and normalized by the injected dose to yield source organ residence times for the no voiding situation. Separate bladder residence-time calculations were performed for the cases of a 1- and a 2-h voiding interval. Using the source organ residence times as input, the program OLINDA/EXM (Stabin et al. in J Nucl Med. 46:1023-1027, 2005) was used to perform dosimetry calculations for the various body organs and for the whole body. RESULTS For the no voiding situation, the average whole-body radiation equivalent dose was 3.02 × 10⁻³ mSv/MBq of injected [¹¹C]FMZ. The average effective dose and effective dose equivalent was 7.57 × 10⁻³ and 1.12 × 10⁻² mSv MBq⁻¹, respectively. The organ receiving the highest equivalent dose was the urinary bladder wall with an average of 6.32 × 10⁻² mSv MBq⁻¹. CONCLUSION On average, the administration of less than 790 MBq (21 mCi) of [¹¹C]FMZ yields (no voiding model) an organ equivalent dose of under 50 mSv [the single dose limit for research studies under US regulations (21CFR361.1) to body organs other than blood forming organs, gonads or the lens of the eye] to all organs. Equivalent dose to the blood forming organs and gonads from a 790 MBq administered FMZ dose is well under the 30 mSv limit provided under 21CFR361.1. Additionally, administration of less than 1320 MBq (35.7 mCi) yields an effective dose [International Commission on Radiation Protection (ICRP) 60 tissue weighting scheme] of under 10 mSv, which is the ICRP IIb (minor to intermediate) risk category limit.
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Affiliation(s)
- Charles M Laymon
- Department of Radiology, UPMC/Presbyterian Hospital, University of Pittsburgh, Room B-938, 200 Lothrop St., Pittsburgh, PA 15213, USA.
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Bartoli A, Vulliemoz S, Haller S, Schaller K, Seeck M. Imaging techniques for presurgical evaluation of temporal lobe epilepsy. ACTA ACUST UNITED AC 2012. [DOI: 10.2217/iim.12.28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Positron emission tomography (PET) has been widely used in the study of seizure disorders. As a research tool, PET has been used to determine the pathophysiology of different seizures disorders, prognostic and diagnostic information, and the response to various interventions. PET imaging has also been used clinically to help with the detection of seizure foci. With the continued development of a large array of radiopharmaceuticals that can evaluate all of the components of different neurotransmitter systems as well as cerebral blood flow and metabolism, PET imaging will continue to play a key role in research and clinical applications for seizure disorders.
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Affiliation(s)
- Abass Alavi
- University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Kumar A, Semah F, Chugani HT, Theodore WH. Epilepsy diagnosis: positron emission tomography. HANDBOOK OF CLINICAL NEUROLOGY 2012; 107:409-24. [PMID: 22938986 DOI: 10.1016/b978-0-444-52898-8.00026-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Ajay Kumar
- Department of Pediatrics & Neurology, Children's Hospital of Michigan, Detroit, MI, USA
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Smith AP, Sani S, Kanner AM, Stoub T, Morrin M, Palac S, Bergen DC, Balabonov A, Smith M, Whisler WW, Byrne RW. Medically intractable temporal lobe epilepsy in patients with normal MRI: Surgical outcome in twenty-one consecutive patients. Seizure 2011; 20:475-9. [DOI: 10.1016/j.seizure.2011.02.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 12/29/2010] [Accepted: 02/25/2011] [Indexed: 10/18/2022] Open
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Abstract
Positron emission tomography (PET) imaging has been widely used in the evaluation and management of patients with seizure disorders. The ability of PET to measure cerebral function makes it ideal for studying the neurophysiologic correlates of seizure activity during ictal and interictal states. PET imaging is also useful for evaluating patients before surgical interventions to determine the best surgical method and maximize outcomes. Thus, PET will continue to play a major role not only in the clinical arena but in further investigations of the pathogenesis and management of various seizure disorders. This article reviews the literature regarding the current uses and indications for PET in the study and management of patients with seizure disorders.
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Affiliation(s)
- Abass Alavi
- Division of Nuclear Medicine, Department of Radiology, Hospital of the University of Pennsylvania, 110 Donner Building, 3400 Spruce Street, Philadelphia, PA 19104, USA.
| | - Andrew B Newberg
- Division of Nuclear Medicine, Department of Radiology, Hospital of the University of Pennsylvania, 110 Donner Building, 3400 Spruce Street, Philadelphia, PA 19104, USA
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Abstract
Positron emission tomography (PET) is a relatively noninvasive imaging test that is able to detect abnormalities in different organs based on derangements in the chemical functions and/or receptor expression at the cellular level. PET imaging of the brain has been shown to be a powerful diagnostic tool for detecting neurochemical abnormalities associated with various neurologic disorders as well as to study normal brain development. Although its use in detecting neurological abnormalities has been well described in adults and pediatrics, its application in the newborn nursery has not been explored adequately. Early detection of brain injury secondary to intrauterine and perinatal insults using PET imaging can provide new insight in prognosis and in instituting early therapy. In this review, the authors describe applications of PET imaging in the newborn nursery specifically related to the detection of metabolic changes seen in hypoxic ischemic encephalopathy, neonatal seizures, and neuroinflammation in the neonatal period.
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Affiliation(s)
- Sujatha Kannan
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan
| | - Harry T. Chugani
- Department of Pediatrics, Wayne State University School of Medicine, Detroit, Michigan,Department of Neurology, Wayne State University School of Medicine, Detroit, Michigan,The PET Center Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, Michigan
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Massaweh G, Schirrmacher E, la Fougere C, Kovacevic M, Wängler C, Jolly D, Gravel P, Reader AJ, Thiel A, Schirrmacher R. Improved work-up procedure for the production of [(18)F]flumazenil and first results of its use with a high-resolution research tomograph in human stroke. Nucl Med Biol 2009; 36:721-7. [PMID: 19720284 DOI: 10.1016/j.nucmedbio.2009.05.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 05/19/2009] [Accepted: 05/27/2009] [Indexed: 10/20/2022]
Abstract
INTRODUCTION The central benzodiazepine receptor (cBZR)-gamma-aminobutyric acid (GABA(A)) receptor complex in the human brain plays an important role in many neurological and psychiatric disorders. (18)F-Labeled flumazenil ([(18)F]FZ) provides a potentially useful tracer to investigate those disorders by means of positron emission tomography (PET). METHODS [(18)F]Flumazenil was synthesized from its nitro-precursor Ro 15-2344 in DMF at high temperatures between 150 degrees C and 160 degrees C. Other solvents like acetonitrile and dimethylsulfoxide were also investigated as reaction media. A new HPLC method for the final purification of [(18)F]FZ was developed to circumvent some difficulties associated with a previously published procedure sometimes led to a contamination of [(18)F]FZ with Ro 15-2344. The final purification of the radiotracer was achieved using a Waters Symmetry Prep C18 HPLC column with elution with 0.05 M sodium acetate (NaOAc) buffer (pH 5)/THF/MeOH (80:10:10). RESULTS [(18)F]FZ could be synthesized in reproducible radiochemical yields (RCYs) of 15-20% (decay corrected to EOB) after 80 min overall synthesis time. The synthesized [(18)F]FZ was applied for the first time in a human PET study in a patient with ischemic right middle cerebral artery stroke using the HRRT high-resolution research scanner (Siemens Medical Solution, Knoxville, TN, USA). CONCLUSIONS [(18)F]FZ is a potentially useful GABA receptor-binding PET ligand. A modified procedure for its preparation in reproducibly high radiochemical yields has been described and the [(18)F]FZ thus produced has been used successfully in a pilot clinical study.
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Affiliation(s)
- Gassan Massaweh
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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la Fougère C, Rominger A, Förster S, Geisler J, Bartenstein P. PET and SPECT in epilepsy: a critical review. Epilepsy Behav 2009; 15:50-5. [PMID: 19236949 DOI: 10.1016/j.yebeh.2009.02.025] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Accepted: 02/19/2009] [Indexed: 11/18/2022]
Abstract
Molecular imaging with ictal and interictal single-photon emission computed tomography (SPECT) as well as positron emission tomography (PET) rank among the established functional imaging tests for the presurgical evaluation of epileptic onset zone in patients with intractable partial epilepsy. In temporal lobe epilepsy the sensitivity of these methods was shown to be excellent, in particular if a multimodal platform is used, which combines the functional imaging with the additional morphological information of magnetic resonance imaging (MRI), but was lower in extra temporal lobe epilepsy. Functional imaging with SPECT and PET reflects seizure related changes of cerebral perfusion, glucose-metabolism and neuroreceptor status. In this review the usefulness of SPECT and PET imaging in clinical routine in epilepsy as well as the role of different neuroreceptor PET-tracer, which were used in epilepsy are discussed. The use of perfusion SPECT tracer allows the investigation of ictal activations, but the low temporal resolution of ictal perfusion SPECT often results in the detection of both the ictal onset zone as well as the propagation pathways, an area that has not always need to be resected in order to render a patient seizure free. The additional use of interictal PET with fluorine-18 fluorodeoxyglucose which measures regional cerebral metabolism or interictal perfusion SPECT enhance the informational value of ictal SPECT and were shown to be important tools to better define the ictal onset and surround inhibition zones. In recent years PET imaging of different cerebral neuroreceptor-systems inter alia GABA(A) receptors, serotonin receptors (5-HT(1A)), opioid receptors as well as dopamine receptors was used to investigate the neurochemical basis of epilepsy, the role of these neurotransmitters for the epileptogenesis as well as the spread of epileptic activity during seizures and partially entered in clinical routine. Currently some of these radioligands are also used to investigate new treatment approaches.
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Affiliation(s)
- C la Fougère
- Department of Nuclear Medicine, Ludwig Maximilian University of Munich, Marchioninistrasse 15, D-81377 Munich, Germany.
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Imaging malformations of cortical development. HANDBOOK OF CLINICAL NEUROLOGY 2008. [PMID: 18809040 DOI: 10.1016/s0072-9752(07)87026-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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Juhász C, Asano E, Shah A, Chugani DC, Batista CEA, Muzik O, Sood S, Chugani HT. Focal decreases of cortical GABAA receptor binding remote from the primary seizure focus: what do they indicate? Epilepsia 2008; 50:240-50. [PMID: 18637829 DOI: 10.1111/j.1528-1167.2008.01721.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To determine the electroclinical significance and histopathological correlates of cortical gamma-aminobutyric acid(A)(GABA(A)) receptor abnormalities detected in and remote from human neocortical epileptic foci. METHODS Cortical areas with decreased(11)C-flumazenil (FMZ) binding were objectively identified on positron emission tomography (PET) images and correlated to intracranial electroencephalography (EEG) findings, clinical seizure variables, histology findings, and surgical outcome in 20 patients (mean age, 9.9 years) with intractable partial epilepsy of neocortical origin and nonlocalizing magnetic resonance imaging (MRI). RESULTS Focal decrease of cortical FMZ binding was detected in the lobe of seizure onset in 17 (85%) patients. Eleven patients (55%) had 17 remote cortical areas with decreased FMZ binding outside the lobe of seizure onset. Thirteen of those 16 (81%) of the 17 remote cortical regions that were covered by subdural EEG were around cortex showing rapid seizure spread on intracranial EEG. Remote FMZ PET abnormalities were associated with high seizure frequency and, when resected, showed gliosis in all six cases where material was available. Higher number of unresected cortical regions with decreased FMZ binding was associated with poorer surgical outcome. CONCLUSIONS Focal decreases of cortical GABA(A) receptor binding on PET may include cortical regions remote from the primary focus, particularly in patients with high seizure frequency, and these regions are commonly involved in rapid seizure propagation. Although these regions may not always need to be resected to achieve seizure freedom, a careful evaluation of cortex with decreased GABA(A) receptor binding prior to resection using intracranial EEG may facilitate optimal surgical outcome in patients with intractable neocortical epilepsy.
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Affiliation(s)
- Csaba Juhász
- Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan and Harper University Hospital, Detroit Medical Center, Wayne State University School of Medcine, Detroit, Michigan, USA.
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Trottier S, Landré E, Biraben A, Chassoux F, Pasnicu A, Scarabin JM, Turak B, Devaux B. [On the best strategies on the best results for surgery of frontal epilepsy]. Neurochirurgie 2008; 54:388-98. [PMID: 18462763 DOI: 10.1016/j.neuchi.2008.02.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 02/25/2008] [Indexed: 12/26/2022]
Abstract
Frontal lobe epilepsy surgery is the second most common surgery performed for drug-resistant partial epilepsy. We investigated the longitudinal outcome in a cohort of patients investigated since 1990 with SEEG and modern diagnostic techniques. We reviewed 105 patients who underwent surgery between 1990 and 2005 (mean follow-up, six years; range: one to 17 years) and analyzed the year-per-year follow-up according to Engel's classification. Favorable outcome (Class I) was observed for 70% and this result was stable at least five years after surgery. More than 90% of patients with lesion-related epilepsies (focal cortical dysplasia and dysembryoplastic neuroepithelial tumors) became seizure-free. Less than 50% of patients classified as having cryptogenic epilepsy (defined as normal imaging and neuropathology on surgical specimen) had a favorable outcome. Permanent neurological sequelae were subtle and rare, especially after surgery for dysplasia in eloquent cortex (primary motor cortex). Our data indicate that frontal surgery is a successful treatment in patients when electrophysiological and morphological investigations demonstrate a well-defined epileptogenic zone or lesion to be surgically resected. Progress in electrophysiological and brain-imaging techniques will further improve the selection of frontal lobe epilepsy surgery candidates.
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Affiliation(s)
- S Trottier
- Service de neurochirurgie, hôpital Sainte-Anne, 1, rue Cabanis, 75014 Paris, France. suzanne.trottier.fr
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L’imagerie de médecine nucléaire : nouveaux traceurs et techniques d’avenir. Neurochirurgie 2008; 54:231-5. [DOI: 10.1016/j.neuchi.2008.02.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 02/23/2008] [Indexed: 11/20/2022]
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Hammers A, Panagoda P, Heckemann RA, Kelsch W, Turkheimer FE, Brooks DJ, Duncan JS, Koepp MJ. [11C]Flumazenil PET in temporal lobe epilepsy: do we need an arterial input function or kinetic modeling? J Cereb Blood Flow Metab 2008; 28:207-16. [PMID: 17579659 DOI: 10.1038/sj.jcbfm.9600515] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Reduced signal on [(11)C]]flumazenil (FMZ) positron emission tomography (PET) is associated with epileptogenic foci. Linear correlations within individuals between parametric and nonparametric images of FMZ binding have been shown, and various methods have been used, without comparison of diagnostic usefulness. Using hippocampal sclerosis (HS) as a test case, we formally compare the diagnostic yield of parametric images obtained either with a parent tracer arterial plasma input function and spectral analysis (yielding volume-of-distribution (VD) images), or with an image-based input function and the simplified reference tissue model (binding potential images, BP-SRTM) with the diagnostic yield of semiquantitative-integrated (ADD) images from 10 to 20 or 20 to 40 mins (ADD1020 and ADD2040). Dynamic 90-min [(11)C]FMZ PET datasets and arterial plasma input functions were available for 15 patients with medically refractory medial temporal lobe epilepsy (TLE) and histologically verified unilateral HS and for 13 control subjects. SPM2 was used for analysis. ADD1020 and ADD2040 images showed decreased FMZ uptake ipsilateral to the epileptogenic hippocampus in 13/15 cases; 6/13 had bilateral decreases in the ADD1020 analysis and 5/13 in the ADD2040 analysis. BP-SRTM images detected ipsilateral decreases in 12/15 cases, with bilateral decreases in three. In contrast, VD images showed ipsilateral hippocampal decreases in all 15 patients, with bilateral decreases in three patients. Bilateral decreases in the ADD images tended to be more symmetrical and in one case were more marked contralaterally. Full quantification with an image-independent input should ideally be used in the evaluation of FMZ PET; at least in TLE, intrasubject correlations do not predict equivalent clinical usefulness.
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Affiliation(s)
- Alexander Hammers
- MRC Clinical Sciences Centre and Division of Neuroscience, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK.
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Patil S, Biassoni L, Borgwardt L. Nuclear Medicine in Pediatric Neurology and Neurosurgery: Epilepsy and Brain Tumors. Semin Nucl Med 2007; 37:357-81. [PMID: 17707242 DOI: 10.1053/j.semnuclmed.2007.04.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In pediatric drug-resistant epilepsy, nuclear medicine can provide important additional information in the presurgical localization of the epileptogenic focus. The main modalities used are interictal (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) and ictal regional cerebral perfusion study with single-photon emission computed tomography (SPECT). Nuclear medicine techniques have a sensitivity of approximately 85% to 90% in the localization of an epileptogenic focus in temporal lobe epilepsy; however, in this clinical setting, they are not always clinically indicated because other techniques (eg, icterictal and ictal electroencephalogram, video telemetry, magnetic resonance imaging [MRI]) may be successful in the identification of the epileptogenic focus. Nuclear medicine is very useful when MRI is negative and/or when electroencephalogram and MRI are discordant. A good technique to identify the epileptogenic focus is especially needed in the setting of extra-temporal lobe epilepsy; however, in this context, identification of the epileptogenic focus is more difficult for all techniques and the sensitivity of the isotope techniques is only 50% to 60%. This review article discusses the clinical value of the different techniques in the clinical context; it also gives practical suggestions on how to acquire good ictal SPECT and interictal FDG-PET scans. Nuclear medicine in pediatric brain tumors can help in differentiating tumor recurrence from post-treatment sequelae, in assessing the response to treatment, in directing biopsy, and in planning therapy. Both PET and SPECT tracers can be used. In this review, we discuss the use of the different tracers available in this still very new, but promising, application of radioisotope techniques.
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Affiliation(s)
- Shekhar Patil
- University College London-Institute of Child Health, Great Ormond Street Hospital for Children NHS Trust and the National Centre for Young People with Epilepsy, London, United Kingdom
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Abstract
Studies using positron emission tomography (PET) have advanced our pathophysiological and biochemical understanding of focal and generalized epilepsies. H(2) (15)O PET allows quantification of cerebral blood flow and (18)F-fluorodeoxyglucose-PET quantification of cerebral glucose metabolism. Neurotransmitters are directly responsible for modulating synaptic activity and newer PET tracers can provide information about synaptic activity and specific ligand-receptor relationships, which are important for epileptogenesis and the spread of epileptic activity.
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Affiliation(s)
- Matthias J Koepp
- National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
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Sood S, Chugani HT. Functional neuroimaging in the preoperative evaluation of children with drug-resistant epilepsy. Childs Nerv Syst 2006; 22:810-20. [PMID: 16799821 DOI: 10.1007/s00381-006-0137-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2006] [Indexed: 10/24/2022]
Abstract
UNLABELLED FUNCTIONAL NEUROIMAGING: Although the primary imaging modality in the management of epilepsy is magnetic resonance imaging MRI, functional neuroimaging with positron-emission tomography (PET) and single photon emission computed tomography (SPECT) often provides complementary information and, in a number of situations, provides unique information that cannot be obtained with MRI. The most commonly used PET tracers used for epilepsy evaluation are 2-deoxy-2-[(18)F]fluoro-D: -glucose (FDG) and [(11)C]flumazenil (FMZ). Recently, interictal PET with alpha-[(11)C]methyl-L: -tryptophan was found to be highly specific for the epileptic focus and can differentiate between epileptogenic and nonepileptogenic lesions in the same patient (e.g., in patients with tuberous sclerosis). DISCUSSION In this review, we discuss clinical applications of these three PET tracers in drug-resistant temporal and extratemporal lobe epilepsy, selected epilepsy syndromes of childhood, lesional and nonlesional epilepsy, and the challenges of imaging secondary epileptic foci. A brief discussion of SPECT applications in epilepsy is also included. With further development of new tracers highly sensitive and specific for epileptogenic brain regions, the presurgical evaluation of refractory epilepsy will be greatly facilitated. Approximately 0.5 to 1.0% of the population suffer from epilepsy, of which 15-20% are intractable. Infants and children, whose seizures have a focal onset are refractory to anticonvulsants and are prolonged, tend to have the worst cognitive outcome [Meador KJ, Neurology 58 (Suppl 5):S21-S26, 2002]. Seizures themselves affect the developing brain and contribute to an adverse neurologic outcome (Holmes, Pediatric Neurology 33:1-110, 2005). CONCLUSION Therefore, in treating children with intractable epilepsy, it is important to consider seizure control and to give allowance for normal cognitive development.
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Affiliation(s)
- Sandeep Sood
- Department of Neurosurgery, Children's Hospital of Michigan, Wayne State University, Detroit, MI, USA
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Abstract
Over the past decade there have been many advances in data acquisition and analysis for structural and functional neuroimaging of people with epilepsy. New imaging sequences and analysis techniques have increased the resolution of images such that underlying structural pathology can be seen in many patients with "cryptogenic" epilepsy. When an epileptogenic lesion is present, antiepileptic drugs alone rarely prevent seizures. However, the success of surgical treatment is improved when a structural lesion has been identified. Lesions might not overlap with the area of the cortex generating seizures and may continue into areas sustaining normal functions. To prevent postsurgical morbidity, the spatial relation between functionally important areas and the epileptogenic lesion must be assessed before surgery. In this review we describe the potential of different neuroimaging techniques to show lesions, assess neuronal function, and assist with the prognosis of postsurgical outcome in patients with refractory focal epilepsy.
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Abstract
PET imaging has been widely used in the evaluation and management of patients with seizure disorders. The ability of PET to measure cerebral function is ideal for studying the neurophysiologic correlates of seizure activity during both ictal and interictal states. PET imaging is also valuable for evaluating patients before surgical interventions to determine the best surgical method and maximize outcomes. PET will continue to play a major role, not only in the clinical arena, but also in investigating the pathogenesis and treatment of various seizure disorders.
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Affiliation(s)
- Andrew B Newberg
- Division of Nuclear Medicine, Hospital of the University of Pennsylvania, 3400 Spruce Street, 110 Donner Building, Philadelphia, PA 19104, USA.
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Morimoto K, Watanabe T, Ninomiya T, Hirao T, Tanaka A, Onishi T, Tamagami H. Quantitative evaluation of central-type benzodiazepine receptors with [125I]Iomazenil in experimental epileptogenesis: II. The rat cortical dysplasia model. Epilepsy Res 2004; 61:113-8. [PMID: 15451013 DOI: 10.1016/j.eplepsyres.2004.07.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2004] [Revised: 06/02/2004] [Accepted: 07/07/2004] [Indexed: 11/15/2022]
Abstract
[(123)I]Iomazenil (IMZ) is a specific ligand for central-type benzodiazepine receptors (BZRs) and is available for single photon emission computed tomography (SPECT) to detect epileptogenic foci. We have recently demonstrated time-dependent alterations of [(125)I]IMZ binding in the rat kainate model of temporal lobe epilepsy. Quantitative evaluation of central-type benzodiazepine receptors with [(125)I]Iomazenil in experimental epileptogenesis. I. The rat kainate model of temporal lobe epilepsy. In the present study, we investigated regional changes in central-type BZRs in the cortical dysplasia (CD) model of epilepsy in rats. Pregnant rats were irradiated at day 17 of gestation with 1.2 Gy to produce CD in their pups, and in vitro autoradiography with [(125)I]IMZ was performed at 8 weeks after birth. Intact rats at the same age were used as controls. [(125)I]IMZ binding was significantly decreased in various cortical regions of the in utero irradiated rats, including the bilateral frontal cortex (down to 92-93% of control), cingulate cortex (91-92%), hippocampal areas CA1 (95%), CA2 (94-95%) and CA4 (95-96%), and caudate/putamen (90-94%). In addition, amygdala-kindling was significantly facilitated in the CD model, especially during the late phase of kindling, suggesting seizure susceptibility of this model. These results may replicate the clinical usefulness of central-type BZRs neuroimaging for detection of human epileptogenic CD and indicate dysfunction of GABA-A/BZR-mediated inhibition responsible for the seizure susceptibility.
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Affiliation(s)
- Kiyoshi Morimoto
- Department of Neuropsychiatry, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan.
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Hammers A. Flumazenil positron emission tomography and other ligands for functional imaging. Neuroimaging Clin N Am 2004; 14:537-51. [PMID: 15324863 DOI: 10.1016/j.nic.2004.04.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Most PET receptor studies in idiopathic generalized epilepsy conducted to date include only small numbers of patients and should be interpreted with caution. Differences between earlier and later studies can largely be explained by different inclusion criteria and improving methodology. The finding of some increase of GABAA receptor binding in IGE has a potential pathologic basis in microdysgenesis. Future studies aiming to elucidate the pathophysiology of IGEs may benefit from the use of subtype-specific opioid ligands, available now, and GABAB ligands, if and when they become available.
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Affiliation(s)
- Alexander Hammers
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, 33 Queen Square, London WC1N 3BG, UK.
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Kotagal P, Arunkumar G, hammel J, Mascha E. Complex partial seizures of frontal lobe onset statistical analysis of ictal semiology. Seizure 2003; 12:268-81. [PMID: 12810339 DOI: 10.1016/s1059-1311(02)00276-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE To identify the ictal semiology of complex partial seizures originating from the frontal lobe (FLCPS) and mesial temporal lobe (MTLE) in patients who became seizure free after surgery. METHODS We analysed 149 seizures from 42 patients, 28 with MTLE (75 seizures) and 14 with FLCPS (74 seizures) seizure free for at least 1 year after surgery. Fifty-eight symptoms and signs were looked for in every seizure and their time of onset and ending noted. Statistical analysis was then used to define the frequency, time of onset and cluster analysis of these symptoms/signs. RESULTS Epigastric aura was more frequent in MTLE while an aura of a general body sensation or indescribable feeling occurred only in FLCPS. Alimentary automatisms were more common and occurred earlier in MTLE (P<0.001). Perseverative automatisms, retching and vomiting occurred exclusively in MTLE while bicycling movements occurred only in FLCPS. Abdominal, psychic or olfactory aura followed by behavioural arrest, alimentary automatisms, repetitive distal upper extremity movements, complete loss of consciousness, looking around and whole body movements were typical of MTLE. Repetitive coarse upper extremity movements, complete loss of consciousness, complex motor and hypermotor activity were typical of FLCPS. CONCLUSION The earliest symptoms and signs as well as their order of appearance allow one to distinguish between complex partial seizures arising from the frontal lobe and mesial temporal lobe.
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MESH Headings
- Adolescent
- Adult
- Child
- Child, Preschool
- Data Interpretation, Statistical
- Diagnosis, Differential
- Electroencephalography/statistics & numerical data
- Epilepsy, Complex Partial/diagnosis
- Epilepsy, Complex Partial/physiopathology
- Epilepsy, Complex Partial/surgery
- Epilepsy, Frontal Lobe/diagnosis
- Epilepsy, Frontal Lobe/physiopathology
- Epilepsy, Frontal Lobe/surgery
- Epilepsy, Temporal Lobe/diagnosis
- Epilepsy, Temporal Lobe/physiopathology
- Epilepsy, Temporal Lobe/surgery
- Follow-Up Studies
- Frontal Lobe/physiopathology
- Frontal Lobe/surgery
- Humans
- Infant
- Mathematical Computing
- Middle Aged
- Monitoring, Physiologic/statistics & numerical data
- Observer Variation
- Postoperative Complications/diagnosis
- Postoperative Complications/physiopathology
- Reproducibility of Results
- Retrospective Studies
- Video Recording/statistics & numerical data
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Affiliation(s)
- P Kotagal
- Department of Neurology, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
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Hammers A, Koepp MJ, Richardson MP, Hurlemann R, Brooks DJ, Duncan JS. Grey and white matter flumazenil binding in neocortical epilepsy with normal MRI. A PET study of 44 patients. Brain 2003; 126:1300-18. [PMID: 12764053 DOI: 10.1093/brain/awg138] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In 20-30% of potential surgical candidates with refractory focal epilepsy, standard MRI does not identify the cause. gamma-Aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the brain. [(11)C]Flumazenil (FMZ) PET images most subtypes of GABA(A) receptors, present on most neurons. We investigated [(11)C]FMZ binding in grey and white matter in 16 normal controls and in 44 patients with refractory neocortical focal epilepsy and normal optimal MRI. Fourteen patients had unilateral frontal lobe epilepsy, five occipital lobe epilepsy (OLE), six parietal lobe epilepsy (PLE) and 19 neocortical epilepsy that was not clearly lobar. Parametric images of FMZ volume of distribution (FMZ-V(d)) were computed. Statistical parametric mapping (SPM99) with explicit masking, including the white matter, was used to analyse individual patients and groups. Thirty-three of the 44 patients showed focal abnormal FMZ-V(d); increases in 16, decreases in eight, and both increases and decreases in nine. In seven patients, the increases in FMZ binding were periventricular, in locations normally seen in periventricular nodular heterotopia on MRI. There were frontal and parietal increases in FMZ binding in grey and white matter in the PLE group and decreases in the cingulate gyrus in the OLE group. FMZ binding increases, particularly periventricular increases, were a prominent feature of MRI-negative focal epilepsies and may represent neuronal migration disturbances.
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Affiliation(s)
- Alexander Hammers
- MRC Clinical Sciences Centre and Division of Neuroscience, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK
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Buck A, Kamel E. [Clinical impact of 18F-fluorodeoxyglucose positron emission tomography in the diagnosis of brain diseases]. ACTA MEDICA AUSTRIACA 2003; 29:156-61. [PMID: 12506766 DOI: 10.1046/j.1563-2571.2002.02041.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In this review it will be discussed in which neurological disorders positron emission tomography can yield important diagnostic information. Because positron emission tomography is an expensive method indications have to be clearly defined. One important question concerns the differentiation of tumor recurrence and scar due to radiation therapy or an operation. The grading of brain tumors is another application. In HIV patients fluorodeoxyglucose positron emission tomography can separate lymphoma and toxoplasmosis. In the evaluation of dementia positron emission tomography can help to clarify the differential diagnosis. Another important area is the presurgical evaluation of epilepsy patients and patients with cerebrovascular disease in whom a surgical revascularisation procedure is planned. In extrapyramidal disorders, positron emission tomography can often help to establish the final diagnosis.
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Affiliation(s)
- A Buck
- PET-Zentrum, Nuklearmedizin des Universitätsspitals Zürich, Rämistrasse 100, CH-8091 Zürich, Schweiz.
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Goethals I, Van de Wiele C, Boon P, Dierckx R. Is central benzodiazepine receptor imaging useful for the identification of epileptogenic foci in localization-related epilepsies? Eur J Nucl Med Mol Imaging 2003; 30:325-8. [PMID: 12552355 DOI: 10.1007/s00259-002-1083-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In the presurgical evaluation of patients with partial epilepsies, the most extensively studied functional neuro-imaging modality to define the origin of seizure onset is fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET). Generally, this technique reveals a widespread zone of interictal glucose hypometabolism in the region of the epileptogenic focus. However, the technique may miss the epileptogenic region and FDG PET abnormalities may extend beyond the seizure onset zone. Consequently, for the precise identification of epileptogenic regions more specific imaging probes than FDG are warranted. This review considers the clinical utility of iomazenil (IMZ) SPET and flumazenil (FMZ) PET for the precise localization of epileptogenic foci in partial epilepsy syndromes.
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Affiliation(s)
- Ingeborg Goethals
- Division of Nuclear Medicine, Polikliniek 7, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
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Juhász C, Chugani HT, Muzik O, Chugani DC. Hypotheses from functional neuroimaging studies. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2002; 49:37-55. [PMID: 12040903 DOI: 10.1016/s0074-7742(02)49005-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Functional neuroimaging, especially positron emission tomography (PET) using various tracers, provided new insights into the pathophysiology of West syndrome in the past decade. Glucose PET studies revealed a unique corticosubcortical circuitry assumed to be involved in the age-dependent generalization of seizure activity leading to symmetric spasms. The findings strongly suggested that cortical abnormalities, mostly consistent with dysplastic lesions or diffuse cortical dysfunction due to an underlying systemic disorder, trigger brain stem nuclei and activate basal ganglia bilaterally. PET is also able to investigate developmental abnormalities of serotonergic and GABAergic neurotransmitter systems in vivo. Involvement of these systems in the pathophysiology of infantile spasms is strongly supported by animal data and can be further elucidated by future PET studies. In addition, the development of new PET tracers (such as neurotracers for imaging NMDA receptors) could help further clarify the role of altered neurotransmission in generation of spasms. This review of the most important functional neuroimaging findings illustrates how human PET and single photon emission computed tomography data help answer basic questions regarding the pathomechanisms involved in this often devastating condition and how these findings might facilitate development of a useful animal model of West syndrome.
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Affiliation(s)
- Csaba Juhász
- Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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Trampal C, Engler H. [PET in neurology and psychiatry. II]. REVISTA ESPANOLA DE MEDICINA NUCLEAR 2002; 21:439-55; quiz 456-60. [PMID: 12425894 DOI: 10.1016/s0212-6982(02)72123-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- C Trampal
- Uppsala University PET Centre. Uppsala. Sweden.
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