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Aslam S, Damodaran N, Rajeshkannan R, Sarma M, Gopinath S, Pillai A. Asymmetry index in anatomically symmetrized FDG-PET for improved epileptogenic focus detection in pharmacoresistant epilepsy. J Neurosurg 2023; 138:828-836. [PMID: 35932262 DOI: 10.3171/2022.6.jns22717] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 06/02/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Positron emission tomography (PET) imaging has assumed an essential role in the presurgical evaluation of epileptogenic foci in drug-resistant epilepsy by identifying the hypometabolic cerebral cortex. The authors herein designed a pilot study to test a novel technique of PET asymmetry after anatomical symmetrization coregistered to MRI (PASCOM), utilizing interhemispheric metabolic asymmetry on interictal fluorine 18-labeled fluorodeoxyglucose (FDG)-PET to better localize the epileptogenic zone. METHODS The authors analyzed interictal FDG-PET scans from 23 patients with drug-resistant epilepsy, mean (± SD) age 20.9 ± 13.1 years old, who had an Engel class I postsurgical outcome while followed up for > 12 months. T1-weighted and FLAIR MRI were used to create a patient-specific, structurally symmetrical template. The asymmetry index (AI) image was computed to detect the cerebral region of hypometabolism using different z-score threshold criteria to optimize sensitivity and specificity. The detected regions were compared with the resection cavity on postoperative MRI using predefined anatomical labels. PASCOM was compared with the visual analysis of FDG-PET by a nuclear medicine consultant blinded to other clinical data (VIS) and visual analysis during multidisciplinary team discussion (MDT). The efficacy of each technique was compared based on a performance score (S), sensitivity, specificity, and correct lateralization of epileptogenicity. RESULTS The mean S was maximum (1.30 ± 1.23) for AI images when thresholded at z > 4 and retaining the cluster of more than 100 voxels containing the peak AI value (Z4C) with 73.03% sensitivity and 96.43% specificity. The mean S was minimum for VIS (0.27 ± 0.31). The mean sensitivity was maximum for MDT (85.04%) and minimum for Z5C (AI images thresholded at z > 5 and clustered; 59.47%), whereas the mean specificity was maximum for Z5C (97.77%) and minimum for VIS (64.60%). Z3C (AI images thresholded at z > 3 and clustered) and Z4C were able to correctly identify the side of epileptogenicity in all the patients. CONCLUSIONS The PASCOM technique with a Z4C threshold had a maximum performance score with good sensitivity and specificity in localizing and lateralizing the epileptogenic zone. The described technique outperformed the conventional visual analysis of FDG-PET and hence warrants further prospective verification.
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Affiliation(s)
| | | | | | - Manjit Sarma
- 4Nuclear Medicine, Amrita Advanced Centre for Epilepsy, Amrita Institute of Medical Sciences & Research Center, Kochi, Kerala, India
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Zhao J, Wang C, Sun W, Li C. Tailoring Materials for Epilepsy Imaging: From Biomarkers to Imaging Probes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2203667. [PMID: 35735191 DOI: 10.1002/adma.202203667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 06/11/2022] [Indexed: 06/15/2023]
Abstract
Excising epileptic foci (EF) is the most efficient approach for treating drug-resistant epilepsy (DRE). However, owing to the vast heterogeneity of epilepsies, EF in one-third of patients cannot be accurately located, even after exhausting all current diagnostic strategies. Therefore, identifying biomarkers that truly represent the status of epilepsy and fabricating probes with high targeting specificity are prerequisites for identifying the "concealed" EF. However, no systematic summary of this topic has been published. Herein, the potential biomarkers of EF are first summarized and classified into three categories: functional, molecular, and structural aberrances during epileptogenesis, a procedure of nonepileptic brain biasing toward epileptic tissue. The materials used to fabricate these imaging probes and their performance in defining the EF in preclinical and clinical studies are highlighted. Finally, perspectives for developing the next generation of probes and their challenges in clinical translation are discussed. In general, this review can be helpful in guiding the development of imaging probes defining EF with improved accuracy and holds promise for increasing the number of DRE patients who are eligible for surgical intervention.
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Affiliation(s)
- Jing Zhao
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Zhangheng Road 826, Shanghai, 201203, China
| | - Cong Wang
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Zhangheng Road 826, Shanghai, 201203, China
- Academy for Engineering and Technology, Fudan University, 20 Handan Road, Yangpu District, Shanghai, 200433, China
- Shanghai Center for Brain Science and Brain-Inspired Technology, Shanghai, 200031, China
| | - Wanbing Sun
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital and Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Cong Li
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Zhangheng Road 826, Shanghai, 201203, China
- State Key Laboratory of Medical Neurobiology, School of Pharmacy, Fudan University, Shanghai, 201203, China
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Zhu Y, Ruan G, Cheng Z, Zou S, Zhu X. Lateralization of the crossed cerebellar diaschisis-associated metabolic connectivities in cortico-ponto-cerebellar and cortico-rubral pathways. Neuroimage 2022; 260:119487. [PMID: 35850160 DOI: 10.1016/j.neuroimage.2022.119487] [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: 11/29/2021] [Revised: 06/21/2022] [Accepted: 07/14/2022] [Indexed: 11/16/2022] Open
Abstract
This study aimed to explore the glucose metabolic profile of extrapyramidal system in patients with crossed cerebellar diaschisis (CCD). Furthermore, the metabolic connectivities in cortico-ponto-cerebellar and cortico-rubral pathways associated with CCD were also investigated. A total of 130 CCD positive (CCD+) and 424 CCD negative (CCD-) patients with unilateral cerebral hemisphere hypometabolism on 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) were enrolled. Besides, the control group consisted of 56 subjects without any brain structural and metabolic abnormalities. Apart from the "autocorrelation", metabolic connectivity pattern of right or left affected cerebellar hemisphere involved unilateral (left or right, respectively) caudate, pallidum, putamen, thalamus and red nucleus, in CCD+ patients with left or right supratentorial lesions, respectively (Puncorrected < 0.001, cluster size > 200). CCD+ group had significantly lower asymmetry index (AI) in cortico-ponto-cerebellar pathway (including ipsilateral cerebral white matter, ipsilateral pons, contralateral cerebellum white matter and contralateral cerebellum exterior cortex) and cortico-rubral pathway (including ipsilateral caudate, thalamus proper, pallidum, putamen, ventral diencephalon and red nucleus) than those of both CCD- and control groups (all P < 0.05). AI in contralateral cerebellum exterior cortex was significantly positively correlated with that in ipsilateral caudate, putamen, pallidum, thalamus proper, ventral diencephalon, red nucleus and pons among CCD+ group (all P < 0.01), but only with that in ipsilateral caudate and putamen among CCD- group (both P < 0.001). These results provide additional insight into the involvement of both cortico-ponto-cerebellar and cortico-rubral pathways in the presence of CCD, underlining the need for further investigation about the role of their aberrant metabolic connectivities in the associated symptoms of CCD.
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Affiliation(s)
- Yuankai Zhu
- Department of Nuclear Medicine and PET Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Ave, Wuhan 430030, China
| | - Ge Ruan
- Department of Radiology, Hospital, Hubei University, Wuhan 430062, China
| | - Zhaoting Cheng
- Department of Nuclear Medicine and PET Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Ave, Wuhan 430030, China
| | - Sijuan Zou
- Department of Nuclear Medicine and PET Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Ave, Wuhan 430030, China
| | - Xiaohua Zhu
- Department of Nuclear Medicine and PET Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Ave, Wuhan 430030, China.
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Spatial normalization and quantification approaches of PET imaging for neurological disorders. Eur J Nucl Med Mol Imaging 2022; 49:3809-3829. [PMID: 35624219 DOI: 10.1007/s00259-022-05809-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/19/2022] [Indexed: 12/17/2022]
Abstract
Quantification approaches of positron emission tomography (PET) imaging provide user-independent evaluation of pathophysiological processes in living brains, which have been strongly recommended in clinical diagnosis of neurological disorders. Most PET quantification approaches depend on spatial normalization of PET images to brain template; however, the spatial normalization and quantification approaches have not been comprehensively reviewed. In this review, we introduced and compared PET template-based and magnetic resonance imaging (MRI)-aided spatial normalization approaches. Tracer-specific and age-specific PET brain templates were surveyed between 1999 and 2021 for 18F-FDG, 11C-PIB, 18F-Florbetapir, 18F-THK5317, and etc., as well as adaptive PET template methods. Spatial normalization-based PET quantification approaches were reviewed, including region-of-interest (ROI)-based and voxel-wise quantitative methods. Spatial normalization-based ROI segmentation approaches were introduced, including manual delineation on template, atlas-based segmentation, and multi-atlas approach. Voxel-wise quantification approaches were reviewed, including voxel-wise statistics and principal component analysis. Certain concerns and representative examples of clinical applications were provided for both ROI-based and voxel-wise quantification approaches. At last, a recipe for PET spatial normalization and quantification approaches was concluded to improve diagnosis accuracy of neurological disorders in clinical practice.
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Zhu Y, Ruan G, Zou S, Cheng Z, Zhu X. Voxel-based analysis of the metabolic asymmetrical and network patterns in hypermetabolism-associated crossed cerebellar diaschisis. Neuroimage Clin 2022; 35:103032. [PMID: 35597028 PMCID: PMC9123269 DOI: 10.1016/j.nicl.2022.103032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/06/2022] [Accepted: 05/02/2022] [Indexed: 10/27/2022]
Abstract
Crossed cerebellar diaschisis (CCD) has been widely investigated in patients with supratentorial hypometabolism, however, the available evidence about the metabolic feature of CCD in patients with contralateral supratentorial hypermetabolism is lacking. This study aimed to assess the metabolic asymmetrical profile, network pattern and predisposing factors for the hypermetabolism-associated CCD, by using voxel-based asymmetry index (AI) and brain network analyses. Seventy CCD positive (CCD+) and 99 CCD negative (CCD-) patients with unilateral supratentorial hypermetabolism were introduced. Among different brain regions with AImax or AImin, striatum & thalamus was accompanied by the highest positive rate of CCD (85.7% or 70.1%, respectively). CCD+ group had significantly greater AImax (median [IQR], 0.62 [0.44-0.84] vs. 0.47 [0.35-0.61]), supratentorial hypermetabolic volume (1183.5 [399.3-3026.8] vs. 386.0 [152.0-1193.0]) and hypometabolic volume (37796.5 [24741.8-53278.0] vs. 3337.0 [1020.0-17193.0]), and lower AImin (-0.85 [-1.05--0.73] vs. -0.49 [-0.68--0.35]) compared with CCD- group (all P < 0.001). Logistic regression analysis manifested that patients with AImin located at striatum & thalamus were 16.4 times more likely to present CCD than those at frontal lobe (OR = 16.393; 95% CI, 4.463-60.207; P < 0.001), and the occurrence of CCD was also associated with AImax (OR = 49.594; 95% CI, 5.519-445.653; P < 0.001) and AImin (OR = 3.133 × 10-4, 95% CI, 1.693 × 10-5-5.799 × 10-3, P < 0.001). Brain network analysis indicated that the relative hypermetabolism in the contralateral supplementary motor cortex (SMC) and precuneus gyrus were constant in the CCD related patterns. These results demonstrated that the greater AImax, lower AImin and AImin located at striatum & thalamus should be predisposing factors for CCD in patients with unilateral supratentorial hypermetabolism. Relative increased activities in the contralateral SMC and precuneus gyrus might be attributed to a compensatory mechanism for the abnormal brain network related to CCD.
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Affiliation(s)
- Yuankai Zhu
- Department of Nuclear Medicine and PET Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Ge Ruan
- Department of Radiology, Hospital, Hubei University, Wuhan 430062, China
| | - Sijuan Zou
- Department of Nuclear Medicine and PET Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Zhaoting Cheng
- Department of Nuclear Medicine and PET Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaohua Zhu
- Department of Nuclear Medicine and PET Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
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Poirier SE, Kwan BYM, Jurkiewicz MT, Samargandy L, Iacobelli M, Steven DA, Lam Shin Cheung V, Moran G, Prato FS, Thompson RT, Burneo JG, Anazodo UC, Thiessen JD. An evaluation of the diagnostic equivalence of 18F-FDG-PET between hybrid PET/MRI and PET/CT in drug-resistant epilepsy: A pilot study. Epilepsy Res 2021; 172:106583. [PMID: 33636504 DOI: 10.1016/j.eplepsyres.2021.106583] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 01/27/2021] [Accepted: 02/09/2021] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Hybrid PET/MRI may improve detection of seizure-onset zone (SOZ) in drug-resistant epilepsy (DRE), however, concerns over PET bias from MRI-based attenuation correction (MRAC) have limited clinical adoption of PET/MRI. This study evaluated the diagnostic equivalency and potential clinical value of PET/MRI against PET/CT in DRE. MATERIALS AND METHODS MRI, FDG-PET and CT images (n = 18) were acquired using a hybrid PET/MRI and a CT scanner. To assess diagnostic equivalency, PET was reconstructed using MRAC (RESOLUTE) and CT-based attenuation correction (CTAC) to generate PET/MRI and PET/CT images, respectively. PET/MRI and PET/CT images were compared qualitatively through visual assessment and quantitatively through regional standardized uptake value (SUV) and z-score assessment. Diagnostic accuracy and sensitivity of PET/MRI and PET/CT for SOZ detection were calculated through comparison to reference standards (clinical hypothesis and histopathology, respectively). RESULTS Inter-reader agreement in visual assessment of PET/MRI and PET/CT images was 78 % and 81 %, respectively. PET/MRI and PET/CT were strongly correlated in mean SUV (r = 0.99, p < 0.001) and z-scores (r = 0.92, p < 0.001) across all brain regions. MRAC SUV bias was <5% in most brain regions except the inferior temporal gyrus, temporal pole, and cerebellum. Diagnostic accuracy and sensitivity were similar between PET/MRI and PET/CT (87 % vs. 85 % and 83 % vs. 83 %, respectively). CONCLUSION We demonstrate here that PET/MRI with optimal MRAC can yield similar diagnostic performance as PET/CT. Nevertheless, further exploration of the potential added value of PET/MRI is necessary before clinical adoption of PET/MRI for epilepsy imaging.
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Affiliation(s)
- Stefan E Poirier
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
| | - Benjamin Y M Kwan
- Department of Diagnostic Radiology, Queen's University, Kingston, ON, Canada
| | - Michael T Jurkiewicz
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Lina Samargandy
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Maryssa Iacobelli
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada
| | - David A Steven
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Victor Lam Shin Cheung
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | | | - Frank S Prato
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - R Terry Thompson
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Jorge G Burneo
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Udunna C Anazodo
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Research Centre for Studies in Aging, McGill University, Montréal, QC, Canada.
| | - Jonathan D Thiessen
- Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
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7
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Zhang Q, Liao Y, Wang X, Zhang T, Feng J, Deng J, Shi K, Chen L, Feng L, Ma M, Xue L, Hou H, Dou X, Yu C, Ren L, Ding Y, Chen Y, Wu S, Chen Z, Zhang H, Zhuo C, Tian M. A deep learning framework for 18F-FDG PET imaging diagnosis in pediatric patients with temporal lobe epilepsy. Eur J Nucl Med Mol Imaging 2021; 48:2476-2485. [PMID: 33420912 PMCID: PMC8241642 DOI: 10.1007/s00259-020-05108-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 11/08/2020] [Indexed: 01/10/2023]
Abstract
PURPOSE Epilepsy is one of the most disabling neurological disorders, which affects all age groups and often results in severe consequences. Since misdiagnoses are common, many pediatric patients fail to receive the correct treatment. Recently, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging has been used for the evaluation of pediatric epilepsy. However, the epileptic focus is very difficult to be identified by visual assessment since it may present either hypo- or hyper-metabolic abnormality with unclear boundary. This study aimed to develop a novel symmetricity-driven deep learning framework of PET imaging for the identification of epileptic foci in pediatric patients with temporal lobe epilepsy (TLE). METHODS We retrospectively included 201 pediatric patients with TLE and 24 age-matched controls who underwent 18F-FDG PET-CT studies. 18F-FDG PET images were quantitatively investigated using 386 symmetricity features, and a pair-of-cube (PoC)-based Siamese convolutional neural network (CNN) was proposed for precise localization of epileptic focus, and then metabolic abnormality level of the predicted focus was calculated automatically by asymmetric index (AI). Performances of the proposed framework were compared with visual assessment, statistical parametric mapping (SPM) software, and Jensen-Shannon divergence-based logistic regression (JS-LR) analysis. RESULTS The proposed deep learning framework could detect the epileptic foci accurately with the dice coefficient of 0.51, which was significantly higher than that of SPM (0.24, P < 0.01) and significantly (or marginally) higher than that of visual assessment (0.31-0.44, P = 0.005-0.27). The area under the curve (AUC) of the PoC classification was higher than that of the JS-LR (0.93 vs. 0.72). The metabolic level detection accuracy of the proposed method was significantly higher than that of visual assessment blinded or unblinded to clinical information (90% vs. 56% or 68%, P < 0.01). CONCLUSION The proposed deep learning framework for 18F-FDG PET imaging could identify epileptic foci accurately and efficiently, which might be applied as a computer-assisted approach for the future diagnosis of epilepsy patients. TRIAL REGISTRATION NCT04169581. Registered November 13, 2019 Public site: https://clinicaltrials.gov/ct2/show/NCT04169581.
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Affiliation(s)
- Qinming Zhang
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yi Liao
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiawan Wang
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, China
| | - Teng Zhang
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianhua Feng
- Department of Pediatrics, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jianing Deng
- College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Kexin Shi
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, China
| | - Lin Chen
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Liu Feng
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, China
| | - Mindi Ma
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, China
| | - Le Xue
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, China
| | - Haifeng Hou
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiaofeng Dou
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Congcong Yu
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Lei Ren
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yao Ding
- Department of Neurology, Epilepsy Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yufei Chen
- College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shuang Wu
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zexin Chen
- Center of Clinical Epidemiology & Biostatistics, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Hong Zhang
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China. .,Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, Zhejiang, China. .,College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Cheng Zhuo
- College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Mei Tian
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
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8
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McGinnity CJ, Riaño Barros DA, Hinz R, Myers JF, Yaakub SN, Thyssen C, Heckemann RA, de Tisi J, Duncan JS, Sander JW, Lingford-Hughes A, Koepp MJ, Hammers A. Αlpha 5 subunit-containing GABA A receptors in temporal lobe epilepsy with normal MRI. Brain Commun 2021; 3:fcaa190. [PMID: 33501420 PMCID: PMC7811756 DOI: 10.1093/braincomms/fcaa190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 09/06/2020] [Accepted: 09/24/2020] [Indexed: 01/08/2023] Open
Abstract
GABAA receptors containing the α5 subunit mediate tonic inhibition and are widely expressed in the limbic system. In animals, activation of α5-containing receptors impairs hippocampus-dependent memory. Temporal lobe epilepsy is associated with memory impairments related to neuron loss and other changes. The less selective PET ligand [11C]flumazenil has revealed reductions in GABAA receptors. The hypothesis that α5 subunit receptor alterations are present in temporal lobe epilepsy and could contribute to impaired memory is untested. We compared α5 subunit availability between individuals with temporal lobe epilepsy and normal structural MRI ('MRI-negative') and healthy controls, and interrogated the relationship between α5 subunit availability and episodic memory performance, in a cross-sectional study. Twenty-three healthy male controls (median ± interquartile age 49 ± 13 years) and 11 individuals with MRI-negative temporal lobe epilepsy (seven males; 40 ± 8) had a 90-min PET scan after bolus injection of [11C]Ro15-4513, with arterial blood sampling and metabolite correction. All those with epilepsy and six controls completed the Adult Memory and Information Processing Battery on the scanning day. 'Bandpass' exponential spectral analyses were used to calculate volumes of distribution separately for the fast component [V F; dominated by signal from α1 (α2, α3)-containing receptors] and the slow component (V S; dominated by signal from α5-containing receptors). We made voxel-by-voxel comparisons between: the epilepsy and control groups; each individual case versus the controls. We obtained parametric maps of V F and V S measures from a single bolus injection of [11C]Ro15-4513. The epilepsy group had higher V S in anterior medial and lateral aspects of the temporal lobes, the anterior cingulate gyri, the presumed area tempestas (piriform cortex) and the insulae, in addition to increases of ∼24% and ∼26% in the ipsilateral and contralateral hippocampal areas (P < 0.004). This was associated with reduced V F:V S ratios within the same areas (P < 0.009). Comparisons of V S for each individual with epilepsy versus controls did not consistently lateralize the epileptogenic lobe. Memory scores were significantly lower in the epilepsy group than in controls (mean ± standard deviation -0.4 ± 1.0 versus 0.7 ± 0.3; P = 0.02). In individuals with epilepsy, hippocampal V S did not correlate with memory performance on the Adult Memory and Information Processing Battery. They had reduced V F in the hippocampal area, which was significant ipsilaterally (P = 0.03), as expected from [11C]flumazenil studies. We found increased tonic inhibitory neurotransmission in our cohort of MRI-negative temporal lobe epilepsy who also had co-morbid memory impairments. Our findings are consistent with a subunit shift from α1/2/3 to α5 in MRI-negative temporal lobe epilepsy.
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Affiliation(s)
- Colm J McGinnity
- Centre for Neuroscience, Department of Medicine, Imperial College London, London W12 0NN, UK
- MRC Clinical Sciences Centre, Hammersmith Hospital, London W12 0NN, UK
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King’s College London, London SE1 7EH, UK
| | - Daniela A Riaño Barros
- Centre for Neuroscience, Department of Medicine, Imperial College London, London W12 0NN, UK
- MRC Clinical Sciences Centre, Hammersmith Hospital, London W12 0NN, UK
| | - Rainer Hinz
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester M20 3LJ, UK
| | - James F Myers
- Centre for Neuroscience, Department of Medicine, Imperial College London, London W12 0NN, UK
| | - Siti N Yaakub
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King’s College London, London SE1 7EH, UK
| | - Charlotte Thyssen
- Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Faculty of Engineering and Architecture, Ghent University, 9000 Ghent, Belgium
| | - Rolf A Heckemann
- Department of Medical Radiation Sciences, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, 413 45 Gothenburg, Sweden
| | - Jane de Tisi
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK, and Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - John S Duncan
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK, and Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Josemir W Sander
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK, and Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede 2103SW, The Netherlands
| | - Anne Lingford-Hughes
- Neuropsychopharmacology Unit, Centre for Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London W12 0NN, UK
| | - Matthias J Koepp
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK, and Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Alexander Hammers
- Centre for Neuroscience, Department of Medicine, Imperial College London, London W12 0NN, UK
- MRC Clinical Sciences Centre, Hammersmith Hospital, London W12 0NN, UK
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering & Imaging Sciences, King’s College London, London SE1 7EH, UK
- Neurodis Foundation, CERMEP, Imagerie du Vivant, 69003 Lyon, France
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9
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Poirier SE, Kwan BYM, Jurkiewicz MT, Samargandy L, Steven DA, Suller-Marti A, Lam Shin Cheung V, Khan AR, Romsa J, Prato FS, Burneo JG, Thiessen JD, Anazodo UC. 18F-FDG PET-guided diffusion tractography reveals white matter abnormalities around the epileptic focus in medically refractory epilepsy: implications for epilepsy surgical evaluation. Eur J Hybrid Imaging 2020; 4:10. [PMID: 34191151 PMCID: PMC8218143 DOI: 10.1186/s41824-020-00079-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/12/2020] [Indexed: 02/28/2023] Open
Abstract
BACKGROUND Hybrid PET/MRI can non-invasively improve localization and delineation of the epileptic focus (EF) prior to surgical resection in medically refractory epilepsy (MRE), especially when MRI is negative or equivocal. In this study, we developed a PET-guided diffusion tractography (PET/DTI) approach combining 18F-fluorodeoxyglucose PET (FDG-PET) and diffusion MRI to investigate white matter (WM) integrity in MRI-negative MRE patients and its potential impact on epilepsy surgical planning. METHODS FDG-PET and diffusion MRI of 14 MRI-negative or equivocal MRE patients were used to retrospectively pilot the PET/DTI approach. We used asymmetry index (AI) mapping of FDG-PET to detect the EF as brain areas showing the largest decrease in FDG uptake between hemispheres. Seed-based WM fiber tracking was performed on DTI images with a seed location in WM 3 mm from the EF. Fiber tractography was repeated in the contralateral brain region (opposite to EF), which served as a control for this study. WM fibers were quantified by calculating the fiber count, mean fractional anisotropy (FA), mean fiber length, and mean cross-section of each fiber bundle. WM integrity was assessed through fiber visualization and by normalizing ipsilateral fiber measurements to contralateral fiber measurements. The added value of PET/DTI in clinical decision-making was evaluated by a senior neurologist. RESULTS In over 60% of the patient cohort, AI mapping findings were concordant with clinical reports on seizure-onset localization and lateralization. Mean FA, fiber count, and mean fiber length were decreased in 14/14 (100%), 13/14 (93%), and 12/14 (86%) patients, respectively. PET/DTI improved diagnostic confidence in 10/14 (71%) patients and indicated that surgical candidacy be reassessed in 3/6 (50%) patients who had not undergone surgery. CONCLUSIONS We demonstrate here the utility of AI mapping in detecting the EF based on brain regions showing decreased FDG-PET activity and, when coupled with DTI, could be a powerful tool for detecting EF and assessing WM integrity in MRI-negative epilepsy. PET/DTI could be used to further enhance clinical decision-making in epilepsy surgery.
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Affiliation(s)
- Stefan E Poirier
- Lawson Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, Ontario, N6A 4 V2, Canada. .,Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
| | - Benjamin Y M Kwan
- Department of Diagnostic Radiology, Queen's University, Kingston, Ontario, Canada
| | - Michael T Jurkiewicz
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Lina Samargandy
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - David A Steven
- Epilepsy Program, Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Ana Suller-Marti
- Epilepsy Program, Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | | | - Ali R Khan
- Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada
| | - Jonathan Romsa
- Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Frank S Prato
- Lawson Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, Ontario, N6A 4 V2, Canada.,Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Jorge G Burneo
- Epilepsy Program, Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Jonathan D Thiessen
- Lawson Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, Ontario, N6A 4 V2, Canada.,Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Udunna C Anazodo
- Lawson Imaging, Lawson Health Research Institute, 268 Grosvenor St., London, Ontario, N6A 4 V2, Canada. .,Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
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10
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Bascuñana P, García-García L, Javela J, Fernández de la Rosa R, Shiha AA, Kelly J, Delgado M, Pozo MÁ. PET Neuroimaging Reveals Serotonergic and Metabolic Dysfunctions in the Hippocampal Electrical Kindling Model of Epileptogenesis. Neuroscience 2019; 409:101-110. [PMID: 31034972 DOI: 10.1016/j.neuroscience.2019.04.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/10/2019] [Accepted: 04/12/2019] [Indexed: 12/29/2022]
Abstract
Glucose metabolism and serotonergic neurotransmission have been reported to play an important role in epileptogenesis. We therefore aimed to use neuroimaging to evaluate potential alterations in serotonin 5-HT1A receptor and glucose metabolism during epileptogenesis in the rat electrical kindling model. To achieve this goal, we performed positron emission tomography (PET) imaging in a rat epileptogenesis model triggered by electrical stimulation of the hippocampus using 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG), a radiolabeled analog of glucose, and 2'-methoxyphenyl-(N-2'-pyridinyl)-p-18F-fluoro-benzamidoethylpiperazine (18F-MPPF), a radiolabeled 5-HT1A receptor ligand, to evaluate brain metabolism and 5-HT1A receptor functionality. Since the 5-HT1A receptor is also highly expressed in astrocytes, glial fibrillary acidic protein (GFAP) immunofluorescence was performed to detect astrogliosis arising from the kindling procedure once the study was finalized. Lastly, in vitro18F-MPPF autoradiography was performed to evaluate changes in 5HT1A receptor expression. 18F-FDG PET showed reduction of glucose uptake in cortical structures, whereas 18F-MPPF PET revealed an enhancement of tracer binding potential (BPND) in key areas rich in 5-HT1A receptor involved in epilepsy, including septum, hippocampus and entorhinal cortex of kindled animals compared to controls. However, in vitro 5-HT1A receptor autoradiography showed no changes in densitometric signal in any brain region, suggesting that the augmentation in BPND found by PET could be caused by reduction of synaptic serotonin. Importantly, astroglial activation was detected in the hippocampus of kindled rats. Overall, electrical kindling induced hypometabolism, astrogliosis and serotonergic alterations in epilepsy-related regions. Furthermore, the present findings point to 5-HT1A receptor as a valuable epileptogenesis biomarker candidate and a potential therapeutic target.
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Affiliation(s)
- Pablo Bascuñana
- Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII, 1, 28040, Madrid, Spain.
| | - Luis García-García
- Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII, 1, 28040, Madrid, Spain; Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain
| | - Julián Javela
- Grupo de Clínica y Salud Mental, Programa de Psicología, Universidad Católica de Pereira, Av Sur/Las Américas, Pereira, Colombia
| | - Rubén Fernández de la Rosa
- Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII, 1, 28040, Madrid, Spain
| | - Ahmed Anis Shiha
- Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII, 1, 28040, Madrid, Spain
| | - James Kelly
- Department of Radiology, Weill Cornell Medicine, New York, NY 10021, USA; Curium Pharma Spain (formerly Instituto Tecnológico PET), C/ Manuel Bartolomé Cossío, 10, 28040, Madrid, Spain
| | - Mercedes Delgado
- Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII, 1, 28040, Madrid, Spain; Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain
| | - Miguel Ángel Pozo
- Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo Juan XXIII, 1, 28040, Madrid, Spain; Curium Pharma Spain (formerly Instituto Tecnológico PET), C/ Manuel Bartolomé Cossío, 10, 28040, Madrid, Spain; Departamento de Fisiología, Facultad de Medicina, Universidad Complutense de Madrid, Plaza Ramón y Cajal s/n, 28040, Madrid, Spain
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11
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Zuanazzi A, Noppeney U. Distinct Neural Mechanisms of Spatial Attention and Expectation Guide Perceptual Inference in a Multisensory World. J Neurosci 2019; 39:2301-2312. [PMID: 30659086 PMCID: PMC6433765 DOI: 10.1523/jneurosci.2873-18.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 01/08/2019] [Accepted: 01/09/2019] [Indexed: 11/21/2022] Open
Abstract
Spatial attention (i.e., task-relevance) and expectation (i.e., signal probability) are two critical top-down mechanisms guiding perceptual inference. Spatial attention prioritizes processing of information at task-relevant locations. Spatial expectations encode the statistical structure of the environment. An unresolved question is how the brain allocates attention and forms expectations in a multisensory environment, where task-relevance and signal probability over space can differ across sensory modalities. We used functional magnetic resonance imaging in human participants (female and male) to investigate whether the brain encodes task-relevance and signal probability over space separately or interactively across sensory modalities. In a novel multisensory paradigm, we manipulated spatial attention and expectation selectively in audition and assessed their effects on behavioral and neural responses to auditory and visual stimuli. Our results show that both auditory and visual stimuli increased activations in a right-lateralized frontoparietal system, when they were presented at locations that were task-irrelevant in audition. Yet, only auditory stimuli increased activations in the medial prefrontal cortex when presented at expected locations and in audiovisual and frontoparietal cortices signaling a prediction error when presented at unexpected locations. This dissociation in multisensory generalization for attention and expectation effects shows that the brain controls attentional resources interactively across the senses but encodes the statistical structure of the environment as spatial expectations independently for each sensory system. Our results demonstrate that spatial attention and expectation engage partly overlapping neural systems via distinct mechanisms to guide perceptual inference in a multisensory world.SIGNIFICANCE STATEMENT In our natural environment the brain is exposed to a constant influx of signals through all our senses. How does the brain allocate attention and form spatial expectations in this multisensory environment? Because observers need to respond to stimuli regardless of their sensory modality, they may allocate attentional resources and encode the probability of events jointly across the senses. This psychophysics and neuroimaging study shows that the brain controls attentional resources interactively across the senses via a frontoparietal system but encodes the statistical structure of the environment independently for each sense in sensory and frontoparietal areas. Thus, spatial attention and expectation engage partly overlapping neural systems via distinct mechanisms to guide perceptual inference in a multisensory world.
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Affiliation(s)
- Arianna Zuanazzi
- Computational Cognitive Neuroimaging Laboratory, Computational Neuroscience and Cognitive Robotics Centre, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Uta Noppeney
- Computational Cognitive Neuroimaging Laboratory, Computational Neuroscience and Cognitive Robotics Centre, University of Birmingham, B15 2TT Birmingham, United Kingdom
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12
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Musical literacy shifts asymmetries in the ventral visual cortex. Neuroimage 2017; 156:445-455. [DOI: 10.1016/j.neuroimage.2017.04.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/07/2017] [Accepted: 04/11/2017] [Indexed: 11/21/2022] Open
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13
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Zhu Y, Feng J, Ji J, Hou H, Chen L, Wu S, Liu Q, Yao Q, Du P, Zhang K, Chen Q, Chen Z, Zhang H, Tian M. Alteration of Monoamine Receptor Activity and Glucose Metabolism in Pediatric Patients with Anticonvulsant-Induced Cognitive Impairment. J Nucl Med 2017; 58:1490-1497. [PMID: 28302757 DOI: 10.2967/jnumed.116.189290] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 02/27/2017] [Indexed: 01/03/2023] Open
Abstract
A landmark study from the Institute of Medicine reported that the assessment of cognitive difficulties in children with epilepsy is timely and imperative. Anticonvulsant-induced cognitive impairment could influence the quality of life more than seizure itself in patients. Although the monoaminergic system is involved in the regulation of cognitive process, its role in anticonvulsant-induced cognitive impairment remains unclear. Methods: To explore in vivo monoamine receptor binding activity in patients with anticonvulsant-induced cognitive impairment, each patient underwent PET imaging with both monoamine receptor binding agent 11C-N-methylspiperone and glucose metabolic agent 18F-FDG. Tests of intelligence quotient (IQ), including verbal IQ (VIQ), performance IQ (PIQ), and full-scale IQ (FSIQ), were performed in each patient. Results: Compared with the patients with monotherapy, patients with polytherapy had significantly lower VIQ, PIQ, and FSIQ (P < 0.01 in each comparison), as well as significantly lower monoamine receptor activities detected in the caudate nucleus, prefrontal cortex, dorsal anterior cingulate cortex, and amygdale (P < 0.05 in each comparison). However, regarding the glucose metabolism, there was no significant difference found in patients with monotherapy or polytherapy (P > 0.05). Conclusion: Monoamine receptor PET imaging could be a promising in vivo imaging biomarker for mapping anticonvulsant-induced cognitive impairment.
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Affiliation(s)
- Yuankai Zhu
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Jianhua Feng
- Department of Paediatrics, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China; and
| | - Jianfeng Ji
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Haifeng Hou
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Lin Chen
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Shuang Wu
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Qing Liu
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Qiong Yao
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Peizhen Du
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Kai Zhang
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Qing Chen
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Zexin Chen
- Department of Clinical Epidemiology & Biostatistics, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Hong Zhang
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China.,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
| | - Mei Tian
- Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, China .,Zhejiang University Medical PET Centre, Zhejiang University, Hangzhou, China.,Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou, China.,Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China
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14
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Sakamoto S, Ikeda H, Tsuyuguchi N, Uda T, Okumura E, Asakawa T, Haruta Y, Nishiyama H, Okada T, Kamada H, Ohata K, Miki Y. MEG Frequency Analysis Depicts the Impaired Neurophysiological Condition of Ischemic Brain. PLoS One 2016; 11:e0168588. [PMID: 27992543 PMCID: PMC5161380 DOI: 10.1371/journal.pone.0168588] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 12/02/2016] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Quantitative imaging of neuromagnetic fields based on automated region of interest (ROI) setting was analyzed to determine the characteristics of cerebral neural activity in ischemic areas. METHODS Magnetoencephalography (MEG) was used to evaluate spontaneous neuromagnetic fields in the ischemic areas of 37 patients with unilateral internal carotid artery (ICA) occlusive disease. Voxel-based time-averaged intensity of slow waves was obtained in two frequency bands (0.3-4 Hz and 4-8 Hz) using standardized low-resolution brain electromagnetic tomography (sLORETA) modified for a quantifiable method (sLORETA-qm). ROIs were automatically applied to the anterior cerebral artery (ACA), anterior middle cerebral artery (MCAa), posterior middle cerebral artery (MCAp), and posterior cerebral artery (PCA) using statistical parametric mapping (SPM). Positron emission tomography with 15O-gas inhalation (15O-PET) was also performed to evaluate cerebral blood flow (CBF) and oxygen extraction fraction (OEF). Statistical analyses were performed using laterality index of MEG and 15O-PET in each ROI with respect to distribution and intensity. RESULTS MEG revealed statistically significant laterality in affected MCA regions, including 4-8 Hz waves in MCAa, and 0.3-4 Hz and 4-8 Hz waves in MCAp (95% confidence interval: 0.020-0.190, 0.030-0.207, and 0.034-0.213), respectively. We found that 0.3-4 Hz waves in MCAp were highly correlated with CBF in MCAa and MCAp (r = 0.74, r = 0.68, respectively), whereas 4-8 Hz waves were moderately correlated with CBF in both the MCAa and MCAp (r = 0.60, r = 0.63, respectively). We also found that 4-8 Hz waves in MCAp were statistically significant for misery perfusion identified on 15O-PET (p<0.05). CONCLUSIONS Quantitatively imaged spontaneous neuromagnetic fields using the automated ROI setting enabled clear depiction of cerebral ischemic areas. Frequency analysis may reveal unique neural activity that is distributed in the impaired vascular metabolic territory, in which the cerebral infarction has not yet been completed.
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Affiliation(s)
- Shinichi Sakamoto
- Department of Diagnostic and Interventional Radiology, Osaka City University Graduate School of Medicine, Osaka, Japan
- * E-mail:
| | - Hidetoshi Ikeda
- Department of Neurosurgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Naohiro Tsuyuguchi
- Department of Neurosurgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Takehiro Uda
- Department of Neurosurgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Eiichi Okumura
- Medical Imaging Business Department, Ricoh Company, Ltd., Kanazawa, Japan
| | - Takashi Asakawa
- Medical Imaging Business Department, Ricoh Company, Ltd., Kanazawa, Japan
| | - Yasuhiro Haruta
- Applied Electronics Laboratory, Kanazawa Institute of Technology, Kanazawa, Japan
| | | | - Toyoji Okada
- Department of Clinical Laboratory, Hokuto Hospital, Obihiro, Japan
| | - Hajime Kamada
- Department of Neurosurgery, Hokuto Hospital, Obihiro, Japan
| | - Kenji Ohata
- Department of Neurosurgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Yukio Miki
- Department of Diagnostic and Interventional Radiology, Osaka City University Graduate School of Medicine, Osaka, Japan
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15
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Abstract
Positron emission tomography (PET) is a neuroimaging method that offers insights into the molecular functioning of a human brain. It has been widely used to study metabolic and neurotransmitter abnormalities in people with epilepsy. This article reviews the development of several PET radioligands and their application in studying the molecular mechanisms of epilepsy. Over the last decade, tracers binding to serotonin and γ-aminobutyric acid (GABA) receptors have been used to delineate the location of the epileptic focus. PET studies have examined the role of opioids, cannabinoids, acetylcholine, and dopamine in modulating neuronal hyperexcitability and seizure termination. In vivo analyses of drug transporters, e.g., P-glycoprotein, have increased our understanding of pharmacoresistance that could inform new therapeutic strategies. Finally, PET experiments targeting neuroinflammation and glutamate receptors might guide the development of novel biomarkers of epileptogenesis.
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Affiliation(s)
- Marian Galovic
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, 33 Queen Square, London, WC1N 3BG, United Kingdom.,Epilepsy Society MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, United Kingdom
| | - Matthias Koepp
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, 33 Queen Square, London, WC1N 3BG, United Kingdom. .,Epilepsy Society MRI Unit, Epilepsy Society, Chalfont St Peter, Buckinghamshire, United Kingdom.
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16
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Wang K, Liu T, Zhao X, Xia X, Zhang K, Qiao H, Zhang J, Meng F. Comparative Study of Voxel-Based Epileptic Foci Localization Accuracy between Statistical Parametric Mapping and Three-dimensional Stereotactic Surface Projection. Front Neurol 2016; 7:164. [PMID: 27729898 PMCID: PMC5037321 DOI: 10.3389/fneur.2016.00164] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 09/15/2016] [Indexed: 11/18/2022] Open
Abstract
Introduction Fluorine-18-fluorodeoxyglucose positron-emission tomography (18F-FDG-PET) is widely used to help localize the hypometabolic epileptogenic focus for presurgical evaluation of drug-refractory epilepsy patients. Two voxel-based brain mapping methods to interpret 18F-FDG-PET, statistical parametric mapping (SPM) and three-dimensional stereotactic surface projection (3D-SSP), improve the detection rate of seizure foci. This study aimed to compare the consistency of epileptic focus detection between SPM and 3D-SSP for 18F-FDG-PET brain mapping analysis. Methods We retrospectively reviewed the clinical, electroecephalographic, and brain imaging results of 35 patients with refractory epilepsy. 18F-FDG-PET studies were revaluated by SPM, 3D-SSP, and visual assessment, and the results were compared to the magnetic resonance imaging (MRI) lesion location and to the presumed epileptogenic zone (PEZ) defined by video-electroencephalogram and other clinical data. A second consistency study compared PET analyses to histopathology and surgical outcomes in the 19 patients who underwent lesion resection surgery. Results Of the 35 patients, consistency with the PEZ was 29/35 for SPM, 25/35 for 3D-SSP, 14/35 for visual assessment, and 10/35 for MRI. Concordance rates with the PEZ were significantly higher for SPM and 3D-SSP than for MRI (P < 0.05) and visual assessment (P < 0.05). Differences between SPM and 3D-SSP and between visual assessment and MRI were not significant. In the 19 surgical patients, concordance with histopathology/clinical outcome was 14/19 for SPM, 15/19 for 3D-SSP, 14/19 for visual assessment, and 9/19 for MRI (P > 0.05). A favorable Engel outcome (class I/II) was found in 16 of 19 cases (84%), and failure of seizure control was found in 3 of 19 patients (class III/IV). Conclusion Voxel-based 18F-FDG-PET brain mapping analysis using SPM or 3D-SSP can improve the detection rate of the epileptic focus compared to visual assessment and MRI. Consistency with PEZ was similar between SPM and 3D-SSP; according to their own characteristics, 3D-SSP is recommended for primary evaluation due to greater efficiency and operability of the software, while SPM is recommended for high-accuracy localization of complex lesions. Therefore, joint application of both software packages may be the best solution for FDG-PET analysis of epileptic focus localization.
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Affiliation(s)
- Kailiang Wang
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China; Beijing Key Laboratory of Neurostimulation, Beijing, China
| | - Tinghong Liu
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China; Beijing Key Laboratory of Neurostimulation, Beijing, China
| | - Xiaobin Zhao
- Department of Nuclear Medicine, Beijing Tiantan Hospital, Capital Medical University , Beijing , China
| | - XiaoTong Xia
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University , Beijing , China
| | - Kai Zhang
- Beijing Key Laboratory of Neurostimulation, Beijing, China; Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Hui Qiao
- Beijing Neurosurgical Institute, Capital Medical University , Beijing , China
| | - Jianguo Zhang
- Beijing Key Laboratory of Neurostimulation, Beijing, China; Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Fangang Meng
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China; Beijing Key Laboratory of Neurostimulation, Beijing, China
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Sims-Williams H, Matthews JC, Talbot PS, Love-Jones S, Brooks JC, Patel NK, Pickering AE. Deep brain stimulation of the periaqueductal gray releases endogenous opioids in humans. Neuroimage 2016; 146:833-842. [PMID: 27554530 PMCID: PMC5312788 DOI: 10.1016/j.neuroimage.2016.08.038] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 07/25/2016] [Accepted: 08/18/2016] [Indexed: 12/11/2022] Open
Abstract
Deep brain stimulation (DBS) of the periaqueductal gray (PAG) is used in the treatment of severe refractory neuropathic pain. We tested the hypothesis that DBS releases endogenous opioids to exert its analgesic effect using [11C]diprenorphine (DPN) positron emission tomography (PET). Patients with de-afferentation pain (phantom limb pain or Anaesthesia Dolorosa (n=5)) who obtained long-lasting analgesic benefit from DBS were recruited. [11C]DPN and [15O]water PET scanning was performed in consecutive sessions; first without, and then with PAG stimulation. The regional cerebral tracer distribution and kinetics were quantified for the whole brain and brainstem. Analysis was performed on a voxel-wise basis using statistical parametric mapping (SPM) and also within brainstem regions of interest and correlated to the DBS-induced improvement in pain score and mood. Brain-wide analysis identified a single cluster of reduced [11C]DPN binding (15.5% reduction) in the caudal, dorsal PAG following DBS from effective electrodes located in rostral dorsal/lateral PAG. There was no evidence for an accompanying focal change in blood flow within the PAG. No correlation was found between the change in PAG [11C]DPN binding and the analgesic effect or the effect on mood (POMSSV) of DBS. The analgesic effect of DBS in these subjects was not altered by systemic administration of the opioid antagonist naloxone (400 ug). These findings indicate that DBS of the PAG does indeed release endogenous opioid peptides focally within the midbrain of these neuropathic pain patients but we are unable to further resolve the question of whether this release is responsible for the observed analgesic benefit. Sequential opioid-PET imaging study of deafferentation pain patients. All obtained analgesic benefit from deep brain stimulators (DBS) in periaqueductal grey (PAG). PET imaging with diprenorphine showed DBS reduced binding of the radioligand in the PAG. Change in binding consistent with DBS-evoked release of endogenous opioids.
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Affiliation(s)
- Hugh Sims-Williams
- School of Physiology, Pharmacology & Neuroscience, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom; Department of Neurosurgery & Pain Medicine, North Bristol NHS Trust, Bristol BS10 5NB, United Kingdom
| | - Julian C Matthews
- Imaging Sciences, MAHSC, University of Manchester, M20 3LJ, United Kingdom
| | - Peter S Talbot
- Imaging Sciences, MAHSC, University of Manchester, M20 3LJ, United Kingdom
| | - Sarah Love-Jones
- Department of Neurosurgery & Pain Medicine, North Bristol NHS Trust, Bristol BS10 5NB, United Kingdom
| | - Jonathan Cw Brooks
- Clinical Research Imaging Centre (CRiCBristol), University of Bristol, Bristol BS2 8DZ, United Kingdom
| | - Nikunj K Patel
- Department of Neurosurgery & Pain Medicine, North Bristol NHS Trust, Bristol BS10 5NB, United Kingdom
| | - Anthony E Pickering
- School of Physiology, Pharmacology & Neuroscience, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom; Department of Anaesthesia, University Hospitals Bristol, Bristol BS2 8HW, United Kingdom.
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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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Pustina D, Avants B, Sperling M, Gorniak R, He X, Doucet G, Barnett P, Mintzer S, Sharan A, Tracy J. Predicting the laterality of temporal lobe epilepsy from PET, MRI, and DTI: A multimodal study. Neuroimage Clin 2015; 9:20-31. [PMID: 26288753 PMCID: PMC4536304 DOI: 10.1016/j.nicl.2015.07.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/11/2015] [Accepted: 07/19/2015] [Indexed: 01/09/2023]
Abstract
Pre-surgical evaluation of patients with temporal lobe epilepsy (TLE) relies on information obtained from multiple neuroimaging modalities. The relationship between modalities and their combined power in predicting the seizure focus is currently unknown. We investigated asymmetries from three different modalities, PET (glucose metabolism), MRI (cortical thickness), and diffusion tensor imaging (DTI; white matter anisotropy) in 28 left and 30 right TLE patients (LTLE and RTLE). Stepwise logistic regression models were built from each modality separately and from all three combined, while bootstrapped methods and split-sample validation verified the robustness of predictions. Among all multimodal asymmetries, three PET asymmetries formed the best predictive model (100% success in full sample, >95% success in split-sample validation). The combinations of PET with other modalities did not perform better than PET alone. Probabilistic classifications were obtained for new clinical cases, which showed correct lateralization for 7/7 new TLE patients (100%) and for 4/5 operated patients with discordant or non-informative PET reports (80%). Metabolism showed closer relationship with white matter in LTLE and closer relationship with gray matter in RTLE. Our data suggest that metabolism is a powerful modality that can predict seizure laterality with high accuracy, and offers high value for automated predictive models. The side of epileptogenic focus can affect the relationship of metabolism with brain structure. The data and tools necessary to obtain classifications for new TLE patients are made publicly available.
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Affiliation(s)
- Dorian Pustina
- Department of Neurology, University of Pennsylvania, Philadelphia, USA
| | - Brian Avants
- Department of Radiology, University of Pennsylvania, Philadelphia, USA
| | - Michael Sperling
- Department of Neurology, Thomas Jefferson University/Sidney Kimmel Medical College, Philadelphia, PA 19107, USA
| | - Richard Gorniak
- Department of Radiology, Thomas Jefferson University/Sidney Kimmel Medical College, Philadelphia, PA 19107, USA
| | - Xiaosong He
- Department of Neurology, Thomas Jefferson University/Sidney Kimmel Medical College, Philadelphia, PA 19107, USA
| | - Gaelle Doucet
- Department of Neurology, Thomas Jefferson University/Sidney Kimmel Medical College, Philadelphia, PA 19107, USA
| | - Paul Barnett
- Department of Neurology, Thomas Jefferson University/Sidney Kimmel Medical College, Philadelphia, PA 19107, USA
| | - Scott Mintzer
- Department of Neurology, Thomas Jefferson University/Sidney Kimmel Medical College, Philadelphia, PA 19107, USA
| | - Ashwini Sharan
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, USA
| | - Joseph Tracy
- Department of Neurology, Thomas Jefferson University/Sidney Kimmel Medical College, Philadelphia, PA 19107, USA
- Department of Radiology, Thomas Jefferson University/Sidney Kimmel Medical College, Philadelphia, PA 19107, USA
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Hubbard IJ, Carey LM, Budd TW, Levi C, McElduff P, Hudson S, Bateman G, Parsons MW. A Randomized Controlled Trial of the Effect of Early Upper-Limb Training on Stroke Recovery and Brain Activation. Neurorehabil Neural Repair 2014; 29:703-13. [DOI: 10.1177/1545968314562647] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background. Upper-limb (UL) dysfunction is experienced by up to 75% of patients poststroke. The greatest potential for functional improvement is in the first month. Following reperfusion, evidence indicates that neuroplasticity is the mechanism that supports this recovery. Objective. This preliminary study hypothesized increased activation of putative motor areas in those receiving intensive, task-specific UL training in the first month poststroke compared with those receiving standard care. Methods. This was a single-blinded, longitudinal, randomized controlled trial in adult patients with an acute, first-ever ischemic stroke; 23 participants were randomized to standard care (n = 12) or an additional 30 hours of task-specific UL training in the first month poststroke beginning week 1. Patients were assessed at 1 week, 1 month, and 3 months poststroke. The primary outcome was change in brain activation as measured by functional magnetic resonance imaging. Results. When compared with the standard-care group, the intensive-training group had increased brain activation in the anterior cingulate and ipsilesional supplementary motor areas and a greater reduction in the extent of activation ( P = .02) in the contralesional cerebellum. Intensive training was associated with a smaller deviation from mean recovery at 1 month (Pr>F0 = 0.017) and 3 months (Pr>F = 0.006), indicating more consistent and predictable improvement in motor outcomes. Conclusion. Early, more-intensive, UL training was associated with greater changes in activation in putative motor (supplementary motor area and cerebellum) and attention (anterior cingulate) regions, providing support for the role of these regions and functions in early recovery poststroke.
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Affiliation(s)
| | | | | | - Christopher Levi
- University of Newcastle, NSW, Australia
- Hunter New England Local Health District, Newcastle, NSW, Australia
| | | | - Steven Hudson
- Hunter New England Local Health District, Newcastle, NSW, Australia
| | - Grant Bateman
- Hunter New England Local Health District, Newcastle, NSW, Australia
| | - Mark W. Parsons
- University of Newcastle, NSW, Australia
- Hunter New England Local Health District, Newcastle, NSW, Australia
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Yankam Njiwa J, Gray K, Costes N, Mauguiere F, Ryvlin P, Hammers A. Advanced [(18)F]FDG and [(11)C]flumazenil PET analysis for individual outcome prediction after temporal lobe epilepsy surgery for hippocampal sclerosis. NEUROIMAGE-CLINICAL 2014; 7:122-31. [PMID: 25610774 PMCID: PMC4299974 DOI: 10.1016/j.nicl.2014.11.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 11/10/2014] [Accepted: 11/15/2014] [Indexed: 11/20/2022]
Abstract
Purpose We have previously shown that an imaging marker, increased periventricular [11C]flumazenil ([11C]FMZ) binding, is associated with failure to become seizure free (SF) after surgery for temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS). Here, we investigated whether increased preoperative periventricular white matter (WM) signal can be detected on clinical [18F]FDG-PET images. We then explored the potential of periventricular FDG WM increases, as well as whole-brain [11C]FMZ and [18F]FDG images analysed with random forest classifiers, for predicting surgery outcome. Methods Sixteen patients with MRI-defined HS had preoperative [18F]FDG and [11C]FMZ-PET. Fifty controls had [18F]FDG-PET (30), [11C]FMZ-PET (41), or both (21). Periventricular WM signal was analysed using Statistical Parametric Mapping (SPM8), and whole-brain image classification was performed using random forests implemented in R (http://www.r-project.org). Surgery outcome was predicted at the group and individual levels. Results At the group level, non-seizure free (NSF) versus SF patients had periventricular increases with both tracers. Against controls, NSF patients showed more prominent periventricular [11C]FMZ and [18F]FDG signal increases than SF patients. All differences were more marked for [11C]FMZ. For individuals, periventricular WM signal increases were seen at optimized thresholds in 5/8 NSF patients for both tracers. For SF patients, 1/8 showed periventricular signal increases for [11C]FMZ, and 4/8 for [18F]FDG. Hence, [18F]FDG had relatively poor sensitivity and specificity. Random forest classification accurately identified 7/8 SF and 7/8 NSF patients using [11C]FMZ images, but only 4/8 SF and 6/8 NSF patients with [18F]FDG. Conclusion This study extends the association between periventricular WM increases and NSF outcome to clinical [18F]FDG-PET, but only at the group level. Whole-brain random forest classification increases [11C]FMZ-PET's performance for predicting surgery outcome.
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Affiliation(s)
- J. Yankam Njiwa
- Neurodis Foundation, Lyon, France
- Correspondence to: Cermep. — Imagerie du vivant, 59 Boulevard Pinel, Lyon/Bron 69677, France. Tel: +33 4 72 68 86 34.
| | - K.R. Gray
- Department Of Computing, Biomedical Image Analysis Group, Imperial College London, UK
| | - N. Costes
- Cermep-Imagerie du vivant, Lyon, France
| | - F. Mauguiere
- Université Lyon 1, Inserm, CNRS, Centre De Recherche en Neuroscience de Lyon, France
- Service de Neurologie Fonctionnelle et d'Epileptologie, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, France
- Université De Lyon, Université Claude Bernard, Lyon, France
| | - P. Ryvlin
- Université Lyon 1, Inserm, CNRS, Centre De Recherche en Neuroscience de Lyon, France
- Service de Neurologie Fonctionnelle et d'Epileptologie, Hôpital Neurologique Pierre Wertheimer, Hospices Civils de Lyon, France
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Abstract
Serotonin (5-HT) and oxytocin (OXT) are two neuromodulators involved in human affect and sociality and in disorders like depression and autism. We asked whether these chemical messengers interact in the regulation of emotion-based behavior by administering OXT or placebo to 24 healthy subjects and mapping cerebral 5-HT system by using 2'-methoxyphenyl-(N-2'-pyridinyl)-p-[(18)F]fluoro-benzamidoethylpiperazine ([(18)F]MPPF), an antagonist of 5-HT1A receptors. OXT increased [(18)F]MPPF nondisplaceable binding potential (BPND) in the dorsal raphe nucleus (DRN), the core area of 5-HT synthesis, and in the amygdala/hippocampal complex, insula, and orbitofrontal cortex. Importantly, the amygdala appears central in the regulation of 5-HT by OXT: [(18)F]MPPF BPND changes in the DRN correlated with changes in right amygdala, which were in turn correlated with changes in hippocampus, insula, subgenual, and orbitofrontal cortex, a circuit implicated in the control of stress, mood, and social behaviors. OXT administration is known to inhibit amygdala activity and results in a decrease of anxiety, whereas high amygdala activity and 5-HT dysregulation have been associated with increased anxiety. The present study reveals a previously unidentified form of interaction between these two systems in the human brain, i.e., the role of OXT in the inhibitory regulation of 5-HT signaling, which could lead to novel therapeutic strategies for mental disorders.
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Glikmann-Johnston Y, Saling MM, Chen J, O’Keefe G, Gong S, Tochon-Danguy H, Mulligan R, Reutens DC. Hippocampal 5-HT1A receptor binding is related to object–location memory in humans. Brain Struct Funct 2014; 220:559-70. [DOI: 10.1007/s00429-013-0675-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 11/07/2013] [Indexed: 11/24/2022]
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The reorganization of motor network in hemidystonia from the perspective of deep brain stimulation. Brain Imaging Behav 2014; 9:223-35. [DOI: 10.1007/s11682-014-9300-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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25
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Monzalvo K, Dehaene-Lambertz G. How reading acquisition changes children's spoken language network. BRAIN AND LANGUAGE 2013; 127:356-365. [PMID: 24216407 DOI: 10.1016/j.bandl.2013.10.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 10/09/2013] [Accepted: 10/19/2013] [Indexed: 06/02/2023]
Abstract
To examine the influence of age and reading proficiency on the development of the spoken language network, we tested 6- and 9-years-old children listening to native and foreign sentences in a slow event-related fMRI paradigm. We observed a stable organization of the peri-sylvian areas during this time period with a left dominance in the superior temporal sulcus and inferior frontal region. A year of reading instruction was nevertheless sufficient to increase activation in regions involved in phonological representations (posterior superior temporal region) and sentence integration (temporal pole and pars orbitalis). A top-down activation of the left inferior temporal cortex surrounding the visual word form area, was also observed but only in 9year-olds (3years of reading practice) listening to their native language. These results emphasize how a successful cultural practice, reading, slots in the biological constraints of the innate spoken language network.
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Affiliation(s)
- Karla Monzalvo
- INSERM, U992, Cognitive Neuroimaging Unit, F-91191 Gif/Yvette, France; CEA, DSV/I2BM, NeuroSpin Center, F-91191 Gif/Yvette, France; University Paris-Sud, Cognitive Neuroimaging Unit, F-91191 Gif/Yvette, France
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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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27
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Yankam Njiwa J, Bouvard S, Catenoix H, Mauguiere F, Ryvlin P, Hammers A. Periventricular [(11)C]flumazenil binding for predicting postoperative outcome in individual patients with temporal lobe epilepsy and hippocampal sclerosis. NEUROIMAGE-CLINICAL 2013; 3:242-8. [PMID: 24273709 PMCID: PMC3814949 DOI: 10.1016/j.nicl.2013.07.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 07/05/2013] [Accepted: 07/25/2013] [Indexed: 11/29/2022]
Abstract
A third of patients with intractable temporal lobe epilepsy and hippocampal sclerosis (HS) are not seizure free (NSF) after surgery. Increased periventricular [11C]flumazenil (FMZ) binding, reflecting heterotopic neuron concentration, has been described as one predictor of NSF outcome at the group level. We aimed to replicate this finding in an independent larger cohort and investigated whether NSF outcome can be predicted in individuals. Preoperative [11C]FMZ summed radioactivity images were available for 16 patients with HS and 41 controls. Images were analyzed using SPM8, explicitly including the white matter, and correction for global radioactivity via group-specific ANCOVA. Periventricular increases were assessed with a mask and different cutoffs for distinguishing NSF and seizure free (SF) patients. NSF patients had increased [11C]FMZ binding around the posterior horn of the ventricles ipsilaterally (z = 2.53) and contralaterally (z = 4.44) to the seizure focus compared with SF patients. Compared with controls, SF patients had fewer periventricular increases (two clusters, total volume 0.87 cm3, zmax = 3.8) than NSF patients (two ipsilateral and three contralateral clusters, 6.15 cm3, zmax = 4.8). In individuals and at optimized cutoffs, five (63%) of eight NSF patients and one (13%) of eight SF patients showed periventricular increases compared with controls (accuracy 75%). Only one (2%) of the 41 controls had increases at the same cutoff. The association between periventricular [11C]FMZ increases and NSF outcome after temporal lobe resection for HS has been confirmed in an independent cohort on simple summed activity images. [11C]FMZ-PET may be useful for individual preoperative counseling with clinically relevant accuracy. [11C]FMZ periventricular WM binding for predicting surgery outcome in mTLE-HS. Summed radioactivity images allowed replicating a prior study at the group level. Blood sampling constraint removed in comparison to the previous study. Periventricular abnormalities may allow predicting surgery outcome in individuals.
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Kuwako T, Mizumura S, Murakami R, Yoshida T, Shiiba M, Sato H, Fukushima Y, Teramoto A, Kumita SI. Voxel-based analysis of (201)Tl SPECT for grading and diagnostic accuracy of gliomas: comparison with ROI analysis. Ann Nucl Med 2013; 27:493-501. [PMID: 23592309 PMCID: PMC3713261 DOI: 10.1007/s12149-013-0711-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 02/24/2013] [Indexed: 11/27/2022]
Abstract
Purpose The aim of this retrospective study was to assess the utility of a voxel-based analysis (VBA) method for 201Tl SPECT in glioma, compared to conventional ROI analysis. Methods We recruited 24 patients with glioma (high-grade 15; low-grade 9), for whom pre-operative 201Tl SPECT and MRI were performed. SPECT images were coregistered with MRI. The uptake ratio (UR) images of tumor to contralateral normal tissue were measured on early and delayed images, and the 201Tl retention index (RI) map was calculated from the early and delayed uptake ratio maps. In the ROI analysis, tumors were traced on a UR map, and the mean and maximal uptake ratio values on the early images were, respectively, defined as the mean and maximal UR. The mean and maximal RI values (mean and maximal RI) were calculated by division of the mean and maximal UR, respectively, on the delayed image by the mean and maximal UR on the early image. For the RI map calculated voxel by voxel, the maximal RI value was defined as VBA-RI. We evaluated sensitivity and accuracy of differential analysis with the mean and maximal UR, RI, and VBA-RI. Results The high- and low-grade groups showed no significant difference in mean and maximal RI (0.98 ± 0.12 vs. 1.05 ± 0.09 and 0.98 ± 0.18 vs. 1.05 ± 0.14, respectively). The AUC and accuracy of the mean and maximal RI were 0.681 and 66.7 %, and 0.622 and 62.5 %, respectively. In contrast, VBA-RI was higher in high-grade than in low-grade glioma (1.69 ± 0.27 vs. 0.68 ± 0.66, p < 0.001). The AUC and accuracy of VBA-RI were 0.963 and 95.8 %, which are higher than those obtained for mean (p < 0.05) and maximal RI (p < 0.01). There was no significant difference in ROC between the VBA-RI and the mean UR (0.911, p = 0.456) and maximal UR (0.933, p = 0.639); however, the AUC, sensitivity, and diagnostic accuracy of VBA-RI were all higher than those of the mean and maximal UR. Conclusion The voxel-based analysis method of 201Tl SPECT may improve diagnostic performance for gliomas, compared with ROI analysis.
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Affiliation(s)
- Tomoyuki Kuwako
- Department of Radiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan.
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Peyron R, Faillenot I, Pomares F, Le Bars D, Garcia-Larrea L, Laurent B. Mechanical allodynia in neuropathic pain. Where are the brain representations located? A positron emission tomography (PET) study. Eur J Pain 2013; 17:1327-37. [DOI: 10.1002/j.1532-2149.2013.00307.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2013] [Indexed: 11/07/2022]
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30
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Hosomi K, Kishima H, Oshino S, Hirata M, Tani N, Maruo T, Khoo HM, Shimosegawa E, Hatazawa J, Kato A, Yoshimine T. Altered extrafocal iomazenil activity in mesial temporal lobe epilepsy. Epilepsy Res 2013; 103:195-204. [DOI: 10.1016/j.eplepsyres.2012.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 06/06/2012] [Accepted: 07/03/2012] [Indexed: 11/28/2022]
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Kranz GS, Hahn A, Baldinger P, Haeusler D, Philippe C, Kaufmann U, Wadsak W, Savli M, Hoeflich A, Kraus C, Vanicek T, Mitterhauser M, Kasper S, Lanzenberger R. Cerebral serotonin transporter asymmetry in females, males and male-to-female transsexuals measured by PET in vivo. Brain Struct Funct 2012; 219:171-83. [PMID: 23224294 DOI: 10.1007/s00429-012-0492-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 11/21/2012] [Indexed: 12/15/2022]
Abstract
The serotonergic system modulates brain functions that are considered to underlie affective states, emotion and cognition. Several lines of evidence point towards a strong lateralization of these mental processes, which indicates similar asymmetries in associated neurotransmitter systems. Here, our aim was to investigate a potential asymmetry of the serotonin transporter distribution using positron emission tomography and the radioligand [(11)C]DASB in vivo. As brain asymmetries may differ between sexes, we further aimed to compare serotonin transporter asymmetry between females, males and male-to-female (MtF) transsexuals whose brains are considered to be partly feminized. Voxel-wise analysis of serotonin transporter binding in all groups showed both strong left and rightward asymmetries in several cortical and subcortical structures including temporal and frontal cortices, anterior cingulate, hippocampus, caudate and thalamus. Further, male controls showed a rightward asymmetry in the midcingulate cortex, which was absent in females and MtF transsexuals. The present data support the notion of a lateralized serotonergic system, which is in line with previous findings of asymmetric serotonin-1A receptor distributions, extracellular serotonin concentrations, serotonin turnover and uptake. The absence of serotonin transporter asymmetry in the midcingulate in MtF transsexuals may be attributed to an absence of brain masculinization in this region.
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Affiliation(s)
- Georg S Kranz
- Functional, Molecular and Translational Neuroimaging Lab, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
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Theodore WH, Martinez AR, Khan OI, Liew CJ, Auh S, Dustin IM, Heiss J, Sato S. PET of serotonin 1A receptors and cerebral glucose metabolism for temporal lobectomy. J Nucl Med 2012; 53:1375-82. [PMID: 22782314 DOI: 10.2967/jnumed.112.103093] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The objective of this study was to compare 5-hydroxytryptamine receptor 1A (5-HT(1A)) PET with cerebral metabolic rate of glucose (CMRglc) PET for temporal lobectomy planning. METHODS We estimated 5-HT(1A) receptor binding preoperatively with (18)F-trans-4-fluoro-N-2-[4-(2-methoxyphenyl) piperazin-1-yl]ethyl-N-(2-pyridyl) cyclohexane carboxamide ((18)F-FCWAY) PET and CMRglc measurement with (18)F-FDG in regions drawn on coregistered MRI after partial-volume correction in 41 patients who had anterior temporal lobectomy with at least a 1-y follow-up. Surgery was tailored to individual preresection evaluations and intraoperative electrocorticography. Mean regional asymmetry values and the number of regions with asymmetry exceeding 2 SDs in 16 healthy volunteers were compared between seizure-free and non-seizure-free patients. (18)F-FCWAY but not (18)F-FDG and MRI data were masked for surgical decisions and outcome assessment. RESULTS Twenty-six of 41 (63%) patients seizure-free since surgery had significantly different mesial temporal asymmetries, compared with 15 non-seizure-free patients for both (18)F-FCWAY (F(1,39) = 5.87; P = 0.02) and (18)F-FDG PET (F(1,38) = 5.79; P = 0.021). The probability of being seizure-free was explained by both (18)F-FDG and (18)F-FCWAY PET, but not MRI, with a significant additional (18)F-FCWAY effect (chi(2)(2) = 9.8796; P = 0.0072) after the probability of being seizure-free was explained by (18)F-FDG. Although MRI alone was not predictive, any combination of 2 lateralizing imaging studies was highly predictive of seizure freedom. CONCLUSION Our study provides class III evidence that both 5-HT(1A) receptor PET and CMRglc PET can contribute to temporal lobectomy planning. Additional studies should explore the potential for temporal lobectomy based on interictal electroencephalography and minimally invasive imaging studies.
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Affiliation(s)
- William H Theodore
- Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Soma T, Momose T, Takahashi M, Koyama K, Kawai K, Murase K, Ohtomo K. Usefulness of extent analysis for statistical parametric mapping with asymmetry index using inter-ictal FGD-PET in mesial temporal lobe epilepsy. Ann Nucl Med 2012; 26:319-26. [PMID: 22311414 DOI: 10.1007/s12149-012-0573-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 01/15/2012] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Inter-ictal (18)F-2-fluoro-deoxy-D: -glucose-positron emission tomography (FDG-PET) is widely used for preoperative evaluation to identify epileptogenic zones in patients with temporal lobe epilepsy. In this study, we combined statistical parametric mapping (SPM) with the asymmetry index and volume-of-interest (VOI) based extent analysis employing preoperative FDG-PET in unilateral mesial temporal lobe epilepsy (MTLE) patients. We also evaluated the detection utility of these techniques for automated identification of abnormalities in the unilateral hippocampal area later confirmed to be epileptogenic zones by surgical treatment and subsequent good seizure control. METHODS FDG-PET scans of 17 patients (9 males, mean age 35 years, age range 16-60 years) were retrospectively analyzed. All patients had been preoperatively diagnosed with unilateral MTLE. The surgical outcomes of all patients were Engel class 1A or 1B with postoperative follow-up of 2 years. FDG-PET images were spatially normalized and smoothed. After two voxel-value adjustments, one employing the asymmetry index and the other global normalization, had been applied to the images separately, voxel-based statistical comparisons were performed with 20 controls. Peak analysis and extent analysis in the VOI in the parahippocampal gyrus were conducted for SPM. For the extent analysis, a receiver operating characteristic (ROC) curve was devised to calculate the area under the curve and to determine the optimal threshold of extent. RESULTS The accuracy of the method employing the asymmetry index was better than that of the global normalization method for both the peak and the extent analysis. The ROC analysis results, for the extent analysis, yielded an area under the curve of 0.971, such that the accuracy and optimal extent threshold of judgment were 92 and 32.9%, respectively. CONCLUSION Statistical z-score mapping with the asymmetry index was more sensitive for detecting regional glucose hypometabolism and more accurate for identifying the side harboring the epileptogenic zone using inter-ictal FDG-PET in unilateral MTLE than z-score mapping with global normalization. Moreover, the automated determination of the side with the epileptogenic zone in unilateral MTLE showed improved accuracy when the combination of SPM with the asymmetry index and extent analysis was applied based on the VOI in the parahippocampal gyrus.
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Affiliation(s)
- Tsutomu Soma
- Department of Radiology, Graduate School of Medicine, University of Tokyo, 3-1 Hongo 7-Chome, Bunkyo-ku, Tokyo, 113-8655, Japan
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