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Bernasconi A, Gill RS, Bernasconi N. The use of automated and AI-driven algorithms for the detection of hippocampal sclerosis and focal cortical dysplasia. Epilepsia 2024. [PMID: 38642009 DOI: 10.1111/epi.17989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/08/2024] [Accepted: 04/08/2024] [Indexed: 04/22/2024]
Abstract
In drug-resistant epilepsy, magnetic resonance imaging (MRI) plays a central role in detecting lesions as it offers unmatched spatial resolution and whole-brain coverage. In addition, the last decade has witnessed continued developments in MRI-based computer-aided machine-learning techniques for improved diagnosis and prognosis. In this review, we focus on automated algorithms for the detection of hippocampal sclerosis and focal cortical dysplasia, particularly in cases deemed as MRI negative, with an emphasis on studies with histologically validated data. In addition, we discuss imaging-derived prognostic markers, including response to anti-seizure medication, post-surgical seizure outcome, and cognitive reserves. We also highlight the advantages and limitations of these approaches and discuss future directions toward person-centered care.
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Affiliation(s)
- Andrea Bernasconi
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Ravnoor S Gill
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
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2
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Cho J, Gagoski B, Kim TH, Wang F, Manhard MK, Dean D, Kecskemeti S, Caprihan A, Lo WC, Splitthoff DN, Liu W, Polak D, Cauley S, Setsompop K, Grant PE, Bilgic B. Time-efficient, high-resolution 3T whole-brain relaxometry using 3D-QALAS with wave-CAIPI readouts. Magn Reson Med 2024; 91:630-639. [PMID: 37705496 DOI: 10.1002/mrm.29865] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/16/2023] [Accepted: 08/25/2023] [Indexed: 09/15/2023]
Abstract
PURPOSE Volumetric, high-resolution, quantitative mapping of brain-tissue relaxation properties is hindered by long acquisition times and SNR challenges. This study combines time-efficient wave-controlled aliasing in parallel imaging (wave-CAIPI) readouts with the 3D quantification using an interleaved Look-Locker acquisition sequence with a T2 preparation pulse (3D-QALAS), enabling full-brain quantitative T1 , T2 , and proton density (PD) maps at 1.15-mm3 isotropic voxels in 3 min. METHODS Wave-CAIPI readouts were embedded in the standard 3D-QALAS encoding scheme, enabling full-brain quantitative parameter maps (T1 , T2 , and PD) at acceleration factors of R = 3 × 2 with minimum SNR loss due to g-factor penalties. The quantitative parameter maps were estimated using a dictionary-based mapping algorithm incorporating inversion efficiency and B1 -field inhomogeneity effects. The parameter maps using the accelerated protocol were quantitatively compared with those obtained from the conventional 3D-QALAS sequence using GRAPPA acceleration of R = 2 in the ISMRM/NIST phantom, and in 10 healthy volunteers. RESULTS When tested in both the ISMRM/NIST phantom and 10 healthy volunteers, the quantitative maps using the accelerated protocol showed excellent agreement against those obtained from conventional 3D-QALAS at RGRAPPA = 2. CONCLUSION Three-dimensional QALAS enhanced with wave-CAIPI readouts enables time-efficient, full-brain quantitative T1 , T2 , and PD mapping at 1.15 mm3 in 3 min at R = 3 × 2 acceleration. The quantitative maps obtained from the accelerated wave-CAIPI 3D-QALAS protocol showed very similar values to those from the standard 3D-QALAS (R = 2) protocol, alluding to the robustness and reliability of the proposed method.
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Affiliation(s)
- Jaejin Cho
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Borjan Gagoski
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Tae Hyung Kim
- Department of Computer Engineering, Hongik University, Seoul, South Korea
| | - Fuyixue Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Mary Kate Manhard
- Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Douglas Dean
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Steven Kecskemeti
- Waisman Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Wei-Ching Lo
- Siemens Medical Solutions USA, Inc., Charlestown, Massachusetts, USA
| | | | - Wei Liu
- Siemens Healthcare GmbH, Erlangen, Germany
| | | | - Stephen Cauley
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Kawin Setsompop
- Department of Electrical Engineering, Stanford University, Stanford, California, USA
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Patricia Ellen Grant
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Berkin Bilgic
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
- Harvard/MIT Health Sciences and Technology, Cambridge, Massachusetts, USA
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Faizo NL, Alrehaili AA. Differentiation of Epileptic Brain Abnormalities among Neurological Patients at Taif Region Using MRI. Int J Clin Pract 2023; 2023:8783446. [PMID: 38020535 PMCID: PMC10657246 DOI: 10.1155/2023/8783446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 11/29/2022] [Accepted: 10/13/2023] [Indexed: 12/01/2023] Open
Abstract
This study was conducted to assess the prevalence of epilepsy among different age groups and gender of neurological patients in the Taif region and define the most common brain lesion, affecting epileptic patients living in the Taif city using MRI. Data from 150 patients who were clinically diagnosed with epilepsy and had brain MRIs were analyzed using SPSS. Statistical significance was considered when the p value is 0.05. The percentage of epilepsy was generally higher in males than in females in the Taif city, and seizures were different between the studied age groups. However, epilepsy was more pronounced in females than in males at certain age groups. Moreover, white matter lesions were most commonly found in the studied group (27.7%), followed by focal lesions, edema, and stroke with equal percentages (16.9%) and less commonly with congenital diseases (12%) and atrophic changes (9.6%). Epilepsy was more pronounced in females than in males at certain age groups. White matter lesions were identified as the most common lesion, presenting in epilepsy patients in the Taif city.
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Affiliation(s)
- Nahla L. Faizo
- Department of Radiological Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Amani A. Alrehaili
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
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Su TY, Tang Y, Choi JY, Hu S, Sakaie K, Murakami H, Jones S, Blümcke I, Najm I, Ma D, Wang ZI. Evaluating whole-brain tissue-property changes in MRI-negative pharmacoresistant focal epilepsies using MR fingerprinting. Epilepsia 2023; 64:430-442. [PMID: 36507762 PMCID: PMC10107443 DOI: 10.1111/epi.17488] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022]
Abstract
OBJECTIVE We aim to quantify whole-brain tissue-property changes in patients with magnetic resonance imaging (MRI)-negative pharmacoresistant focal epilepsy by three-dimensional (3D) magnetic resonance fingerprinting (MRF). METHODS We included 30 patients with pharmacoresistant focal epilepsy and negative MRI by official radiology report, as well as 40 age- and gender-matched healthy controls (HCs). MRF scans were obtained with 1 mm3 isotropic resolution. Quantitative T1 and T2 relaxometry maps were reconstructed from MRF and registered to the Montreal Neurological Institute (MNI) space. A two-sample t test was performed in Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (FSL) to evaluate significant abnormalities in patients comparing to HCs, with correction by the threshold-free cluster enhancement (TFCE) method. Subgroups analyses were performed for extra-temporal epilepsy/temporal epilepsy (ETLE/TLE), and for those with/without subtle abnormalities detected by morphometric analysis program (MAP), to investigate each subgroup's pattern of MRF changes. Correlation analyses were performed between the mean MRF values in each significant cluster and seizure-related clinical variables. RESULTS Compared to HCs, patients exhibited significant group-level T1 increase ipsilateral to the epileptic origin, in the mesial temporal gray matter (GM) and white matter (WM), temporal pole GM, orbitofrontal GM, hippocampus, and amygdala, with scattered clusters in the neocortical temporal and insular GM. No significant T2 changes were detected. The ETLE subgroup showed a T1-increase pattern similar to the overall cohort, with additional involvement of the ipsilateral anterior cingulate GM. The subgroup of MAP+ patients also showed a T1-increase pattern similar to the overall cohort, with additional cluster in the ipsilateral lateral orbitofrontal GM. Higher T1 was associated with younger seizure-onset age, longer epilepsy duration, and higher seizure frequency. SIGNIFICANCE MRF revealed group-level T1 increase in limbic/paralimbic structures ipsilateral to the epileptic origin, in patients with pharmacoresistant focal epilepsy and no apparent lesions on MRI, suggesting that these regions may be commonly affected by seizures in the epileptic brain. The significant association between T1 increase and higher seizure burden may reflect progressive tissue damage.
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Affiliation(s)
- Ting-Yu Su
- Epilepsy Center, Cleveland Clinic, Cleveland, Ohio, USA
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yingying Tang
- Epilepsy Center, Cleveland Clinic, Cleveland, Ohio, USA
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Joon Yul Choi
- Epilepsy Center, Cleveland Clinic, Cleveland, Ohio, USA
| | - Siyuan Hu
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ken Sakaie
- Imaging Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | | | - Stephen Jones
- Imaging Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Ingmar Blümcke
- Epilepsy Center, Cleveland Clinic, Cleveland, Ohio, USA
- Neuropathology, University of Erlangen, Erlangen, Germany
| | - Imad Najm
- Epilepsy Center, Cleveland Clinic, Cleveland, Ohio, USA
| | - Dan Ma
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
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Liu C, Hu Y, Zhou J, Guan Y, Wang M, Qi X, Wang X, Zhang H, Adilijiang A, Li T, Luan G. Retrospective Clinical Analysis of Epilepsy Treatment for Children with Drug-Resistant Epilepsy (A Single-Center Experience). Brain Sci 2022; 13:brainsci13010014. [PMID: 36671996 PMCID: PMC9856722 DOI: 10.3390/brainsci13010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/17/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022] Open
Abstract
Objectives: This retrospective cohort study investigated the clinical characteristics and seizure outcomes of patients aged 1−14 years with drug-resistant epilepsy (DRE) who were treated by different typologies of therapy. Methods: Four hundred and eighteen children with DRE were recruited from Sanbo Brain Hospital of Capital Medical University from April 2008 to February 2015. The patients were divided into three groups: medication (n = 134, 32.06%), resection surgery (n = 185, 44.26%), and palliative surgery (n = 99, 23.68%) groups. Demographic characteristics were attained from medical records. All patients were followed up for at least 5 years, with seizure outcomes classified according to International League Against Epilepsy criteria. The psychological outcome was evaluated with the development quotient and Wechsler Intelligence Quotient Scale for children (Chinese version). Results: The most frequent seizure type was generalized tonic seizure in 53.83% of patients. Age at seizure onset in 54.55% of patients was <3 years. The most frequent etiologies were focal cortical dysplasia (FCD). West syndrome was the most common epilepsy syndrome. Favorable seizure outcomes at the 5-year follow-up in the medication, resection surgery, and palliative surgery groups were 5.22%, 77.30%, and 14.14%, respectively. The patients showed varying degrees of improvement in terms of developmental and intellectual outcomes post-treatment. Conclusions: Pediatric patients with DRE were characterized by frequent seizures, a variety of seizure types, and complex etiology. Recurrent seizures severely affected the cognitive function and development of children. Early surgical intervention would be beneficial for seizure control and prevention of mental retardation. Palliative surgery was also a reasonable option for patients who were not suitable candidates for resection surgery.
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Affiliation(s)
- Changqing Liu
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Beijing Key Laboratory of Epilepsy, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Center of Epilepsy, Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100093, China
| | - Yue Hu
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Department of Neurosurgery, Aviation General Hospital, China Medical University, Beijing 100012, China
| | - Jian Zhou
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Beijing Key Laboratory of Epilepsy, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Center of Epilepsy, Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100093, China
| | - Yuguang Guan
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Beijing Key Laboratory of Epilepsy, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Center of Epilepsy, Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100093, China
| | - Mengyang Wang
- Center of Epilepsy, Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100093, China
- Department of Neurology, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Xueling Qi
- Department of Pathology, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Xiongfei Wang
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Center of Epilepsy, Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100093, China
| | - Huawei Zhang
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | | | - Tiemin Li
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Guoming Luan
- Department of Neurosurgery, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Beijing Key Laboratory of Epilepsy, Sanbo Brain Hospital, Capital Medical University, Beijing 100093, China
- Center of Epilepsy, Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100093, China
- Correspondence:
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6
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Choi JY, Krishnan B, Hu S, Martinez D, Tang Y, Wang X, Sakaie K, Jones S, Murakami H, Blümcke I, Najm I, Ma D, Wang ZI. Using magnetic resonance fingerprinting to characterize periventricular nodular heterotopias in pharmacoresistant epilepsy. Epilepsia 2022; 63:1225-1237. [PMID: 35343593 PMCID: PMC9081261 DOI: 10.1111/epi.17191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 02/05/2023]
Abstract
OBJECTIVE We aimed to use a novel magnetic resonance fingerprinting (MRF) technique to examine in vivo tissue property characteristics of periventricular nodular heterotopia (PVNH). These characteristics were further correlated with stereotactic-electroencephalographic (SEEG) ictal onset findings. METHODS We included five patients with PVNH who had SEEG-guided surgery and at least 1 year of seizure freedom or substantial seizure reduction. High-resolution MRF scans were acquired at 3 T, generating three-dimensional quantitative T1 and T2 maps. We assessed the differences between T1 and T2 values from the voxels in the nodules located in the SEEG-defined seizure onset zone (SOZ) and non-SOZ, on -individual and group levels. Receiver operating characteristic analyses were performed to obtain the optimal classification performance. Quantification of SEEG ictal onset signals from the nodules was performed by calculating power spectrum density (PSD). The association between PSD and T1 /T2 values was further assessed at different frequency bands. RESULTS Individual-level analysis showed T1 was significantly higher in SOZ voxels than non-SOZ voxels (p < .05), with an average 73% classification accuracy. Group-level analysis also showed higher T1 was significantly associated with SOZ voxels (p < .001). At the optimal cutoff (normalized T1 of 1.1), a 76% accuracy for classifying SOZ nodules from non-SOZ nodules was achieved. T1 values were significantly associated with ictal onset PSD at the ultraslow, θ, β, γ, and ripple bands (p < .05). T2 values were significantly associated with PSD only at the ultraslow band (p < .05). SIGNIFICANCE Quantitative MRF measures, especially T1 , can provide additional noninvasive information to separate nodules in SOZ and non-SOZ. The T1 and T2 tissue property changes carry electrophysiological underpinnings relevant to the epilepsy, as shown by their significant positive associations with power changes during the SEEG seizure onset. The use of MRF as a supplementary noninvasive tool may improve presurgical evaluation for patients with PVNH and pharmacoresistant epilepsy.
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Affiliation(s)
- Joon Yul Choi
- Charles Shor Epilepsy Center, Cleveland Clinic, Neurological Institute, Cleveland, Ohio, USA
| | - Balu Krishnan
- Charles Shor Epilepsy Center, Cleveland Clinic, Neurological Institute, Cleveland, Ohio, USA
| | - Siyuan Hu
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - David Martinez
- Charles Shor Epilepsy Center, Cleveland Clinic, Neurological Institute, Cleveland, Ohio, USA
| | - Yinging Tang
- Charles Shor Epilepsy Center, Cleveland Clinic, Neurological Institute, Cleveland, Ohio, USA.,Department of Neurology, West China Hospital of Sichuan University, Chengdu, China
| | - Xiaofeng Wang
- Quantitative Health Science, Cleveland Clinic, Cleveland, Ohio, USA
| | - Ken Sakaie
- Imaging Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Stephen Jones
- Imaging Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Hiroatsu Murakami
- Charles Shor Epilepsy Center, Cleveland Clinic, Neurological Institute, Cleveland, Ohio, USA
| | - Ingmar Blümcke
- Charles Shor Epilepsy Center, Cleveland Clinic, Neurological Institute, Cleveland, Ohio, USA.,Neuropathology, University of Erlangen, Erlangen, Germany
| | - Imad Najm
- Charles Shor Epilepsy Center, Cleveland Clinic, Neurological Institute, Cleveland, Ohio, USA
| | - Dan Ma
- Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Zhong Irene Wang
- Charles Shor Epilepsy Center, Cleveland Clinic, Neurological Institute, Cleveland, Ohio, USA
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Habibabadi JM, Doroudinia A, Koma AY, Fesharaki SSH, Aarabi S. Comparison of non-invasive imaging modalities in presurgical evaluation of temporal lobe epilepsy patients: a multicenter study. Acta Neurol Belg 2021; 121:1815-1821. [PMID: 33230739 DOI: 10.1007/s13760-020-01550-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 11/08/2020] [Indexed: 11/28/2022]
Abstract
Intractable drug-resistant magnetic resonance imaging (MRI) negative epilepsy in one of the complicated issues in neurology. Epilepsy surgery is beneficial treatment of intractable seizures, but precise localization of epileptogenic zone is a major concern. Thirty-four MRI negative drug-resistant epilepsy patients underwent video electroencephalography (EEG), positron emission tomography (PET) scan, and voxel-based morphometry (VBM) MRI from 2014 to 2019. Then, the findings of PET scan and VBM were compared with semiology and long-term electrophysiology. Cohen's kappa-coefficient (k) test was utilized to measure the agreement between our modalities. Among 34 patients with age ranging from 8 to 49 (mean: 29.00 ± standard deviation: 10.35), 19 were male (55.9%) and 15 were female (44.1%). Twenty-one patients (61.76%) had right temporal, 12 patients (35.3%) had left and one patient had bilateral temporal ictal focus according to video EEG. Inter-rater agreement analysis showed that the kappa index between video EEG and PET scan was of almost acceptable (more than 0.4) and there was poor agreement between video EEG and VBM (kappa index = 0.099). PET is highly concordant with video EEG in temporal lobe epilepsy (TLE) and has a considerable agreement in localizing epileptogenic zone while VBM is less.
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Affiliation(s)
| | - Abtin Doroudinia
- Chronic Respiratory Diseases Research Center (CRDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Yousefi Koma
- Chronic Respiratory Diseases Research Center (CRDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Sobhan Aarabi
- Comprehensive Epilepsy Program, Epilepsy Monitoring Unit, Pars Hospital, Tehran, Iran.
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Isen J, Perera-Ortega A, Vos SB, Rodionov R, Kanber B, Chowdhury FA, Duncan JS, Mousavi P, Winston GP. Non-parametric combination of multimodal MRI for lesion detection in focal epilepsy. NEUROIMAGE-CLINICAL 2021; 32:102837. [PMID: 34619650 PMCID: PMC8503566 DOI: 10.1016/j.nicl.2021.102837] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 09/10/2021] [Accepted: 09/20/2021] [Indexed: 12/21/2022]
Abstract
Multivariate voxel-based analysis useful for lesion detection in focal epilepsy. Non-parametric combination algorithm used to combine data from various MR sequences. Successful lesion detection demonstrated in MRI-positive and MRI-negative patients. Multimodal analysis detected abnormalities from diverse epileptogenic pathologies. Sensitivity of multivariate analysis notably higher than univariate analyses.
One third of patients with medically refractory focal epilepsy have normal-appearing MRI scans. This poses a problem as identification of the epileptogenic region is required for surgical treatment. This study performs a multimodal voxel-based analysis (VBA) to identify brain abnormalities in MRI-negative focal epilepsy. Data was collected from 69 focal epilepsy patients (42 with discrete lesions on MRI scans, 27 with no visible findings on scans), and 62 healthy controls. MR images comprised T1-weighted, fluid-attenuated inversion recovery (FLAIR), fractional anisotropy (FA) and mean diffusivity (MD) from diffusion tensor imaging, and neurite density index (NDI) from neurite orientation dispersion and density imaging. These multimodal images were coregistered to T1-weighted scans, normalized to a standard space, and smoothed with 8 mm FWHM. Initial analysis performed voxel-wise one-tailed t-tests separately on grey matter concentration (GMC), FLAIR, FA, MD, and NDI, comparing patients with epilepsy to controls. A multimodal non-parametric combination (NPC) analysis was also performed simultaneously on FLAIR, FA, MD, and NDI. Resulting p-maps were family-wise error rate corrected, threshold-free cluster enhanced, and thresholded at p < 0.05. Sensitivity was established through visual comparison of results to manually drawn lesion masks or seizure onset zone (SOZ) from stereoelectroencephalography. A leave-one-out cross-validation with the same analysis protocols was performed on controls to determine specificity. NDI was the best performing individual modality, detecting focal abnormalities in 38% of patients with normal MRI and conclusive SOZ. GMC demonstrated the lowest sensitivity at 19%. NPC provided superior performance to univariate analyses with 50% sensitivity. Specificity in controls ranged between 96 and 100% for all analyses. This study demonstrated the utility of a multimodal VBA utilizing NPC for detecting epileptogenic lesions in MRI-negative focal epilepsy. Future work will apply this approach to datasets from other centres and will experiment with different combinations of MR sequences.
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Affiliation(s)
- Jonah Isen
- School of Computing, Queen's University, Kingston, Canada
| | | | - Sjoerd B Vos
- Centre for Medical Image Computing, University College London, London, UK; Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK; MRI Unit, Epilepsy Society, Chalfont St Peter, UK; National Institute for Health Research Biomedical Research Centre at University College London and University College London NHS Foundation Trust, London, UK; Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Roman Rodionov
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK; MRI Unit, Epilepsy Society, Chalfont St Peter, UK
| | - Baris Kanber
- Centre for Medical Image Computing, University College London, London, UK; Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK; MRI Unit, Epilepsy Society, Chalfont St Peter, UK; National Institute for Health Research Biomedical Research Centre at University College London and University College London NHS Foundation Trust, London, UK
| | - Fahmida A Chowdhury
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK; National Institute for Health Research Biomedical Research Centre at University College London and University College London NHS Foundation Trust, London, UK
| | - John S Duncan
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK; MRI Unit, Epilepsy Society, Chalfont St Peter, UK; National Institute for Health Research Biomedical Research Centre at University College London and University College London NHS Foundation Trust, London, UK
| | - Parvin Mousavi
- School of Computing, Queen's University, Kingston, Canada
| | - Gavin P Winston
- School of Computing, Queen's University, Kingston, Canada; Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK; MRI Unit, Epilepsy Society, Chalfont St Peter, UK; National Institute for Health Research Biomedical Research Centre at University College London and University College London NHS Foundation Trust, London, UK; Department of Medicine, Division of Neurology & Centre for Neuroscience Studies, Queen's University, Kingston, Canada.
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9
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González-Ortiz S, Medrano S, Capellades J, Vilas M, Mestre A, Serrano L, Conesa G, Pérez-Enríquez C, Arumi M, Bargalló N, Delgado-Martinez I, Rocamora R. Voxel-based morphometry for the evaluation of patients with pharmacoresistant epilepsy with apparently normal MRI. J Neuroimaging 2021; 31:560-568. [PMID: 33817887 DOI: 10.1111/jon.12849] [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: 11/07/2020] [Revised: 02/15/2021] [Accepted: 02/18/2021] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Magnetic resonance imaging (MRI) is essential in the diagnosis of pharmacoresistant epilepsy (PRE), because patients with lesions detected by MRI have a better prognosis after surgery. Focal cortical dysplasia (FCD) is one of the most frequent etiologies of PRE but can be difficult to identify by MRI. Voxel-based morphometric analysis programs, like the Morphometric Analysis Program (MAP), have been developed to help improve MRI detection. Our objective was to evaluate the clinical usefulness of MAP in patients with PRE and an apparently normal MRI. METHODS We studied 70 patients with focal PRE and a nonlesional MRI. The 3DT1 sequence was processed with MAP, obtaining three z-score maps. Patients were classified as MAP+ if one or more z-score maps showed a suspicious area of brightness, and MAP- if the z-score maps did not show any suspicious areas. For MAP+ cases, a second-look MRI was performed with a dedicated inspection based on the MAP findings. The MAP results were correlated with the epileptogenic zone. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. RESULTS Thirty-one percent of patients were classified as MAP+ and 69% were MAP-. Results showed a sensitivity of 0.57, specificity of 0.8, PPV of 0.91, and NPV of 0.35. In 19% of patients, an FCD was found in the second-look MRI after MAP. CONCLUSIONS MAP was helpful in the detection of lesions in PRE patients with a nonlesional MRI, which could have important repercussions for the clinical management and postoperative prognosis of these patients.
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Affiliation(s)
- Sofía González-Ortiz
- Radiology Department, Hospital del Mar, Barcelona, Spain.,Epilpsy Reserach Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
| | | | | | - Marta Vilas
- Radiology Department, Hospital del Mar, Barcelona, Spain
| | - Antoni Mestre
- Nuclear Medicine Department, Hospital Trueta, Girona, Spain
| | - Laura Serrano
- Neurosurgery Department, Hospital del Mar, Barcelona, Spain
| | - Gerardo Conesa
- Neurosurgery Department, Hospital del Mar, Barcelona, Spain.,Epilpsy Reserach Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
| | - Carmen Pérez-Enríquez
- Neurology Department, Hospital del Mar, Barcelona, Spain.,Epilpsy Reserach Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
| | - Montserrat Arumi
- Anatomic Pathology Department, Hospital del Mar, Barcelona, Spain
| | - Nuria Bargalló
- Centre de Diagnosi per la Imatge, Hospital Clínic, Barcelona, Spain
| | - Ignacio Delgado-Martinez
- Neurosurgery Department, Hospital del Mar, Barcelona, Spain.,Epilpsy Reserach Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
| | - Rodrigo Rocamora
- Neurology Department, Hospital del Mar, Barcelona, Spain.,Epilpsy Reserach Group, Institut Hospital del Mar d'Investigacions Mèdiques, Barcelona, Spain
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10
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Neshige S, Aoki S, Shishido T, Morino H, Iida K, Maruyama H. Socio-economic impact on epilepsy outside of the nation-wide COVID-19 pandemic area. Epilepsy Behav 2021; 117:107886. [PMID: 33714184 PMCID: PMC9760559 DOI: 10.1016/j.yebeh.2021.107886] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/18/2021] [Accepted: 02/18/2021] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To identify people with epilepsy (PWE) who required extensive care before the novel coronavirus disease 2019 (COVID-19) pandemic that had world-wide impacts on medical care and on socio-economic conditions. METHODS Consecutive PWE who were treated at the epilepsy center of Hiroshima University Hospital, which was located in the COVID-19 non-pandemic area, between March 2019 and August 2020 were enrolled. We evaluated clinical and socioeconomic factors that were associated with seizure exacerbation (an increase in seizure frequency) during the first 6 months after the COVID-19 pandemic started compared with the previous 6 months. RESULTS Among the 196 PWE who were evaluated (mean age was 37.8 ± 16.2 years), there were 33 PWE (16.8%) whose seizure frequency had increased after the pandemic began. People with epilepsy with a seizure increase showed a significant association with living alone (p < 0.001), a higher seizure frequency (p < 0.001), negative findings on MRI (p = 0.020), history of dissociative seizure (p < 0.001), mood disorders (p < 0.001), insomnia (p < 0.001), and high psychological stress levels (p = 0.024) at baseline compared with PWE without seizure exacerbation. Multivariate logistic regression analysis revealed that "living alone" (odds ratio (OR) 3.69; 95%CI 1.29-10.52), "high seizure frequency at baseline" (OR 4.53; 95%CI 1.63-12.57), and "comorbidity of insomnia" (OR 9.55; 95%CI 3.71-24.55) were independently associated with seizure exacerbation. CONCLUSIONS Even in the non-pandemic area, PWE had seizure exacerbation, suggesting that clinicians should screen patients' mental health before the outbreak to provide care, reduce the burden, and prevent social isolation in PWE. This should be addressed particularly in patients with medically refractory seizures with insomnia who live alone.
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Affiliation(s)
- Shuichiro Neshige
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Graduate School of Biomedical and Health Sciences, Japan; Epilepsy Center, Hiroshima University Hospital, Japan.
| | - Shiro Aoki
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Graduate School of Biomedical and Health Sciences, Japan
| | - Takeo Shishido
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Graduate School of Biomedical and Health Sciences, Japan
| | - Hiroyuki Morino
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Graduate School of Biomedical and Health Sciences, Japan
| | - Koji Iida
- Epilepsy Center, Hiroshima University Hospital, Japan,Department of Neurosurgery, Hiroshima University, Graduate School of Biomedical and Health Sciences, Japan
| | - Hirofumi Maruyama
- Department of Clinical Neuroscience and Therapeutics, Hiroshima University, Graduate School of Biomedical and Health Sciences, Japan,Epilepsy Center, Hiroshima University Hospital, Japan
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11
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Use of Innovative SPECT Techniques in the Presurgical Evaluation of Patients with Nonlesional Extratemporal Drug-Resistant Epilepsy. Mol Imaging 2021; 2021:6614356. [PMID: 33746629 PMCID: PMC7953581 DOI: 10.1155/2021/6614356] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 02/04/2021] [Accepted: 02/18/2021] [Indexed: 12/27/2022] Open
Abstract
Up to 30% of patients with epilepsy may not respond to antiepileptic drugs. Patients with drug-resistant epilepsy (DRE) should undergo evaluation for seizure onset zone (SOZ) localization to consider surgical treatment. Cases of drug-resistant nonlesional extratemporal lobe epilepsy (ETLE) pose the biggest challenge in localizing the SOZ and require multiple noninvasive diagnostic investigations before planning the intracranial monitoring (ICM) or direct resection. Ictal Single Photon Emission Computed Tomography (i-SPECT) is a unique functional diagnostic tool that assesses the SOZ using the localized hyperperfusion that occurs early in the seizure. Subtraction ictal SPECT coregistered to MRI (SISCOM), statistical ictal SPECT coregistered to MRI (STATISCOM), and PET interictal subtracted ictal SPECT coregistered with MRI (PISCOM) are innovative SPECT methods for the determination of the SOZ. This article comprehensively reviews SPECT and sheds light on its vital role in the presurgical evaluation of the nonlesional extratemporal DRE.
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12
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Kanber B, Vos SB, de Tisi J, Wood TC, Barker GJ, Rodionov R, Chowdhury FA, Thom M, Alexander DC, Duncan JS, Winston GP. Detection of covert lesions in focal epilepsy using computational analysis of multimodal magnetic resonance imaging data. Epilepsia 2021; 62:807-816. [PMID: 33567113 PMCID: PMC8436754 DOI: 10.1111/epi.16836] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/24/2020] [Accepted: 01/21/2021] [Indexed: 02/01/2023]
Abstract
Objective To compare the location of suspect lesions detected by computational analysis of multimodal magnetic resonance imaging data with areas of seizure onset, early propagation, and interictal epileptiform discharges (IEDs) identified with stereoelectroencephalography (SEEG) in a cohort of patients with medically refractory focal epilepsy and radiologically normal magnetic resonance imaging (MRI) scans. Methods We developed a method of lesion detection using computational analysis of multimodal MRI data in a cohort of 62 control subjects, and 42 patients with focal epilepsy and MRI‐visible lesions. We then applied it to detect covert lesions in 27 focal epilepsy patients with radiologically normal MRI scans, comparing our findings with the areas of seizure onset, early propagation, and IEDs identified at SEEG. Results Seizure‐onset zones (SoZs) were identified at SEEG in 18 of the 27 patients (67%) with radiologically normal MRI scans. In 11 of these 18 cases (61%), concordant abnormalities were detected by our method. In the remaining seven cases, either early seizure propagation or IEDs were observed within the abnormalities detected, or there were additional areas of imaging abnormalities found by our method that were not sampled at SEEG. In one of the nine patients (11%) in whom SEEG was inconclusive, an abnormality, which may have been involved in seizures, was identified by our method and was not sampled at SEEG. Significance Computational analysis of multimodal MRI data revealed covert abnormalities in the majority of patients with refractory focal epilepsy and radiologically normal MRI that co‐located with SEEG defined zones of seizure onset. The method could help identify areas that should be targeted with SEEG when considering epilepsy surgery.
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Affiliation(s)
- Baris Kanber
- Centre for Medical Image Computing, University College London, London, UK.,Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,MRI Unit, Epilepsy Society, Chalfont St Peter, UK.,National Institute for Health Research Biomedical Research Centre at University College London and University College London NHS Foundation Trust, London, UK
| | - Sjoerd B Vos
- Centre for Medical Image Computing, University College London, London, UK.,Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,MRI Unit, Epilepsy Society, Chalfont St Peter, UK.,National Institute for Health Research Biomedical Research Centre at University College London and University College London NHS Foundation Trust, London, UK.,Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, London, UK
| | - Jane de Tisi
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Tobias C Wood
- Department of Neuroimaging, King's College London, London, UK
| | - Gareth J Barker
- Department of Neuroimaging, King's College London, London, UK
| | - Roman Rodionov
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,MRI Unit, Epilepsy Society, Chalfont St Peter, UK
| | - Fahmida Amin Chowdhury
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Maria Thom
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Division of Neuropathology, The National Hospital for Neurology and Neurosurgery, London, UK
| | - Daniel C Alexander
- Centre for Medical Image Computing, University College London, London, UK.,National Institute for Health Research Biomedical Research Centre at University College London and University College London NHS Foundation Trust, London, UK
| | - John S Duncan
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,MRI Unit, Epilepsy Society, Chalfont St Peter, UK.,National Institute for Health Research Biomedical Research Centre at University College London and University College London NHS Foundation Trust, London, UK
| | - Gavin P Winston
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,MRI Unit, Epilepsy Society, Chalfont St Peter, UK.,Department of Medicine, Division of Neurology, Queen's University, Kingston, Canada
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13
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Sharma AA, Nenert R, Mueller C, Maudsley AA, Younger JW, Szaflarski JP. Repeatability and Reproducibility of in-vivo Brain Temperature Measurements. Front Hum Neurosci 2020; 14:598435. [PMID: 33424566 PMCID: PMC7785722 DOI: 10.3389/fnhum.2020.598435] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/30/2020] [Indexed: 12/11/2022] Open
Abstract
Background: Magnetic resonance spectroscopic imaging (MRSI) is a neuroimaging technique that may be useful for non-invasive mapping of brain temperature (i.e., thermometry) over a large brain volume. To date, intra-subject reproducibility of MRSI-based brain temperature (MRSI-t) has not been investigated. The objective of this repeated measures MRSI-t study was to establish intra-subject reproducibility and repeatability of brain temperature, as well as typical brain temperature range. Methods: Healthy participants aged 23-46 years (N = 18; 7 females) were scanned at two time points ~12-weeks apart. Volumetric MRSI data were processed by reconstructing metabolite and water images using parametric spectral analysis. Brain temperature was derived using the frequency difference between water and creatine (TCRE) for 47 regions of interest (ROIs) delineated by the modified Automated Anatomical Labeling (AAL) atlas. Reproducibility was measured using the coefficient of variation for repeated measures (COVrep), and repeatability was determined using the standard error of measurement (SEM). For each region, the upper and lower bounds of Minimal Detectable Change (MDC) were established to characterize the typical range of TCRE values. Results: The mean global brain temperature over all subjects was 37.2°C with spatial variations across ROIs. There was a significant main effect for time [F (1, 1,591) = 37.0, p < 0.0001] and for brain region [F (46, 1,591) = 2.66, p < 0.0001]. The time*brain region interaction was not significant [F (46, 1,591) = 0.80, p = 0.83]. Participants' TCRE was stable for each ROI across both time points, with ROIs' COVrep ranging from 0.81 to 3.08% (mean COVrep = 1.92%); majority of ROIs had a COVrep <2.0%. Conclusions: Brain temperature measurements were highly consistent between both time points, indicating high reproducibility and repeatability of MRSI-t. MRSI-t may be a promising diagnostic, prognostic, and therapeutic tool for non-invasively monitoring brain temperature changes in health and disease. However, further studies of healthy participants with larger sample size(s) and numerous repeated acquisitions are imperative for establishing a reference range of typical brain TCRE, as well as the threshold above which TCRE is likely pathological.
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Affiliation(s)
- Ayushe A. Sharma
- Department of Psychology, University of Alabama at Birmingham (UAB), Birmingham, AL, United States
- Department of Neurobiology, University of Alabama at Birmingham (UAB), Birmingham, AL, United States
- University of Alabama at Birmingham Epilepsy Center (UABEC), Birmingham, AL, United States
| | - Rodolphe Nenert
- University of Alabama at Birmingham Epilepsy Center (UABEC), Birmingham, AL, United States
- Department of Neurology, University of Alabama at Birmingham (UAB), Birmingham, AL, United States
| | - Christina Mueller
- Department of Psychology, University of Alabama at Birmingham (UAB), Birmingham, AL, United States
| | - Andrew A. Maudsley
- Department of Radiology, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Jarred W. Younger
- Department of Psychology, University of Alabama at Birmingham (UAB), Birmingham, AL, United States
| | - Jerzy P. Szaflarski
- Department of Neurobiology, University of Alabama at Birmingham (UAB), Birmingham, AL, United States
- University of Alabama at Birmingham Epilepsy Center (UABEC), Birmingham, AL, United States
- Department of Neurology, University of Alabama at Birmingham (UAB), Birmingham, AL, United States
- Department of Neurosurgery, University of Alabama at Birmingham (UAB), Birmingham, AL, United States
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14
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Sharma AA, Szaflarski JP. In Vivo Imaging of Neuroinflammatory Targets in Treatment-Resistant Epilepsy. Curr Neurol Neurosci Rep 2020; 20:5. [PMID: 32166626 DOI: 10.1007/s11910-020-1025-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE OF REVIEW Recent evidence indicates that chronic, low-level neuroinflammation underlies epileptogenesis. Targeted imaging of key neuroinflammatory cells, receptors, and tissues may enable localizing epileptogenic onset zone, especially in those patients who are treatment-resistant and considered MRI-negative. Finding a specific, sensitive neuroimaging-based biomarker could aid surgical planning and improve overall prognosis in eligible patients. This article reviews recent research on in vivo imaging of neuroinflammatory targets in patients with treatment-resistant, non-lesional epilepsy. RECENT FINDINGS A number of advanced approaches based on imaging neuroinflammation are being implemented in order to assist localization of epileptogenic onset zone. The most exciting tools are based on radioligand-based nuclear imaging or revisiting of existing technology in novel ways. The greatest limitations stem from gaps in knowledge about the exact function of neuroinflammatory targets (e.g., neurotoxic or neuroprotective). Further, lingering questions about each approach's specificity, reliability, and sensitivity must be addressed, and clinical utility must be validated before any novel method is incorporated into mainstream clinical practice. Current applications of imaging neuroinflammation in humans are limited and underutilized, but offer hope for finding sensitive and specific neuroimaging-based biomarker(s). Future work necessitates appreciation of investigations to date, significant findings, and neuroinflammatory targets worth exploring further.
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Affiliation(s)
- Ayushe A Sharma
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA. .,Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35249-0021, USA.
| | - Jerzy P Szaflarski
- Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35249-0021, USA.,University of Alabama at Birmingham Epilepsy Center, Birmingham, AL, USA
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15
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Abud LG, Velasco TR, Salmon CEG, Sakamoto AC, Abud TG, Pessini RA, Abud DG, Leite JP, dos Santos AC. Multimodal quantitative magnetic resonance imaging analysis with individualized postprocessing in patients with drug-resistant focal epilepsy and conventional visual inspection negative for epileptogenic lesions. Clinics (Sao Paulo) 2019; 74:e908. [PMID: 31340255 PMCID: PMC6636588 DOI: 10.6061/clinics/2019/e908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 04/02/2019] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES Approximately one-third of candidates for epilepsy surgery have no visible abnormalities on conventional magnetic resonance imaging. This is extremely discouraging, as these patients have a less favorable prognosis. We aimed to evaluate the utility of quantitative magnetic resonance imaging in patients with drug-resistant neocortical focal epilepsy and negative imaging. METHODS A prospective study including 46 patients evaluated through individualized postprocessing of five quantitative measures: cortical thickness, white and gray matter junction signal, relaxation rate, magnetization transfer ratio, and mean diffusivity. Scalp video-electroencephalography was used to suggest the epileptogenic zone. A volumetric fluid-attenuated inversion recovery sequence was performed to aid visual inspection. A critical assessment of follow-up was also conducted throughout the study. RESULTS In the subgroup classified as having an epileptogenic zone, individualized postprocessing detected abnormalities within the region of electroclinical origin in 9.7% to 31.0% of patients. Abnormalities outside the epileptogenic zone were more frequent, up to 51.7%. In five patients initially included with negative imaging, an epileptogenic structural abnormality was identified when a new visual magnetic resonance imaging inspection was guided by information gleaned from postprocessing. In three patients, epileptogenic lesions were detected after visual evaluation with volumetric fluid-attenuated sequence guided by video electroencephalography. CONCLUSION Although quantitative magnetic resonance imaging analyses may suggest hidden structural lesions, caution is warranted because of the apparent low specificity of these findings for the epileptogenic zone. Conversely, these methods can be used to prevent visible lesions from being ignored, even in referral centers. In parallel, we need to highlight the positive contribution of the volumetric fluid-attenuated sequence.
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Affiliation(s)
- Lucas Giansante Abud
- Divisao de Neurorradiologia, Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP, BR
- *Corresponding author. E-mail:
| | - Tonicarlo Rodrigues Velasco
- Departamento de Neurologia, Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP, BR
| | - Carlos Ernesto Garrido Salmon
- Departamento de Fisica e Matematica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP, BR
| | - Americo Ceiki Sakamoto
- Departamento de Neurologia, Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP, BR
| | - Thiago Giansante Abud
- Departamento de Diagnostico por Imagem, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, SP, BR
| | - Rodrigo Antonio Pessini
- Divisao de Ciencias da Imagem e Fisica Medica, Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP, BR
| | - Daniel Giansante Abud
- Divisao de Neurorradiologia, Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP, BR
| | - João Pereira Leite
- Departamento de Neurologia, Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP, BR
| | - Antonio Carlos dos Santos
- Divisao de Neurorradiologia, Faculdade de Medicina de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, SP, BR
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16
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Ma D, Jones SE, Deshmane A, Sakaie K, Pierre EY, Larvie M, McGivney D, Blümcke I, Krishnan B, Lowe M, Gulani V, Najm I, Griswold MA, Wang ZI. Development of high-resolution 3D MR fingerprinting for detection and characterization of epileptic lesions. J Magn Reson Imaging 2018; 49:1333-1346. [DOI: 10.1002/jmri.26319] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/10/2018] [Accepted: 08/10/2018] [Indexed: 12/25/2022] Open
Affiliation(s)
- Dan Ma
- Radiology; Case Western Reserve University; Cleveland Ohio USA
| | | | - Anagha Deshmane
- Magnetic Resonance Center; Max Planck Institute for Biological Cybernetics; Tuebingen Germany
| | - Ken Sakaie
- Imaging Institute, Cleveland Clinic; Cleveland Ohio USA
| | - Eric Y. Pierre
- Florey Institute of Neuroscience and Mental Health; Melbourne Australia
| | - Mykol Larvie
- Imaging Institute, Cleveland Clinic; Cleveland Ohio USA
| | - Debra McGivney
- Radiology; Case Western Reserve University; Cleveland Ohio USA
| | - Ingmar Blümcke
- Epilepsy Center; Cleveland Clinic; Cleveland Ohio USA
- Institute of Neuropathology, University Hospitals Erlangen; Erlangen Germany
| | - Balu Krishnan
- Epilepsy Center; Cleveland Clinic; Cleveland Ohio USA
| | - Mark Lowe
- Imaging Institute, Cleveland Clinic; Cleveland Ohio USA
| | - Vikas Gulani
- Radiology; Case Western Reserve University; Cleveland Ohio USA
| | - Imad Najm
- Epilepsy Center; Cleveland Clinic; Cleveland Ohio USA
| | | | - Z. Irene Wang
- Epilepsy Center; Cleveland Clinic; Cleveland Ohio USA
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17
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Umino M, Maeda M, Ii Y, Tomimoto H, Sakuma H. 3D double inversion recovery MR imaging: Clinical applications and usefulness in a wide spectrum of central nervous system diseases. J Neuroradiol 2018; 46:107-116. [PMID: 30016704 DOI: 10.1016/j.neurad.2018.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/03/2018] [Accepted: 06/23/2018] [Indexed: 12/31/2022]
Abstract
Double inversion recovery (DIR) imaging provides two inversion pulses that attenuate signals from cerebrospinal fluid and normal white matter. This review was undertaken to describe the principle of the DIR sequence, the clinical applications of 3D DIR in various central nervous system diseases and the clinical benefits of the 3D DIR compared with those of other MR sequences. 3D DIR imaging provides better lesion conspicuity and topography than other MR techniques. It is particularly useful for diagnosing the following disease entities: cortical and subcortical abnormalities such as multiple sclerosis, cortical microinfarcts and cortical development anomalies; sulcal abnormalities such as meningitis and subacute/chronic subarachnoid hemorrhage; and optic neuritis caused by multiple sclerosis or neuromyelitis optica.
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Affiliation(s)
- Maki Umino
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, 514-8507 Tsu, Mie, Japan.
| | - Masayuki Maeda
- Department of Advanced Diagnostic Imaging, Mie University School of Medicine, Tsu, Mie, Japan
| | - Yuichiro Ii
- Department of Neurology, Mie University School of Medicine, Tsu, Mie, Japan
| | - Hidekazu Tomimoto
- Department of Neurology, Mie University School of Medicine, Tsu, Mie, Japan
| | - Hajime Sakuma
- Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, 514-8507 Tsu, Mie, Japan
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18
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Martin P, Winston GP, Bartlett P, de Tisi J, Duncan JS, Focke NK. Voxel-based magnetic resonance image postprocessing in epilepsy. Epilepsia 2017; 58:1653-1664. [PMID: 28745400 PMCID: PMC5601223 DOI: 10.1111/epi.13851] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2017] [Indexed: 12/20/2022]
Abstract
Objective Although the general utility of voxel‐based processing of structural magnetic resonance imaging (MRI) data for detecting occult lesions in focal epilepsy is established, many differences exist among studies, and it is unclear which processing method is preferable. The aim of this study was to compare the ability of commonly used methods to detect epileptogenic lesions in magnetic resonance MRI‐positive and MRI‐negative patients, and to estimate their diagnostic yield. Methods We identified 144 presurgical focal epilepsy patients, 15 of whom had a histopathologically proven and MRI‐visible focal cortical dysplasia; 129 patients were MRI negative with a clinical hypothesis of seizure origin, 27 of whom had resections. We applied four types of voxel‐based morphometry (VBM), three based on T1 images (gray matter volume, gray matter concentration, junction map [JM]) and one based on normalized fluid‐attenuated inversion recovery (nFSI). Specificity was derived from analysis of 50 healthy controls. Results The four maps had different sensitivity and specificity profiles. All maps showed detection rates for focal cortical dysplasia patients (MRI positive and negative) of >30% at a strict threshold of p < 0.05 (family‐wise error) and >60% with a liberal threshold of p < 0.0001 (uncorrected), except for gray matter volume (14% and 27% detection rate). All maps except nFSI showed poor specificity, with high rates of false‐positive findings in controls. In the MRI‐negative patients, absolute detection rates were lower. A concordant nFSI finding had a significant positive odds ratio of 7.33 for a favorable postsurgical outcome in the MRI‐negative group. Spatial colocalization of JM and nFSI was rare, yet showed good specificity throughout the thresholds. Significance All VBM variants had specific diagnostic properties that need to be considered for an adequate interpretation of the results. Overall, structural postprocessing can be a useful tool in presurgical diagnostics, but the low specificity of some maps has to be taken into consideration.
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Affiliation(s)
- Pascal Martin
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Gavin P Winston
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom.,Epilepsy Society MRI Unit, Chalfont St, Peter, United Kingdom
| | - Philippa Bartlett
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom.,Epilepsy Society MRI Unit, Chalfont St, Peter, United Kingdom
| | - Jane de Tisi
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom.,Epilepsy Society MRI Unit, Chalfont St, Peter, United Kingdom
| | - John S Duncan
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, United Kingdom.,Epilepsy Society MRI Unit, Chalfont St, Peter, United Kingdom
| | - Niels K Focke
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,Clinical Neurophysiology, University Clinic, Göttingen, Germany
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19
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Abstract
PURPOSE OF REVIEW Advanced MRI postprocessing techniques are increasingly used to complement visual analysis and elucidate structural epileptogenic lesions. This review summarizes recent developments in MRI postprocessing in the context of epilepsy presurgical evaluation, with the focus on patients with unremarkable MRI by visual analysis (i.e. 'nonlesional' MRI). RECENT FINDINGS Various methods of MRI postprocessing have been reported to show additional clinical values in the following areas: lesion detection on an individual level; lesion confirmation for reducing the risk of over reading the MRI; detection of sulcal/gyral morphologic changes that are particularly difficult for visual analysis; and delineation of cortical abnormalities extending beyond the visible lesion. Future directions to improve the performance of MRI postprocessing include using higher magnetic field strength for better signal-to-noise ratio and contrast-to-noise ratio adopting a multicontrast frame work and integration with other noninvasive modalities. SUMMARY MRI postprocessing can provide essential value to increase the yield of structural MRI and should be included as part of the presurgical evaluation of nonlesional epilepsies. MRI postprocessing allows for more accurate identification/delineation of cortical abnormalities, which should then be more confidently targeted and mapped.
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20
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Wychowski T, Hussain A, Tivarus ME, Birbeck GL, Berg MJ, Potchen M. Qualitative analysis of double inversion recovery MRI in drug-resistant epilepsy. Epilepsy Res 2016; 127:195-199. [PMID: 27619358 DOI: 10.1016/j.eplepsyres.2016.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 08/12/2016] [Accepted: 09/01/2016] [Indexed: 11/17/2022]
Abstract
PURPOSE To determine whether Double Inversion Recovery (DIR) on 3T MRI can enhance detection of epileptogenic lesions Methods: 29 adult patients with DRE were enrolled in a prospective pilot study. Brain MRIs were obtained using a specialized protocol that included: (1) Fast-Spin EchoT2, (2) T2 fluid attenuated inversion recovery (FLAIR), and (3) DIR sequences. Two neuroradiologists blinded to clinical information independently reviewed each sequence in the order listed above for T2-hyperintense lesions. Cortical lesions were determined to be concordant with the epileptic focus based upon available clinical and electrodiagnostic testing. RESULTS Of 29 studies, 21 had a lesion identified with 13/21 abnormalities being non-specific. Of 8 remaining studies, 3 revealed a lesion only with DIR sequencing. DIR-lesions were concordant with clinical data in 1 subject, non-discordant in 1 subject, and discordant in 1 subject. SIGNIFICANCE DIR has the potential to be more sensitive in detecting cortically based lesions relative to standard imaging. More data are needed to assess the sensitivity and specificity of DIR, particularly as it pertains to identification of epileptogenic lesions using electrodiagnostic testing and outcome after surgery.
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Affiliation(s)
- Thomas Wychowski
- Department of Neurology, Strong Memorial Hospital, University of Rochester, 601 Elmwood Ave., Box 673, Rochester, NY 14642 USA.
| | - Ali Hussain
- Department of Imaging Sciences, Strong Memorial Hospital, University of Rochester, 601 Elmwood Ave., Box 648, Rochester, NY 14642 USA
| | - Madalina E Tivarus
- Department of Imaging Sciences, Strong Memorial Hospital, University of Rochester, 601 Elmwood Ave., Box 648, Rochester, NY 14642 USA
| | - Gretchen L Birbeck
- Department of Neurology, Strong Memorial Hospital, University of Rochester, 601 Elmwood Ave., Box 673, Rochester, NY 14642 USA
| | - Michel J Berg
- Department of Neurology, Strong Memorial Hospital, University of Rochester, 601 Elmwood Ave., Box 673, Rochester, NY 14642 USA
| | - Michael Potchen
- Department of Imaging Sciences, Strong Memorial Hospital, University of Rochester, 601 Elmwood Ave., Box 648, Rochester, NY 14642 USA
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Colon AJ, van Osch MJP, Buijs M, Grond JVD, Boon P, van Buchem MA, Hofman PAM. Detection superiority of 7 T MRI protocol in patients with epilepsy and suspected focal cortical dysplasia. Acta Neurol Belg 2016; 116:259-69. [PMID: 27389578 PMCID: PMC4989014 DOI: 10.1007/s13760-016-0662-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 06/14/2016] [Indexed: 12/12/2022]
Abstract
In 11 adult patients with suspicion of Focal cortical dysplasia (FCD) on 1.5 T (n = 1) or 3 T (n = 10) magnetic resonance imaging (MRI), 7 T MRI was performed. Visibility, extent, morphological features and delineation were independently rated and subsequently discussed by three observers. Additionally, head-to-head comparisons with corresponding 3 T images were made in the eight patients with a previous 3 T MRI and sustained suspicion of FCD. Comparison with histopathology was done in the five patients that underwent surgery. All lesions, seen at 1.5 and 3 T, were also recognized on 7 T. At 7 T FLAIR highlighted the FCD-like lesions best, whereas T2 and T2* were deemed better suited to review structure and extent of the lesion. Image quality with the used 7 T MRI setup was higher than the quality with the used 3 T MRI setup. In 2 out of 11 patients diagnosis changed, in one after re-evaluation of the images, and in the other based on histopathology. With the used 7 T MRI setup, FCD-like lesions can be detected with more confidence and detail as compared to lower field strength. However, concordance between radiologic diagnosis and final diagnosis seems to be lower than expected.
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Affiliation(s)
- A J Colon
- Academic Center for Epileptology Kempenhaeghe, Maastricht Universitair Medisch Centrum + (MUMC+), Sterkselseweg 65, 5590 VE, Heeze, The Netherlands.
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands.
- Department of Neurology, University Hospital Gent, Ghent, Belgium.
| | - M J P van Osch
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - M Buijs
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - J V D Grond
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - P Boon
- Academic Center for Epileptology Kempenhaeghe, Maastricht Universitair Medisch Centrum + (MUMC+), Sterkselseweg 65, 5590 VE, Heeze, The Netherlands
- Department of Neurology, University Hospital Gent, Ghent, Belgium
| | - M A van Buchem
- Department of Radiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - P A M Hofman
- Academic Center for Epileptology Kempenhaeghe, Maastricht Universitair Medisch Centrum + (MUMC+), Sterkselseweg 65, 5590 VE, Heeze, The Netherlands
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Martinez-Rios C, McAndrews MP, Logan W, Krings T, Lee D, Widjaja E. MRI in the evaluation of localization-related epilepsy. J Magn Reson Imaging 2016; 44:12-22. [PMID: 27115073 DOI: 10.1002/jmri.25269] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 03/28/2016] [Indexed: 11/06/2022] Open
Abstract
This article covers the MRI evaluation of patients with epilepsy, with a focus on neuroimaging in those with localization-related epilepsy who may be potential epilepsy surgery candidates. The article includes structural MRI to identify a lesion, functional MRI to identify the eloquent cortex and diffusion tensor imaging to identify the eloquent white matter tracts. We consider the equipment, protocol or procedures, and reporting of MRI in patients with epilepsy. Recommendations for both adult and pediatric patients are described for protocols and procedures. The authors hope that this article will provide a standardized approach for clinical imaging of patients with suspected localization-related epilepsy who may be evaluated for epilepsy surgery. J. Magn. Reson. Imaging 2016.
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Affiliation(s)
| | | | - William Logan
- Division of Neurology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Timo Krings
- University Health Network, Toronto, Ontario, Canada
| | - Donald Lee
- London Health Sciences Center, London, Ontario, Canada
| | - Elysa Widjaja
- Department of Radiology, Hospital for Sick Children, Toronto, Ontario, Canada
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Duncan JS, Winston GP, Koepp MJ, Ourselin S. Brain imaging in the assessment for epilepsy surgery. Lancet Neurol 2016; 15:420-33. [PMID: 26925532 DOI: 10.1016/s1474-4422(15)00383-x] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/22/2015] [Accepted: 12/02/2015] [Indexed: 01/14/2023]
Abstract
Brain imaging has a crucial role in the presurgical assessment of patients with epilepsy. Structural imaging reveals most cerebral lesions underlying focal epilepsy. Advances in MRI acquisitions including diffusion-weighted imaging, post-acquisition image processing techniques, and quantification of imaging data are increasing the accuracy of lesion detection. Functional MRI can be used to identify areas of the cortex that are essential for language, motor function, and memory, and tractography can reveal white matter tracts that are vital for these functions, thus reducing the risk of epilepsy surgery causing new morbidities. PET, SPECT, simultaneous EEG and functional MRI, and electrical and magnetic source imaging can be used to infer the localisation of epileptic foci and assist in the design of intracranial EEG recording strategies. Progress in semi-automated methods to register imaging data into a common space is enabling the creation of multimodal three-dimensional patient-specific datasets. These techniques show promise for the demonstration of the complex relations between normal and abnormal structural and functional data and could be used to direct precise intracranial navigation and surgery for individual patients.
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Affiliation(s)
- John S Duncan
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK; Chalfont Centre for Epilepsy, Chalfont St Peter, Gerrards Cross, UK.
| | - Gavin P Winston
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK; Chalfont Centre for Epilepsy, Chalfont St Peter, Gerrards Cross, UK
| | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK; Chalfont Centre for Epilepsy, Chalfont St Peter, Gerrards Cross, UK
| | - Sebastien Ourselin
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK; Translational Imaging Group, Centre for Medical Image Computing, University College London, London, UK; National Hospital for Neurology and Neurosurgery, London, UK
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Wang ZI, Jones SE, Jaisani Z, Najm IM, Prayson RA, Burgess RC, Krishnan B, Ristic A, Wong CH, Bingaman W, Gonzalez-Martinez JA, Alexopoulos AV. Voxel-based morphometric magnetic resonance imaging (MRI) postprocessing in MRI-negative epilepsies. Ann Neurol 2015; 77:1060-75. [PMID: 25807928 DOI: 10.1002/ana.24407] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 03/02/2015] [Accepted: 03/15/2015] [Indexed: 11/06/2022]
Abstract
OBJECTIVE In the presurgical workup of magnetic resonance imaging (MRI)-negative (MRI(-) or "nonlesional") pharmacoresistant focal epilepsy (PFE) patients, discovering a previously undetected lesion can drastically change the evaluation and likely improve surgical outcome. Our study utilizes a voxel-based MRI postprocessing technique, implemented in a morphometric analysis program (MAP), to facilitate detection of subtle abnormalities in a consecutive cohort of MRI(-) surgical candidates. METHODS Included in this retrospective study was a consecutive cohort of 150 MRI(-) surgical patients. MAP was performed on T1-weighted MRI, with comparison to a scanner-specific normal database. Review and analysis of MAP were performed blinded to patients' clinical information. The pertinence of MAP(+) areas was confirmed by surgical outcome and pathology. RESULTS MAP showed a 43% positive rate, sensitivity of 0.9, and specificity of 0.67. Overall, patients with the MAP(+) region completely resected had the best seizure outcomes, followed by the MAP(-) patients, and patients who had no/partial resection of the MAP(+) region had the worst outcome (p < 0.001). Subgroup analysis revealed that visually identified subtle findings are more likely correct if also MAP(+) . False-positive rate in 52 normal controls was 2%. Surgical pathology of the resected MAP(+) areas contained mainly non-balloon-cell focal cortical dysplasia (FCD). Multiple MAP(+) regions were present in 7% of patients. INTERPRETATION MAP can be a practical and valuable tool to: (1) guide the search for subtle MRI abnormalities and (2) confirm visually identified questionable abnormalities in patients with PFE due to suspected FCD. A MAP(+) region, when concordant with the patient's electroclinical presentation, should provide a legitimate target for surgical exploration.
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Affiliation(s)
- Z Irene Wang
- Epilepsy Center, Cleveland Clinic, Cleveland, OH
| | - Stephen E Jones
- Department of Diagnostic Radiology, Mellen Imaging Center, Cleveland Clinic, Cleveland, OH
| | | | - Imad M Najm
- Epilepsy Center, Cleveland Clinic, Cleveland, OH
| | | | | | | | - Aleksandar Ristic
- Clinic of Neurology, Epilepsy Center, Clinical Center of Serbia, Belgrade, Serbia
| | - Chong H Wong
- Department of Neurology, Westmead Hospital, Sydney, Australia
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Martin P, Bender B, Focke NK. Post-processing of structural MRI for individualized diagnostics. Quant Imaging Med Surg 2015; 5:188-203. [PMID: 25853079 DOI: 10.3978/j.issn.2223-4292.2015.01.10] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 01/28/2015] [Indexed: 11/14/2022]
Abstract
Currently, a relevant proportion of all histopathologically proven focal cortical dysplasia (FCD) escape visual detection; this shows the need for additional improvements in analyzing MRI data. A positive MRI is still the strongest prognostic factor for postoperative freedom of seizures. Among several post-processing methods voxel-based morphometry (VBM) of T1- and T2-weighted sequences and T2 relaxometry are routinely applied in pre-surgical diagnostics of cryptogenic epilepsy in epilepsy centers. VBM is superior to conventional visual analysis with 9-15% more identified epileptogenic foci, while T2 relaxometry has its main application in (mesial) temporal lobe epilepsy. Further methods such as surface-based morphometry (SBM) or diffusion tensor imaging are promising but there is a lack of current studies comparing their individual diagnostic value. Post-processing methods represent an important addition to conventional visual analysis but need to be interpreted with expertise and experience so that they should be apprehended as a complementary tool within the context of the multi-modal evaluation of epilepsy patients. This review will give an overview of existing post-processing methods of structural MRI and outline their clinical relevance in detection of epileptogenic structural changes.
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Affiliation(s)
- Pascal Martin
- 1 Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, 2 Department of Diagnostic and Interventional Neuroradiology, University of Tübingen, 72076 Tübingen, Germany
| | - Benjamin Bender
- 1 Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, 2 Department of Diagnostic and Interventional Neuroradiology, University of Tübingen, 72076 Tübingen, Germany
| | - Niels K Focke
- 1 Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, 2 Department of Diagnostic and Interventional Neuroradiology, University of Tübingen, 72076 Tübingen, Germany
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Gasparini S, Ferlazzo E, Beghi E, Sofia V, Mumoli L, Labate A, Cianci V, Fatuzzo D, Bellavia MA, Arcudi L, Russo E, De Sarro G, Gambardella A, Aguglia U. Epilepsy associated with Leukoaraiosis mainly affects temporal lobe: a casual or causal relationship? Epilepsy Res 2015; 109:1-8. [DOI: 10.1016/j.eplepsyres.2014.10.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/14/2014] [Accepted: 10/18/2014] [Indexed: 10/24/2022]
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Wang ZI, Alexopoulos AV, Jones SE, Najm IM, Ristic A, Wong C, Prayson R, Schneider F, Kakisaka Y, Wang S, Bingaman W, Gonzalez-Martinez JA, Burgess RC. Linking MRI postprocessing with magnetic source imaging in MRI-negative epilepsy. Ann Neurol 2014; 75:759-70. [PMID: 24777960 DOI: 10.1002/ana.24169] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 04/25/2014] [Accepted: 04/26/2014] [Indexed: 11/08/2022]
Abstract
OBJECTIVE MRI-negative (MRI-) pharmacoresistant focal epilepsy (PFE) patients are most challenging for epilepsy surgical management. This study utilizes a voxel-based MRI postprocessing technique, implemented using a morphometric analysis program (MAP), aiming to facilitate detection of subtle focal cortical dysplasia (FCD) in MRI- patients. Furthermore, the study examines the concordance between MAP-identified regions and localization from magnetic source imaging (MSI). METHODS Included in this retrospective study were 25 MRI- surgical patients. MAP was performed on T1-weighted MRI, with comparison to a normal database. The pertinence of MAP+ areas was confirmed by MSI, surgical outcome and pathology. Analyses of MAP and MSI were performed blindly from patients' clinical information and independently from each other. RESULTS The detection rate of subtle changes by MAP was 48% (12/25). Once MAP+ areas were resected, patients were more likely to be seizure-free (p=0.02). There were no false positives in the 25 age-matched normal controls. Seven patients had a concordant MSI correlate. Patients in whom a concordant area was identified by both MAP and MSI had a significantly higher chance of achieving a seizure-free outcome following complete resection of this area (p=0.008). In the 9 resected MAP+ areas, pathology revealed FCD type IA in 7 and type IIB in 2. INTERPRETATION MAP shows promise in identifying subtle FCD abnormalities and increasing the diagnostic yield of conventional MRI visual analysis in presurgical evaluation of PFE. Concordant MRI postprocessing and MSI analyses may lead to the noninvasive identification of a structurally and electrically abnormal subtle lesion that can be surgically targeted.
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Affiliation(s)
- Zhong I Wang
- Epilepsy Center, Cleveland Clinic, Cleveland, OH
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Morimoto E, Okada T, Kanagaki M, Yamamoto A, Fushimi Y, Matsumoto R, Takaya S, Ikeda A, Kunieda T, Kikuchi T, Paul D, Miyamoto S, Takahashi R, Togashi K. Evaluation of focus laterality in temporal lobe epilepsy: A quantitative study comparing double inversion-recovery MR imaging at 3T with FDG-PET. Epilepsia 2013; 54:2174-83. [DOI: 10.1111/epi.12396] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2013] [Indexed: 11/26/2022]
Affiliation(s)
- Emiko Morimoto
- Diagnostic Imaging and Nuclear Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Tomohisa Okada
- Diagnostic Imaging and Nuclear Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Mitsunori Kanagaki
- Diagnostic Imaging and Nuclear Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Akira Yamamoto
- Diagnostic Imaging and Nuclear Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Yasutaka Fushimi
- Diagnostic Imaging and Nuclear Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Riki Matsumoto
- Neurology; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Shigetoshi Takaya
- Human Brain Research Center; Kyoto University Graduate School of Medicine; Kyoto Japan
- Radioisotope Research Center; Kyoto University; Kyoto Japan
- Athinoula A. Martinos Center for Biomedical Imaging; Harvard Medical School; Massachusetts General Hospital; Charlestown Massachusetts U.S.A
| | - Akio Ikeda
- Neurology; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Takeharu Kunieda
- Neurosurgery; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Takayuki Kikuchi
- Neurosurgery; Kyoto University Graduate School of Medicine; Kyoto Japan
| | | | - Susumu Miyamoto
- Neurosurgery; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Ryosuke Takahashi
- Neurology; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Kaori Togashi
- Diagnostic Imaging and Nuclear Medicine; Kyoto University Graduate School of Medicine; Kyoto Japan
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Wang ZI, Ristic AJ, Wong CH, Jones SE, Najm IM, Schneider F, Wang S, Gonzalez-Martinez JA, Bingaman W, Alexopoulos AV. Neuroimaging characteristics of MRI-negative orbitofrontal epilepsy with focus on voxel-based morphometric MRI postprocessing. Epilepsia 2013; 54:2195-2203. [PMID: 24116733 DOI: 10.1111/epi.12390] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2013] [Indexed: 11/30/2022]
Abstract
PURPOSE The orbitofrontal (OF) region is one of the least explored regions of the cerebral cortex. There are few studies on patients with electrophysiologically and surgically confirmed OF epilepsy and a negative magnetic resonance imaging (MRI) study. We aimed to examine the neuroimaging characteristics of MRI-negative OF epilepsy with the focus on a voxel-based morphometric MRI postprocessing technique. METHODS We included six patients with OF epilepsy, who met the following criteria: surgical resection of the OF lobe with/without adjacent cortex, seizure-free for ≥12 months, invasive video-electroencephalography (EEG) monitoring showing ictal onset from the OF area, and preoperative MRI regarded as negative. Patients were investigated in terms of their image postprocessing and functional neuroimaging characteristics, electroclinical characteristics obtained from noninvasive and invasive evaluations, and surgical pathology. MRI postprocessing on T1 -weighted high-resolution scans was implemented with a morphometric analysis program (MAP) in MATLAB. KEY FINDINGS Single MAP+ abnormalities were found in four patients; three were in the OF region and one in the ipsilateral mesial frontal area. These abnormalities were included in the resection. One patient had bilateral MAP+ abnormalities in the OF region, with the ipsilateral one completely removed. The MAP+ foci were concordant with invasive electrophysiologic data in the majority of MAP+ patients (four of five). The localization value of 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) and ictal single-photon emission computed tomography (SPECT) is low in this cohort. Surgical pathology included focal cortical dysplasia, remote infarct, Rosenthal fiber formation and gliosis. SIGNIFICANCE Our study highlights the importance of MRI postprocessing in the process of presurgical evaluation of patients with suspected orbitofrontal epilepsy and "normal" MRI. Using MAP, we were able to positively identify subtle focal abnormalities in the majority of the patients. MAP results need to be interpreted in the context of their electroclinical findings and can provide valuable targets in the process of planning invasive evaluation.
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Affiliation(s)
| | - Aleksandar J Ristic
- Epilepsy Center Neurology Clinic, Clinical Center of Serbia Dr Subotica 6, 11000 Belgrade, Serbia
| | - Chong H Wong
- Department of Neurology, Westmead Hospital, Sydney, Australia
| | | | | | - Felix Schneider
- Department of Neurology, Epilepsy Center, University of Greifswald, Greifswald, Germany
| | - Shuang Wang
- Epilepsy Center, Second Affiliated Hospital, Zhejiang University, Hangzhou, China
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Memarian N, Thompson PM, Engel J, Staba RJ. Quantitative analysis of structural neuroimaging of mesial temporal lobe epilepsy. ACTA ACUST UNITED AC 2013; 5. [PMID: 24319498 DOI: 10.2217/iim.13.28] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mesial temporal lobe epilepsy (MTLE) is the most common of the surgically remediable drug-resistant epilepsies. MRI is the primary diagnostic tool to detect anatomical abnormalities and, when combined with EEG, can more accurately identify an epileptogenic lesion, which is often hippocampal sclerosis in cases of MTLE. As structural imaging technology has advanced the surgical treatment of MTLE and other lesional epilepsies, so too have the analysis techniques that are used to measure different structural attributes of the brain. These techniques, which are reviewed here and have been used chiefly in basic research of epilepsy and in studies of MTLE, have identified different types and the extent of anatomical abnormalities that can extend beyond the affected hippocampus. These results suggest that structural imaging and sophisticated imaging analysis could provide important information to identify networks capable of generating spontaneous seizures and ultimately help guide surgical therapy that improves postsurgical seizure-freedom outcomes.
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Affiliation(s)
- Negar Memarian
- Department of Neurology, Reed, Neurological Research Center, Suite, 2155, University of California, 710 Westwood Plaza, Los Angeles, CA 90095, USA
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Mueller SG, Young K, Hartig M, Barakos J, Garcia P, Laxer KD. A two-level multimodality imaging Bayesian network approach for classification of partial epilepsy: preliminary data. Neuroimage 2013; 71:224-32. [PMID: 23353601 PMCID: PMC3619666 DOI: 10.1016/j.neuroimage.2013.01.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 12/27/2012] [Accepted: 01/13/2013] [Indexed: 10/27/2022] Open
Abstract
BACKGROUND Quantitative neuroimaging analyses have demonstrated gray and white matter abnormalities in group comparisons of different types of non-lesional partial epilepsy. It is unknown to what degree these type-specific patterns exist in individual patients and if they could be exploited for diagnostic purposes. In this study, a two-level multi-modality imaging Bayesian network approach is proposed that uses information about individual gray matter volume loss and white matter integrity to classify non-lesional temporal lobe epilepsy with (TLE-MTS) and without (TLE-no) mesial-temporal sclerosis and frontal lobe epilepsy (FLE). METHODS 25 controls, 19 TLE-MTS, 22 TLE-no and 14 FLE were studied on a 4T MRI and T1 weighted structural and DTI images acquired. Spatially normalized gray matter (GM) and fractional anisotropy (FA) abnormality maps (binary maps with voxels 1 SD below control mean) were calculated for each subject. At the first level, each group's abnormality maps were compared with those from all the other groups using Graphical-Model-based Morphometric Analysis (GAMMA). GAMMA uses a Bayesian network and a Markov random field based contextual clustering method to produce maps of voxels that provide the maximal distinction between two groups and calculates a probability distribution and a group assignment based on this information. The information was then combined in a second level Bayesian network and the probability of each subject to belong to one of the three epilepsy types calculated. RESULTS The specificities of the two level Bayesian network to distinguish between the three patient groups were 0.87 for TLE-MTS and TLE-no and 0.86 for FLE, the corresponding sensitivities were 0.84 for TLE-MTS, 0.72 for TLE-no and 0.64 for FLE. CONCLUSION The two-level multi-modality Bayesian network approach was able to distinguish between the three epilepsy types with a reasonably high accuracy even though the majority of the images were completely normal on visual inspection.
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Affiliation(s)
- Susanne G Mueller
- Center for Imaging of Neurodegenerative Diseases, VA Medical Center, San Francisco, USA.
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Anterior temporal lobe white matter abnormal signal (ATLAS) as an indicator of seizure focus laterality in temporal lobe epilepsy: comparison of double inversion recovery, FLAIR and T2W MR imaging. Eur Radiol 2012; 23:3-11. [PMID: 22811046 DOI: 10.1007/s00330-012-2565-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 05/17/2012] [Accepted: 05/28/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVES To investigate the diagnostic capability of anterior temporal lobe white matter abnormal signal (ATLAS) for determining seizure focus laterality in temporal lobe epilepsy (TLE) by comparing different MR sequences. METHODS This prospective study was approved by the institutional review board and written informed consent was obtained. Three 3D sequences (double inversion recovery (DIR), fluid-attenuated inversion recovery (FLAIR) and T2-weighted imaging (T2WI)) and two 2D sequences (FLAIR and T2WI) were acquired at 3 T. Signal changes in the anterior temporal white matter of 21 normal volunteers were evaluated. ATLAS laterality was evaluated in 21 TLE patients. Agreement of independent evaluations by two neuroradiologists was assessed using κ statistics. Differences in concordance between ATLAS laterality and clinically defined seizure focus laterality were analysed using McNemar's test with multiple comparisons. RESULTS Pre-amygdala high signals (PAHS) were detected in all volunteers only on 3D-DIR. Inter-evaluator agreement was moderate to almost perfect for each sequence. Correct diagnosis of seizure laterality was significantly more frequent on 3D-DIR than on any other sequences (P ≤ 0.031 for each evaluator). CONCLUSIONS The most sensitive sequence for detecting ATLAS laterality was 3D-DIR. ATLAS laterality on 3D-DIR can be a good indicator for determining seizure focus localization in TLE.
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Riney CJ, Chong WK, Clark CA, Cross JH. Voxel based morphometry of FLAIR MRI in children with intractable focal epilepsy: Implications for surgical intervention. Eur J Radiol 2012; 81:1299-305. [DOI: 10.1016/j.ejrad.2010.12.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 12/17/2010] [Indexed: 10/18/2022]
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Voxel-based relaxometry for cases of an unresolved epilepsy diagnosis. Epilepsy Res 2012; 99:46-54. [PMID: 22342566 DOI: 10.1016/j.eplepsyres.2011.10.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Revised: 10/03/2011] [Accepted: 10/09/2011] [Indexed: 11/23/2022]
Abstract
PURPOSE Voxel-based relaxometry (VBR) is a technique in which a voxel-level statistical comparison of quantitative MR T2 maps is performed to identify regions with significantly elevated T2 relaxation time. Our objective was to assess the performance of single-subject VBR at 3T as a diagnostic tool for patients whose diagnosis of epilepsy or seizure focus location is uncertain. METHODS Fifty-nine patients with possible epilepsy or known epilepsy, but an unknown focus and forty-five healthy controls were studied. All subjects were scanned at 3T using a Carr-Purcell-Meiboom-Gill MR sequence. Single-subject VBR was performed at a significance level of α=0.001. Patients were classified based on whether the diagnosis of epilepsy was in question and whether there was a suspected focus. A VBR score was determined based on the presence of VBR abnormalities in any of 13 predefined regions per hemisphere. RESULTS All patients exhibited significantly more median VBR abnormalities than controls (p<0.05). VBR abnormalities were seen in 69% and 89% of patients with a normal or questionably abnormal MR scan, respectively. Nineteen of the 27 patients with a suspected focus (70%) had VBR abnormalities in the suspected focus, with additional regions of involvement being elucidated. VBR also correctly predicted the seizure focus in 50% of patients whose seizure foci were confirmed based on follow-up history or clinical investigations. CONCLUSIONS Single subject VBR can help identify potential seizure foci in patients whose seizure foci are uncertain.
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Automated MR image classification in temporal lobe epilepsy. Neuroimage 2012; 59:356-62. [DOI: 10.1016/j.neuroimage.2011.07.068] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 06/29/2011] [Accepted: 07/22/2011] [Indexed: 11/23/2022] Open
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Lockwood-Estrin G, Thom M, Focke NK, Symms MR, Martinian L, Sisodiya SM, Duncan JS, Eriksson SH. Correlating 3T MRI and histopathology in patients undergoing epilepsy surgery. J Neurosci Methods 2011; 205:182-9. [PMID: 22227441 DOI: 10.1016/j.jneumeth.2011.12.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate whether specific semi-quantitative 3T MRI parameters are associated with particular histological features in temporal lobe specimens in epilepsy surgery patients whose conventional MRI scan appeared normal. These MRI techniques have the potential to visualise subtle structural abnormalities currently undetected on conventional MRI; but correlation between pre-operative in vivo MRI and histopathology is needed to understand the basis of these MRI abnormalities. Predicting subtle histopathology with semi-quantitative MRI techniques could contribute to pre-surgical evaluation of epilepsy patients. MATERIALS AND METHODS MRI techniques: normalised FLAIR signal intensity (nFSI), grey matter probability and diffusion tensor imaging (DTI) were correlated with quantitative histopathological measures: NeuN (neuronal nuclear antigen); GFAP (glial fibrillary acidic protein) and MBP (myelin basic protein) field fractions and stereological neuronal densities obtained in grey and white matter regions in twenty-four patients who underwent anterior temporal lobe resections. RESULTS There were no significant correlations between the histopathological measurements and MRI values in grey or white matter in macroscopically normal appearing tissue. CONCLUSION Findings suggest that in macroscopically normal appearing tissue, the studied semiquantitative MRI measurements are not significantly related to the measures of gliosis, neuronal loss/gain and myelin used in the current study. Studies of macroscopically abnormal tissue as well as improvements to the MRI techniques may increase the sensitivity of future correlative studies to improve our understanding of the histopathological basis of MRI signal characteristics.
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Affiliation(s)
- Georgia Lockwood-Estrin
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, UCL, London WC1N 3BG, UK.
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Rubí S, Setoain X, Donaire A, Bargalló N, Sanmartí F, Carreño M, Rumià J, Calvo A, Aparicio J, Campistol J, Pons F. Validation of FDG-PET/MRI coregistration in nonlesional refractory childhood epilepsy. Epilepsia 2011; 52:2216-24. [PMID: 22050207 DOI: 10.1111/j.1528-1167.2011.03295.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE To validate the use of 18F-fluorodeoxyglucose-positron emission tomography/magnetic resonance imaging (FDG-PET/MRI) coregistration for epileptogenic zone detection in children with MRI nonlesional refractory epilepsy and to assess its ability to guide a second interpretation of the MRI studies. METHODS Thirty-one children with refractory epilepsy whose MRI results were nonlesional were included prospectively. All patients underwent presurgical evaluation following the standard protocol of our epilepsy unit, which included FDG-PET and FDG-PET/MRI coregistration. Cerebral areas of decreased uptake in PET and PET/MRI fusion images were compared visually and then contrasted with presumed epileptogenic zone localization, which had been obtained from other clinical data. A second interpretation of MRI studies was carried out, focusing on the exact anatomic region in which hypometabolism was located in FDG-PET/MRI fusion images. KEY FINDINGS Both FDG-PET and FDG-PET/MRI detected hypometabolism in 67.8% of patients, with good concordance on a subject basis and on the cerebral region involved (κ statistic = 0.83 and 0.79, respectively). Hypometabolism detected by single PET, as well as by PET/MRI fusion images, was located in the same hemisphere, as indicated by electroclinical data in 58% of patients, and at the same place in 39% of cases. Of the patients who showed hypometabolism on PET/MRI, 43% also experienced changes in the guided second MRI interpretation, from nonlesional to subtle-lesional. SIGNIFICANCE PET/MRI coregistration is an imaging variant that is at least as accurate as PET alone in detecting epileptogenic zone in pediatric nonlesional patients, and can guide a second look at MRI studies previously reported as nonlesional, turning a meaningful percentage into subtle-lesional.
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Affiliation(s)
- Sebastià Rubí
- Department of Nuclear Medicine, Hospital Clinic, Barcelona, Spain.
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Danfors T, Åhs F, Appel L, Linnman C, Fredrikson M, Furmark T, Kumlien E. Increased neurokinin-1 receptor availability in temporal lobe epilepsy: a positron emission tomography study using [(11)C]GR205171. Epilepsy Res 2011; 97:183-9. [PMID: 21925840 DOI: 10.1016/j.eplepsyres.2011.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 08/04/2011] [Accepted: 08/06/2011] [Indexed: 11/19/2022]
Abstract
PURPOSE Activation of the neurokinin-1 (NK1) receptor by neuropeptide substance P (SP) induces and maintains epileptic activity in various experimental models of epilepsy. The primary objective of this study was to investigate whether neurobiological changes linked to NK1-SP receptor system are associated with hyperexcitability in patients with temporal lobe epilepsy (TLE). A secondary objective was to investigate the relationship between seizure frequency and NK1 receptor availability. METHODS A positron emission tomography study was conducted with the selective NK1 receptor antagonist [(11)C]GR205171 in nine patients with TLE and 18 healthy control participants. Parametric PET images were generated using the Patlak graphical method, with cerebellum as reference region. Data analyses including group comparisons were performed using statistical parametric mapping. RESULTS Patients with TLE showed increased NK1 receptor availability in both hemispheres with the most pronounced increase in anterior cingulate gyrus ipsilateral to seizure onset. A positive correlation between NK1 receptor availability and seizure frequency was observed in the medial temporal lobe and in the lentiform nucleus ipsilateral to the seizure onset. CONCLUSION Our results suggest that there is an intrinsic network using the NK1-SP receptor system for synaptic transmission and epileptiform activity in TLE.
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Affiliation(s)
- Torsten Danfors
- Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
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Gaillard WD, Cross JH, Duncan JS, Stefan H, Theodore WH. Epilepsy imaging study guideline criteria: commentary on diagnostic testing study guidelines and practice parameters. Epilepsia 2011; 52:1750-6. [PMID: 21740417 PMCID: PMC3169743 DOI: 10.1111/j.1528-1167.2011.03155.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Recognition of limited economic resources, as well as potential adverse effects of "over testing," has increased interest in "evidence-based" assessment of new medical technology. This creates a particular problem for evaluation and treatment of epilepsy, which are increasingly dependent on advanced imaging and electrophysiology, since there is a marked paucity of epilepsy diagnostic and prognostic studies that meet rigorous standards for evidence classification. The lack of high quality data reflects fundamental weaknesses in many imaging studies but also limitations in the assumptions underlying evidence classification schemes as they relate to epilepsy, and to the practicalities of conducting adequately powered studies of rapidly evolving technologies. We review the limitations of current guidelines and propose elements for imaging studies that can contribute meaningfully to the epilepsy literature.
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Affiliation(s)
- William D Gaillard
- Center for Neuroscience, Children's National Medical Center, George Washington University, Washington, District of Columbia 20010, USA.
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Kosior RK, Lauzon ML, Federico P, Frayne R. Algebraic T2 estimation improves detection of right temporal lobe epilepsy by MR T2 relaxometry. Neuroimage 2011; 58:189-97. [PMID: 21689766 DOI: 10.1016/j.neuroimage.2011.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 05/06/2011] [Accepted: 06/06/2011] [Indexed: 11/18/2022] Open
Abstract
Seizure related abnormalities may be detected with T2 relaxometry, which involves quantitative estimation of T2 values. Accounting for the partial-volume effect of cerebrospinal fluid (CSF) is important, especially for voxel-based relaxometry, VBR. With a mono-exponential decay model, this can be accomplished by including a baseline constant. An algebraic calculation, which accommodates this constant, offers improved T2 estimation speed over the commonly used non-linear fitting approach. Our objective was to compare the algebraic approach against three fitting approaches for the detection of seizure related abnormalities. We tested the performance of the four methods in the presence of noise using simulated data as well as real data acquired at 3 T with a Carr-Purcell-Meiboom-Gill sequence from 45 healthy subjects and 24 patients with confirmed right temporal lobe epilepsy. A quantitative analysis was performed on spatially normalized data by measuring T2 in various regions and with a whole brain tissue segmentation analysis. The detection rate of hippocampal T2 changes in patients was assessed by comparing the regional T2 measurements from each patient against the control data with a z-score threshold of 2.33. The algebraic method yielded high sensitivity for detection of hippocampal abnormalities in the epileptic patients in regional assessment and in follow-up single-subject VBR. This can be attributed to the relatively small variance across healthy subjects and improved precision in the presence of CSF and noise in simulation. In conclusion, the algebraic method is better than fitting based on faster calculation speed and better sensitivity for detecting seizure-related T2 changes.
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Affiliation(s)
- Robert K Kosior
- Department of Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada
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Sumar I, Kosior RK, Frayne R, Federico P. Hippocampal T2 abnormalities in healthy adults. Epilepsy Res 2011; 95:273-6. [PMID: 21550208 DOI: 10.1016/j.eplepsyres.2011.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 03/17/2011] [Accepted: 04/03/2011] [Indexed: 10/18/2022]
Abstract
We compared hippocampal abnormalities in 42 healthy adults identified by voxel-based relaxometry (VBR) and by visual inspection. Hippocampal abnormalities were seen in 8 (19.0%) and 10 (23.8%) of subjects by VBR and visual inspection, respectively (p>0.05). Notably, 50% of the abnormalities seen by visual inspection were likely false positive. This suggests that VBR is a more specific measure and should be considered in subjects with questionable hippocampal abnormalities.
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Affiliation(s)
- Imran Sumar
- Department of Electrical and Computer Engineering, University of Calgary, Alberta, Canada
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Betting LE, Li LM, Lopes-Cendes I, Guerreiro MM, Guerreiro CAM, Cendes F. Correlation between quantitative EEG and MRI in idiopathic generalized epilepsy. Hum Brain Mapp 2011; 31:1327-38. [PMID: 20082332 DOI: 10.1002/hbm.20944] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The objective of this study was to investigate the relationship between the focal discharges sometimes observed in the electroencephalogram of patients with idiopathic generalized epilepsies and subtle structural magnetic resonance imaging abnormalities. The main hypothesis to be assessed is that focal discharges may arise from areas of structural abnormality which can be detected by quantitative neuroimaging. Focal discharges were used for quantitative electroencephalogram source detection. Neuroimaging investigations consisted of voxel-based morphometry and region of interest volumetry. For voxel-based morphometry, volumetric MRI were acquired and processed. The images of each patient were individually compared with a control group. Statistical analysis was used to detect differences in gray matter volumes. Region of interest-based morphometry was automatically performed and used essentially to confirm voxel-based morphometry findings. The localization of the focal discharges on the electroencephalogram was compared to the neuroimaging results. Twenty-two patients with idiopathic generalized epilepsies were evaluated. Gray matter abnormalities were detected by voxel-based morphometry analysis in 77% of the patients. There was a good concordance between EEG source detection and voxel-based morphometry. On average, the nearest voxels detected by these methods were 19 mm (mm) apart and the most statistically significant voxels were 34 mm apart. This study suggests that in some cases subtle gray matter abnormalities are associated with focal epileptiform discharges observed in the electroencephalograms of patients with idiopathic generalized epilepsies.
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Affiliation(s)
- Luiz E Betting
- Department of Neurology, Faculty of Medical Sciences, University of Campinas--UNICAMP, Campinas, SP, Brazil
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Immonen A, Jutila L, Muraja-Murro A, Mervaala E, Äikiä M, Lamusuo S, Kuikka J, Vanninen E, Alafuzoff I, Ikonen A, Vanninen R, Vapalahti M, Kälviäinen R. Long-term epilepsy surgery outcomes in patients with MRI-negative temporal lobe epilepsy. Epilepsia 2010; 51:2260-9. [PMID: 21175607 DOI: 10.1111/j.1528-1167.2010.02720.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE The outcome of surgery in patients with temporal lobe epilepsy (TLE) and normal high-resolution magnetic resonance imaging (MRI) has been significantly worse than in patients with unilateral hippocampal damage upon MRI. The purpose of this study was to determine the long-term outcomes of consecutive true MRI-negative TLE patients who all underwent standardized preoperative evaluation with intracranial electroencephalography (EEG) electrodes. METHODS In this study we present all adult MRI-negative TLE surgery candidates evaluated between January 1990 and December 2006 at Kuopio Epilepsy Center in Kuopio University Hospital, which provides a national center for epilepsy surgery in Finland. During this period altogether 146 TLE surgery candidates were evaluated with intracranial electrodes, of whom 64 patients with normal high-resolution MRI were included in this study. RESULTS Among the 38 patients who finally underwent surgery, at the latest follow-up (mean 5.8 years), 15 (40%) were free of disabling seizures (Engel class I) and 6 (16%) were seizure-free (Engel class IA). Twenty-one (55%) of 38 patients had poor outcomes (Engel class III-IV). Outcomes did not change compared to 12-month follow-up. Histopathologic examination failed to reveal any focal pathology in 68% of our MR-negative cases. Only patients with noncongruent positron emission tomography (PET) results had worse outcomes (p = 0.044). DISCUSSION Our results suggest that epilepsy surgery outcomes in MRI-negative TLE patients are comparable with extratemporal epilepsy surgery in general. Seizure outcomes in the long-term also remain stable. Modern imaging techniques could further improve the postsurgical seizure-free rate. However, these patients usually require chronic intracranial EEG evaluation to define epileptogenic areas.
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Affiliation(s)
- Arto Immonen
- Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland.
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Abstract
Medically refractory focal epilepsy is potentially curable by surgery. This Review considers the application of recent advances in structural and functional brain imaging to increase the number of patients with epilepsy who are treated surgically, and to reduce the risk of complications arising from such intervention. Current optimal MRI of brain structure can identify previously undetectable lesions, with voxel-based and quantitative analyses further increasing the diagnostic yield. If MRI proves unremarkable, PET (with (18)F-fluorodeoxyglucose) and single-photon emission CT of ictal-interictal cerebral blood flow might identify the brain region that contains the epileptic focus. Magnetoencephalography plus simultaneous EEG and functional MRI can map the location of interictal epileptic discharges, thereby facilitating placement of intracranial recording electrodes to define the site of seizure onset. Functional MRI can also lateralize language and localize primary motor, somatosensory and language areas, and shows promise for predicting the effects of temporal lobe resection on memory. Tractography can visualize the main cerebral white matter tracts, thereby predicting and reducing surgery risk. Currently, displays of the optic radiation and pyramidal tracts are the most relevant for epilepsy surgery. Reliable integration of structural and functional data into surgical image-guidance systems is being pursued, and promises safer neurosurgery for epilepsy in the future.
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Affiliation(s)
- John S Duncan
- National Society for Epilepsy, Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, Queen Square, London, UK.
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Abstract
Neuroimaging in epilepsy is a very large and growing field. Researchers in this area have quickly adopted new methods, resulting in a lively literature. Basic features of common epilepsies are well known, but, outside of the specific area of epilepsy surgery evaluation, new methods evolving in the last few years have had limited new beneficial clinical impact. Here, an overview of the epilepsy neuroimaging literature of the last 5 years, with an emphasis on mesial temporal lobe epilepsy, idiopathic generalized epilepsies, presurgical evaluation and new developments in functional MRI is presented. The need for attention to clinical translation, as well as immediate opportunities and future trends in this field, are discussed.
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Affiliation(s)
- Mark Richardson
- P043 Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK.
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Guedj E, Aubert S, McGonigal A, Mundler O, Bartolomei F. Déjà-vu in temporal lobe epilepsy: metabolic pattern of cortical involvement in patients with normal brain MRI. Neuropsychologia 2010; 48:2174-81. [PMID: 20398682 DOI: 10.1016/j.neuropsychologia.2010.04.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 04/05/2010] [Accepted: 04/07/2010] [Indexed: 10/19/2022]
Abstract
To contribute to the identification of brain regions involved in déjà-vu, we studied the metabolic pattern of cortical involvement in patients with seizures of temporal lobe origin presenting with or without déjà-vu. Using voxel-based analysis of 18FDG-PET brain scans, we compared glucose metabolic rate of 8 patients with déjà-vu, 8 patients without déjà-vu, and 20 age-matched healthy subjects. Patients were selected after comprehensive non-invasive presurgical evaluation, including normal brain MRI and surface electroclinical features compatible with unilateral temporal lobe epilepsy (TLE). Patients with and without déjà-vu did not differ in terms of age, gender, epilepsy lateralization, epilepsy onset, epilepsy duration, and other subjective ictal manifestations. TLE patients with déjà-vu exhibited ipsilateral hypometabolism of superior temporal gyrus and of parahippocampal region, in the vicinity of perirhinal/entorhinal cortex, in comparison either to healthy subjects or to TLE patients without déjà-vu (p<0.05 FDR-corrected). By contrast, no difference was found between patient subgroups for hypometabolism of hippocampus and amygdala. At an individual-level, in comparison to healthy subjects, hypometabolism of both parahippocampal region and superior temporal gyrus was present in 7/8 patients with déjà-vu. Hippocampal metabolism was spared in 3 of these 7 patients. These findings argue for metabolic dysfunction of a medial-lateral temporal network in patients with déjà-vu and normal brain MRI. Within the medial temporal lobe, specific involvement of the parahippocampal region, often in the absence of hippocampal impairment, suggests that the feeling of familiarity during seizures greatly depends on alteration of the recognition memory system.
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Affiliation(s)
- Eric Guedj
- Service Central de Biophysique et Médecine Nucléaire, CHU Timone & Centre Européen de Recherche en Imagerie Médicale, CERIMED & Centre d'Investigation Clinique, CIC, INSERM, Université de la Méditerranée, Marseille F-13000, France.
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Richardson M. Current themes in neuroimaging of epilepsy: brain networks, dynamic phenomena, and clinical relevance. Clin Neurophysiol 2010; 121:1153-75. [PMID: 20185365 DOI: 10.1016/j.clinph.2010.01.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Revised: 12/24/2009] [Accepted: 01/05/2010] [Indexed: 11/15/2022]
Abstract
Brain scanning methods were first applied in patients with epilepsy more than 30years ago. A very substantial literature now exists in this field, which is exponentially increasing. Contemporary neuroimaging studies in epilepsy reflect new concepts in the epilepsies, as well as current methodological developments. In particular, this area is emphasising the role of networks in epileptogenicity, the existence of dynamic phenomena which can be captured by imaging, and is beginning to validate the implementation of neuroimaging in the clinic. Here, recent studies of the last 5years are reviewed, covering the full range of neuroimaging methods with SPECT, PET and MRI in epilepsy.
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Affiliation(s)
- Mark Richardson
- P043 Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK.
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Eriksson SH, Thom M, Symms MR, Focke NK, Martinian L, Sisodiya SM, Duncan JS. Cortical neuronal loss and hippocampal sclerosis are not detected by voxel-based morphometry in individual epilepsy surgery patients. Hum Brain Mapp 2009; 30:3351-60. [PMID: 19347875 PMCID: PMC2771105 DOI: 10.1002/hbm.20757] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Voxel‐based morphometry (VBM) has detected differences between brains of groups of patients with epilepsy and controls, but the sensitivity for detecting subtle pathological changes in single subjects has not been established. The aim of the study was to test the sensitivity of VBM using statistical parametric mapping (SPM5) to detect hippocampal sclerosis (HS) and cortical neuronal loss in individual patients. T1‐weighted volumetric 1.5 T MR images from 13 patients with HS and laminar cortical neuronal loss were segmented, normalised and smoothed using SPM5. Both modulated and non‐modulated analyses were performed. Comparisons of one control subject against the rest (n = 23) were first performed to ascertain the smoothing level with the lowest number of SPM changes in controls. Each patient was then compared against the whole control group. The lowest number of SPM changes in control subjects was found at a smoothing level of 10 mm full width half maximum for modulated and non‐modulated data. In the patient group, no SPM abnormalities were found in the affected temporal lobe or hippocampus at this smoothing level. At lower smoothing levels there were numerous SPM findings in controls and patients. VBM did not detect any abnormalities associated with either laminar cortical neuronal loss or HS. This may be due to normalisation and smoothing of images and low statistical power in areas with larger inter‐individual differences. This suggests that the methodology may currently not be suitable to detect particular occult abnormalities possibly associated with seizure onset zone in individual epilepsy patients with unremarkable standard structural MRI. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
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Affiliation(s)
- Sofia H Eriksson
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London WC1N3BG, United Kingdom.
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