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Yoganathan K, Malek N, Torzillo E, Paranathala M, Greene J. Neurological update: structural and functional imaging in epilepsy surgery. J Neurol 2023; 270:2798-2808. [PMID: 36792721 PMCID: PMC10130132 DOI: 10.1007/s00415-023-11619-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/05/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023]
Abstract
Structural and functional imaging prior to surgery in drug-resistant focal epilepsy, has an important role to play alongside electroencephalography (EEG) techniques, in planning the surgical approach and predicting post-operative outcome. This paper reviews the role of structural and functional imaging of the brain, namely computed tomography (CT), magnetic resonance imaging (MRI), functional MRI (fMRI), single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging in the preoperative work-up of people with medically refractory epilepsy. In MRI-negative patients, the precise localisation of the epileptogenic zone may be established by demonstrating hypometabolism on PET imaging or hyperperfusion on SPECT imaging in the area surrounding the seizure focus. These imaging modalities are far less invasive than intracranial EEG, which is the gold standard but requires surgical placement of electrodes or recording grids. Even when intracranial EEG is needed, PET or SPECT imaging can assist in the planning of EEG electrode placement, due to its' limited spatial sampling. Multimodal imaging techniques now allow the multidisciplinary epilepsy surgery team to identify and better characterise focal pathology, determine its' relationship to eloquent areas of the brain and the degree of interconnectedness within both physiological and pathological networks, as well as improve planning and surgical outcomes for patients. This paper will update the reader on this whole field and provide them with a practical guide, to aid them in the selection of appropriate investigations, interpretation of the findings and facilitating patient discussions in individuals with drug-resistant focal epilepsy.
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Affiliation(s)
- Katie Yoganathan
- University of Oxford and Oxford University Hospitals, Oxford, UK. .,Department of Neurology, National Hospital for Neurology and Neurosurgery, London, UK.
| | - Naveed Malek
- Department of Neurology, Queen's Hospital, Romford, UK
| | - Emma Torzillo
- Department of Neurology, National Hospital for Neurology and Neurosurgery, London, UK
| | | | - John Greene
- Department of Neurology, Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, UK
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Crossed cerebellar diaschisis: risk factors and prognostic value in focal cortical dysplasia by 18F-FDG PET/CT. Ann Nucl Med 2021; 35:719-727. [PMID: 33840039 DOI: 10.1007/s12149-021-01613-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 03/26/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Crossed cerebellar diaschisis (CCD) has been widely studied in hemispheric stroke but is less characterized in epilepsy. In this study, we used 18F-FDG PET/CT to investigate the risk factors for CCD and its prognostic value for intractable epilepsy caused by focal cortical dysplasia (FCD). METHODS One hundred medically intractable epilepsy patients pathologically diagnosed with FCD postoperatively were included and classified into two groups: CCD+ and CCD-. PET/CT images were analyzed qualitatively by visual assessment and semi-quantitatively using the absolute asymmetry index (|AI|). Clinical factors, including age, sex, body mass index (BMI), age at seizure onset, epilepsy duration, seizure type, seizure frequency, electroencephalography (EEG) and brain magnetic resonance imaging (MRI), were retrospectively assessed from medical records. Follow-up outcomes were evaluated according to the Engel classification at 3, 6, 12, 24 and 36 months postoperatively. RESULTS Of the 100 patients, 77 (77.0%) were classified as CCD-, and 23 (23.0%) were classified as CCD + . CCD+ patients had a higher number of lobes involved on PET (3.61 ± 2.16 vs 2.26 ± 1.01, P < 0.001) than CCD- patients. CCD- patients showed more negative MRI results than CCD + patients (P = 0.02). At 12 months postoperatively, 70.7% (29/41) of CCD- patients and 30.8% (4/13) of CCD + patients presented a favourable prognosis (P = 0.02). Significant differences in the average |AI| values in the posterior frontal and anterior temporal lobes were found between CCD+ and CCD- patients (P < 0.05). CONCLUSION The number of lobes involved on PET, structural anomalies on MRI, the |AI| values in the posterior frontal and anterior temporal lobes may be predisposing factors for CCD. CCD occurrence may help predict the prognosis of FCD patients at 12 months postoperatively.
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18 F-FDG-PET hypometabolic pattern reveals multifocal epileptic foci despite limited unique stereotyped seizures. Epilepsy Res 2021; 172:106589. [PMID: 33640665 DOI: 10.1016/j.eplepsyres.2021.106589] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/29/2021] [Accepted: 02/16/2021] [Indexed: 02/03/2023]
Abstract
PURPOSE Interictal positron emission tomography (PET) with 18F-FDG has largely proved its utility in presurgical evaluation of drug-resistant epilepsies (DRE) and in the surgical outcomes. Interictal hypometabolism topography is related to the neuronal networks involved in the seizure onset zone (SOZ) and spread pathways. 18F-FDG PET has a good prognostic value for post-surgical outcome, especially in cases with unique focal ictal semiology and a limited extent of hypometabolism. Surprisingly few patients have similar limited ictal features but extended hypometabolism. The objective of this study is to show that stereoelectro encephalography (SEEG) provides an explanation for this large hypometabolism, which impacts the surgical strategy. METHODS A cohort of 248 patients underwent 18F-FDG PET and SEEG to explore for refractory epilepsy in two close tertiary epilepsy centers between January 2009 and December 2017. From this cohort, a subset of patients was selected with extended PET metabolism despite showing unique and limited ictal features in scalp EEG. The surgical outcome of this subset of patients has been analysed with respect to their FDG-PET and SEEG to understand the relationship between PET/SEEG/ presentation and surgical outcome. RESULTS We report a series of seven patients with DRE and unique stereotyped ictal semiology but extensive 18F-FDG-PET hypometabolism revealing unexpected multifocal SOZ using SEEG. All SOZ were encompassed by the hypometabolic area. CONCLUSION Our results demonstrate the necessity of accounting for the discrepancy between limited symptoms and widespread hypometabolism which can reveal multifocal SOZ. In those patients, surgical possibilities should be considered carefully.
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Sun K, Ren Z, Yang D, Wang X, Yu T, Ni D, Qiao L, Xu C, Gao R, Lin Y, Zhang X, Shang K, Chen X, Wang Y, Zhang G. Voxel-based morphometric MRI post-processing and PET/MRI co-registration reveal subtle abnormalities in cingulate epilepsy. Epilepsy Res 2021; 171:106568. [PMID: 33610065 DOI: 10.1016/j.eplepsyres.2021.106568] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 01/14/2021] [Accepted: 02/01/2021] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Diagnostic challenges exist in the presurgical evaluation of patients with magnetic resonance imaging (MRI) negative cingulate epilepsy (CE) because of the heterogeneity in clinical semiology and lack of localizing findings on scalp electroencephalographic (EEG) recordings. We aimed to examine the neuroimaging characteristics in a consecutive cohort of patients with MRI-negative CE with a focus on two image post-processing methods, including the MRI post-processing morphometric analysis program (MAP) and 18F-fluorodeoxyglucose-positron emission tomography-MRI (PET/MRI) co-registration. METHODS Included in this retrospective study were patients with MRI-negative CE who met the following criteria: negative on preoperative MRI, invasive EEG (iEEG) confirmed cingulate gyrus-onset seizures, surgical resection of the cingulate gyrus with/without adjacent cortex, and seizure-free for more than 12 months. MAP and PET/MRI co-registration were performed and investigated by comparison to ictal intracranial EEG findings. Other characteristics obtained from scalp EEG, magnetoencephalography (MEG), iEEG, and pathological study were also reported. RESULTS Ten patients were included, of which eight were diagnosed with anterior CE, one with middle CE, and one with posterior CE. The semiology included fear, embarrassment, vocalization, ictal pouting, asymmetric tonic posture, hypermotor, and automatism. Scalp EEG revealed unilateral or bilateral frontal-temporal onset. MEG localized the dipoles correctly in one patient (1/10). MAP detected subtle abnormalities in regions concordant with iEEG onset in seven patients (7/10) while PET/MRI co-registration revealed focal concordant hypometabolism in five patients (5/10). Combining MAP with PET/MRI co-registration improved the detection rate to 90 % in this cohort. The pathology was focal cortical dysplasia (FCD), including FCD type IIA in three, type IIB in three, and type I in four. CONCLUSION MAP and PET/MRI co-registration show promising results in identifying subtle FCD abnormalities in CE with negative results on conventional MRI, which can be otherwise challenging. More importantly, a combination of MRI post-processing and PET/MRI co-registration can greatly improve the identification of epileptic abnormalities, which can be used as surgical target. MAP and PET/MRI co-registration should be incorporated into the routine presurgical evaluation.
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Affiliation(s)
- Ke Sun
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhiwei Ren
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Dongju Yang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xueyuan Wang
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Tao Yu
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Duanyu Ni
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Liang Qiao
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Cuiping Xu
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Runshi Gao
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yicong Lin
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiating Zhang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Kun Shang
- Department of Nuclear Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xin Chen
- Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yajie Wang
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Guojun Zhang
- Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China.
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Hu WH, Wang X, Liu LN, Shao XQ, Zhang K, Ma YS, Ai L, Li JJ, Zhang JG. Multimodality Image Post-processing in Detection of Extratemporal MRI-Negative Cortical Dysplasia. Front Neurol 2018; 9:450. [PMID: 29963006 PMCID: PMC6010529 DOI: 10.3389/fneur.2018.00450] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 05/28/2018] [Indexed: 11/13/2022] Open
Abstract
Purpose: To determine the diagnostic value of individual image post-processing techniques in a series of patients who underwent extratemporal operations for histologically proven, MRI-negative focal cortical dysplasia (FCD). Methods: The morphometric analysis program (MAP), PET/MRI co-registration and statistical parametric mapping (SPM) analysis of PET (SPM-PET) techniques were analyzed in 33 consecutive patients. The epileptogenic zone (EZ) assumed by MAP, PET/MRI, and SPM-PET was compared with the location of the FCD lesions determined by stereoelectroencephalography (SEEG) and histopathological study. The detection rate of each modality was statistically compared. Results: Three lesions were simultaneously detected by the three post-processing methods, while two lesions were only MAP positive, and 8 were only PET/MRI positive. The detection rate of MAP, PET/MRI, SPM-PET and the combination of the three modalities was 24.2, 90.9, 57.6, and 97.0%, respectively. Taking the pathological subtype into account, no type I lesions were detected by MAP, and PET/MRI was the most sensitive method for detecting FCD types II and IIA. During a mean follow-up period of 22.94 months, seizure freedom was attained in 26/33 patients (78.8%) after focal corticectomy. Conclusions: MAP, PET/MRI, and SPM-PET provide complementary information for FCD detection, intracranial electrode design, and lesion resection. PET/MRI was particularly useful, with the highest detection rate of extratemporal MRI-negative FCD.
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Affiliation(s)
- Wen-Han Hu
- Stereotactic and Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neurostimulation, Beijing, China
| | - Xiu Wang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Li-Na Liu
- Department of Pathology, Peking University First Hospital Fengtai Hospital, Beijing, China
| | - Xiao-Qiu Shao
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Kai Zhang
- Beijing Key Laboratory of Neurostimulation, Beijing, China.,Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yan-Shan Ma
- Department of Epilepsy Center, Peking University First Hospital Fengtai Hospital, Beijing, China
| | - Lin Ai
- Department of Neuroimage, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jun-Ju Li
- Department of Neurosurgery, Hainan General Hospital, Haikou, China
| | - Jian-Guo Zhang
- Stereotactic and Functional Neurosurgery Laboratory, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neurostimulation, Beijing, China.,Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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Verger A, Lagarde S, Maillard L, Bartolomei F, Guedj E. Brain molecular imaging in pharmacoresistant focal epilepsy: Current practice and perspectives. Rev Neurol (Paris) 2018; 174:16-27. [DOI: 10.1016/j.neurol.2017.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 05/11/2017] [Indexed: 10/19/2022]
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Mendes Coelho VC, Morita ME, Amorim BJ, Ramos CD, Yasuda CL, Tedeschi H, Ghizoni E, Cendes F. Automated Online Quantification Method for 18F-FDG Positron Emission Tomography/CT Improves Detection of the Epileptogenic Zone in Patients with Pharmacoresistant Epilepsy. Front Neurol 2017; 8:453. [PMID: 28919879 PMCID: PMC5585153 DOI: 10.3389/fneur.2017.00453] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 08/15/2017] [Indexed: 12/02/2022] Open
Abstract
Aims To assess the validity of an online method to quantitatively evaluate cerebral hypometabolism in patients with pharmacoresistant focal epilepsy as a complement to the visual analysis of the 18F-FDG positron emission tomography (PET)/CT exam. Methods A total of 39 patients with pharmacoresistant epilepsy and probable focal cortical dysplasia [22 patients with frontal lobe epilepsy (FLE) and 17 with temporal lobe epilepsy (TLE)] underwent a presurgical evaluation including EEG, video-EEG, MRI, and 18F-FDG PET/CT. We conducted the automated quantification of their 18F-FDG PET/CT data and compared the results with those of the visual-PET analysis conducted by experienced nuclear medicine physicians. For each patient group, we calculated Cohen’s Kappa coefficient for the visual and quantitative analyses, as well as each method’s sensitivity, specificity, and positive and negative predictive values. Results For the TLE group, both the visual and quantitative analyses showed high agreement. Thus, although the quantitative analysis could be used as a complement, the visual analysis on its own was consistent and precise. For the FLE group, on the other hand, the visual analysis categorized almost half of the cases as normal, revealing very low agreement. For those patients, the quantitative analysis proved critical to identify the focal hypometabolism characteristic of the epileptogenic zone. Our results suggest that the quantitative analysis of 18F-FDG PET/CT data is critical for patients with extratemporal epilepsies, and especially those with subtle MRI findings. Furthermore, it can easily be used during the routine clinical evaluation of 18F-FDG PET/CT exams. Significance Our results show that quantification of 18F-FDG PET is an informative complementary method that can be added to the routine visual evaluation of patients with subtle lesions, particularly those in the frontal lobes.
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Affiliation(s)
| | - Marcia E Morita
- Neurology/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
| | - Barbara J Amorim
- Nuclear Medicine Department, Unicamp - University of Campinas, Campinas, Brazil
| | - Celso Darío Ramos
- Nuclear Medicine Department, Unicamp - University of Campinas, Campinas, Brazil
| | - Clarissa L Yasuda
- Neurology/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
| | - Helder Tedeschi
- Neurosurgery/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
| | - Enrico Ghizoni
- Neurosurgery/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
| | - Fernando Cendes
- Neurology/Epilepsy, Unicamp - University of Campinas, Campinas, Brazil
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Loesch AM, Steger H, Losher C, Hartl E, Rémi J, Vollmar C, Noachtar S. Seizure-associated aphasia has good lateralizing but poor localizing significance. Epilepsia 2017; 58:1551-1555. [DOI: 10.1111/epi.13835] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2017] [Indexed: 12/01/2022]
Affiliation(s)
- Anna Mira Loesch
- Department of Neurology; Epilepsy Center; University of Munich; Munich Germany
| | - Hannah Steger
- Department of Neurology; Epilepsy Center; University of Munich; Munich Germany
| | - Claudia Losher
- Department of Neurology; Epilepsy Center; University of Munich; Munich Germany
| | - Elisabeth Hartl
- Department of Neurology; Epilepsy Center; University of Munich; Munich Germany
| | - Jan Rémi
- Department of Neurology; Epilepsy Center; University of Munich; Munich Germany
| | - Christian Vollmar
- Department of Neurology; Epilepsy Center; University of Munich; Munich Germany
| | - Soheyl Noachtar
- Department of Neurology; Epilepsy Center; University of Munich; Munich Germany
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