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Rácz A, Galvis-Montes DS, Borger V, Becker AJ, Pitsch J. Focused review: Clinico-neuropathological aspects of late onset epilepsies: Pathogenesis. Seizure 2024:S1059-1311(24)00182-1. [PMID: 38918105 DOI: 10.1016/j.seizure.2024.06.015] [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: 01/24/2024] [Revised: 05/21/2024] [Accepted: 06/19/2024] [Indexed: 06/27/2024] Open
Abstract
The aim of the present study was to review the current knowledge on the neuropathological spectrum of late onset epilepsies. Several terms including 'neuropathology*' AND 'late onset epilepsy' (LOE) combined with distinct neuropathological diagnostic terms were used to search PubMed until November 15, 2023. We report on the relevance of definitional aspects of LOE with implications for the diagnostic spectrum of epilepsies. The neuropathological spectrum in patients with LOE is described and includes vascular lesions, low-grade neuroepithelial neoplasms and focal cortical dysplasias (FCD). Among the latter, the frequency of the FCD subtypes appears to differ between LOE patients and those with seizure onset at a younger age. Neurodegenerative neuropathological changes in the seizure foci of LOE patients require careful interdisciplinary interpretation with respect to the differential diagnosis of primary neurodegenerative changes or epilepsy-related changes. Innate and adaptive neuroinflammation represents an important cause of LOE with intriguing therapeutic options.
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Affiliation(s)
- Attila Rácz
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | | | - Valeri Borger
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Albert J Becker
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Julika Pitsch
- Department of Epileptology, University Hospital Bonn, Bonn, Germany.
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Casella C, Vecchiato K, Cromb D, Guo Y, Winkler AM, Hughes E, Dillon L, Green E, Colford K, Egloff A, Siddiqui A, Price A, Grande LC, Wood TC, Malik S, Teixeira RPA, Carmichael DW, O’Muircheartaigh J. Widespread, depth-dependent cortical microstructure alterations in pediatric focal epilepsy. Epilepsia 2024; 65:739-752. [PMID: 38088235 PMCID: PMC7616339 DOI: 10.1111/epi.17861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 12/11/2023] [Accepted: 12/11/2023] [Indexed: 12/27/2023]
Abstract
OBJECTIVE Tissue abnormalities in focal epilepsy may extend beyond the presumed focus. The underlying pathophysiology of these broader changes is unclear, and it is not known whether they result from ongoing disease processes or treatment-related side effects, or whether they emerge earlier. Few studies have focused on the period of onset for most focal epilepsies, childhood. Fewer still have utilized quantitative magnetic resonance imaging (MRI), which may provide a more sensitive and interpretable measure of tissue microstructural change. Here, we aimed to determine common spatial modes of changes in cortical architecture in children with heterogeneous drug-resistant focal epilepsy and, secondarily, whether changes were related to disease severity. METHODS To assess cortical microstructure, quantitative T1 and T2 relaxometry (qT1 and qT2) was measured in 43 children with drug-resistant focal epilepsy (age range = 4-18 years) and 46 typically developing children (age range = 2-18 years). We assessed depth-dependent qT1 and qT2 values across the neocortex, as well as their gradient of change across cortical depths. We also determined whether global changes seen in group analyses were driven by focal pathologies in individual patients. Finally, as a proof-of-concept, we trained a classifier using qT1 and qT2 gradient maps from patients with radiologically defined abnormalities (MRI positive) and healthy controls, and tested whether this could classify patients without reported radiological abnormalities (MRI negative). RESULTS We uncovered depth-dependent qT1 and qT2 increases in widespread cortical areas in patients, likely representing microstructural alterations in myelin or gliosis. Changes did not correlate with disease severity measures, suggesting they may represent antecedent neurobiological alterations. Using a classifier trained with MRI-positive patients and controls, sensitivity was 71.4% at 89.4% specificity on held-out MRI-negative patients. SIGNIFICANCE These findings suggest the presence of a potential imaging endophenotype of focal epilepsy, detectable irrespective of radiologically identified abnormalities.
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Affiliation(s)
- Chiara Casella
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department for Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London, London, UK
| | - Katy Vecchiato
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department for Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London, London, UK
| | - Daniel Cromb
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Yourong Guo
- Department for Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London, London, UK
| | - Anderson M. Winkler
- Department of Human Genetics, University of Texas Rio Grande Valley, Brownsville, Texas, USA
| | - Emer Hughes
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Louise Dillon
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Elaine Green
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Kathleen Colford
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Alexia Egloff
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Ata Siddiqui
- Department of Radiology, Guy’s and Saint Thomas’ Hospitals NHS Trust, London, UK
| | - Anthony Price
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
| | - Lucilio Cordero Grande
- Department of Biomedical Engineering, King’s College London, London, UK
- Biomedical Image Technologies, Telecommunication Engineering School (ETSIT), Technical University of Madrid, Bioengineering, Biomaterials and Nanomedicine Networking Biomedical Research Centre, National Institute of Health Carlos III, Madrid, Spain
| | - Tobias C. Wood
- Department of Neuroimaging, King’s College London, London, UK
| | - Shaihan Malik
- Department of Biomedical Engineering, King’s College London, London, UK
| | | | | | - Jonathan O’Muircheartaigh
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, UK
- Department for Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London, London, UK
- Medical Research Council (MRC) Centre for Neurodevelopmental Disorders, London, UK
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Tang Y, Xiao L, Deng C, Zhu H, Gao X, Li J, Yang Z, Liu D, Feng L, Hu S. [ 18F]FDG PET metabolic patterns in mesial temporal lobe epilepsy with different pathological types. Eur Radiol 2024; 34:887-898. [PMID: 37581655 DOI: 10.1007/s00330-023-10089-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/23/2023] [Accepted: 07/01/2023] [Indexed: 08/16/2023]
Abstract
OBJECTIVES To investigate [18F]FDG PET patterns of mesial temporal lobe epilepsy (MTLE) patients with distinct pathologic types and provide possible guidance for predicting long-term prognoses of patients undergoing epilepsy surgery. METHODS This was a retrospective review of MTLE patients who underwent anterior temporal lobectomy between 2016 and 2021. Patients were classified as having chronic inflammation and gliosis (gliosis, n = 44), hippocampal sclerosis (HS, n = 43), or focal cortical dysplasia plus HS (FCD-HS, n = 13) based on the postoperative pathological diagnosis. Metabolic patterns and the severity of metabolic abnormalities were investigated among MTLE patients and healthy controls (HCs). The standardized uptake value (SUV), SUV ratio (SUVr), and asymmetry index (AI) of regions of interest were applied to evaluate the severity of metabolic abnormalities. Imaging processing was performed with statistical parametric mapping (SPM12). RESULTS With a mean follow-up of 2.8 years, the seizure freedom (Engel class IA) rates of gliosis, HS, and FCD-HS were 54.55%, 62.79%, and 69.23%, respectively. The patients in the gliosis group presented a metabolic pattern with a larger involvement of extratemporal areas, including the ipsilateral insula. SUV, SUVr, and AI in ROIs were decreased for patients in all three MTLE groups compared with those of HCs, but the differences among all three MTLE groups were not significant. CONCLUSIONS MTLE patients with isolated gliosis had the worst prognosis and hypometabolism in the insula, but the degree of metabolic decrease did not differ from the other two groups. Hypometabolic regions should be prioritized for [18F]FDG PET presurgical evaluation rather than [18F]FDG uptake values. CLINICAL RELEVANCE STATEMENT This study proposes guidance for optimizing the operation scheme in patients with refractory MTLE and emphasizes the potential of molecular neuroimaging with PET using selected tracers to predict the postsurgical histology of patients with refractory MTLE epilepsy. KEY POINTS • MTLE patients with gliosis had poor surgical outcomes and showed a distinct pattern of decreased metabolism in the ipsilateral insula. • In the preoperative assessment of MTLE, it is recommended to prioritize the evaluation of glucose hypometabolism areas over [18F]FDG uptake values. • The degree of glucose hypometabolism in the epileptogenic focus was not associated with the surgical outcomes of MTLE.
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Affiliation(s)
- Yongxiang Tang
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China
| | - Ling Xiao
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China
| | - Chijun Deng
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Haoyue Zhu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiaomei Gao
- Department of Pathology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jian Li
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China
| | - Zhiquan Yang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Dingyang Liu
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Li Feng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Department of Neurology, Xiangya Hospital, Central South University (Jiangxi Branch), Nanchang, Jiangxi, China.
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, Hunan, China.
| | - Shuo Hu
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, China.
- National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Key Laboratory of Biological, Nanotechnology of National Health Commission, Xiangya Hospital, Central South University, Changsha, Hunan, China.
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Urbach H, Scheiwe C, Shah MJ, Nakagawa JM, Heers M, San Antonio-Arce MV, Altenmueller DM, Schulze-Bonhage A, Huppertz HJ, Demerath T, Doostkam S. Diagnostic Accuracy of Epilepsy-dedicated MRI with Post-processing. Clin Neuroradiol 2023; 33:709-719. [PMID: 36856785 PMCID: PMC10449992 DOI: 10.1007/s00062-023-01265-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 01/17/2023] [Indexed: 03/02/2023]
Abstract
PURPOSE To evaluate the diagnostic accuracy of epilepsy-dedicated 3 Tesla MRI including post-processing by correlating MRI, histopathology, and postsurgical seizure outcomes. METHODS 3 Tesla-MRI including a magnetization-prepared two rapid acquisition gradient echo (MP2RAGE) sequence for post-processing using the morphometric analysis program MAP was acquired in 116 consecutive patients with drug-resistant focal epilepsy undergoing resection surgery. The MRI, histopathology reports and postsurgical seizure outcomes were recorded from the patient's charts. RESULTS The MRI and histopathology were concordant in 101 and discordant in 15 patients, 3 no hippocampal sclerosis/gliosis only lesions were missed on MRI and 1 of 28 focal cortical dysplasia (FCD) type II associated with a glial scar was considered a glial scar only on MRI. In another five patients, MRI was suggestive of FCD, the histopathology was uneventful but patients were seizure-free following surgery. The MRI and histopathology were concordant in 20 of 21 glioneuronal tumors, 6 cavernomas, and 7 glial scars. Histopathology was negative in 10 patients with temporal lobe epilepsy, 4 of them had anteroinferior meningoencephaloceles. Engel class IA outcome was reached in 71% of patients. CONCLUSION The proposed MRI protocol is highly accurate. No hippocampal sclerosis/gliosis only lesions are typically MRI negative. Small MRI positive FCD can be histopathologically missed, most likely due to sampling errors resulting from insufficient harvesting of tissue.
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Affiliation(s)
- Horst Urbach
- Dept. of Neuroradiology, Medical Center, University of Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany.
| | - Christian Scheiwe
- Dept. of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Muskesh J Shah
- Dept. of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Julia M Nakagawa
- Dept. of Neurosurgery, Medical Center, University of Freiburg, Freiburg, Germany
| | - Marcel Heers
- Dept. of Epileptology, Medical Center, University of Freiburg, Freiburg, Germany
| | | | | | | | | | - Theo Demerath
- Dept. of Neuroradiology, Medical Center, University of Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany
| | - Soroush Doostkam
- Dept. of Neuropathology, Medical Center, University of Freiburg, Freiburg, Germany
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Reimers A, Helmstaedter C, Elger CE, Pitsch J, Hamed M, Becker AJ, Witt JA. Neuropathological Insights into Unexpected Cognitive Decline in Epilepsy. Ann Neurol 2023; 93:536-550. [PMID: 36411525 DOI: 10.1002/ana.26557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 10/10/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Some patients unexpectedly display an unfavorable cognitive course after epilepsy surgery subsequent to any direct cognitive sequelae of the surgical treatment. Therefore, we conducted in-depth neuropathological examinations of resective specimens from corresponding patients to provide insights as to the underlying disease processes. METHODS In this study, cases with significant cognitive deterioration following a previous postoperative assessment were extracted from the neuropsychological database of a longstanding epilepsy surgical program. An extensive reanalysis of available specimens was performed using current, state-of-the-art neuropathological examinations. Patients without cognitive deterioration but matched in regard to basic pathologies served as controls. RESULTS Among the 355 operated patients who had undergone more than one postoperative neuropsychological examination, 30 (8%) showed significant cognitive decline in the period after surgery. Of the 24 patients with available specimens, 71% displayed further neuropathological changes in addition to the typical spectrum (ie, hippocampal sclerosis, focal cortical dysplasias, vascular lesions, and low-grade tumors), indicating (1) a secondary, putatively epilepsy-independent neurodegenerative disease process; (2) limbic inflammation; or (3) the enigmatic pathology pattern of "hippocampal gliosis" without segmental neurodegeneration. In the controls, the matched individual principal epilepsy-associated pathologies were not found in combination with the secondary pathology patterns of the study group. INTERPRETATION Our findings indicate that patients who unexpectedly displayed unfavorable cognitive development beyond any direct surgical effects show rare and very particular pathogenetic causes or parallel, presumably independent, neurodegenerative alterations. A multicenter collection of such cases would be appreciated to discern presurgical biomarkers that help with surgical decision-making. ANN NEUROL 2023;93:536-550.
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Affiliation(s)
- Annika Reimers
- Section for Translational Epilepsy Research, Institute of Neuropathology, Medical Faculty, University of Bonn, Bonn, Germany
| | | | | | - Julika Pitsch
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Motaz Hamed
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Albert J Becker
- Section for Translational Epilepsy Research, Institute of Neuropathology, Medical Faculty, University of Bonn, Bonn, Germany
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Taube J, Witt JA, Grote A, Delev D, Enkirch J, Hattingen E, Becker AJ, Elger CE, Helmstaedter C. Preoperative and postoperative memory in epilepsy patients with 'gliosis only' versus hippocampal sclerosis: a matched case-control study. J Neurol Neurosurg Psychiatry 2022; 93:jnnp-2022-329224. [PMID: 36008114 DOI: 10.1136/jnnp-2022-329224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 08/14/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND Gliosis only (GO) and hippocampal sclerosis (HS) are distinct histopathological entities in mesial temporal lobe epilepsy. This study explores whether this distinction also exists on a functional level when evaluating pre- and postoperative memory. METHODS Using a retrospective matched case-control study design, we analysed verbal and visual memory performance in 49 patients with GO and 49 patients with HS before and one year after elective surgery. RESULTS Clinical differences were evident with a later age at seizure onset (18±12 vs 12±9 years) and fewer postoperative seizure-free patients in the GO group (63% vs 82%). Preoperatively, group and individual-level data demonstrated that memory impairments were less frequent, less severe and relatively non-specific in patients with GO compared with HS. Postoperatively, verbal memory declined in both groups, particularly after left-sided resections, with more significant losses in patients with GO. Factoring in floor effects, GO was also associated with more significant visual memory loss, particularly after left resections. CONCLUSIONS Compared with HS, GO is characterised by (1) a later onset of epilepsy, (2) less pronounced and more non-specific memory impairments before surgery, (3) a less successful surgical outcome and (4) a more significant memory decline after surgery. Overall, our results regarding cognition provide further evidence that GO and HS are distinct clinical entities. Functional integrity of the hippocampus appears higher in GO, as indicated by a better preoperative memory performance and worse memory outcome after surgery. The different risk-benefit ratios should be considered during presurgical patient counselling.
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Affiliation(s)
- Julia Taube
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | | | - Alexander Grote
- Department of Neurosurgery, University of Marburg, Marburg, Germany
| | - Daniel Delev
- Clinic for Neurosurgery, University Medical Center Aachen, Aachen, Germany
| | - Jonas Enkirch
- Department of Neuroradiology, University Hospital Bonn, Bonn, Germany
| | - Elke Hattingen
- Institute of Neuroradiology, University Hospital Frankfurt, Goethe-University, Frankfurt am Main, Germany
| | - Albert J Becker
- Institute of Neuropathology, Section for Translational Epilepsy Research, University of Bonn, Medical Faculty, Bonn, Germany
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Grote A, Heiland DH, Taube J, Helmstaedter C, Ravi VM, Will P, Hattingen E, Schüre JR, Witt JA, Reimers A, Elger C, Schramm J, Becker AJ, Delev D. 'Hippocampal innate inflammatory gliosis only' in pharmacoresistant temporal lobe epilepsy. Brain 2022; 146:549-560. [PMID: 35978480 PMCID: PMC9924906 DOI: 10.1093/brain/awac293] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 07/03/2022] [Accepted: 07/31/2022] [Indexed: 11/12/2022] Open
Abstract
Drug-resistant mesial-temporal lobe epilepsy is a devastating disease with seizure onset in the hippocampal formation. A fraction of hippocampi samples from epilepsy-surgical procedures reveals a peculiar histological pattern referred to as 'gliosis only' with unresolved pathogenesis and enigmatic sequelae. Here, we hypothesize that 'gliosis only' represents a particular syndrome defined by distinct clinical and molecular characteristics. We curated an in-depth multiparameter integration of systematic clinical, neuropsychological as well as neuropathological analysis from a consecutive cohort of 627 patients, who underwent hippocampectomy for drug-resistant temporal lobe epilepsy. All patients underwent either classic anterior temporal lobectomy or selective amygdalohippocampectomy. On the basis of their neuropathological exam, patients with hippocampus sclerosis and 'gliosis only' were characterized and compared within the whole cohort and within a subset of matched pairs. Integrated transcriptional analysis was performed to address molecular differences between both groups. 'Gliosis only' revealed demographics, clinical and neuropsychological outcome fundamentally different from hippocampus sclerosis. 'Gliosis only' patients had a significantly later seizure onset (16.3 versus 12.2 years, P = 0.005) and worse neuropsychological outcome after surgery compared to patients with hippocampus sclerosis. Epilepsy was less amendable by surgery in 'gliosis only' patients, resulting in a significantly worse rate of seizure freedom after surgery in this subgroup (43% versus 68%, P = 0.0001, odds ratio = 2.8, confidence interval 1.7-4.7). This finding remained significant after multivariate and matched-pairs analysis. The 'gliosis only' group demonstrated pronounced astrogliosis and lack of significant neuronal degeneration in contrast to characteristic segmental neuron loss and fibrillary astrogliosis in hippocampus sclerosis. RNA-sequencing of gliosis only patients deciphered a distinct transcriptional programme that resembles an innate inflammatory response of reactive astrocytes. Our data indicate a new temporal lobe epilepsy syndrome for which we suggest the term 'Innate inflammatory gliosis only'. 'Innate inflammatory gliosis only' is characterized by a diffuse gliosis pattern lacking restricted hippocampal focality and is poorly controllable by surgery. Thus, 'innate inflammatory gliosis only' patients need to be clearly identified by presurgical examination paradigms of pharmacoresistant temporal lobe epilepsy patients; surgical treatment of this subgroup should be considered with great precaution. 'Innate inflammatory gliosis only' requires innovative pharmacotreatment strategies.
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Affiliation(s)
- Alexander Grote
- Correspondence to: Alexander Grote UKGM—Klinik für Neurochirurgie Baldingerstraße 35033 Marburg, Germany E-mail:
| | | | - Julia Taube
- Clinic for Epileptology, University Hospital of Bonn, 53127 Bonn, Germany
| | | | - Vidhya M Ravi
- Clinic for Neurosurgery, University Medical Center Freiburg, 79106 Freiburg, Germany
| | - Paulina Will
- Clinic for Neurosurgery, University Medical Center Freiburg, 79106 Freiburg, Germany
| | - Elke Hattingen
- Department of Neuroradiology, Hospital of Goethe University Frankfurt, 60528 Frankfurt am Main, Germany
| | - Jan-Rüdiger Schüre
- Department of Neuroradiology, Hospital of Goethe University Frankfurt, 60528 Frankfurt am Main, Germany
| | | | - Annika Reimers
- Institute of Neuropathology, Section for Translational Epilepsy Research, University Hospital of Bonn, 53127 Bonn, Germany
| | - Christian Elger
- Clinic for Neurology and Competence Center for Epilepsy, Beta Klinik Bonn GmbH, 53227 Bonn, Germany
| | - Johannes Schramm
- Medical Faculty, University Medical Center Bonn, 53127 Bonn, Germany
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Chronic clomipramine treatment increases hippocampal volume in rats exposed to chronic unpredictable mild stress. Transl Psychiatry 2022; 12:245. [PMID: 35688836 PMCID: PMC9187713 DOI: 10.1038/s41398-022-02006-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 05/23/2022] [Accepted: 05/26/2022] [Indexed: 12/29/2022] Open
Abstract
It is well known that neuroinflammation is closely related to the pathophysiology of depression. Due to individual differences in clinical research, the reduction of hippocampal volume in patients with depression is still controversial. In this experiment, we studied a typical kind of tricyclic antidepressant, clomipramine. We designed a series of experiments to find its role in depressive-like behavior, hippocampal neuroinflammation as well as hippocampal volume changes induced by chronic unpredictable mild stress (CMS). Rats exhibited defective behavior and hippocampal neuroinflammation after 12 weeks of CMS, which included elevated expression of cleaved interleukin-1β (IL-1β) and NLRP3 inflammasome together with the activation of microglia. Rats exposed to CMS showed weakened behavioral defects, reduced expression of IL-18, IL-6, and IL-1β along with reversed activation of microglia after clomipramine treatment. This indicates that the antidepressant effect of clomipramine may be related to the reduced expression of NLRP3 inflammasome and cleaved IL-1β. Moreover, we found an increased hippocampal volume in rats exposed to CMS after clomipramine treatment while CMS failed to affect hippocampal volume. All these results indicate that the NLRP3 inflammasome of microglia in the hippocampus is related to the antidepressant effects of clomipramine and CMS-induced depressive-like behavior in rats.
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Harms A, Bauer T, Fischbach L, David B, Ernst L, Witt JA, Diers K, Baumgartner T, Weber B, Radbruch A, Becker AJ, Helmstaedter C, Reuter M, Elger CE, Surges R, Rüber T. Shape description and volumetry of hippocampus and amygdala in temporal lobe epilepsy - A beneficial combination with a clinical perspective. Epilepsy Behav 2022; 128:108560. [PMID: 35066389 DOI: 10.1016/j.yebeh.2022.108560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 01/02/2022] [Accepted: 01/04/2022] [Indexed: 11/25/2022]
Abstract
Shape-based markers have entered the field of morphometric neuroimaging analysis as a second mainstay alongside conventional volumetric approaches. We aimed to assess the added value of shape description for the analysis of lesional and autoimmune temporal lobe epilepsy (TLE) focusing on hippocampus and amygdala. We retrospectively investigated MRI and clinical data from 65 patients with lesional TLE (hippocampal sclerosis (HS) and astrogliosis) and from 62 patients with limbic encephalitis (LE) with serologically proven autoantibodies. Surface reconstruction and volumetric segmentation were performed with FreeSurfer. For the shape analysis, we used BrainPrint, a tool that utilizes eigenvalues of the Laplace-Beltrami operator on triangular meshes to calculate intra-subject asymmetry. Psychometric tests of memory performance were ascertained, to evaluate clinical relevance of the shape descriptor. The potential benefit of shape in addition to volumetric information for classification was assessed by five-fold repeated cross validation and logistic regression. For the LE group, the best performing classification model consisted of a combination of volume and shape asymmetry (mean AUC = 0.728), the logistic regression model was significantly improved considering both modalities instead of just volume asymmetry. For lesional TLE, the best model only considered volumetric information (mean AUC = 0.867). Shape asymmetry of the hippocampus was largely associated with verbal memory performance only in LE patients (OR = 1.07, p = 0.02). For lesional TLE, shape description is robust, but redundant when compared to volumetric approaches. For LE, in contrast, shape asymmetry as a complementary modality significantly improves the detection of subtle morphometric changes and is further associated with memory performance, which underscores the clinical relevance of shape asymmetry as a novel imaging biomarker.
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Affiliation(s)
- Antonia Harms
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Tobias Bauer
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Laura Fischbach
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Bastian David
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Leon Ernst
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Juri-Alexander Witt
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Kersten Diers
- Deutsches Zentrum für neurodegenerative Erkrankungen (DZNE), Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Tobias Baumgartner
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Bernd Weber
- Institute of Experimental Epileptology and Cognition Research, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Alexander Radbruch
- Department of Neuroradiology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Albert J Becker
- Department of Neuropathology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Christoph Helmstaedter
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Martin Reuter
- Deutsches Zentrum für neurodegenerative Erkrankungen (DZNE), Venusberg-Campus 1, 53127 Bonn, Germany; Martinos Center for Biomedical Imaging, MGH/Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA.
| | - Christian E Elger
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Rainer Surges
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
| | - Theodor Rüber
- Department of Epileptology, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany.
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10
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Caldairou B, Foit NA, Mutti C, Fadaie F, Gill R, Lee HM, Demerath T, Urbach H, Schulze-Bonhage A, Bernasconi A, Bernasconi N. MRI-Based Machine Learning Prediction Framework to Lateralize Hippocampal Sclerosis in Patients With Temporal Lobe Epilepsy. Neurology 2021; 97:e1583-e1593. [PMID: 34475125 DOI: 10.1212/wnl.0000000000012699] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 07/30/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND OBJECTIVES MRI fails to reveal hippocampal pathology in 30% to 50% of temporal lobe epilepsy (TLE) surgical candidates. To address this clinical challenge, we developed an automated MRI-based classifier that lateralizes the side of covert hippocampal pathology in TLE. METHODS We trained a surface-based linear discriminant classifier that uses T1-weighted (morphology) and T2-weighted and fluid-attenuated inversion recovery (FLAIR)/T1 (intensity) features. The classifier was trained on 60 patients with TLE (mean age 35.6 years, 58% female) with histologically verified hippocampal sclerosis (HS). Images were deemed to be MRI negative in 42% of cases on the basis of neuroradiologic reading (40% based on hippocampal volumetry). The predictive model automatically labeled patients as having left or right TLE. Lateralization accuracy was compared to electroclinical data, including side of surgery. Accuracy of the classifier was further assessed in 2 independent TLE cohorts with similar demographics and electroclinical characteristics (n = 57, 58% MRI negative). RESULTS The overall lateralization accuracy was 93% (95% confidence interval 92%-94%), regardless of HS visibility. In MRI-negative TLE, the combination of T2 and FLAIR/T1 intensities provided the highest accuracy in both the training (84%, area under the curve [AUC] 0.95 ± 0.02) and validation (cohort 1 90%, AUC 0.99; cohort 2 76%, AUC 0.94) cohorts. DISCUSSION This prediction model for TLE lateralization operates on readily available conventional MRI contrasts and offers gain in accuracy over visual radiologic assessment. The combined contribution of decreased T1- and increased T2-weighted intensities makes the synthetic FLAIR/T1 contrast particularly effective in MRI-negative HS, setting the basis for broad clinical translation. CLASSIFICATION OF EVIDENCE This study provides Class II evidence that in people with TLE and MRI-negative HS, an automated MRI-based classifier accurately determines the side of pathology.
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Affiliation(s)
- Benoit Caldairou
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany
| | - Niels A Foit
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany
| | - Carlotta Mutti
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany
| | - Fatemeh Fadaie
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany
| | - Ravnoor Gill
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany
| | - Hyo Min Lee
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany
| | - Theo Demerath
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany
| | - Horst Urbach
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany
| | - Andreas Schulze-Bonhage
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany
| | - Andrea Bernasconi
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany.
| | - Neda Bernasconi
- From the Neuroimaging of Epilepsy Laboratory (B.C., N.A.F., C.M., F.F., R.G., H.M.L., A.B., N.B.), McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Quebec, Canada; and Departments of Neurosurgery (N.A.F.) and Neuroradiology (T.D., H.U.), Freiburg Medical Center, and Department of Neurology (A.S.-B.), University of Freiburg, Germany.
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11
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Borger V, Hamed M, Taube J, Aydin G, Ilic I, Schneider M, Schuss P, Güresir E, Becker A, Helmstaedter C, Elger CE, Vatter H. Resective temporal lobe surgery in refractory temporal lobe epilepsy: prognostic factors of postoperative seizure outcome. J Neurosurg 2021. [DOI: 10.3171/2020.7.jns20284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE
Temporal lobe epilepsy (TLE) is one of the most common forms of epilepsy. In approximately 30% of patients, seizures are refractory to drug treatment. Despite the achievements of modern presurgical evaluation in recent years, the presurgical prediction of seizure outcome remains difficult. The aim of this study was to evaluate the seizure outcome in patients with drug-refractory TLE who underwent resective temporal lobe surgery (rTLS) and to determine features associated with unfavorable postsurgical seizure outcome.
METHODS
Patients with medically refractory TLE who underwent rTLS between 2012 and 2017 were reviewed from the prospectively collected epilepsy surgery database. A retrospective analysis of clinical, radiological, neuropsychological, histopathological, and perioperative findings of 161 patients was performed. The patients were divided into two groups according to seizure outcome (group I, International League Against Epilepsy [ILAE] class 1; group II, ILAE class ≥ 2). For identification of independent risk factors for unfavorable postoperative seizure outcome (ILAE class ≥ 2), a multivariate logistic regression analysis was performed.
RESULTS
Seizure freedom (ILAE class 1) was achieved in 121 patients (75.2%). The neuropsychological evaluation demonstrated that losses in cognitive performance were more pronounced in verbal memory after resections in the left temporal lobe and in nonverbal memory after right-sided resections, whereas attention improved after surgery. Overall, postoperative visual field deficits (VFDs) were common and occurred in 51% of patients. There was no statistically significant difference in the incidence of VFD in patients with selective surgical procedures compared to the patients with nonselective procedures. The lack of MRI lesions and placement of depth electrodes were preoperatively identified as predictors for unfavorable seizure outcome.
CONCLUSIONS
rTLS is an effective treatment method in patients with refractory TLE. However, patients with a lack of MRI lesions and placement of depth electrodes prior to rTLS are at higher risk for an unfavorable postsurgical seizure outcome.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Albert Becker
- Institute of Neuropathology, University Hospital Bonn, Germany
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12
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Ahmad R, Maiworm M, Nöth U, Seiler A, Hattingen E, Steinmetz H, Rosenow F, Deichmann R, Wagner M, Gracien RM. Cortical Changes in Epilepsy Patients With Focal Cortical Dysplasia: New Insights With T 2 Mapping. J Magn Reson Imaging 2020; 52:1783-1789. [PMID: 32383241 DOI: 10.1002/jmri.27184] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/17/2020] [Accepted: 04/17/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND In epilepsy patients with focal cortical dysplasia (FCD) as the epileptogenic focus, global cortical signal changes are generally not visible on conventional MRI. However, epileptic seizures or antiepileptic medication might affect normal-appearing cerebral cortex and lead to subtle damage. PURPOSE To investigate cortical properties outside FCD regions with T2 -relaxometry. STUDY TYPE Prospective study. SUBJECTS Sixteen patients with epilepsy and FCD and 16 age-/sex-matched healthy controls. FIELD STRENGTH/SEQUENCE 3T, fast spin-echo T2 -mapping, fluid-attenuated inversion recovery (FLAIR), and synthetic T1 -weighted magnetization-prepared rapid acquisition of gradient-echoes (MP-RAGE) datasets derived from T1 -maps. ASSESSMENT Reconstruction of the white matter and cortical surfaces based on MP-RAGE structural images was performed to extract cortical T2 values, excluding lesion areas. Three independent raters confirmed that morphological cortical/juxtacortical changes in the conventional FLAIR datasets outside the FCD areas were definitely absent for all patients. Averaged global cortical T2 values were compared between groups. Furthermore, group comparisons of regional cortical T2 values were performed using a surface-based approach. Tests for correlations with clinical parameters were carried out. STATISTICAL TESTS General linear model analysis, permutation simulations, paired and unpaired t-tests, and Pearson correlations. RESULTS Cortical T2 values were increased outside FCD regions in patients (83.4 ± 2.1 msec, control group 81.4 ± 2.1 msec, P = 0.01). T2 increases were widespread, affecting mainly frontal, but also parietal and temporal regions of both hemispheres. Significant correlations were not observed (P ≥ 0.55) between cortical T2 values in the patient group and the number of seizures in the last 3 months or the number of anticonvulsive drugs in the medical history. DATA CONCLUSION Widespread increases in cortical T2 in FCD-associated epilepsy patients were found, suggesting that structural epilepsy in patients with FCD is not only a symptom of a focal cerebral lesion, but also leads to global cortical damage not visible on conventional MRI. EVIDENCE LEVEL 21 TECHNICAL EFFICACY STAGE: 3 J. MAGN. RESON. IMAGING 2020;52:1783-1789.
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Affiliation(s)
- Rida Ahmad
- Department of Neurology, Goethe University, Frankfurt/Main, Germany.,Department of Neuroradiology, Goethe University, Frankfurt/Main, Germany.,Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER) Consortium, Germany
| | - Michelle Maiworm
- Department of Neurology, Goethe University, Frankfurt/Main, Germany.,Department of Neuroradiology, Goethe University, Frankfurt/Main, Germany.,Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER) Consortium, Germany
| | - Ulrike Nöth
- Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER) Consortium, Germany
| | - Alexander Seiler
- Department of Neurology, Goethe University, Frankfurt/Main, Germany.,Brain Imaging Center, Goethe University, Frankfurt/Main, Germany
| | - Elke Hattingen
- Department of Neuroradiology, Goethe University, Frankfurt/Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER) Consortium, Germany
| | - Helmuth Steinmetz
- Department of Neurology, Goethe University, Frankfurt/Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER) Consortium, Germany
| | - Felix Rosenow
- Department of Neurology, Goethe University, Frankfurt/Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER) Consortium, Germany.,Epilepsy Center Frankfurt Rhine-Main, Center of Neurology and Neurosurgery, Goethe University, Frankfurt/Main, Germany
| | - Ralf Deichmann
- Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER) Consortium, Germany
| | - Marlies Wagner
- Department of Neuroradiology, Goethe University, Frankfurt/Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER) Consortium, Germany
| | - René-Maxime Gracien
- Department of Neurology, Goethe University, Frankfurt/Main, Germany.,Brain Imaging Center, Goethe University, Frankfurt/Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER) Consortium, Germany
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13
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Ono SE, de Carvalho Neto A, Joaquim MJM, Dos Santos GR, de Paola L, Silvado CES. Mesial temporal lobe epilepsy: Revisiting the relation of hippocampal volumetry with memory deficits. Epilepsy Behav 2019; 100:106516. [PMID: 31574430 DOI: 10.1016/j.yebeh.2019.106516] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/12/2019] [Accepted: 08/23/2019] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Neuropsychological tests can infer the lateralization of the epileptogenic focus, associating verbal memory to mesial structures in the left temporal lobe and visual or nonverbal memory to the right side. High-field magnetic resonance imaging (MRI) with high-resolution protocols allows acquisitions suitable for advanced postprocessing with precise volumetry of brain structures, and functional MRI demonstrates evidence that epilepsy should be seen as a network pathology, involving several structures in the brain. Since the literature showing associations between the volumetry of brain structures in left and right mesial temporal lobe epilepsy (MTLE) and verbal and visual memory performance on neuropsychological tests is conflicting, we revisited these relationships, considering the hippocampal volumetry of patients with unilateral MTLE. METHODS Automatized hippocampal volumes were obtained using FreeSurfer software from MRI exams of 35 patients with unilateral MTLE and hippocampal atrophy and homolateral ictal onset zone defined by video electroencephalography concordant to the side of hippocampal volume reduction (15 on the left side). Verbal memory was assessed using the Rey Auditory-Verbal Learning Test (RAVLT), and visual memory tests employed the Rey-Osterrieth Complex Figure Test (ROCFT). The statistical analysis explored relationships between hippocampal volumetry, lateralization, and performance on memory tests. RESULTS In general, we observed deficits in both verbal and visual memory for patients with left and right hippocampal volume reduction. Patients with left hippocampal volume reduction had poorer performance on verbal memory tests compared with those with right hippocampal atrophy (t = -3.813, p < 0.001). Visual memory deficits were seen on both left and right MTLE without a statistically significant difference (t = 0.074, p = 0.942). The correlation between the Hippocampal Asymmetry Index (HAI) and visual and verbal Z-scores was significant only for visual Z-score in right MTLE (R = -0.45, p = 0.048). CONCLUSIONS Verbal memory deficit seems to be more consistent in patients with left hippocampal volume reduction. Although it had only a moderate correlation to HAI, visual memory deficit is suggested as a poorer indicator for right MTLE. Considering that verbal and visual memory deficits are seen on both right and left MTLE, MTLE should not be regarded as a unilateral, focal, or local insult but as a multifactorial and network pathology, possibly involving several brain structures.
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Affiliation(s)
- Sergio Eiji Ono
- Clínica Diagnóstico Avançado por Imagem - DAPI, Curitiba, PR, Brazil.
| | - Arnolfo de Carvalho Neto
- Clínica Diagnóstico Avançado por Imagem - DAPI, Curitiba, PR, Brazil; Epilepsy and EEG Service, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil
| | | | | | - Luciano de Paola
- Epilepsy and EEG Service, Hospital de Clínicas, Federal University of Paraná, Curitiba, PR, Brazil
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