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Feng Y, Diego KS, Dong Z, Wick ZC, Page-Harley L, Page-Harley V, Schnipper J, Lamsifer SI, Pennington ZT, Vetere LM, Philipsberg PA, Soler I, Jurkowski A, Rosado CJ, Khan NN, Cai DJ, Shuman T. Distinct changes to hippocampal and medial entorhinal circuits emerge across the progression of cognitive deficits in epilepsy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.12.584697. [PMID: 38559224 PMCID: PMC10979962 DOI: 10.1101/2024.03.12.584697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Temporal lobe epilepsy (TLE) causes pervasive and progressive memory impairments, yet the specific circuit changes that drive these deficits remain unclear. To investigate how hippocampal-entorhinal dysfunction contributes to progressive memory deficits in epilepsy, we performed simultaneous in vivo electrophysiology in hippocampus (HPC) and medial entorhinal cortex (MEC) of control and epileptic mice 3 or 8 weeks after pilocarpine-induced status epilepticus (Pilo-SE). We found that HPC synchronization deficits (including reduced theta power, coherence, and altered interneuron spike timing) emerged within 3 weeks of Pilo-SE, aligning with early-onset, relatively subtle memory deficits. In contrast, abnormal synchronization within MEC and between HPC-MEC emerged later, by 8 weeks after Pilo-SE, when spatial memory impairment was more severe. Furthermore, a distinct subpopulation of MEC layer 3 excitatory neurons (active at theta troughs) was specifically impaired in epileptic mice. Together, these findings suggest that hippocampal-entorhinal circuit dysfunction accumulates and shifts as cognitive impairment progresses in TLE.
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Affiliation(s)
- Yu Feng
- Icahn School of Medicine at Mount Sinai, New York, NY
| | | | - Zhe Dong
- Icahn School of Medicine at Mount Sinai, New York, NY
| | | | | | | | | | | | | | | | | | - Ivan Soler
- Icahn School of Medicine at Mount Sinai, New York, NY
| | | | | | - Nadia N Khan
- Icahn School of Medicine at Mount Sinai, New York, NY
| | - Denise J Cai
- Icahn School of Medicine at Mount Sinai, New York, NY
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Royer J, Larivière S, Rodriguez-Cruces R, Cabalo DG, Tavakol S, Auer H, Ngo A, Park BY, Paquola C, Smallwood J, Jefferies E, Caciagli L, Bernasconi A, Bernasconi N, Frauscher B, Bernhardt BC. Cortical microstructural gradients capture memory network reorganization in temporal lobe epilepsy. Brain 2023; 146:3923-3937. [PMID: 37082950 PMCID: PMC10473569 DOI: 10.1093/brain/awad125] [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: 11/07/2022] [Revised: 02/21/2023] [Accepted: 03/23/2023] [Indexed: 04/22/2023] Open
Abstract
Temporal lobe epilepsy (TLE), one of the most common pharmaco-resistant epilepsies, is associated with pathology of paralimbic brain regions, particularly in the mesiotemporal lobe. Cognitive dysfunction in TLE is frequent, and particularly affects episodic memory. Crucially, these difficulties challenge the quality of life of patients, sometimes more than seizures, underscoring the need to assess neural processes of cognitive dysfunction in TLE to improve patient management. Our work harnessed a novel conceptual and analytical approach to assess spatial gradients of microstructural differentiation between cortical areas based on high-resolution MRI analysis. Gradients track region-to-region variations in intracortical lamination and myeloarchitecture, serving as a system-level measure of structural and functional reorganization. Comparing cortex-wide microstructural gradients between 21 patients and 35 healthy controls, we observed a reorganization of this gradient in TLE driven by reduced microstructural differentiation between paralimbic cortices and the remaining cortex with marked abnormalities in ipsilateral temporopolar and dorsolateral prefrontal regions. Findings were replicated in an independent cohort. Using an independent post-mortem dataset, we observed that in vivo findings reflected topographical variations in cortical cytoarchitecture. We indeed found that macroscale changes in microstructural differentiation in TLE reflected increased similarity of paralimbic and primary sensory/motor regions. Disease-related transcriptomics could furthermore show specificity of our findings to TLE over other common epilepsy syndromes. Finally, microstructural dedifferentiation was associated with cognitive network reorganization seen during an episodic memory functional MRI paradigm and correlated with interindividual differences in task accuracy. Collectively, our findings showing a pattern of reduced microarchitectural differentiation between paralimbic regions and the remaining cortex provide a structurally-grounded explanation for large-scale functional network reorganization and cognitive dysfunction characteristic of TLE.
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Affiliation(s)
- Jessica Royer
- Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
- Analytical Neurophysiology Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Sara Larivière
- Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Raul Rodriguez-Cruces
- Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Donna Gift Cabalo
- Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Shahin Tavakol
- Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Hans Auer
- Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Alexander Ngo
- Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Bo-yong Park
- Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
- Department of Data Science, Inha University, Incheon 22212, Republic of Korea
- Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon 34126, Republic of Korea
| | - Casey Paquola
- Multiscale Neuroanatomy Lab, INM-1, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Jonathan Smallwood
- Department of Psychology, Queen’s University, Kingston, ON, K7L 3N6, Canada
| | | | - Lorenzo Caciagli
- Department of Bioengineering, University of Pennsylvania, Philadelphia, MA 19104, USA
| | - Andrea Bernasconi
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Birgit Frauscher
- Analytical Neurophysiology Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Boris C Bernhardt
- Multimodal Imaging and Connectome Analysis Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC H3A 2B4, Canada
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Dasgupta D, Finn R, Chari A, Giampiccolo D, de Tisi J, O'Keeffe AG, Miserocchi A, McEvoy AW, Vos SB, Duncan JS. Hippocampal resection in temporal lobe epilepsy: Do we need to resect the tail? Epilepsy Res 2023; 190:107086. [PMID: 36709527 PMCID: PMC10626579 DOI: 10.1016/j.eplepsyres.2023.107086] [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: 08/22/2022] [Revised: 12/24/2022] [Accepted: 01/09/2023] [Indexed: 01/13/2023]
Abstract
INTRODUCTION Anteromesial temporal lobe resection is the most common surgical technique used to treat drug-resistant mesial temporal lobe epilepsy, particularly when secondary to hippocampal sclerosis. Structural and functional imaging data suggest the importance of sparing the posterior hippocampus for minimising language and memory deficits. Recent work has challenged the view that maximal posterior hippocampal resection improves seizure outcome. This study was designed to assess whether resection of posterior hippocampal atrophy was associated with improved seizure outcome. METHODS Retrospective analysis of a prospective database of all anteromesial temporal lobe resections performed in individuals with hippocampal sclerosis at our epilepsy surgery centre, 2013-2021. Pre- and post-operative MRI were reviewed by 2 neurosurgical fellows to assess whether the atrophic segment, displayed by automated hippocampal morphometry, was resected, and ILAE seizure outcomes were collected at 1 year and last clinical follow-up. Data analysis used univariate and binary logistic regression. RESULTS Sixty consecutive eligible patients were identified of whom 70% were seizure free (ILAE Class 1 & 2) at one year. There was no statistically significant difference in seizure freedom outcomes in patients who had complete resection of atrophic posterior hippocampus or not (Fisher's Exact test statistic 0.69, not significant at p < .05) both at one year, and at last clinical follow-up. In the multivariate analysis only a history of status epilepticus (OR=0.2, 95%CI:0.042-0.955, p = .04) at one year, and pre-operative psychiatric disorder (OR=0.145, 95%CI:0.036-0.588, p = .007) at last clinical follow-up, were associated with a reduced chance of seizure freedom. SIGNIFICANCE Our data suggest that seizure freedom is not associated with whether or not posterior hippocampal atrophy is resected. This challenges the traditional surgical dogma of maximal posterior hippocampal resection in anteromesial temporal lobe resections and is a step further optimising this surgical procedure to maximise seizure freedom and minimise associated language and memory deficits.
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Affiliation(s)
- Debayan Dasgupta
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK; Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
| | - Roisin Finn
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
| | - Aswin Chari
- Department of Neurosurgery, Great Ormond Street Hospital, London, UK; Developmental Neuroscience, Great Ormond Street Institute of Child Health, University College London, London, UK.
| | - Davide Giampiccolo
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK; Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK; Institute of Neurosciences, Cleveland Clinic London, London, UK.
| | - Jane de Tisi
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK.
| | - Aidan G O'Keeffe
- School of Mathematical Sciences, University of Nottingham, Nottingham, UK. aidan.o'
| | - Anna Miserocchi
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
| | - Andrew W McEvoy
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
| | - Sjoerd B Vos
- Centre for Medical Image Computing, Department of Computer Science, University College London, London, UK; Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK; Centre for Microscopy, Characterisation, and Analysis, The University of Western Australia, Nedlands, Australia.
| | - John S Duncan
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK.
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Hassankhani A, Stein JM, Haboosheh AG, Vossough A, Loevner LA, Nabavizadeh SA. Anatomical Variations, Mimics, and Pitfalls in Imaging of Patients with Epilepsy. J Neuroimaging 2020; 31:20-34. [PMID: 33314527 DOI: 10.1111/jon.12809] [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: 08/31/2020] [Revised: 10/22/2020] [Accepted: 10/26/2020] [Indexed: 11/27/2022] Open
Abstract
Epilepsy is among one of the most common neurologic disorders. The role of magnetic resonance imaging (MRI) in the diagnosis and management of patients with epilepsy is well established, and most patients with epilepsy are likely to undergo at least one or more MRI examinations in the course of their disease. Recent advances in high-field MRI have enabled high resolution in vivo visualization of small and intricate anatomic structures that are of great importance in the assessment of seizure disorders. Familiarity with normal anatomic variations is essential in the accurate diagnosis and image interpretation, as these variations may be mistaken for epileptogenic foci, leading to unnecessary follow-up imaging, or worse, unnecessary treatment. After a brief overview of normal imaging anatomy of the mesial temporal lobe, this article will review a few important common and uncommon anatomic variations, mimics, and pitfalls that may be encountered in the imaging evaluation of patients with epilepsy.
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Affiliation(s)
- Alvand Hassankhani
- Division of Neuroradiology, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Joel M Stein
- Division of Neuroradiology, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Amit G Haboosheh
- Department of Radiology, Hadassah Ein Karem Hospital, Jerusalem, Israel
| | - Arastoo Vossough
- Division of Neuroradiology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Laurie A Loevner
- Division of Neuroradiology, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
| | - Seyed Ali Nabavizadeh
- Division of Neuroradiology, Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
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5
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Goodkin O, Pemberton HG, Vos SB, Prados F, Das RK, Moggridge J, De Blasi B, Bartlett P, Williams E, Campion T, Haider L, Pearce K, Bargallό N, Sanchez E, Bisdas S, White M, Ourselin S, Winston GP, Duncan JS, Cardoso J, Thornton JS, Yousry TA, Barkhof F. Clinical evaluation of automated quantitative MRI reports for assessment of hippocampal sclerosis. Eur Radiol 2020; 31:34-44. [PMID: 32749588 PMCID: PMC7755617 DOI: 10.1007/s00330-020-07075-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/07/2020] [Accepted: 07/15/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Hippocampal sclerosis (HS) is a common cause of temporal lobe epilepsy. Neuroradiological practice relies on visual assessment, but quantification of HS imaging biomarkers-hippocampal volume loss and T2 elevation-could improve detection. We tested whether quantitative measures, contextualised with normative data, improve rater accuracy and confidence. METHODS Quantitative reports (QReports) were generated for 43 individuals with epilepsy (mean age ± SD 40.0 ± 14.8 years, 22 men; 15 histologically unilateral HS; 5 bilateral; 23 MR-negative). Normative data was generated from 111 healthy individuals (age 40.0 ± 12.8 years, 52 men). Nine raters with different experience (neuroradiologists, trainees, and image analysts) assessed subjects' imaging with and without QReports. Raters assigned imaging normal, right, left, or bilateral HS. Confidence was rated on a 5-point scale. RESULTS Correct designation (normal/abnormal) was high and showed further trend-level improvement with QReports, from 87.5 to 92.5% (p = 0.07, effect size d = 0.69). Largest magnitude improvement (84.5 to 93.8%) was for image analysts (d = 0.87). For bilateral HS, QReports significantly improved overall accuracy, from 74.4 to 91.1% (p = 0.042, d = 0.7). Agreement with the correct diagnosis (kappa) tended to increase from 0.74 ('fair') to 0.86 ('excellent') with the report (p = 0.06, d = 0.81). Confidence increased when correctly assessing scans with the QReport (p < 0.001, η2p = 0.945). CONCLUSIONS QReports of HS imaging biomarkers can improve rater accuracy and confidence, particularly in challenging bilateral cases. Improvements were seen across all raters, with large effect sizes, greatest for image analysts. These findings may have positive implications for clinical radiology services and justify further validation in larger groups. KEY POINTS • Quantification of imaging biomarkers for hippocampal sclerosis-volume loss and raised T2 signal-could improve clinical radiological detection in challenging cases. • Quantitative reports for individual patients, contextualised with normative reference data, improved diagnostic accuracy and confidence in a group of nine raters, in particular for bilateral HS cases. • We present a pre-use clinical validation of an automated imaging assessment tool to assist clinical radiology reporting of hippocampal sclerosis, which improves detection accuracy.
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Affiliation(s)
- Olivia Goodkin
- Centre for Medical Image Computing (CMIC), University College London, London, UK. .,Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK.
| | - Hugh G Pemberton
- Centre for Medical Image Computing (CMIC), University College London, London, UK.,Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Sjoerd B Vos
- Centre for Medical Image Computing (CMIC), University College London, London, UK.,Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK.,Epilepsy Society MRI Unit, Chalfont St Peter, UK
| | - Ferran Prados
- Centre for Medical Image Computing (CMIC), University College London, London, UK.,Universitat Oberta de Catalunya, Barcelona, Spain
| | - Ravi K Das
- Clinical, Educational and Health Psychology, University College London, London, UK
| | - James Moggridge
- Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK.,Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Bianca De Blasi
- Department of Medical Physics and Bioengineering, University College London, London, UK
| | - Philippa Bartlett
- Epilepsy Society MRI Unit, Chalfont St Peter, UK.,Department of Clinical and Experimental Epilepsy, University College London, London, UK
| | - Elaine Williams
- Wellcome Trust Centre for Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Thomas Campion
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Lukas Haider
- Department of Biomedical Imaging and Image Guided Therapy, Medical University of Vienna, Vienna, Austria.,NMR Research Unit, Department of Neuroinflammation, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Kirsten Pearce
- Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Nuria Bargallό
- Radiology Department, Hospital Clínic de Barcelona and Magnetic Resonance Image Core Facility, Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
| | - Esther Sanchez
- Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Sotirios Bisdas
- Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK.,Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Mark White
- Digital Services, University College London Hospital, London, UK
| | - Sebastien Ourselin
- Department of Medical Physics and Bioengineering, University College London, London, UK.,School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Gavin P Winston
- Epilepsy Society MRI Unit, Chalfont St Peter, UK.,Department of Clinical and Experimental Epilepsy, University College London, London, UK.,Department of Medicine, Division of Neurology, Queen's University, Kingston, Ontario, Canada
| | - John S Duncan
- Epilepsy Society MRI Unit, Chalfont St Peter, UK.,Department of Clinical and Experimental Epilepsy, University College London, London, UK
| | - Jorge Cardoso
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - John S Thornton
- Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK.,Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Tarek A Yousry
- Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK.,Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK
| | - Frederik Barkhof
- Centre for Medical Image Computing (CMIC), University College London, London, UK.,Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK.,Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCLH NHS Foundation Trust, London, UK.,Radiology & Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
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6
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Hermann B, Conant LL, Cook CJ, Hwang G, Garcia-Ramos C, Dabbs K, Nair VA, Mathis J, Bonet CNR, Allen L, Almane DN, Arkush K, Birn R, DeYoe EA, Felton E, Maganti R, Nencka A, Raghavan M, Shah U, Sosa VN, Struck AF, Ustine C, Reyes A, Kaestner E, McDonald C, Prabhakaran V, Binder JR, Meyerand ME. Network, clinical and sociodemographic features of cognitive phenotypes in temporal lobe epilepsy. Neuroimage Clin 2020; 27:102341. [PMID: 32707534 PMCID: PMC7381697 DOI: 10.1016/j.nicl.2020.102341] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 06/10/2020] [Accepted: 07/03/2020] [Indexed: 01/14/2023]
Abstract
This study explored the taxonomy of cognitive impairment within temporal lobe epilepsy and characterized the sociodemographic, clinical and neurobiological correlates of identified cognitive phenotypes. 111 temporal lobe epilepsy patients and 83 controls (mean ages 33 and 39, 57% and 61% female, respectively) from the Epilepsy Connectome Project underwent neuropsychological assessment, clinical interview, and high resolution 3T structural and resting-state functional MRI. A comprehensive neuropsychological test battery was reduced to core cognitive domains (language, memory, executive, visuospatial, motor speed) which were then subjected to cluster analysis. The resulting cognitive subgroups were compared in regard to sociodemographic and clinical epilepsy characteristics as well as variations in brain structure and functional connectivity. Three cognitive subgroups were identified (intact, language/memory/executive function impairment, generalized impairment) which differed significantly, in a systematic fashion, across multiple features. The generalized impairment group was characterized by an earlier age at medication initiation (P < 0.05), fewer patient (P < 0.001) and parental years of education (P < 0.05), greater racial diversity (P < 0.05), and greater number of lifetime generalized seizures (P < 0.001). The three groups also differed in an orderly manner across total intracranial (P < 0.001) and bilateral cerebellar cortex volumes (P < 0.01), and rate of bilateral hippocampal atrophy (P < 0.014), but minimally in regional measures of cortical volume or thickness. In contrast, large-scale patterns of cortical-subcortical covariance networks revealed significant differences across groups in global and local measures of community structure and distribution of hubs. Resting-state fMRI revealed stepwise anomalies as a function of cluster membership, with the most abnormal patterns of connectivity evident in the generalized impairment group and no significant differences from controls in the cognitively intact group. Overall, the distinct underlying cognitive phenotypes of temporal lobe epilepsy harbor systematic relationships with clinical, sociodemographic and neuroimaging correlates. Cognitive phenotype variations in patient and familial education and ethnicity, with linked variations in total intracranial volume, raise the question of an early and persisting socioeconomic-status related neurodevelopmental impact, with additional contributions of clinical epilepsy factors (e.g., lifetime generalized seizures). The neuroimaging features of cognitive phenotype membership are most notable for disrupted large scale cortical-subcortical networks and patterns of functional connectivity with bilateral hippocampal and cerebellar atrophy. The cognitive taxonomy of temporal lobe epilepsy appears influenced by features that reflect the combined influence of socioeconomic, neurodevelopmental and neurobiological risk factors.
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Affiliation(s)
- Bruce Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Lisa L Conant
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Cole J Cook
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Gyujoon Hwang
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Camille Garcia-Ramos
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Kevin Dabbs
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Veena A Nair
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jedidiah Mathis
- Department of Radiology Froedtert & Medical College of Wisconsin, Milwaukee, WI, USA
| | - Charlene N Rivera Bonet
- Neuroscience Training Program, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Linda Allen
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Dace N Almane
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Karina Arkush
- Neuroscience Innovation Institute, Aurora St. Luke's Medical Center, Milwaukee, WI, USA
| | - Rasmus Birn
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Neuroscience Training Program, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Psychiatry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Edgar A DeYoe
- Department of Radiology Froedtert & Medical College of Wisconsin, Milwaukee, WI, USA; Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Elizabeth Felton
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Rama Maganti
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Andrew Nencka
- Department of Radiology Froedtert & Medical College of Wisconsin, Milwaukee, WI, USA
| | - Manoj Raghavan
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Umang Shah
- Neuroscience Innovation Institute, Aurora St. Luke's Medical Center, Milwaukee, WI, USA
| | - Veronica N Sosa
- Neuroscience Innovation Institute, Aurora St. Luke's Medical Center, Milwaukee, WI, USA
| | - Aaron F Struck
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Candida Ustine
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Anny Reyes
- Department of Psychiatry, University of California-San Diego, La Jolla, CA, USA
| | - Erik Kaestner
- Department of Psychiatry, University of California-San Diego, La Jolla, CA, USA
| | - Carrie McDonald
- Department of Psychiatry, University of California-San Diego, La Jolla, CA, USA
| | - Vivek Prabhakaran
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Neuroscience Training Program, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Psychiatry, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jeffrey R Binder
- Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Mary E Meyerand
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Neuroscience Training Program, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
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7
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Beilharz JE, Thayer Z, Nikpour A, Lah S. Accelerated long-term forgetting is not evident in adults with genetic generalized epilepsy irrespective of the paradigm used. Epilepsy Behav 2020; 104:106920. [PMID: 32035340 DOI: 10.1016/j.yebeh.2020.106920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/10/2020] [Accepted: 01/17/2020] [Indexed: 10/24/2022]
Abstract
Accelerated long-term forgetting (ALF) is a recently discovered memory disorder characterized by intact acquisition and retention over short delays, followed by abnormally fast rates of forgetting. Accelerated long-term forgetting has been repeatedly found in children, but not in adults, with genetic generalized epilepsy (GGE). It is possible that this discrepancy is due to a difference in paradigms used in these studies. The current study aimed to determine whether adults with GGE displayed ALF using two paradigms, one that required complete learning and another one that did not. In addition, we explored the relationships with everyday memory difficulties, working memory, mood, and epilepsy variables. Fourteen adults with GGE were compared with 16 healthy controls on two verbal memory tests: a modified version of the California Verbal Learning Test learned to a criterion of 100% (complete learning) and Logical Memory from the Wechsler Memory Scale (Fourth Edition) presented only once (incomplete learning). Recall was tested at 2 min, 30 min, and 1 week, and recognition at 1 week only. Working memory, everyday memory, and mood were also assessed. We found no evidence of ALF on either of the two verbal memory paradigms on recall or recognition tests although patients displayed significantly poorer working memory. Moreover, patients with GGE reported significantly more memory difficulties in everyday life, and these were associated with greater mood disturbances but not with memory tests scores. Greater number of antiepileptic drugs and epilepsy severity also related to memory scores on some tests. Our study suggests that a difference in paradigms used to investigate ALF in children and adults with GGE is unlikely to explain the differences in findings. The study tentatively raises a hypothesis that developmental factors may play a role in ALF in patients with GGE; children with GGE may grow out of ALF. Nevertheless, this hypothesis would need to be tested in a longitudinal study that would follow patients from childhood to early adulthood.
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Affiliation(s)
| | - Zoe Thayer
- Neurology Department, Royal Prince Alfred Hospital, Sydney, NSW 2050, Australia
| | - Armin Nikpour
- Neurology Department, Royal Prince Alfred Hospital, Sydney, NSW 2050, Australia
| | - Suncica Lah
- School of Psychology, University of Sydney, Sydney, NSW 2006, Australia.
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Alterations in the functional brain network in a rat model of epileptogenesis: A longitudinal resting state fMRI study. Neuroimage 2019; 202:116144. [PMID: 31473355 DOI: 10.1016/j.neuroimage.2019.116144] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 08/13/2019] [Accepted: 08/28/2019] [Indexed: 11/21/2022] Open
Abstract
Epilepsy is a neurological disorder characterized by recurrent epileptic seizures. Electrophysiological and neuroimaging studies in patients with epilepsy suggest that abnormal functional brain networks play a role in the development of epilepsy, i.e. epileptogenesis, resulting in the generation of spontaneous seizures and cognitive impairment. In this longitudinal study, we investigated changes in functional brain networks during epileptogenesis in the intraperitoneal kainic acid (IPKA) rat model of temporal lobe epilepsy (TLE) using resting state functional magnetic resonance imaging (rsfMRI) and graph theory. Additionally, we investigated whether these changes are related to the frequency of occurrence of spontaneous epileptic seizures in the chronic phase of epilepsy. Using a 7T MRI system, rsfMRI images were acquired under medetomidine anaesthesia before and 1, 3, 6, 10 and 16 weeks after status epilepticus (SE) induction in 20 IPKA animals and 7 healthy control animals. To obtain a functional network, correlation between fMRI time series of 38 regions of interest (ROIs) was calculated. Then, several graph theoretical network measures were calculated to describe and quantify the network changes. At least 17 weeks post-SE, IPKA animals were implanted with electrodes in the left and right dorsal hippocampus, EEG was measured for 7 consecutive days and spontaneous seizures were counted. Our results show that correlation coefficients of fMRI time series shift to lower values during epileptogenesis, indicating weaker whole brain network connections. Segregation and integration in the functional brain network also decrease, indicating a lower local interconnectivity and a lower overall communication efficiency. Secondly, this study demonstrates that the largest decrease in functional connectivity is observed for the retrosplenial cortex. Finally, post-SE changes in functional connectivity, segregation and integration are correlated with seizure frequency in the IPKA rat model.
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9
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Standardization of an Arabic-Language Neuropsychological Battery for Epilepsy Surgical Evaluations. J Int Neuropsychol Soc 2019; 25:761-771. [PMID: 31084648 DOI: 10.1017/s1355617719000432] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVES This study provides a standardized Arabic language neuropsychological test battery and tests its ability to distinguish patients with left and right hemisphere epileptic foci who are candidates for surgical resection. METHODS An Arabic language battery of 15 tests was developed based on the neuropsychological test battery used at the Johns Hopkins Hospital for surgical evaluation of patients undergoing temporal lobe resection. With modifications where culturally required, 11 tests were translated to Arabic by the principal investigator and back-translated by two bilingual health professionals; four tests were available in Arabic and added to the battery. The battery was administered to 21 Arabic-speaking patients with left temporal epileptic foci, 21 with right temporal epileptic foci, and 46 neurologically and psychiatrically healthy adults. RESULTS Nearly all the Arabic test versions were capable of differentiating healthy controls and the temporal lobe epilepsy (TLE) groups. Tests known to distinguish left and right temporal lobectomy candidates, such as wordlist memory and prose recall, were able to do so as accurately as the English versions. Also, a roughly "culturally free" task (the Baltimore Board) and a newly developed version of the Boston Naming Test demonstrated some sensitivity to left temporal lobe involvement. CONCLUSIONS Arabic-language neuropsychological tests for epilepsy surgical evaluations are made available, demonstrate cultural sensitivity and clinical validity, and require further psychometric property and normative research. (JINS, 2019, 25, 761-771).
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Milak MS, Potter WA, Pantazatos SP, Keilp JG, Zanderigo F, Schain M, Sublette ME, Oquendo MA, Malone KM, Brandenburg H, Parsey RV, Mann JJ. Resting regional brain activity correlates of verbal learning deficit in major depressive disorder. Psychiatry Res Neuroimaging 2019; 283:96-103. [PMID: 30580237 DOI: 10.1016/j.pscychresns.2018.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 10/31/2018] [Accepted: 12/06/2018] [Indexed: 02/06/2023]
Abstract
Memory deficits are reported in major depressive disorder (MDD). Prefrontal cortical and mesiotemporal cortical (MTC)/subcortical regions are involved in the Buschke Selective Reminding Task (SRT), a verbal list-learning task. To determine whether depression-related changes in resting brain metabolism explain (in part) the deficits in SRT performance found in MDD, statistical correlation maps were calculated between SRT total recall score (TR) and relative regional cerebral metabolic rate for glucose (rCMRglu), measured by [18F]-flourodeoxyglucose (FDG) positron emission tomography (PET), in unmedicated, depressed MDD patients (N = 29). Subsequently, to explore hypothesized loss of top-down control in MDD, we compared the correlations between rCMRglu of SRT-relevant regions of the dorsolateral prefrontal cortex (dlPFC) and amygdala in a larger cohort of MDD (N = 60; 29 inclusive) versus healthy controls (HC) (N = 43). SRT performance of patients is on average 0.5 standard deviation below published normative mean. TR and rCMRglu positively correlate in bilateral dorsomedial PFC, dlPFC, dorsal anterior cingulate; negatively correlate in bilateral MTC/subcortical regions, and cerebellum. rCMRglu in dlPFC correlates negatively with that in amygdala in HC but not in MDD. Depression-related changes present in FDG-PET measured resting brain activity may be in part responsible for memory deficit found in MDD.
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Affiliation(s)
- Matthew S Milak
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA.
| | - W Antonio Potter
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
| | - Spiro P Pantazatos
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
| | - John G Keilp
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
| | - Francesca Zanderigo
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
| | - Martin Schain
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
| | - M Elizabeth Sublette
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
| | - Maria A Oquendo
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kevin M Malone
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
| | - Holly Brandenburg
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
| | - Ramin V Parsey
- Stony Brook Medicine, Stony Brook University, Stony Brook, NY, USA
| | - J John Mann
- Departments of Psychiatry and Radiology, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, USA; Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, NY, USA
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11
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Accelerated long-term forgetting in resected and seizure-free temporal lobe epilepsy patients. Cortex 2019; 110:80-91. [DOI: 10.1016/j.cortex.2018.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/17/2018] [Accepted: 02/27/2018] [Indexed: 11/19/2022]
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12
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Kuhn T, Gullett JM, Boutzoukas AE, Bohsali A, Mareci TH, FitzGerald DB, Carney PR, Bauer RM. Temporal lobe epilepsy affects spatial organization of entorhinal cortex connectivity. Epilepsy Behav 2018; 88:87-95. [PMID: 30243111 PMCID: PMC6294293 DOI: 10.1016/j.yebeh.2018.06.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/18/2018] [Accepted: 06/20/2018] [Indexed: 12/15/2022]
Abstract
Evidence for structural connectivity patterns within the medial temporal lobe derives primarily from postmortem histological studies. In humans and nonhuman primates, the parahippocampal gyrus (PHg) is subdivided into parahippocampal (PHc) and perirhinal (PRc) cortices, which receive input from distinct cortical networks. Likewise, their efferent projections to the entorhinal cortex (ERc) are distinct. The PHc projects primarily to the medial ERc (M-ERc). The PRc projects primarily to the lateral portion of the ERc (L-ERc). Both M-ERc and L-ERc, via the perforant pathway, project to the dentate gyrus and hippocampal (HC) subfields. Until recently, these neural circuits could not be visualized in vivo. Diffusion tensor imaging algorithms have been developed to segment gray matter structures based on probabilistic connectivity patterns. However, these algorithms have not yet been applied to investigate connectivity in the temporal lobe or changes in connectivity architecture related to disease processes. In this study, this segmentation procedure was used to classify ERc gray matter based on PRc, ERc, and HC connectivity patterns in 7 patients with temporal lobe epilepsy (TLE) without hippocampal sclerosis (mean age, 14.86 ± 3.34 years) and 7 healthy controls (mean age, 23.86 ± 2.97 years). Within samples paired t-tests allowed for comparison of ERc connectivity between epileptogenic and contralateral hemispheres. In healthy controls, there were no significant within-group differences in surface area, volume, or cluster number of ERc connectivity-defined regions (CDR). Likewise, in line with histology results, ERc CDR in the control group were well-organized, uniform, and segregated via PRc/PHc afferent and HC efferent connections. Conversely, in TLE, there were significantly more PRc and HC CDR clusters in the epileptogenic than the contralateral hemisphere. The surface area of the PRc CDR was greater, and that of the HC CDRs was smaller, in the epileptogenic hemisphere as well. Further, there was no clear delineation between M-ERc and L-ERc connectivity with PRc, PHc or HC in TLE. These results suggest a breakdown of the spatial organization of PHg-ERc-HC connectivity in TLE. Whether this breakdown is the cause or result of epileptic activity remains an exciting research question.
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Affiliation(s)
- Taylor Kuhn
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States of America; Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
| | - Joseph M Gullett
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States of America; Department of VA Brain Rehabilitation Research Center, Malcolm Randall VA Center Gainesville, FL, United States of America
| | - Angelique E Boutzoukas
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States of America
| | - Anastasia Bohsali
- Department of Neurology, University of Florida, Gainesville, FL, United States of America
| | - Thomas H Mareci
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, United States of America
| | - David B FitzGerald
- Department of VA Brain Rehabilitation Research Center, Malcolm Randall VA Center Gainesville, FL, United States of America
| | - Paul R Carney
- Department of Pediatrics, University of Florida, Gainesville, FL, United States of America; Department of Neurology, University of Florida, Gainesville, FL, United States of America; Department of Neuroscience, University of Florida, Gainesville, FL, United States of America; J. Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States of America; B.J. and Eve Wilder Epilepsy Center Excellence, University of Florida, Gainesville, FL, United States of America
| | - Russell M Bauer
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States of America; Department of VA Brain Rehabilitation Research Center, Malcolm Randall VA Center Gainesville, FL, United States of America
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13
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Quantitative volume-based morphometry in focal cortical dysplasia: A pilot study for lesion localization at the individual level. Eur J Radiol 2018; 105:240-245. [DOI: 10.1016/j.ejrad.2018.06.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 06/16/2018] [Accepted: 06/21/2018] [Indexed: 12/27/2022]
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14
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Abstract
This article reviews the major paradigm shifts that have occurred in the area of the application of clinical and experimental neuropsychology to epilepsy and epilepsy surgery since the founding of the International Neuropsychological Society. The five paradigm shifts discussed include: 1) The neurobiology of cognitive disorders in epilepsy - expanding the landscape of syndrome-specific neuropsychological impairment; 2) pathways to comorbidities: bidirectional relationships and their clinical implications; 3) discovering quality of life: The concept, its quantification and applicability; 4) outcomes of epilepsy surgery: challenging conventional wisdom; and 5) Iatrogenic effects of treatment: cognitive and behavioral effects of antiepilepsy drugs. For each area we characterize the status of knowledge, the key developments that have occurred, and how they have altered our understanding of the epilepsies and their management. We conclude with a brief overview of where we believe the field will be headed in the next decade which includes changes in assessment paradigms, moving from characterization of comorbidities to interventions; increasing development of new measures, terminology and classification; increasing interest in neurodegenerative proteins; transitioning from clinical seizure features to modifiable risk factors; and neurobehavioral phenotypes. Overall, enormous progress has been made over the lifespan of the INS with promise of ongoing improvements in understanding of the cognitive and behavioral complications of the epilepsies and their treatment. (JINS, 2017, 23, 791-805).
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Affiliation(s)
- Bruce Hermann
- 1Department of Neurology,University of Wisconsin School of Medicine and Public Health,Madison Wisconsin
| | - David W Loring
- 2Departments of Neurology and Pediatrics,Emory University School of Medicine,Atlanta Georgia
| | - Sarah Wilson
- 3Department of Psychology,Melbourne University,Melbourne,Australia
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15
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Comper SM, Jardim AP, Corso JT, Gaça LB, Noffs MHS, Lancellotti CLP, Cavalheiro EA, Centeno RS, Yacubian EMT. Impact of hippocampal subfield histopathology in episodic memory impairment in mesial temporal lobe epilepsy and hippocampal sclerosis. Epilepsy Behav 2017; 75:183-189. [PMID: 28873362 DOI: 10.1016/j.yebeh.2017.08.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 08/06/2017] [Accepted: 08/07/2017] [Indexed: 12/30/2022]
Abstract
OBJECTIVE The objective of the study was to analyze preoperative visual and verbal episodic memories in a homogeneous series of patients with mesial temporal lobe epilepsy (MTLE) and unilateral hippocampal sclerosis (HS) submitted to corticoamygdalohippocampectomy and its association with neuronal cell density of each hippocampal subfield. METHODS The hippocampi of 72 right-handed patients were collected and prepared for histopathological examination. Hippocampal sclerosis patterns were determined, and neuronal cell density was calculated. Preoperatively, two verbal and two visual memory tests (immediate and delayed recalls) were applied, and patients were divided into two groups, left and right MTLE (36/36). RESULTS There were no statistical differences between groups regarding demographic and clinical data. Cornu Ammonis 4 (CA4) neuronal density was significantly lower in the right hippocampus compared with the left (p=0.048). The groups with HS presented different memory performance - the right HS were worse in visual memory test [Complex Rey Figure, immediate (p=0.001) and delayed (p=0.009)], but better in one verbal task [RAVLT delayed (p=0.005)]. Multiple regression analysis suggested that the verbal memory performance of the group with left HS was explained by CA1 neuronal density since both tasks were significantly influenced by CA1 [Logical Memory immediate recall (p=0.050) and Logical Memory and RAVLT delayed recalls (p=0.004 and p=0.001, respectively)]. For patients with right HS, both CA1 subfield integrity (p=0.006) and epilepsy duration (p=0.012) explained Complex Rey Figure immediate recall performance. Ultimately, epilepsy duration also explained the performance in the Complex Rey Figure delayed recall (p<0.001). SIGNIFICANCE Cornu Ammonis 1 (CA1) hippocampal subfield was related to immediate and delayed recalls of verbal memory tests in left HS, while CA1 and epilepsy duration were associated with visual memory performance in patients with right HS.
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Affiliation(s)
- Sandra Mara Comper
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Anaclara Prada Jardim
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
| | - Jeana Torres Corso
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Larissa Botelho Gaça
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Maria Helena Silva Noffs
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | | | - Esper Abrão Cavalheiro
- Neuroscience Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Ricardo Silva Centeno
- Neurosurgery Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Elza Márcia Targas Yacubian
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
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Stoub TR, Chicharro AV, Grote CL, Kanner AM. Disconnection of hippocampal networks contributes to memory dysfunction in individuals with temporal lobe epilepsy. Hippocampus 2017; 29:451-457. [DOI: 10.1002/hipo.22800] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/30/2017] [Accepted: 09/05/2017] [Indexed: 11/05/2022]
Affiliation(s)
- Travis R. Stoub
- Department of Neurological SciencesRush University Medical CenterChicago Illinois, 60612
| | - Ada V. Chicharro
- Department of NeurologyClinica Alemana, Universidad del DesarrolloSantiago Chile
| | - Christopher L. Grote
- Department of Neurological SciencesRush University Medical CenterChicago Illinois, 60612
- Department of Behavioral SciencesRush University Medical CenterChicago Illinois, 60612
| | - Andres M. Kanner
- Department of NeurologyUniversity of Miami, Miller School of MedicineMiami Florida, 33136
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17
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Zhou Q, Zhu S, Guo Y, Lian L, Hu Q, Liu X, Xu F, Zhang N, Kang H. Adenosine A1 Receptors Play an Important Protective Role Against Cognitive Impairment and Long-Term Potentiation Inhibition in a Pentylenetetrazol Mouse Model of Epilepsy. Mol Neurobiol 2017; 55:3316-3327. [PMID: 28492982 DOI: 10.1007/s12035-017-0571-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 04/21/2017] [Indexed: 12/20/2022]
Abstract
Epilepsy is a complicated neurological disorder that occurs worldwide and features several kinds of comorbidities in addition to recurrent seizures. One of the most common comorbidities is cognitive impairment, which seriously affects patients' quality of life. Through activating pre- and postsynaptic adenosine A1 receptors (A1Rs), adenosine has demonstrated anticonvulsant and neuroprotective effects in many epileptic animal models. However, whether the neuroprotective effect of A1Rs will protect cognition during epileptogenesis remains unknown. Therefore, by using A1R knockout (KO) mice and establishing a pentylenetetrazole (PTZ)-kindled model of epilepsy, the present study investigated A1Rs' influences on memory and synaptic function. Morris water maze test results indicated that A1R knockout exacerbated the memory impairment induced by PTZ kindling compared with the wild-type group. To further study the synaptic function of epileptic A1Rs KO mice, we recorded long-term potentiation (LTP) in the hippocampal CA3-CA1 pathway, and LTP was highly inhibited in kindled A1R KO mice compared with kindled wild-type mice. To reveal the mechanisms underlying these effects, neuronal loss, cell apoptosis, and relevant synaptic protein levels in hippocampus were assessed. Epileptic A1R KO mice exhibited significant reductions in neuronal cell survival in the CA1 region and a marked increase in the activation of caspase-3 in the hippocampus compared with epileptic wild-type mice. In addition, an obvious decrease in the PSD95 and BDNF expression levels of epileptic A1R KO mice was observed 7 days after complete kindling. In conclusion, these findings indicated that A1Rs play an important protective role against cognitive impairment by reducing neuron loss and increasing BDNF and PSD95 levels. Activation of A1Rs during epileptogenesis might be beneficial to the preservation of epileptic individuals' cognitive functions.
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Affiliation(s)
- Qing Zhou
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Suiqiang Zhu
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Yuchen Guo
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Lifei Lian
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Qi Hu
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Xiaoyan Liu
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Feng Xu
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Na Zhang
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China
| | - Huicong Kang
- Department of Neurology, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Road, Wuhan, 430030, People's Republic of China.
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Lapa AT, Pedro T, Francischinelli J, Coan AC, Costallat LTL, Cendes F, Appenzeller S. Abnormality in hippocampal signal intensity predicts atrophy in patients with systemic lupus erythematosus. Lupus 2016; 26:633-639. [DOI: 10.1177/0961203316673151] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Objectives To quantify signal abnormalities in the hippocampus (Hsig) of patients with systemic lupus erythematosus (SLE) and to determine if Hsig predict hippocampal atrophy (HA) in SLE. Methods We included all SLE patients and healthy age- and sex-matched individuals with two magnetic resonance imaging (MRI) scans performed with a minimum of 1 year interval. All individuals underwent a standardized neuropsychological evaluation. Individual results were converted into standard scores and compared to normative data. SLE patients were additionally assessed for disease activity (SLE Disease Activity Index (SLEDAI)), damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI)), and the presence of antiphospholipid antibodies. MRI was performed on an Elscint 2 T scanner and T1 inversion recovery and T2 coronal images were used for analysis. Volumetric (HV) and signal quantification (Hsig) were determined by standardized protocols. Results We included 54 SLE patients (48 women; mean age 32.2 ± 10.56 years). Hsig were found at study entry in 15 (45.5%) patients. Hsig in the body and tail of non-atrophic hippocampi correlated with progression of volume loss during the follow-up period ( r = 0.8, p < 0.001). The presence of Hsig in the head of atrophic hippocampi correlated with progression of HA ( r = 0.73, p = 0.005) during the same period. No correlation of Hsig and disease activity or prednisone dose was observed. Conclusion HA is frequently observed in SLE patients and volume loss is progressive in a subgroup of patients. The evaluation of Hsig is an easy tool to determine patients that may have progressive hippocampal volume loss and should be followed more closely with MRI and cognitive evaluation.
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Affiliation(s)
- A T Lapa
- MSc Graduate (Postgraduate) Program in Child and Adolescent Health, Faculty of Medical Science, State University of Campinas, Brazil
| | - T Pedro
- Department of Neurology, Faculty of Medical Science, State University of Campinas, Brazil
| | - J Francischinelli
- Department of Neurology, Faculty of Medical Science, State University of Campinas, Brazil
| | - A C Coan
- Department of Neurology, Faculty of Medical Science, State University of Campinas, Brazil
| | - L T Lavras Costallat
- Department of Medicine, Faculty of Medical Science, State University of Campinas, Brazil
| | - F Cendes
- Department of Neurology, Faculty of Medical Science, State University of Campinas, Brazil
| | - S Appenzeller
- Department of Medicine, Faculty of Medical Science, State University of Campinas, Brazil
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The new approach to epilepsy classification: Cognition and behavior in adult epilepsy syndromes. Epilepsy Behav 2016; 64:253-256. [PMID: 27776297 DOI: 10.1016/j.yebeh.2016.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 11/23/2022]
Abstract
The revised terminology and concepts for the organization of seizures and epilepsy proposed by the ILAE Commission on Classification and Terminology in 2010 allows for a number of new opportunities in the study of cognition and behavior in adults. This review examines the literature that has looked for behavioral and cognitive correlates of the newly recognized genetic epilepsies in adults. While some studies report clear cognitive phenotypes associated with specific genetic mutations in adults with epilepsy, others report remarkable clinical heterogeneity. In the second part of this review, we discuss some of the factors that may influence the findings in this literature. Cognitive function is the product of both genetic and environmental influences. Neuropsychological phenotypes under direct genetic influence may be wider and more subtle than specific deficits within discreet cognitive domains and may be reflected in broader, multidimensional measures of cognitive function than those tapped by scores on standardized tests of function. Future studies must be carefully designed to reflect these factors. It is also imperative that studies with negative findings are assigned as much value as those with positive results and published accordingly. This article is part of a Special Issue titled "The new approach to classification: Rethinking cognition and behavior in epilepsy.
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Baxendale S, Thompson P. Reprint of: The new approach to epilepsy classification: Cognition and behavior in adult epilepsy syndromes. Epilepsy Behav 2016; 64:318-321. [PMID: 27876294 DOI: 10.1016/j.yebeh.2016.11.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 02/05/2023]
Abstract
The revised terminology and concepts for the organization of seizures and epilepsy proposed by the ILAE Commission on Classification and Terminology in 2010 allows for a number of new opportunities in the study of cognition and behavior in adults. This review examines the literature that has looked for behavioral and cognitive correlates of the newly recognized genetic epilepsies in adults. While some studies report clear cognitive phenotypes associated with specific genetic mutations in adults with epilepsy, others report remarkable clinical heterogeneity. In the second part of this review, we discuss some of the factors that may influence the findings in this literature. Cognitive function is the product of both genetic and environmental influences. Neuropsychological phenotypes under direct genetic influence may be wider and more subtle than specific deficits within discreet cognitive domains and may be reflected in broader, multidimensional measures of cognitive function than those tapped by scores on standardized tests of function. Future studies must be carefully designed to reflect these factors. It is also imperative that studies with negative findings are assigned as much value as those with positive results and published accordingly. This article is part of a Special Issue titled "The new approach to classification: Rethinking cognition and behavior in epilepsy".
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Affiliation(s)
- Sallie Baxendale
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, UCL, UK; University College Hospital, London, UK.
| | - Pamela Thompson
- Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK; University College Hospital, London, UK
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Chen H, Yu G, Wang J, Li F, Li G. Application of T2 relaxometry in lateralization and localization of mesial temporal lobe epilepsy and corresponding comparison with MR volumetry. Acta Radiol 2016; 57:1107-13. [PMID: 26622058 DOI: 10.1177/0284185115617345] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 10/19/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Magnetic resonance (MR) volumetry is insensitive to subtle mesial temporal sclerosis (MTS), while T2 relaxometry is potential useful in detecting MTS, especially MTS in early course. PURPOSE To explore and compare the feasibility of T2 relaxometry and MR volumetry in evaluation of mesial temporal lobe epilepsy (MTLE) and lateralization of the epileptogenic zone, so as to optimize and enhance lesion depiction. MATERIAL AND METHODS For the 17 unilateral MTLE patients and 14 normal participants, the hippocampus and amygdala were contoured on axial T2-weighted (T2W) images and then co-registered onto T2 relaxation maps. Abnormal is defined as an elevated asymmetric ratio of larger than 2 SD. Visual and quantitative volumetric assessment were combined as outcomes of MR volumetry to distinguish MR-positive and MR-negative lesions. Operative and pathological findings were used as gold standard. RESULTS T2 values of lesions were significantly elevated. In lateralizing the epileptogenic zones, T2 relaxometry yielded an overall accuracy of 94.1% (sensitivity 92.6%, specificity 100%), and MR volumetry yielded an overall accuracy of 82.4% (sensitivity 88.9%, specificity 57.1%), meaning a better performance of T2 relaxometry (P < 0.001, by chi-square test). For pathologically sclerotic structures, most (25/27) were recognized by T2 relaxometry, while 24 of 27 sclerotic structures were detected via MR volumetry. MR volumetry wrongly discerned three normal regions as MTS, while one MR-negative sclerotic hippocampus was detected by T2 relaxometry. CONCLUSION T2 relaxometry is feasible in non-invasive lateralization of epileptogenic zone, and more advantaged than MR volumetry in detecting MR-negative lesions, facilitating prompt diagnosis and longitudinal disease monitoring.
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Affiliation(s)
- Hui Chen
- Department of Radiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China
| | - Guilian Yu
- Reproductive Center, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China
| | - Jiangtao Wang
- Department of Radiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China
| | - Feng Li
- Department of Radiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China
| | - Guangming Li
- Department of Radiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Hubei, PR China
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Goubran M, Bernhardt BC, Cantor‐Rivera D, Lau JC, Blinston C, Hammond RR, de Ribaupierre S, Burneo JG, Mirsattari SM, Steven DA, Parrent AG, Bernasconi A, Bernasconi N, Peters TM, Khan AR. In vivo MRI signatures of hippocampal subfield pathology in intractable epilepsy. Hum Brain Mapp 2016; 37:1103-19. [PMID: 26679097 PMCID: PMC6867266 DOI: 10.1002/hbm.23090] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/20/2015] [Accepted: 12/05/2015] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVES Our aim is to assess the subfield-specific histopathological correlates of hippocampal volume and intensity changes (T1, T2) as well as diff!usion MRI markers in TLE, and investigate the efficacy of quantitative MRI measures in predicting histopathology in vivo. EXPERIMENTAL DESIGN We correlated in vivo volumetry, T2 signal, quantitative T1 mapping, as well as diffusion MRI parameters with histological features of hippocampal sclerosis in a subfield-specific manner. We made use of on an advanced co-registration pipeline that provided a seamless integration of preoperative 3 T MRI with postoperative histopathological data, on which metrics of cell loss and gliosis were quantitatively assessed in CA1, CA2/3, and CA4/DG. PRINCIPAL OBSERVATIONS MRI volumes across all subfields were positively correlated with neuronal density and size. Higher T2 intensity related to increased GFAP fraction in CA1, while quantitative T1 and diffusion MRI parameters showed negative correlations with neuronal density in CA4 and DG. Multiple linear regression analysis revealed that in vivo multiparametric MRI can predict neuronal loss in all the analyzed subfields with up to 90% accuracy. CONCLUSION Our results, based on an accurate co-registration pipeline and a subfield-specific analysis of MRI and histology, demonstrate the potential of MRI volumetry, diffusion, and quantitative T1 as accurate in vivo biomarkers of hippocampal pathology.
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Affiliation(s)
- Maged Goubran
- Imaging Research Laboratories, Robarts Research InstituteLondonOntarioCanada
- Biomedical Engineering Graduate ProgramWestern UniversityLondonOntarioCanada
| | - Boris C. Bernhardt
- Neuroimaging of Epilepsy LaboratoryMcConnell Brain Imaging Center, Montreal Neurological Institute, McGill UniversityMontrealQuebecCanada
| | - Diego Cantor‐Rivera
- Imaging Research Laboratories, Robarts Research InstituteLondonOntarioCanada
- Biomedical Engineering Graduate ProgramWestern UniversityLondonOntarioCanada
| | - Jonathan C. Lau
- Department of Clinical Neurological SciencesEpilepsy Program, Western UniversityLondonOntarioCanada
| | - Charlotte Blinston
- Imaging Research Laboratories, Robarts Research InstituteLondonOntarioCanada
- Biomedical Engineering Graduate ProgramWestern UniversityLondonOntarioCanada
| | - Robert R. Hammond
- Department of PathologyDivision of NeuropathologyLondonOntarioCanada
| | - Sandrine de Ribaupierre
- Biomedical Engineering Graduate ProgramWestern UniversityLondonOntarioCanada
- Department of Clinical Neurological SciencesEpilepsy Program, Western UniversityLondonOntarioCanada
- Department of Medical BiophysicsWestern UniversityLondonOntarioCanada
| | - Jorge G. Burneo
- Department of Clinical Neurological SciencesEpilepsy Program, Western UniversityLondonOntarioCanada
| | - Seyed M. Mirsattari
- Department of Clinical Neurological SciencesEpilepsy Program, Western UniversityLondonOntarioCanada
- Department of Medical BiophysicsWestern UniversityLondonOntarioCanada
- Department of Medical ImagingWestern UniversityLondonOntarioCanada
| | - David A. Steven
- Department of Clinical Neurological SciencesEpilepsy Program, Western UniversityLondonOntarioCanada
| | - Andrew G. Parrent
- Department of Clinical Neurological SciencesEpilepsy Program, Western UniversityLondonOntarioCanada
| | - Andrea Bernasconi
- Neuroimaging of Epilepsy LaboratoryMcConnell Brain Imaging Center, Montreal Neurological Institute, McGill UniversityMontrealQuebecCanada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy LaboratoryMcConnell Brain Imaging Center, Montreal Neurological Institute, McGill UniversityMontrealQuebecCanada
| | - Terry M. Peters
- Imaging Research Laboratories, Robarts Research InstituteLondonOntarioCanada
- Biomedical Engineering Graduate ProgramWestern UniversityLondonOntarioCanada
- Department of Medical BiophysicsWestern UniversityLondonOntarioCanada
| | - Ali R. Khan
- Department of Medical BiophysicsWestern UniversityLondonOntarioCanada
- Department of Medical ImagingWestern UniversityLondonOntarioCanada
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Soble JR, Osborn KE, Mattingly ML, Vale FL, Benbadis SR, Rodgers-Neame NT, Schoenberg MR. Utility of Green's Word Memory Test Free Recall Subtest as a Measure of Verbal Memory: Initial Evidence from a Temporal Lobe Epilepsy Clinical Sample. Arch Clin Neuropsychol 2015; 31:79-87. [PMID: 26663824 DOI: 10.1093/arclin/acv084] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2015] [Indexed: 11/14/2022] Open
Abstract
This study investigated the Word Memory Test (WMT) Free Recall (FR) subtest as a conventional memory measure. Nineteen participants with pharmacoresistant left temporal lobe epilepsy (LTLE) and 16 with right temporal lobe epilepsy (RTLE) completed the WMT, Rey Auditory Verbal Learning Test (RAVLT), and Wechsler Memory Scale-Fourth Edition Logical Memory (LM) subtest during presurgical evaluation. LTLE participants performed significantly worse on FR subtest (p < .05, [Formula: see text]) and RAVLT Trial 7 (p < .01, [Formula: see text]), but not on LM subtest. Age was a significant covariate for FR (p < .01, [Formula: see text]). Logistic regression revealed FR plus age and RAVLT age-adjusted T-scores both yielded 77.1% classification accuracy and respective diagnostic odds ratios of 11.36 and 11.84. Receiver operating characteristic curves to classify seizure laterality found that RAVLT and FR were significant (area under the curve [AUC] = 0.82 and 0.74), whereas LM was nonsignificant (AUC = 0.67). Cut scores and positive/negative predictive values were established for improved clinical classification.
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Affiliation(s)
- Jason R Soble
- Psychology Service, South Texas Veterans Health Care System, San Antonio, TX, USA
| | - Katie E Osborn
- Department of Psychiatry and Behavioral Neurosciences, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Michelle L Mattingly
- Department of Psychiatry and Behavioral Neurosciences, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Fernando L Vale
- Department of Neurosurgery and Brain Repair, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Selim R Benbadis
- Department of Neurology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Nancy T Rodgers-Neame
- Private Practice, Florida Comprehensive Epilepsy and Seizure Disorders Center, Tampa, FL, USA
| | - Mike R Schoenberg
- Department of Psychiatry and Behavioral Neurosciences, Morsani College of Medicine, University of South Florida, Tampa, FL, USA Department of Neurosurgery and Brain Repair, Morsani College of Medicine, University of South Florida, Tampa, FL, USA Department of Neurology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
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Weiss AR, Bachevalier J. Object and spatial memory after neonatal perirhinal lesions in monkeys. Behav Brain Res 2015; 298:210-7. [PMID: 26593109 DOI: 10.1016/j.bbr.2015.11.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 11/02/2015] [Accepted: 11/09/2015] [Indexed: 12/19/2022]
Abstract
The contribution of the perirhinal cortex (PRh) to recognition memory is well characterized in adults, yet the same lesions have limited effect on recognition of spatial locations. Here, we assessed whether the same outcomes will follow when perirhinal lesions are performed in infancy. Monkeys with neonatal perirhinal (Neo-PRh) lesions and control animals were tested in three operant recognition tasks as they reached adulthood: Delayed Nonmatching-to-Sample (DNMS) and Object Memory Span (OMS), measuring object recognition, and Spatial Memory Span (SMS), measuring recognition of spatial locations. Although Neo-PRh lesions did not impact acquisition of the DNMS rule, they did impair performance when the delays were extended from 30s to 600s. In contrast, the same neonatal lesions had no impact on either the object or spatial memory span tasks, suggesting that the lesions impacted the maintenance of information across longer delays and not memory capacity. Finally, the magnitude of recognition memory impairment after the Neo-PRh lesions was similar to that previously observed after adult-onset perirhinal lesions, indicating minimal, or no, functional compensation after the early PRh lesions. Overall, the results indicate that the PRh is a cortical structure that is important for the normal development of mechanisms supporting object recognition memory. Its contribution may be relevant to the memory impairment observed with human cases of temporal lobe epilepsy without hippocampal sclerosis, but not to the memory impairment found in developmental amnesia cases.
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Affiliation(s)
| | - Jocelyne Bachevalier
- Emory University, Georgia; Yerkes National Primate Research Center, Atlanta, Georgia
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25
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Peixoto-Santos JE, Velasco TR, Galvis-Alonso OY, Araujo D, Kandratavicius L, Assirati JA, Carlotti CG, Scandiuzzi RC, Santos ACD, Leite JP. Temporal lobe epilepsy patients with severe hippocampal neuron loss but normal hippocampal volume: Extracellular matrix molecules are important for the maintenance of hippocampal volume. Epilepsia 2015. [PMID: 26218733 DOI: 10.1111/epi.13082] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Hippocampal sclerosis is a common finding in patients with temporal lobe epilepsy (TLE), and magnetic resonance imaging (MRI) studies associate the reduction of hippocampal volume with the neuron loss seen on histologic evaluation. Astrogliosis and increased levels of chondroitin sulfate, a major component of brain extracellular matrix, are also seen in hippocampal sclerosis. Our aim was to evaluate the association between hippocampal volume and chondroitin sulfate, as well as neuronal and astroglial populations in the hippocampus of patients with TLE. METHODS Patients with drug-resistant TLE were subdivided, according to hippocampal volume measured by MRI, into two groups: hippocampal atrophy (HA) or normal volume (NV) cases. Hippocampi from TLE patients and age-matched controls were submitted to immunohistochemistry to evaluate neuronal population, astroglial population, and chondroitin sulfate expression with antibodies against neuron nuclei protein (NeuN), glial fibrillary acidic protein (GFAP), and chondroitin sulfate (CS-56) antigens, respectively. RESULTS Both TLE groups were clinically similar. NV cases had higher hippocampal volume, both ipsilateral and contralateral, when compared to HA. Compared to controls, NV and HA patients had reduced neuron density, and increased GFAP and CS-56 immunopositive area. There was no statistical difference between NV and HA groups in neuron density or immunopositive areas for GFAP and CS-56. Hippocampal volume correlated positively with neuron density in CA1 and prosubiculum, and with immunopositive areas for CS-56 in CA1, and negatively with immunopositive area for GFAP in CA1. Multiple linear regression analysis indicated that both neuron density and CS-56 immunopositive area in CA1 were statistically significant predictors of hippocampal volume. SIGNIFICANCE Our findings indicate that neuron density and chondroitin sulfate immunopositive area in the CA1 subfield are crucial for the hippocampal volume, and that chondroitin sulfate is important for the maintenance of a normal hippocampal volume in some cases with severe neuron loss.
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Affiliation(s)
- Jose Eduardo Peixoto-Santos
- Department of Neurosciences and Behavior, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Tonicarlo Rodrigues Velasco
- Department of Neurosciences and Behavior, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Orfa Yineth Galvis-Alonso
- Department of Molecular Biology, São José do Rio Preto Medical School, Sao Jose do Rio Preto, Sao Paulo, Brazil
| | - David Araujo
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Ludmyla Kandratavicius
- Department of Neurosciences and Behavior, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Joao Alberto Assirati
- Department of Surgery, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Brazil
| | - Carlos Gilberto Carlotti
- Department of Surgery, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Brazil
| | - Renata Caldo Scandiuzzi
- Department of Neurosciences and Behavior, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Antonio Carlos dos Santos
- Department of Internal Medicine, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Brazil
| | - Joao Pereira Leite
- Department of Neurosciences and Behavior, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Sao Paulo, Brazil
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Vismer MS, Forcelli PA, Skopin MD, Gale K, Koubeissi MZ. The piriform, perirhinal, and entorhinal cortex in seizure generation. Front Neural Circuits 2015; 9:27. [PMID: 26074779 PMCID: PMC4448038 DOI: 10.3389/fncir.2015.00027] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 05/15/2015] [Indexed: 12/11/2022] Open
Abstract
Understanding neural network behavior is essential to shed light on epileptogenesis and seizure propagation. The interconnectivity and plasticity of mammalian limbic and neocortical brain regions provide the substrate for the hypersynchrony and hyperexcitability associated with seizure activity. Recurrent unprovoked seizures are the hallmark of epilepsy, and limbic epilepsy is the most common type of medically-intractable focal epilepsy in adolescents and adults that necessitates surgical evaluation. In this review, we describe the role and relationships among the piriform (PIRC), perirhinal (PRC), and entorhinal cortex (ERC) in seizure-generation and epilepsy. The inherent function, anatomy, and histological composition of these cortical regions are discussed. In addition, the neurotransmitters, intrinsic and extrinsic connections, and the interaction of these regions are described. Furthermore, we provide evidence based on clinical research and animal models that suggest that these cortical regions may act as key seizure-trigger zones and, even, epileptogenesis.
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Affiliation(s)
- Marta S Vismer
- Department of Neurology, The George Washington University Washington, DC, USA
| | | | - Mark D Skopin
- Department of Neurology, The George Washington University Washington, DC, USA
| | - Karen Gale
- Department of Pharmacology, Georgetown University Washington, DC, USA
| | - Mohamad Z Koubeissi
- Department of Neurology, The George Washington University Washington, DC, USA
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Bonilha L, Keller SS. Quantitative MRI in refractory temporal lobe epilepsy: relationship with surgical outcomes. Quant Imaging Med Surg 2015; 5:204-24. [PMID: 25853080 DOI: 10.3978/j.issn.2223-4292.2015.01.01] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 01/07/2015] [Indexed: 11/14/2022]
Abstract
Medically intractable temporal lobe epilepsy (TLE) remains a serious health problem. Across treatment centers, up to 40% of patients with TLE will continue to experience persistent postoperative seizures at 2-year follow-up. It is unknown why such a large number of patients continue to experience seizures despite being suitable candidates for resective surgery. Preoperative quantitative MRI techniques may provide useful information on why some patients continue to experience disabling seizures, and may have the potential to develop prognostic markers of surgical outcome. In this article, we provide an overview of how quantitative MRI morphometric and diffusion tensor imaging (DTI) data have improved the understanding of brain structural alterations in patients with refractory TLE. We subsequently review the studies that have applied quantitative structural imaging techniques to identify the neuroanatomical factors that are most strongly related to a poor postoperative prognosis. In summary, quantitative imaging studies strongly suggest that TLE is a disorder affecting a network of neurobiological systems, characterized by multiple and inter-related limbic and extra-limbic network abnormalities. The relationship between brain alterations and postoperative outcome are less consistent, but there is emerging evidence suggesting that seizures are less likely to remit with surgery when presurgical abnormalities are observed in the connectivity supporting brain regions serving as network nodes located outside the resected temporal lobe. Future work, possibly harnessing the potential from multimodal imaging approaches, may further elucidate the etiology of persistent postoperative seizures in patients with refractory TLE. Furthermore, quantitative imaging techniques may be explored to provide individualized measures of postoperative seizure freedom outcome.
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Affiliation(s)
- Leonardo Bonilha
- 1 Department of Neurology and Neurosurgery, Medical University of South Carolina, Charleston, SC 29425, USA ; 2 Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK ; 3 Department of Radiology, The Walton Centre NHS Foundation Trust, Liverpool, UK ; 4 Department of Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Simon S Keller
- 1 Department of Neurology and Neurosurgery, Medical University of South Carolina, Charleston, SC 29425, USA ; 2 Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK ; 3 Department of Radiology, The Walton Centre NHS Foundation Trust, Liverpool, UK ; 4 Department of Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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Hamelin S, Depaulis A. Revisiting hippocampal sclerosis in mesial temporal lobe epilepsy according to the "two-hit" hypothesis. Rev Neurol (Paris) 2015; 171:227-35. [PMID: 25748332 DOI: 10.1016/j.neurol.2015.01.560] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 01/20/2015] [Indexed: 12/28/2022]
Abstract
Hippocampal sclerosis (HS) is the most common neuropathological pattern observed in pharmacoresistant epilepsy and represents a critical feature in mesial temporal lobe epilepsy syndrome. However, its pathophysiological mechanisms and neuropathological consequences on seizures remain mostly unresolved. The new international classification of hippocampal sclerosis aims at standardizing its description to allow comparisons between different clinical studies. However, several aspects are not considered in this classification (granule cell dispersion, sprouting, glial modifications…). In this chapter, we discuss these different features associated with hippocampal sclerosis in perspective with the "two-hit" hypothesis and propose mechanisms that could be involved in the modulation of some specific neuropathological aspects like early life stress, hyperthermic seizures, brain lesions or hormonal modifications.
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Affiliation(s)
- S Hamelin
- Inserm, U836, université Joseph-Fourier, dite Santé, bâtiment Edmond-J.-Safra, chemin Fortuné-Ferrini, 38706 La Tronche cedex, France; University Grenoble-Alpes, Grenoble institut des neurosciences, chemin Fortuné-Ferrini, 38700 La Tronche, France; Hôpital Pierre-Oudot, 30, avenue du Médipôle, BP 40348, 38302 Bourgoin-Jallieu cedex, France.
| | - A Depaulis
- Inserm, U836, université Joseph-Fourier, dite Santé, bâtiment Edmond-J.-Safra, chemin Fortuné-Ferrini, 38706 La Tronche cedex, France; University Grenoble-Alpes, Grenoble institut des neurosciences, chemin Fortuné-Ferrini, 38700 La Tronche, France; CHU de Grenoble, avenue Maquis-du-Grésivaudan, 38700 La Tronche, France
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29
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Isnard J, Bourdillon P. Morphological imaging of the hippocampus in epilepsy. Rev Neurol (Paris) 2015; 171:298-306. [PMID: 25744767 DOI: 10.1016/j.neurol.2014.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 12/11/2014] [Indexed: 10/23/2022]
Abstract
The hippocampus is a structure frequently involved in epilepsy, especially in partial drug-resistant forms. In addition, some hippocampal pathologies are associated with specific types of epilepsy presenting specific clinical courses and requiring specific treatments. Considering these major implications for treatment, morphological investigations of the hippocampus are crucial for epileptic patients. Indeed, discovery of hippocampal sclerosis may (depending on the clinical and electrophysiological findings) lead to the diagnosis of mesial temporal lobe epilepsy (MTLE). If the diagnosis of MTLE is retained in a case of drug-resistance, surgery may be proposed without invasive phase II investigations such as stereoelectroencephalograpy. In other instances, hippocampal abnormalities may be associated with epilepsy, but without the same value for localizing the ictal onset zone. Hippocampal dysgenesis is a strong argument for non-temporo-mesial ictal onset ipsilateral to the malformation. We describe here the specific MRI modalities adapted for hippocampal investigations and the radiological signs of hippocampal pathologies associated with epilepsy (especially hippocampal sclerosis and hippocamal dysgenesis). Hippocampus morphological investigations in epilepsy require specific MRI modalities and appropriate knowledge of the specific signs of each pathology. Careful analysis is crucial since the results may have a major impact on the therapeutic management of epileptic patients.
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Affiliation(s)
- J Isnard
- Hospices Civils de Lyon, Hospital for neurology and neurosurgery Pierre Wertheimer, Department of neurology and epileptology, 59, boulevard Pinel, 69500 Bron, France; University of Lyon, Université Claude Bernard Lyon 1, 8, avenue Rockfeller, 69373 Lyon cedex 08, France; Neuroscience research center of Lyon, Inserm, U1028, CNRS UMR5292, 95, boulevard Pinel, 69675 Bron cedex, France
| | - P Bourdillon
- University of Lyon, Université Claude Bernard Lyon 1, 8, avenue Rockfeller, 69373 Lyon cedex 08, France; Neuroscience research center of Lyon, Inserm, U1028, CNRS UMR5292, 95, boulevard Pinel, 69675 Bron cedex, France; Hospices Civils de Lyon, Hospital for neurology and neurosurgery Pierre Wertheimer, Department of neurosurgery, 59, boulevard Pinel, 69500 Bron, France.
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30
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Bonilha L, Lee CY, Jensen JH, Tabesh A, Spampinato MV, Edwards JC, Breedlove J, Helpern JA. Altered microstructure in temporal lobe epilepsy: a diffusional kurtosis imaging study. AJNR Am J Neuroradiol 2014; 36:719-24. [PMID: 25500311 DOI: 10.3174/ajnr.a4185] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 10/19/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Temporal lobe epilepsy is associated with regional abnormalities in tissue microstructure, as demonstrated by DTI. However, the full extent of these abnormalities has not yet been defined because DTI conveys only a fraction of the information potentially accessible with diffusion MR imaging. In this study, we assessed the added value of diffusional kurtosis imaging, an extension of DTI, to evaluate microstructural abnormalities in patients with temporal lobe epilepsy. MATERIALS AND METHODS Thirty-two patients with left temporal lobe epilepsy and 36 matched healthy subjects underwent diffusion MR imaging. To evaluate abnormalities in patients, we performed voxelwise analyses, assessing DTI-derived mean diffusivity, fractional anisotropy, and diffusional kurtosis imaging-derived mean diffusional kurtosis, as well as diffusional kurtosis imaging and DTI-derived axial and radial components, comparing patients with controls. RESULTS We replicated findings from previous studies demonstrating a reduction in fractional anisotropy and an increase in mean diffusivity preferentially affecting, but not restricted to, the temporal lobe ipsilateral to seizure onset. We also noted a pronounced pattern of diffusional kurtosis imaging abnormalities in gray and white matter tissues, often extending into regions that were not detected as abnormal by DTI measures. CONCLUSIONS Diffusional kurtosis is a sensitive and complementary measure of microstructural compromise in patients with temporal lobe epilepsy. It provides additional information regarding the anatomic distribution and degree of damage in this condition. Diffusional kurtosis imaging may be used as a biomarker for disease severity, clinical phenotypes, and treatment monitoring in epilepsy.
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Affiliation(s)
- L Bonilha
- From the Departments of Neurology and Neurosurgery (L.B., J.C.E.) Comprehensive Epilepsy Center (L.B., J.C.E., J.B.) Center for Biomedical Imaging (L.B., C.-Y.L., J.H.J., A.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina.
| | - C-Y Lee
- Radiology and Radiological Science (C.-Y.L., J.H.J., A.T., M.V.S., J.A.H.) Center for Biomedical Imaging (L.B., C.-Y.L., J.H.J., A.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - J H Jensen
- Radiology and Radiological Science (C.-Y.L., J.H.J., A.T., M.V.S., J.A.H.) Center for Biomedical Imaging (L.B., C.-Y.L., J.H.J., A.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - A Tabesh
- Radiology and Radiological Science (C.-Y.L., J.H.J., A.T., M.V.S., J.A.H.) Center for Biomedical Imaging (L.B., C.-Y.L., J.H.J., A.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - M V Spampinato
- Radiology and Radiological Science (C.-Y.L., J.H.J., A.T., M.V.S., J.A.H.) Center for Biomedical Imaging (L.B., C.-Y.L., J.H.J., A.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina
| | - J C Edwards
- From the Departments of Neurology and Neurosurgery (L.B., J.C.E.) Comprehensive Epilepsy Center (L.B., J.C.E., J.B.)
| | - J Breedlove
- Comprehensive Epilepsy Center (L.B., J.C.E., J.B.)
| | - J A Helpern
- Radiology and Radiological Science (C.-Y.L., J.H.J., A.T., M.V.S., J.A.H.)
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Mohandas AN, Bharath RD, Prathyusha PV, Gupta AK. Hippocampal volumetry: Normative data in the Indian population. Ann Indian Acad Neurol 2014; 17:267-71. [PMID: 25221393 PMCID: PMC4162010 DOI: 10.4103/0972-2327.138482] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/07/2013] [Accepted: 01/14/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Mesial temporal sclerosis (MTS) is the most common cause of temporal lobe epilepsy. Quantitative analysis of the hippocampus using volumetry is commonly being used in the diagnosis of MTS and is being used as a marker in prognostication of seizure control. Although normative data for hippocampal volume (HV) is available for the western population, no such data is available for the Indian population. AIM The aim of the study was to establish normative data for HV for the Indian population, which can aid in the accurate diagnosis of MTS. MATERIALS AND METHODS Magnetic resonance imaging (MRI) scans of 200 healthy volunteers were acquired using a 3 Tesla (3T) MRI scanner. Manual segmentation and volumetry was done using Siemens Syngo software. The data was analyzed using two tailed t-test to detect associations between HV and age, gender, and education. The data so obtained was also correlated with the data available from the rest of the world. RESULTS A mean HV of 2.411 cm(3) (standard deviation -0.299) was found in the study, which was significantly smaller when compared to the data from the western population. The right hippocampus was larger than the left, with a mean volume of 2.424 cm(3) and 2.398 cm(3), respectively. HV was detected to be significantly higher in males. No association was found between HV and age and education. CONCLUSION The values obtained in this study may be adopted as a standard in the evaluation of patients with intractable epilepsy.
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Affiliation(s)
- Aravind Narayan Mohandas
- Department of Neuro Imaging and Interventional Radiology, National Institute of Mental Health and Neuroscience, Banglore, Karnataka, India
| | - Rose Dawn Bharath
- Department of Neuro Imaging and Interventional Radiology, National Institute of Mental Health and Neuroscience, Banglore, Karnataka, India
| | - Parthipulli Vasuki Prathyusha
- Department of Neuro Imaging and Interventional Radiology, National Institute of Mental Health and Neuroscience, Banglore, Karnataka, India
| | - Arun K Gupta
- Department of Neuro Imaging and Interventional Radiology, National Institute of Mental Health and Neuroscience, Banglore, Karnataka, India
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Hogan RE, Moseley ED, Maccotta L. Hippocampal surface deformation accuracy in T1-weighted volumetric MRI sequences in subjects with epilepsy. J Neuroimaging 2014; 25:452-9. [PMID: 24942549 DOI: 10.1111/jon.12135] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/07/2014] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE To demonstrate the accuracy across different acquisition and analysis methods, we evaluated the variability in hippocampal volumetric and surface displacement measurements resulting from two different MRI (magnetic resonance imaging) acquisition protocols. METHODS Nine epilepsy patients underwent two independent T1-weighted magnetization prepared spoiled gradient sequences during a single 3T MRI session. Using high-dimension mapping-large deformation (HDM-LD) segmentation, we calculated volumetric estimates and generated a vector-based 3-dimensional surface model of each subject's hippocampi, and evaluated volume and surface changes, the latter using a cluster-based noise estimation model. RESULTS Mean hippocampal volumes and standard deviations for the left hippocampi were 2,750 (826) mm3 and 2,782 (859) mm3 (P = .13), and for the right hippocampi were 2,558 (750) mm3 and 2,547 (692) mm3 (P = .76), respectively for the MPR1 and MPR2 sequences. Average Dice coefficient comparing overlap for segmentations was 86%. There was no significant effect of MRI sequence on volume estimates and no significant hippocampal surface change between sequences. CONCLUSION Statistical comparison of hippocampal volumes and statistically thresholded HDM-LD surfaces in TLE patients showed no differences between the segmentations obtained in the two MRI acquisition sequences. This validates the robustness across MRI sequences of the HDM-LD technique for estimating volume and surface changes in subjects with epilepsy.
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Affiliation(s)
- R Edward Hogan
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri
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McDonald CR, Leyden KM, Hagler DJ, Kucukboyaci NE, Kemmotsu N, Tecoma ES, Iragui VJ. White matter microstructure complements morphometry for predicting verbal memory in epilepsy. Cortex 2014; 58:139-50. [PMID: 25016097 DOI: 10.1016/j.cortex.2014.05.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 04/02/2014] [Accepted: 05/28/2014] [Indexed: 11/20/2022]
Abstract
Verbal memory is the most commonly impaired cognitive domain in patients with temporal lobe epilepsy (TLE). Although damage to the hippocampus and adjacent temporal lobe structures is known to contribute to memory impairment, little is known of the relative contributions of white versus gray matter structures, or whether microstructural versus morphometric measures of temporal lobe pathology are stronger predictors of impairment. We evaluate whether measures of temporal lobe pathology derived from diffusion tensor imaging (DTI; microstructural) versus structural MRI (sMRI; morphometric) contribute the most to memory performances in TLE, after controlling for hippocampal volume (HCV). DTI and sMRI were performed on 26 patients with TLE and 35 controls. Verbal memory was measured with the Logical Memory (LM) subtest of the Wechsler Memory Scale-III. Hierarchical regression analyses were performed to examine unique contributions of DTI and sMRI measures to verbal memory with HCV entered in block 1. In patients, impaired recall was associated with increased mean diffusivity (MD) of multiple fiber tracts that project through the temporal lobes. In addition, increased MD of the left cortical and bilateral pericortical white matter was associated with impaired recall. After controlling for left HCV, only microstructural measures of white matter pathology contributed to verbal recall. The best predictive model included left HCV and MD of the left inferior longitudinal fasciculus (ILF) and pericortical white matter beneath the left entorhinal cortex. This model explained 60% of the variance in delayed recall and revealed that MD of the left ILF was the strongest predictor. These data reveal that white matter microstructure within the temporal lobe can be used in conjunction with left HCV to enhance the prediction of verbal memory impairment, and speak to the complementary nature of DTI and sMRI for understanding cognitive dysfunction in epilepsy and possibly other memory disorders.
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Affiliation(s)
- Carrie R McDonald
- Department of Psychiatry, University of California, San Diego, CA, USA; Multimodal Imaging Laboratory, University of California, San Diego, CA, USA.
| | - Kelly M Leyden
- Multimodal Imaging Laboratory, University of California, San Diego, CA, USA
| | - Donald J Hagler
- Multimodal Imaging Laboratory, University of California, San Diego, CA, USA; Department of Radiology, University of California, San Diego, CA, USA
| | - Nuri E Kucukboyaci
- Multimodal Imaging Laboratory, University of California, San Diego, CA, USA; San Diego State University/University of California, San Diego Joint Doctoral Program in Clinical Psychology, San Diego, CA, USA
| | - Nobuko Kemmotsu
- Department of Psychiatry, University of California, San Diego, CA, USA; Multimodal Imaging Laboratory, University of California, San Diego, CA, USA
| | - Evelyn S Tecoma
- Department of Neurosciences, University of California, San Diego, CA, USA
| | - Vicente J Iragui
- Department of Neurosciences, University of California, San Diego, CA, USA
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Watson C. Hippocampal sclerosis and the syndrome of medial temporal lobe epilepsy. Expert Rev Neurother 2014. [DOI: 10.1586/14737175.3.6.821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Gold JJ, Trauner DA. Hippocampal volume and memory performance in children with perinatal stroke. Pediatr Neurol 2014; 50:18-25. [PMID: 24188909 PMCID: PMC4208717 DOI: 10.1016/j.pediatrneurol.2013.08.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 08/21/2013] [Accepted: 08/27/2013] [Indexed: 11/17/2022]
Abstract
BACKGROUND Pediatric neurologists and neonatologists often are asked to predict cognitive outcome after perinatal brain injury (including likely memory and learning outcomes). However, relatively few data exist on how accurate predictions can be made. Furthermore, although the consequences of brain injury on hippocampal volume and memory performance have been studied extensively in adults, little work has been done in children. METHODS We measured the volume of the hippocampus in 27 children with perinatal stroke and 19 controls, and measured their performance on standardized verbal and non-verbal memory tests. RESULTS We discovered the following: (1) As a group, children with perinatal stroke had smaller left and right hippocampi compared with control children. (2) Individually, children with perinatal stroke demonstrated 1 of 3 findings: no hippocampal loss, unilateral hippocampal loss, or bilateral hippocampal volume loss compared with control children. (3) Hippocampal volume inversely correlated with memory test performance in the perinatal stroke group, with smaller left and right hippocampal volumes related to poorer verbal and non-verbal memory test performance, respectively. (4) Seizures played a significant role in determining memory deficit and extent of hippocampal volume reduction in patients with perinatal stroke. CONCLUSIONS These findings support the view that, in the developing brain, the left and right hippocampi preferentially support verbal and nonverbal memory respectively, a consistent finding in the adult literature but a subject of debate in the pediatric literature. This is the first work to report that children with focal brain injury incurred from perinatal stroke have volume reduction in the hippocampus and impairments in certain aspects of declarative memory.
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Affiliation(s)
- Jeffrey J Gold
- University of California, San Diego, La Jolla, California; Rady Children's Hospital, San Diego, California.
| | - Doris A Trauner
- University of California, San Diego, La Jolla, California; Rady Children's Hospital, San Diego, California.
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Travis SG, Huang Y, Fujiwara E, Radomski A, Olsen F, Carter R, Seres P, Malykhin NV. High field structural MRI reveals specific episodic memory correlates in the subfields of the hippocampus. Neuropsychologia 2013; 53:233-45. [PMID: 24296251 DOI: 10.1016/j.neuropsychologia.2013.11.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 11/22/2013] [Accepted: 11/23/2013] [Indexed: 10/25/2022]
Abstract
The involvement of the hippocampus (HC) in episodic memory is well accepted; however it is unclear how each subfield within the HC contributes to memory function. Recent magnetic resonance imaging (MRI) studies suggest differential involvement of hippocampal subfields and subregions in episodic memory. However, most structural MRI studies have examined the HC subfields within a single subregion of the HC and used specialised experimental memory paradigms. The purpose of the present study was to determine the association between volumes of HC subfields throughout the entire HC structure and performance on standard neuropsychological memory tests in a young, healthy population. We recruited 34 healthy participants under the age of 50. MRI data was acquired with a fast spin echo (FSE) sequence yielding a 0.52×0.68×1.0 mm(3) native resolution. The HC subfields - the cornu ammonis 1-3 (CA), dentate gyrus (DG), and subiculum (SUB) - were segmented manually within three hippocampal subregions using a previously defined protocol. Participants were administered the Wechsler Memory Scale, 4th edition (WMS-IV) to assess performance in episodic memory using verbal (Logical Memory, LM) and visual (Designs, DE; visual-spatial memory, DE-Spatial; visual-content memory, DE-Content) memory subtests. Working memory subtests (Spatial Addition, SA; and Symbol Span, SSP) were included as well. Working memory was not associated with any HC volumes. Volumes of the DG were correlated with verbal memory (LM) and visual-spatial memory (DE-Spatial). Posterior CA volumes correlated with both visual-spatial and visual-object memory (DE-Spatial, DE-Content). In general, anterior subregion volumes (HC head) correlated with verbal memory, while some anterior and many posterior HC subregion volumes (body and tail) correlated with visual memory scores (DE-Spatial, DE-Content). In addition, while verbal memory showed left-lateralized associations with HC volumes, visual memory was associated with HC volumes bilaterally. This the first study to examine the associations between hippocampal subfield volumes across the entire hippocampal formation with performance in a set of standard memory tasks.
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Affiliation(s)
- S G Travis
- Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada
| | - Y Huang
- Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada
| | - E Fujiwara
- Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada; Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada
| | - A Radomski
- Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada
| | - F Olsen
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2V2
| | - R Carter
- Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada
| | - P Seres
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2V2
| | - N V Malykhin
- Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada; Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada; Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2V2.
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Tsai MH, Pardoe HR, Perchyonok Y, Fitt GJ, Scheffer IE, Jackson GD, Berkovic SF. Etiology of hippocampal sclerosis: evidence for a predisposing familial morphologic anomaly. Neurology 2013; 81:144-9. [PMID: 23749796 DOI: 10.1212/wnl.0b013e31829a33ac] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE We sought evidence of a hereditary component for hippocampal sclerosis (HS) by determining whether close relatives of probands with temporal lobe epilepsy (TLE) with HS also had asymptomatic HS or subtle variation in hippocampal morphology. METHODS First-degree relatives from 15 families in which probands had TLE with HS and 32 age- and sex-matched controls were included in the study. Left and right hippocampal volumes and T2 relaxometry were measured using 3-tesla MRI. RESULTS Thirty-two asymptomatic first-degree relatives and 3 relatives with a history of seizures or epilepsy were studied. None of the first-degree relatives had HS on visual analysis and T2 relaxation times were normal, excluding the presence of HS. Mean hippocampal volume was smaller (6.4%) in asymptomatic relatives (2.94 ± 0.27 cm(3), 95% confidence interval = 2.87-3.01) than in controls (3.14 ± 0.22 cm(3), 95% confidence interval = 3.09-3.19, p < 0.005); the effect was greater in relatives of probands with a positive family history of epilepsy. The relatives also had more asymmetric hippocampi (asymmetric index 0.92 ± 0.05) than controls (0.96 ± 0.03, p = 0.001). CONCLUSIONS Small asymmetric hippocampi in healthy relatives are likely to represent a familial developmental variant that may predispose to the formation of TLE with HS. The underlying histopathology of these small hippocampi is unknown. This observation may provide an imaging marker for future studies seeking susceptibility genes for HS.
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Affiliation(s)
- Meng-Han Tsai
- Epilepsy Research Centre, Department of Medicine, Austin Health, University of Melbourne, Australia
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Beaton AE, Durnford A, Heffer-Rahn PE, Kirkham F, Griffin A, Gray W. Transsylvian selective amygdalohippocampectomy in children with hippocampal sclerosis: Seizure, intellectual and memory outcome. Seizure 2012; 21:699-705. [DOI: 10.1016/j.seizure.2012.07.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 07/23/2012] [Accepted: 07/26/2012] [Indexed: 10/28/2022] Open
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Farid N, Girard HM, Kemmotsu N, Smith ME, Magda SW, Lim WY, Lee RR, McDonald CR. Temporal lobe epilepsy: quantitative MR volumetry in detection of hippocampal atrophy. Radiology 2012; 264:542-50. [PMID: 22723496 DOI: 10.1148/radiol.12112638] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To determine the ability of fully automated volumetric magnetic resonance (MR) imaging to depict hippocampal atrophy (HA) and to help correctly lateralize the seizure focus in patients with temporal lobe epilepsy (TLE). MATERIALS AND METHODS This study was conducted with institutional review board approval and in compliance with HIPAA regulations. Volumetric MR imaging data were analyzed for 34 patients with TLE and 116 control subjects. Structural volumes were calculated by using U.S. Food and Drug Administration-cleared software for automated quantitative MR imaging analysis (NeuroQuant). Results of quantitative MR imaging were compared with visual detection of atrophy, and, when available, with histologic specimens. Receiver operating characteristic analyses were performed to determine the optimal sensitivity and specificity of quantitative MR imaging for detecting HA and asymmetry. A linear classifier with cross validation was used to estimate the ability of quantitative MR imaging to help lateralize the seizure focus. RESULTS Quantitative MR imaging-derived hippocampal asymmetries discriminated patients with TLE from control subjects with high sensitivity (86.7%-89.5%) and specificity (92.2%-94.1%). When a linear classifier was used to discriminate left versus right TLE, hippocampal asymmetry achieved 94% classification accuracy. Volumetric asymmetries of other subcortical structures did not improve classification. Compared with invasive video electroencephalographic recordings, lateralization accuracy was 88% with quantitative MR imaging and 85% with visual inspection of volumetric MR imaging studies but only 76% with visual inspection of clinical MR imaging studies. CONCLUSION Quantitative MR imaging can depict the presence and laterality of HA in TLE with accuracy rates that may exceed those achieved with visual inspection of clinical MR imaging studies. Thus, quantitative MR imaging may enhance standard visual analysis, providing a useful and viable means for translating volumetric analysis into clinical practice.
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Affiliation(s)
- Nikdokht Farid
- Department of Radiology, University of California, San Diego, CA 92037, USA
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Bonilha L, Halford JJ, Morgan PS, Edwards JC. Hippocampal atrophy in temporal lobe epilepsy: the 'generator' and 'receiver'. Acta Neurol Scand 2012; 125:105-10. [PMID: 21470191 DOI: 10.1111/j.1600-0404.2011.01510.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Some patients with unilateral medial temporal lobe epilepsy (MTLE) display bilateral hippocampal atrophy on MRI, even though seizures originate in only one hippocampus. The correct identification of the epileptogenic hippocampus (the 'generator') vs the non-epileptogenic (the 'receiver') may lead to better surgical planning and results. MATERIALS AND METHODS We studied 14 patients with MTLE (eight left and six right) who became seizure free after unilateral hippocampal resection, with hippocampal sclerosis confirmed by histology. Hippocampal tridimensional morphometry was performed comparing patients and healthy controls employing a voxel-wise Wilcoxon test. Results were corrected for multiple comparisons with the application of a False Discovery Rate (FDR)-corrected threshold for q < 0.05. RESULTS Patients with MTLE showed atrophy involving the ipsilateral hippocampus and the contralateral hippocampus, more pronouncedly within the ipsilateral hippocampus in the anterior-inferior aspect of the hippocampal head (left MTLE, left hippocampus x = -28, y = -16, z = -24, Z = 3.6; right MTLE, right hippocampus x = 22, y = -11, z = -27, Z = 2.9). On the contralateral hippocampus, the atrophy was more noticeable in the posterior head and body areas. CONCLUSION The epileptogenic hippocampal atrophy has an anatomically distinct pattern compared with the contralateral hippocampus. This information may help guide the presurgical assessment of MTLE.
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Affiliation(s)
- L Bonilha
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, Charleston, 29425, USA.
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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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Bonilha L, Martz GU, Glazier SS, Edwards JC. Subtypes of medial temporal lobe epilepsy: influence on temporal lobectomy outcomes? Epilepsia 2011; 53:1-6. [PMID: 22050314 DOI: 10.1111/j.1528-1167.2011.03298.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Surgical resection of the hippocampus is the most successful treatment for medication-refractory medial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis. Unfortunately, at least one of four operated patients continue to have disabling seizures after surgery, and there is no existing method to predict individual surgical outcome. Prior to surgery, patients who become seizure free appear identical to those who continue to have seizures after surgery. Interestingly, newly converging presurgical data from magnetic resonance imaging (MRI) and intracranial electroencephalography (EEG) suggest that the entorhinal and perirhinal cortices may play an important role in seizure generation. These areas are not consistently resected with surgery and it is possible that they continue to generate seizures after surgery in some patients. Therefore, subtypes of MTLE patients can be considered according to the degree of extrahippocampal damage and epileptogenicity of the medial temporal cortex. The identification of these subtypes has the potential to drastically improve surgical results via optimized presurgical planning. In this review, we discuss the current data that suggests neural network damage in MTLE, focusing on the medial temporal cortex. We explore how this evidence may be applied to presurgical planning and suggest approaches for future investigation.
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Affiliation(s)
- Leonardo Bonilha
- Comprehensive Epilepsy Center, Medical University of South Carolina, Charleston, South Carolina, USA.
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Alessio A, Pereira FRS, Sercheli MS, Rondina JM, Ozelo HB, Bilevicius E, Pedro T, Covolan RJM, Damasceno BP, Cendes F. Brain plasticity for verbal and visual memories in patients with mesial temporal lobe epilepsy and hippocampal sclerosis: an fMRI study. Hum Brain Mapp 2011; 34:186-99. [PMID: 22038783 DOI: 10.1002/hbm.21432] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 06/13/2011] [Accepted: 07/08/2011] [Indexed: 11/08/2022] Open
Abstract
We aimed to identify the brain areas involved in verbal and visual memory processing in normal controls and patients with unilateral mesial temporal lobe epilepsy (MTLE) associated with unilateral hippocampal sclerosis (HS) by means of functional magnetic resonance imaging (fMRI). The sample comprised nine normal controls, eight patients with right MTLE, and nine patients with left MTLE. All subjects underwent fMRI with verbal and visual memory paradigms, consisting of encoding and immediate recall of 17 abstract words and 17 abstract drawings. A complex network including parietal, temporal, and frontal cortices seems to be involved in verbal memory encoding and retrieval in normal controls. Although similar areas of activation were identified in both patient groups, the extension of such activations was larger in the left-HS group. Patients with left HS also tended to exhibit more bilateral or right lateralized encoding related activations. This finding suggests a functional reorganization of verbal memory processing areas in these patients due to the failure of left MTL system. As regards visual memory encoding and retrieval, our findings support the hypothesis of a more diffuse and bilateral representation of this cognitive function in the brain. Compared to normal controls, encoding in the left-HS group recruited more widespread cortical areas, which were even more widespread in the right-HS group probably to compensate for their right mesial temporal dysfunction. In contrast, the right-HS group exhibited fewer activated areas during immediate recall than the other two groups, probably related to their greater difficulty in dealing with visual memory content.
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Affiliation(s)
- Andréa Alessio
- Neuroimaging Laboratory, School of Medical Sciences, University of Campinas, Unicamp, Campinas, Brazil
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McDonald CR, Taylor J, Hamberger M, Helmstaedter C, Hermann BP, Schefft B. Future directions in the neuropsychology of epilepsy. Epilepsy Behav 2011; 22:69-76. [PMID: 21795122 DOI: 10.1016/j.yebeh.2011.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 06/05/2011] [Indexed: 11/17/2022]
Abstract
Two important themes for future clinical research in the neuropsychology of epilepsy are proposed: (1) the neurobiological abnormalities that underlie neuropsychological impairment in people with epilepsy, and (2) neuropsychological status of persons with new-onset epilepsy.
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Affiliation(s)
- Carrie R McDonald
- Multimodal Imaging Laboratory, Department of Psychiatry, University of California, San Diego, San Diego, CA, USA
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46
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Das SR, Mechanic-Hamilton D, Pluta J, Korczykowski M, Detre JA, Yushkevich PA. Heterogeneity of functional activation during memory encoding across hippocampal subfields in temporal lobe epilepsy. Neuroimage 2011; 58:1121-30. [PMID: 21763431 DOI: 10.1016/j.neuroimage.2011.06.085] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 06/28/2011] [Indexed: 11/27/2022] Open
Abstract
Pathology studies have shown that the anatomical subregions of the hippocampal formation are differentially affected in various neurological disorders, including temporal lobe epilepsy (TLE). Analysis of structure and function within these subregions using magnetic resonance imaging (MRI) has the potential to generate insights on disease associations as well as normative brain function. In this study, an atlas-based normalization method (Yushkevich, P.A., Avants, B.B., Pluta, J., Das, S., Minkoff, D., Mechanic-Hamilton, D., Glynn, S., Pickup, S., Liu, W., Gee, J.C., Grossman, M., Detre, J.A., 2009. A high-resolution computational atlas of the human hippocampus from postmortem magnetic resonance imaging at 9.4 T. NeuroImage 44 (2), 385-398) was used to label hippocampal subregions, making it possible to examine subfield-level functional activation during an episodic memory task in two different cohorts of healthy controls and subjects diagnosed with intractable unilateral TLE. We report, for the first time, functional activation patterns within hippocampal subfields in TLE. We detected group differences in subfield activation between patients and controls as well as inter-hemispheric activation asymmetry within subfields in patients, with dentate gyrus (DG) and the anterior hippocampus region showing the greatest effects. DG was also found to be more active than CA1 in controls, but not in patients' epileptogenic side. These preliminary results will encourage further research on the utility of subfield-based biomarkers in TLE.
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Affiliation(s)
- Sandhitsu R Das
- Penn Image Computing and Science Laboratory (PICSL), Department of Radiology, University of Pennsylvania, PA, USA.
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Bell B, Lin JJ, Seidenberg M, Hermann B. The neurobiology of cognitive disorders in temporal lobe epilepsy. Nat Rev Neurol 2011; 7:154-64. [PMID: 21304484 DOI: 10.1038/nrneurol.2011.3] [Citation(s) in RCA: 308] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cognitive impairment, particularly memory disruption, is a major complicating feature of epilepsy. This Review will begin with a focus on the problem of memory impairment in temporal lobe epilepsy (TLE). We present a brief overview of anatomical substrates of memory disorders in TLE, followed by a discussion of how our understanding of these disorders has been improved by studying the outcomes of anterior temporal lobectomy. The clinical efforts made to predict which patients are at greatest risk of experiencing adverse cognitive outcomes following epilepsy surgery are also considered. Finally, we examine the vastly changing view of TLE, including findings demonstrating that anatomical abnormalities extend far outside the temporal lobe, and that cognitive impairments extend beyond memory function. Linkage between these distributed cognitive and anatomical abnormalities point to a new understanding of the anatomical architecture of cognitive impairment in epilepsy. Clarifying the origin of these cognitive and anatomical abnormalities, their progression over time and, most importantly, methods for protecting cognitive and brain health in epilepsy, present a challenge to neurologists.
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Affiliation(s)
- Brian Bell
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, 600 North Highland Avenue, Madison, WI 53792, USA
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48
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Mittal D, Stevenson RJ, Oaten MJ, Miller LA. Snacking while watching TV impairs food recall and promotes food intake on a later TV free test meal. APPLIED COGNITIVE PSYCHOLOGY 2010. [DOI: 10.1002/acp.1760] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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49
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Performance in recognition memory is correlated with entorhinal/perirhinal interictal metabolism in temporal lobe epilepsy. Epilepsy Behav 2010; 19:612-7. [PMID: 21035404 DOI: 10.1016/j.yebeh.2010.09.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 09/18/2010] [Accepted: 09/20/2010] [Indexed: 11/22/2022]
Abstract
In addition to the hippocampus, the entorhinal/perirhinal cortices are often involved in temporal lobe epilepsy (TLE). It has been proposed that these anterior parahippocampal structures play a key role in recognition memory. We studied the voxel-based PET correlation between number of correctly recognized targets in a new recognition memory paradigm and interictal cerebral metabolic rate for glucose, in 15 patients with TLE with hippocampal sclerosis. In comparison to healthy subjects, patients had decreased recognition of targets (P<0.001) and ipsilateral hypometabolism (relative to side of hippocampal sclerosis) of the hippocampus, entorhinal/perirhinal cortices, medial temporal pole, and middle temporal gyrus (P<0.05, corrected by false discovery rate method). Performance correlated with interictal metabolism of ipsilateral entorhinal/perirhinal cortices (P<0.005, Spearman's rank test), but this relationship was not significant in the hippocampus itself (P>0.18, Spearman's rank test). These findings highlight the preferential involvement of entorhinal/perirhinal cortices in recognition memory in patients with TLE, and suggest that recognition memory paradigms may be useful in assessing anterior parahippocampal functional status in TLE.
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Baxendale S, Thompson P. Beyond localization: the role of traditional neuropsychological tests in an age of imaging. Epilepsia 2010; 51:2225-30. [PMID: 21175602 DOI: 10.1111/j.1528-1167.2010.02710.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Rapid advances in structural and functional magnetic resonance imaging (MRI) present two significant challenges to the rationale and role of the traditional neuropsychological assessment in the presurgical evaluation of epilepsy surgery candidates today. The first is a direct challenge to the model of material-specific memory that has underpinned much clinical practice over the last 50 years. The second, more fundamental, challenge goes to the very heart of the lateralizing/localizing approach that has been the cornerstone of clinical neuropsychology practice in epilepsy surgery centers to date. This review examines these challenges and suggests some ways in which the profession might respond and adapt. We conclude that noninvasive neuropsychological assessment remains a critical investigation in the presurgical evaluation of epilepsy surgery patients. Its value stretches beyond the localization of a surgically remediable seizure focus. Once a vital test, other investigations are now superior in this respect in many cases. However, new technologies have enhanced the role of the traditional neuropsychological assessment, which is now able to provide unparalleled insights and predictions into the way in which the underlying pathology, seizures, and proposed surgery shape an individual's profile of cognitive abilities. Detailed neuropsychological feedback enables the patient to make an informed decision, and forms the basis of the tailor made preemptive rehabilitation programs that can be implemented preoperatively, minimizing the most significant morbidity associated with epilepsy surgery today.
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Affiliation(s)
- Sallie Baxendale
- Department of Clinical and Experimental Epilepsy, Institute of Neurology UCL, Queen Square, London, United Kingdom.
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