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Yang X, Ge M, Chen S, Wang K, Cheng H, Zhang Z. A specific model of resting-state functional brain network in MRI-negative temporal lobe epilepsy. Heliyon 2025; 11:e42695. [PMID: 40040985 PMCID: PMC11876875 DOI: 10.1016/j.heliyon.2025.e42695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/11/2025] [Accepted: 02/12/2025] [Indexed: 03/06/2025] Open
Abstract
Purpose Without any visible indicator on structure magnetic resonance imaging (MRI), the diagnosis of MRI-negative temporal lobe epilepsy (NTLE) gets harder. By considering healthy control (HC), a specific functional connectivity (FC) model was constructed in a network topology to improve FC computation to a high-level. Methods MRI data of 20 NTLE patients and 60 HC were pre-processed. Relative to HC, a network-level specific FC model of each network index was built to score the network functions for each NTLE patient. The specific brain areas (regarded as ROIs) were extracted for NTLE by sensitivity analysis of scores. By considering scores of specific ROIs as feature vectors to input into a SVM respectively, a specific NTLE classifier was constructed. Both 10-fold cross validation and hold-out method were utilized to validate the classification and to evaluate the effectiveness of our specific FC models. Simultaneously, the specific FC model was compared to the conventional FC model of Pearson correlation. Results By the constructed model for specific FC at a network-level, 11 specific ROIs, such as, frontal lobe, temporal lobe, parietal lobe, hippocampus, and occipital lobe, were extracted for NTLE. Accuracy of our specific NTLE classifier could reach up nearly 93 %, over 6 % greater than conventional FC model of Pearson correlation. Conclusions The network-level specific FC model might provide a new methodology for machine-aiding detection of functional abnormal lesions of NTLE by resting-state functional MRI.
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Affiliation(s)
- Xue Yang
- School of Life Science and Health Engineering, Hebei University of Technology, Tianjin, China
| | - Manling Ge
- Hebei Province Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability, Hebei University of Technology, Tianjin, China
| | - Shenghua Chen
- Hebei Province Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability, Hebei University of Technology, Tianjin, China
| | - Kaiwei Wang
- School of Life Science and Health Engineering, Hebei University of Technology, Tianjin, China
| | - Hao Cheng
- School of Life Science and Health Engineering, Hebei University of Technology, Tianjin, China
| | - Zhiqiang Zhang
- Department of Medical Imaging, Clinical School of Nanjing University School of Medicine (affiliated to Jinling Hospital), Nanjing, China
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George AG, Beers CA, Wilson W, Mosher V, Pittman DJ, Dykens P, Peedicail JS, Gill L, Gaxiola-Valdez I, Goodyear BG, LeVan P, Federico P. Mesial temporal lobe spiking reveals distinct patterns of blood oxygen level-dependent functional magnetic resonance imaging activation using simultaneous intracranial electroencephalography-functional magnetic resonance imaging. Epilepsia 2024; 65:2295-2307. [PMID: 38845414 DOI: 10.1111/epi.18036] [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: 02/09/2024] [Revised: 05/23/2024] [Accepted: 05/23/2024] [Indexed: 08/10/2024]
Abstract
OBJECTIVE Temporal lobe epilepsy (TLE) has a high probability of becoming drug resistant and is frequently considered for surgical intervention. However, 30% of TLE cases have nonlesional magnetic resonance imaging (MRI) scans, which is associated with worse surgical outcomes. Characterizing interactions between temporal and extratemporal structures in these patients may help understand these poor outcomes. Simultaneous intracranial electroencephalography-functional MRI (iEEG-fMRI) can measure the hemodynamic changes associated with interictal epileptiform discharges (IEDs) recorded directly from the brain. This study was designed to characterize the whole brain patterns of IED-associated fMRI activation recorded exclusively from the mesial temporal lobes of patients with nonlesional TLE. METHODS Eighteen patients with nonlesional TLE undergoing iEEG monitoring with mesial temporal IEDs underwent simultaneous iEEG-fMRI at 3 T. IEDs were marked, and statistically significant clusters of fMRI activation were identified. The locations of IED-associated fMRI activation for each patient were determined, and patients were grouped based on the location and pattern of fMRI activation. RESULTS Two patterns of IED-associated fMRI activation emerged: primarily localized (n = 7), where activation was primarily located within the ipsilateral temporal lobe, and primarily diffuse (n = 11), where widespread bilateral extratemporal activation was detected. The primarily diffuse group reported significantly fewer focal to bilateral tonic-clonic seizures and had better postsurgical outcomes. SIGNIFICANCE Simultaneous iEEG-fMRI can measure the hemodynamic changes associated with focal IEDs not visible on scalp EEG, such as those arising from the mesial temporal lobe. Significant fMRI activation associated with these IEDs was observed in all patients. Two distinct patterns of IED-associated activation were seen: primarily localized to the ipsilateral temporal lobe and more widespread, bilateral activation. Patients with widespread IED associated-activation had fewer focal to bilateral tonic-clonic seizures and better postsurgical outcome, which may suggest a neuroprotective mechanism limiting the spread of ictal events.
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Affiliation(s)
- Antis G George
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
| | - Craig A Beers
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
| | - William Wilson
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
| | - Victoria Mosher
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
| | - Daniel J Pittman
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
| | - Perry Dykens
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
| | - Joseph S Peedicail
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
| | - Laura Gill
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
| | - Ismael Gaxiola-Valdez
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
| | - Bradley G Goodyear
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
- Cumming School of Medicine, Department of Radiology, University of Calgary, Calgary, Alberta, Canada
| | - Pierre LeVan
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Cumming School of Medicine, Department of Radiology, University of Calgary, Calgary, Alberta, Canada
| | - Paolo Federico
- Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
- Seaman Family MR Research Centre, Foothills Medical Centre, University of Calgary, Calgary, Alberta, Canada
- Cumming School of Medicine, Department of Radiology, University of Calgary, Calgary, Alberta, Canada
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Sen A, Sankaran S. Detection of partial loss of hippocampal striation at 1.5 Tesla magnetic resonance imaging. Insights Imaging 2019; 10:103. [PMID: 31655929 PMCID: PMC6815302 DOI: 10.1186/s13244-019-0783-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 08/19/2019] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVES Partial loss of hippocampal striation (PLHS) is recently described in 3 T and 7 T MR imaging as a sensitive indicator of hippocampal sclerosis. PRIMARY OBJECTIVE We described the demographic characteristics of the population with seizure disorder having PLHS at 1.5 T MR imaging and tried to see the relation of PLHS to the classic signs of hippocampal sclerosis. SECONDARY OBJECTIVE PLHS was also looked for in a small control population that had no seizure history. METHODS This retrospective study had the approval of the institutional review board. In patients demonstrating PLHS on oblique coronal T2-weighted images, the following were recorded: age, sex, EEG findings, side of PLHS, hippocampal atrophy and high signal intensity of the hippocampus. In control population, the following were recorded: age, sex, presence/absence of PLHS and indication for imaging. RESULTS The 116 PLHS subjects (age range 2-73 years) included 62 males and 54 females. Sixty-six (56.9%) of our PLHS subjects were less than 18 years of age: 44 (37.9%) under the age of 12 years and 22 (19%) of 12-18 years of age. Classic signs of hippocampal sclerosis were found in only 7 (6%) of the 116 subjects showing PLHS. All patients with classic signs showed PLHS on the same side. Of the control population (25 subjects, age range 3-76 years, 17 males and 8 females), one showed PLHS-he was a treated case of CNS lymphoma with gliotic changes, though there was no history of seizure. CONCLUSION PLHS is demonstrated at 1.5 T in both adult and paediatric population in this article and is much more common than the classic signs of hippocampal sclerosis (increased signal intensity and volume loss).
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Affiliation(s)
- Anitha Sen
- Department of Radiodiagnosis, RCC, Thiruvananthapuram, 695011, India.
| | - Sudhakaran Sankaran
- Department of Radiodiagnosis, Government Medical College Kottayam, Kerala, 686008, India
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Blackmon K, Barr WB, Morrison C, MacAllister W, Kruse M, Pressl C, Wang X, Dugan P, Liu AA, Halgren E, Devinsky O, Thesen T. Cortical gray-white matter blurring and declarative memory impairment in MRI-negative temporal lobe epilepsy. Epilepsy Behav 2019; 97:34-43. [PMID: 31181427 PMCID: PMC8162756 DOI: 10.1016/j.yebeh.2019.05.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/06/2019] [Accepted: 05/08/2019] [Indexed: 11/26/2022]
Abstract
Magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE) may be a distinct syndrome from TLE with mesial temporal sclerosis (TLE-MTS). Imaging and neuropsychological features of TLE-MTS are well-known; yet, these features are only beginning to be described in MRI-negative TLE. This study examined whether a quantitative measure of cortical gray and white matter blurring (GWB) was elevated in the temporal lobes ipsilateral to the seizure onset zone of individuals with MRI-negative TLE relative to TLE-MTS and healthy controls (HCs) and whether GWB elevations were associated with neuropsychological comorbidity. Gray-white matter blurring from 34 cortical regions and hippocampal volumes were quantified and compared across 28 people with MRI-negative TLE, 15 people with TLE-MTS, and 51 HCs. Declarative memory was assessed with standard neuropsychological tests and the intracarotid amobarbital procedure (IAP). In the group with MRI-negative TLE (left and right onsets combined), hippocampal volumes were within normal range but GWB was elevated, relative to HCs, across several mesial and lateral temporal lobe regions ipsilateral to the seizure onset zone. Gray-white matter blurring did not differ between the groups with TLE-MTS and HC or between the groups with TLE-MTS and MRI-negative TLE. The group with MRI-negative TLE could not be distinguished from the group with TLE-MTS on any of the standard neuropsychological tests; however, ipsilateral hippocampal volumes and IAP memory scores were lower in the group with TLE-MTS than in the group with MRI-negative TLE. The group with left MRI-negative TLE had lower general cognitive abilities and verbal fluency relative to the HC group, which adds to the characterization of neuropsychological comorbidities in left MRI-negative TLE. In addition, ipsilateral IAP memory performance was reduced relative to contralateral memory performance in MRI-negative TLE, indicating some degree of ipsilateral memory dysfunction. There was no relationship between hippocampal volume and IAP memory scores in MRI-negative TLE; however, decreased ipsilateral IAP memory scores were correlated with elevated GWB in the ipsilateral superior temporal sulcus of people with left MRI-negative TLE. In sum, GWB elevations in the ipsilateral temporal lobe of people with MRI-negative TLE suggest that GWB may serve as a marker for reduced structural integrity in regions in or near the seizure onset zone. Although mesial temporal abnormalities might be the major driver of memory dysfunction in TLE-MTS, a loss of structural integrity in lateral temporal lobe regions may contribute to IAP memory dysfunction in MRI-negative TLE.
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Affiliation(s)
- Karen Blackmon
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America; St. George's University School of Medicine, Department of Physiology, Neuroscience, and Behavioral Sciences, West Indies, Grenada.
| | - William B. Barr
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America
| | - Chris Morrison
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America
| | - William MacAllister
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America,University of Calgary, Alberta Children’s Hospital, Calgary, Alberta, Canada
| | - Michelle Kruse
- St. George’s University School of Medicine, Department of Physiology, Neuroscience, and Behavioral Sciences, West Indies, Grenada
| | - Christina Pressl
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America,The Rockefeller University, Laboratory of Neural Systems, New York, NY 10065, United States of America
| | - Xiuyuan Wang
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America,New York University School of Medicine, Department of Radiology, New York, NY 10016, United States of America
| | - Patricia Dugan
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America
| | - Anli A. Liu
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America
| | - Eric Halgren
- University of California San Diego, Multimodal Imaging Laboratory, San Diego, CA 92093, United States of America
| | - Orrin Devinsky
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America
| | - Thomas Thesen
- New York University School of Medicine, Department of Neurology, Epilepsy Division, New York, NY 10016, United States of America,St. George’s University School of Medicine, Department of Physiology, Neuroscience, and Behavioral Sciences, West Indies, Grenada
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Orlowski HLP, Smyth MD, Parsons MS, Dahiya S, Sharifai N, Hildebolt C, Sharma A. Enhancing contrast to noise ratio of hippocampi affected with mesial temporal sclerosis: A case-control study in children undergoing epilepsy surgeries. Clin Neurol Neurosurg 2018; 174:144-148. [PMID: 30241008 DOI: 10.1016/j.clineuro.2018.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/27/2018] [Accepted: 09/03/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVE Detection of mesial temporal sclerosis (MTS) in children with epilepsy is important. We assessed whether an image-processing algorithm (Correlative Image Enhancement, CIE) could facilitate recognition of hippocampal signal abnormality in the presence of MTS by increasing contrast to noise ratio between affected hippocampus and normal gray matter. PATIENTS AND METHODS Baseline coronal FLAIR images from brain MRIs of 27 children with epilepsy who underwent hippocampal resection were processed using CIE. These included 19 hippocampi with biopsy proven MTS and 8 biopsy proven normal hippocampi resected in conjunction with hemispherotomy. We assessed the effect of processing on contrast to noise ratio (CNR) between hippocampus and normal insular gray matter, and on assessment of hippocampal signal abnormality by two masked neuroradiologists. RESULTS Processing resulted in a significant increase in mean CNR (from 3.9 ± 5.3 to 25.3 ± 25.8; P < 0.01) for hippocampi with MTS, with a substantial (>100%) increase from baseline seen in 15/19 (78.9%) cases. Baseline CNR of 1.7 ± 5.3 for normal hippocampi did not change significantly after processing (1.8 ± 5.3; P = 1.00). For one reader, baseline sensitivity (14/19; 73.6%) was unaffected but the specificity improved from 62.5% (5/8) to 100%. An increase in both sensitivity (from 73.6% to 78.9%) and specificity (from 62.5% to 75%) was seen for the second reader. CONCLUSION By enhancing CNR for diseased hippocampi while leaving normal hippocampi relatively unaffected, CIE may improve the diagnostic accuracies of radiologists in detecting MTS-related signal alteration within the affected hippocampus.
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Affiliation(s)
- Hilary L P Orlowski
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Boulevard, St. Louis, MO 63110, United States.
| | - Matthew D Smyth
- Department of Neurological Surgery, Washington University School of Medicine, 660 South Euclid, Box 8057, St. Louis, MO 63110, United States.
| | - Matthew S Parsons
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Boulevard, St. Louis, MO 63110, United States.
| | - Sonika Dahiya
- Department of Pathology & Immunology, Washington University School of Medicine, 509 S. Euclid Ave, St. Louis, MO 63110, United States.
| | - Nima Sharifai
- Department of Pathology & Immunology, Washington University School of Medicine, 509 S. Euclid Ave, St. Louis, MO 63110, United States.
| | - Charles Hildebolt
- Division of Biostatistics, Washington University School of Medicine, 660 S. Euclid Ave. St. Louis, MO 63110, United States.
| | - Aseem Sharma
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 S. Kingshighway Boulevard, St. Louis, MO 63110, United States.
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6
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The roles of surgery and technology in understanding focal epilepsy and its comorbidities. Lancet Neurol 2018; 17:373-382. [DOI: 10.1016/s1474-4422(18)30031-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 01/12/2018] [Accepted: 01/16/2018] [Indexed: 01/21/2023]
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Factors that Can Help Select the Timing for Decompressive Hemicraniectomy for Malignant MCA Stroke. Transl Stroke Res 2018; 9:600-607. [DOI: 10.1007/s12975-018-0616-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 02/10/2018] [Accepted: 02/14/2018] [Indexed: 10/17/2022]
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Ivanovic J, Larsson PG, Østby Y, Hald J, Krossnes BK, Fjeld JG, Pripp AH, Alfstad KÅ, Egge A, Stanisic M. Seizure outcomes of temporal lobe epilepsy surgery in patients with normal MRI and without specific histopathology. Acta Neurochir (Wien) 2017; 159:757-766. [PMID: 28281007 PMCID: PMC5385196 DOI: 10.1007/s00701-017-3127-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/16/2017] [Indexed: 12/02/2022]
Abstract
BACKGROUND Seizure outcome following surgery in pharmacoresistant temporal lobe epilepsy patients with normal magnetic resonance imaging and normal or non-specific histopathology is not sufficiently presented in the literature. METHODS In a retrospective design, we reviewed data of 263 patients who had undergone temporal lobe epilepsy surgery and identified 26 (9.9%) who met the inclusion criteria. Seizure outcomes were determined at 2-year follow-up. Potential predictors of Engel class I (satisfactory outcome) were identified by logistic regression analyses. RESULTS Engel class I outcome was achieved in 61.5% of patients, 50% being completely seizure free (Engel class IA outcome). The strongest predictors of satisfactory outcome were typical ictal seizure semiology (p = 0.048) and localised ictal discharges on scalp EEG (p = 0.036). CONCLUSION Surgery might be an effective treatment choice for the majority of these patients, although outcomes are less favourable than in patients with magnetic resonance imaging-defined lesional temporal lobe epilepsy. Typical ictal seizure semiology and localised ictal discharges on scalp EEG were predictors of Engel class I outcome.
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Affiliation(s)
- Jugoslav Ivanovic
- Department of Neurosurgery, Oslo University Hospital, Sognsvannsveien 20, N-0027, Oslo, Norway.
| | - Pål G Larsson
- Clinical Neurophysiologic Laboratory, Department of Neurosurgery, Oslo University Hospital, Oslo, Norway
| | - Ylva Østby
- Department of Clinical Psychology and Neuropsychology, National Centre for Epilepsy, Oslo University Hospital, Oslo, Norway
| | - John Hald
- Department of Radiology, Oslo University Hospital, Oslo, Norway
| | - Bård K Krossnes
- Department of Pathology, Oslo University Hospital, Oslo, Norway
| | - Jan G Fjeld
- Department of Nuclear Medicine, Oslo University Hospital, Oslo, Norway
- Oslo and Akershus University College of Applied Sciences, Oslo, Norway
| | - Are H Pripp
- Oslo Centre for Biostatistics and Epidemiology, Research Support Service, Oslo University Hospital, Oslo, Norway
| | - Kristin Å Alfstad
- Department of Adult Epilepsy, National Centre for Epilepsy, Oslo University Hospital, Oslo, Norway
| | - Arild Egge
- Department of Neurosurgery, Oslo University Hospital, Sognsvannsveien 20, N-0027, Oslo, Norway
| | - Milo Stanisic
- Department of Neurosurgery, Oslo University Hospital, Sognsvannsveien 20, N-0027, Oslo, Norway
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Muhlhofer W, Tan Y, Mueller SG, Knowlton R. MRI
‐negative temporal lobe epilepsy—What do we know? Epilepsia 2017; 58:727-742. [DOI: 10.1111/epi.13699] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2017] [Indexed: 01/01/2023]
Affiliation(s)
- Wolfgang Muhlhofer
- University of California San Francisco (UCSF) San Francisco California U.S.A
- University of Alabama Birmingham (UAB) Birmingham Alabama U.S.A
| | - Yee‐Leng Tan
- University of California San Francisco (UCSF) San Francisco California U.S.A
- National Neuroscience Institute Singapore Singapore
| | - Susanne G. Mueller
- University of California San Francisco (UCSF) San Francisco California U.S.A
- Center for Imaging of Neurodegenerative Diseases (CIND) San Francisco California U.S.A
- Department of Radiology UCSF San Francisco CaliforniaU.S.A
| | - Robert Knowlton
- University of California San Francisco (UCSF) San Francisco California U.S.A
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Tract-specific atrophy in focal epilepsy: Disease, genetics, or seizures? Ann Neurol 2017; 81:240-250. [DOI: 10.1002/ana.24848] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/29/2016] [Accepted: 12/11/2016] [Indexed: 12/13/2022]
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Kurita T, Sakurai K, Takeda Y, Horinouchi T, Kusumi I. Very Long-Term Outcome of Non-Surgically Treated Patients with Temporal Lobe Epilepsy with Hippocampal Sclerosis: A Retrospective Study. PLoS One 2016; 11:e0159464. [PMID: 27415827 PMCID: PMC4944917 DOI: 10.1371/journal.pone.0159464] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 07/01/2016] [Indexed: 11/23/2022] Open
Abstract
Objective Surgical intervention can result in complete seizure remission rates of up to 80% in patients with temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). However, certain patients cannot be treated surgically for various reasons. We analyzed the very long-term clinical outcomes of patients with TLE-HS who could not be treated surgically. Methods Subjects were selected from among patients with TLE-HS who were actively followed up for >10 years and treated with medication without surgical treatment. Patient medical records were used to retrospectively study seizure frequency, various clinical factors, and social adjustment. Patients who were seizure-free or had only aura were classified into Group 1; the others were classified into Group 2. Clinical factors including both patient and disease-specific factors were compared between the two groups. Current social adjustment, including the education, work, and economic status of each patient, was also investigated. Results Forty-one (41) subjects met the criteria for analysis, of which 12 (29%) were classified into Group 1. The average age of patients in Group 1 was higher than that of Group 2 (p = 0.0468). Group 2 included a significantly higher rate of patients who had more than one seizure per week at the onset (p = 0.0328), as well as a greater mean number of anti-epileptic drugs taken (p = 0.0024). Regarding social adjustment, Group 2 contained significantly fewer current jobholders than Group 1 (p = 0.0288). Conclusions After very long-term follow-up periods, 29% of patients with TLE-HS had a good outcome through treatment with anticonvulsant medications. Older patients tended to have fewer seizures, and seizure frequency at the onset was the only factor that predicted outcome.
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Affiliation(s)
- Tsugiko Kurita
- Department of Psychiatry and Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
- * E-mail:
| | - Kotaro Sakurai
- Department of Psychiatry and Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Youji Takeda
- Department of Psychiatry and Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Toru Horinouchi
- Department of Psychiatry and Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Ichiro Kusumi
- Department of Psychiatry and Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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Bernhardt BC, Bernasconi A, Liu M, Hong SJ, Caldairou B, Goubran M, Guiot MC, Hall J, Bernasconi N. The spectrum of structural and functional imaging abnormalities in temporal lobe epilepsy. Ann Neurol 2016; 80:142-53. [PMID: 27228409 DOI: 10.1002/ana.24691] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 05/24/2016] [Accepted: 05/24/2016] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Although most temporal lobe epilepsy (TLE) patients show marked hippocampal sclerosis (HS) upon pathological examination, 40% present with no significant cell loss but gliotic changes only. To evaluate effects of hippocampal pathology on brain structure and functional networks, we aimed at dissociating multimodal magnetic resonance imaging (MRI) characteristics in patients with HS (TLE-HS) and those with gliosis only (TLE-G). METHODS In 20 TLE-HS, 19 TLE-G, and 25 healthy controls, we carried out a novel MRI-based hippocampal subfield surface analysis that integrated volume, T2 signal intensity, and diffusion markers with seed-based hippocampal functional connectivity. RESULTS Compared to controls, TLE-HS presented with marked ipsilateral atrophy, T2 hyperintensity, and mean diffusivity increases across all subfields, whereas TLE-G presented with dentate gyrus hypertrophy, focal increases in T2 intensity and mean diffusivity. Multivariate assessment confirmed a more marked ipsilateral load of anomalies across all subfields in TLE-HS, whereas anomalies in TLE-G were restricted to the subiculum. A between-cohort dissociation was independently suggested by resting-state functional connectivity analysis, revealing marked hippocampal decoupling from anterior and posterior default mode hubs in TLE-HS, whereas TLE-G did not differ from controls. Back-projection connectivity analysis from cortical targets revealed consistently decreased network embedding across all subfields in TLE-HS, while changes in TLE-G were limited to the subiculum. Hippocampal disconnectivity strongly correlated to T2 hyperintensity and marginally to atrophy. INTERPRETATION Multimodal MRI reveals diverging structural and functional connectivity profiles across the TLE spectrum. Pathology-specific modulations of large-scale functional brain networks lend novel evidence for a close interplay of structural and functional disruptions in focal epilepsy. Ann Neurol 2016;80:142-153.
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Affiliation(s)
- Boris C Bernhardt
- From the Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Andrea Bernasconi
- From the Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Min Liu
- From the Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Seok-Jun Hong
- From the Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Benoit Caldairou
- From the Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Maged Goubran
- From the Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Radiology, Stanford School of Medicine, Stanford University, CA
| | - Marie C Guiot
- Department of Pathology, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Jeff Hall
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Neda Bernasconi
- From the Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.,Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
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Wang X, Zhang C, Wang Y, Hu W, Shao X, Zhang JG, Zhang K. Prognostic factors for seizure outcome in patients with MRI-negative temporal lobe epilepsy: A meta-analysis and systematic review. Seizure 2016; 38:54-62. [PMID: 27182689 DOI: 10.1016/j.seizure.2016.04.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 04/04/2016] [Accepted: 04/05/2016] [Indexed: 11/15/2022] Open
Abstract
PURPOSE To perform a systematic review and meta-analysis to identify predictors of postoperative seizure freedom in patients with magnetic resonance imaging (MRI)-negative temporal lobe epilepsy. METHOD Publications were screened from electronic databases (MEDLINE, EMBASE), epilepsy archives, and bibliographies of relevant articles that were written in English. We recorded all possible risk factors that might predict seizure outcome after surgery. We calculated odds ratio (OR) with corresponding 95% confidence intervals (95% CI) of predictors for postoperative seizure freedom. Heterogeneity was assessed with I(2). All meta-analyses were performed using Review Manager. RESULTS Epilepsy duration (OR=2.57, 95% CI=1.21-5.47, p<0.05, I(2)=1%) and ictal or interictal electroencephalographic anomalies precisely localized in the ipsilateral temporal lobe (OR=3.89, 95% CI=1.66-9.08, p<0.01, I(2)=0 and OR=3.38, 95% CI=1.57-7.25, p<0.05, I(2)=0, respectively) were significantly associated with a higher rate of seizure freedom after surgery. However, the positron emission tomography (PET) results were not predictive of postoperative seizure freedom (OR=2.11, 95% CI=0.95-4.65, p=0.06, I(2)=0). No significant difference in seizure freedom was observed between the positive and negative pathology groups (OR=1.36, 95% CI=0.70-2.63, p=0.36, I(2)=0). CONCLUSIONS A shorter epilepsy duration and scalp electroencephalogram (EEG) signals localized precisely in the temporal lobe predicted a better seizure outcome in patients with MRI-negative temporal lobe epilepsy.
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Affiliation(s)
- Xiu Wang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China
| | - Chao Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China
| | - Yao Wang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China
| | - Wenhan Hu
- Beijing Neurosurgical Institute, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China
| | - Xiaoqiu Shao
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China
| | - Jian-Guo Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China
| | - Kai Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Tiantan xili 6, Dongcheng, Beijing 100050, China; Beijing Key Laboratory of Neurostimulation, Tiantan xili 6, Dongcheng, Beijing 100050, China.
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Panov F, Li Y, Chang EF, Knowlton R, Cornes SB. Epilepsy with temporal encephalocele: Characteristics of electrocorticography and surgical outcome. Epilepsia 2015; 57:e33-8. [DOI: 10.1111/epi.13271] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Fedor Panov
- Department of Neurosurgery; University of California; San Francisco California U.S.A
| | - Yi Li
- Department of Neurology; University of Massachusetts Medical School; Worcester Massachusetts U.S.A
| | - Edward F. Chang
- Department of Neurosurgery; University of California; San Francisco California U.S.A
| | - Robert Knowlton
- Departments of Neurology, Radiology, and Neurological Surgery; University of California; San Francisco California U.S.A
| | - Susannah B. Cornes
- Departments of Neurology, Radiology, and Neurological Surgery; University of California; San Francisco California U.S.A
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15
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Coan AC, Campos BM, Bergo FPG, Kubota BY, Yasuda CL, Morita ME, Guerreiro CAM, Cendes F. Patterns of seizure control in patients with mesial temporal lobe epilepsy with and without hippocampus sclerosis. ARQUIVOS DE NEURO-PSIQUIATRIA 2015; 73:79-82. [PMID: 25742574 DOI: 10.1590/0004-282x20140199] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 10/14/2014] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Patients with mesial temporal lobe epilepsy (MTLE) may present unstable pattern of seizures. We aimed to evaluate the occurrence of relapse-remitting seizures in MTLE with (MTLE-HS) and without (MTLE-NL) hippocampal sclerosis. METHOD We evaluated 172 patients with MTLE-HS (122) or MTLE-NL (50). Relapse-remitting pattern was defined as periods longer than two years of seizure-freedom intercalated with seizure recurrence. "Infrequent seizures" was considered as up to three seizures per year and "frequent seizures" as any period of seizures higher than that. RESULTS Thirty-seven (30%) MTLE-HS and 18 (36%) MTLE-NL patients had relapse-remitting pattern (X2, p = 0.470). This was more common in those with infrequent seizures (X2, p < 0.001). Twelve MTLE-HS and one MTLE-NL patients had prolonged seizure remission between the first and second decade of life (X2, p = 0.06). CONCLUSION Similar proportion of MTLE-HS or MTLE-NL patients present relapse-remitting seizures and this occurs more often in those with infrequent seizures.
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Affiliation(s)
- Ana Carolina Coan
- Laboratório de Neuroimagem, Departamento de Neurologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Brunno M Campos
- Laboratório de Neuroimagem, Departamento de Neurologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Felipe P G Bergo
- Laboratório de Neuroimagem, Departamento de Neurologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Bruno Y Kubota
- Laboratório de Neuroimagem, Departamento de Neurologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Clarissa L Yasuda
- Laboratório de Neuroimagem, Departamento de Neurologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Marcia E Morita
- Laboratório de Neuroimagem, Departamento de Neurologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Carlos A M Guerreiro
- Laboratório de Neuroimagem, Departamento de Neurologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Fernando Cendes
- Laboratório de Neuroimagem, Departamento de Neurologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
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Goubran M, Hammond RR, de Ribaupierre S, Burneo JG, Mirsattari S, Steven DA, Parrent AG, Peters TM, Khan AR. Magnetic resonance imaging and histology correlation in the neocortex in temporal lobe epilepsy. Ann Neurol 2014; 77:237-50. [PMID: 25424188 DOI: 10.1002/ana.24318] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 11/17/2014] [Accepted: 11/18/2014] [Indexed: 12/23/2022]
Abstract
OBJECTIVE To investigate the histopathological correlates of quantitative relaxometry and diffusion tensor imaging (DTI) and to determine their efficacy in epileptogenic lesion detection for preoperative evaluation of focal epilepsy. METHODS We correlated quantitative relaxometry and DTI with histological features of neuronal density and morphology in 55 regions of the temporal lobe neocortex, selected from 13 patients who underwent epilepsy surgery. We made use of a validated nonrigid image registration protocol to obtain accurate correspondences between in vivo magnetic resonance imaging and histology images. RESULTS We found T1 to be a predictor of neuronal density in the neocortical gray matter (GM) using linear mixed effects models with random effects for subjects. Fractional anisotropy (FA) was a predictor of neuronal density of large-caliber neurons only (pyramidal cells, layers 3 and 5). Comparing multivariate to univariate mixed effects models with nested variables demonstrated that employing T1 and FA together provided a significantly better fit than T1 or FA alone in predicting density of large-caliber neurons. Correlations with clinical variables revealed significant positive correlations between neuronal density and age (rs = 0.726, pfwe = 0.021). This study is the first to relate in vivo T1 and FA values to the proportion of neurons in GM. INTERPRETATION Our results suggest that quantitative T1 mapping and DTI may have a role in preoperative evaluation of focal epilepsy and can be extended to identify GM pathology in a variety of neurological disorders.
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Affiliation(s)
- Maged Goubran
- Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; Biomedical Engineering Graduate Program, London, Ontario, Canada
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17
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Aghakhani Y, Liu X, Jette N, Wiebe S. Epilepsy surgery in patients with bilateral temporal lobe seizures: A systematic review. Epilepsia 2014; 55:1892-901. [DOI: 10.1111/epi.12856] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Yahya Aghakhani
- Department of Clinical Neurosciences; University of Calgary; Calgary Alberta Canada
| | - Xiaorong Liu
- Institute of Neuroscience and the Second Affiliated Hospital; Guangzhou Medical University; Guangzhou China
| | - Nathalie Jette
- Department of Clinical Neurosciences; University of Calgary; Calgary Alberta Canada
- Department of Community Health Sciences; Institute of Public Health and Hotchkiss Brain Institute; University of Calgary; Calgary Alberta Canada
| | - Samuel Wiebe
- Department of Clinical Neurosciences; University of Calgary; Calgary Alberta Canada
- Department of Community Health Sciences; Institute of Public Health and Hotchkiss Brain Institute; University of Calgary; Calgary Alberta Canada
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18
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Coan AC, Campos BM, Yasuda CL, Kubota BY, Bergo FPG, Guerreiro CAM, Cendes F. Frequent seizures are associated with a network of gray matter atrophy in temporal lobe epilepsy with or without hippocampal sclerosis. PLoS One 2014; 9:e85843. [PMID: 24475055 PMCID: PMC3903486 DOI: 10.1371/journal.pone.0085843] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 12/02/2013] [Indexed: 11/23/2022] Open
Abstract
Objective Patients with temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) have diffuse subtle gray matter (GM) atrophy detectable by MRI quantification analyses. However, it is not clear whether the etiology and seizure frequency are associated with this atrophy. We aimed to evaluate the occurrence of GM atrophy and the influence of seizure frequency in patients with TLE and either normal MRI (TLE-NL) or MRI signs of HS (TLE-HS). Methods We evaluated a group of 172 consecutive patients with unilateral TLE-HS or TLE-NL as defined by hippocampal volumetry and signal quantification (122 TLE-HS and 50 TLE-NL) plus a group of 82 healthy individuals. Voxel-based morphometry was performed with VBM8/SPM8 in 3T MRIs. Patients with up to three complex partial seizures and no generalized tonic-clonic seizures in the previous year were considered to have infrequent seizures. Those who did not fulfill these criteria were considered to have frequent seizures. Results Patients with TLE-HS had more pronounced GM atrophy, including the ipsilateral mesial temporal structures, temporal lobe, bilateral thalami and pre/post-central gyri. Patients with TLE-NL had more subtle GM atrophy, including the ipsilateral orbitofrontal cortex, bilateral thalami and pre/post-central gyri. Both TLE-HS and TLE-NL showed increased GM volume in the contralateral pons. TLE-HS patients with frequent seizures had more pronounced GM atrophy in extra-temporal regions than TLE-HS with infrequent seizures. Patients with TLE-NL and infrequent seizures had no detectable GM atrophy. In both TLE-HS and TLE-NL, the duration of epilepsy correlated with GM atrophy in extra-hippocampal regions. Conclusion Although a diffuse network GM atrophy occurs in both TLE-HS and TLE-NL, this is strikingly more evident in TLE-HS and in patients with frequent seizures. These findings suggest that neocortical atrophy in TLE is related to the ongoing seizures and epilepsy duration, while thalamic atrophy is more probably related to the original epileptogenic process.
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Affiliation(s)
- Ana C. Coan
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Brunno M. Campos
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Clarissa L. Yasuda
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Bruno Y. Kubota
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Felipe PG. Bergo
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Carlos AM. Guerreiro
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
| | - Fernando Cendes
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil
- * E-mail:
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19
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Coan AC, Cendes F. Understanding the spectrum of temporal lobe epilepsy: contributions for the development of individualized therapies. Expert Rev Neurother 2014; 13:1383-94. [DOI: 10.1586/14737175.2013.857604] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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20
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Coan AC, Kubota B, Bergo FPG, Campos BM, Cendes F. 3T MRI quantification of hippocampal volume and signal in mesial temporal lobe epilepsy improves detection of hippocampal sclerosis. AJNR Am J Neuroradiol 2014; 35:77-83. [PMID: 23868151 DOI: 10.3174/ajnr.a3640] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE In mesial temporal lobe epilepsy, MR imaging quantification of hippocampal volume and T2 signal can improve the sensitivity for detecting hippocampal sclerosis. However, the current contributions of these analyses for the diagnosis of hippocampal sclerosis in 3T MRI are not clear. Our aim was to compare visual analysis, volumetry, and signal quantification of the hippocampus for detecting hippocampal sclerosis in 3T MRI. MATERIALS AND METHODS Two hundred three patients with mesial temporal lobe epilepsy defined by clinical and electroencephalogram criteria had 3T MRI visually analyzed by imaging epilepsy experts. As a second step, we performed automatic quantification of hippocampal volumes with FreeSurfer and T2 relaxometry with an in-house software. MRI of 79 healthy controls was used for comparison. RESULTS Visual analysis classified 125 patients (62%) as having signs of hippocampal sclerosis and 78 (38%) as having normal MRI findings. Automatic volumetry detected atrophy in 119 (95%) patients with visually detected hippocampal sclerosis and in 10 (13%) with visually normal MR imaging findings. Relaxometry analysis detected hyperintense T2 signal in 103 (82%) patients with visually detected hippocampal sclerosis and in 15 (19%) with visually normal MR imaging findings. Considered together, volumetry plus relaxometry detected signs of hippocampal sclerosis in all except 1 (99%) patient with visually detected hippocampal sclerosis and in 22 (28%) with visually normal MR imaging findings. CONCLUSIONS In 3T MRI visually inspected by experts, quantification of hippocampal volume and signal can increase the detection of hippocampal sclerosis in 28% of patients with mesial temporal lobe epilepsy.
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Affiliation(s)
- A C Coan
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, São Paulo, Brazil
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Khan AR, Goubran M, de Ribaupierre S, Hammond RR, Burneo JG, Parrent AG, Peters TM. Quantitative relaxometry and diffusion MRI for lateralization in MTS and non-MTS temporal lobe epilepsy. Epilepsy Res 2013; 108:506-16. [PMID: 24423692 DOI: 10.1016/j.eplepsyres.2013.12.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/14/2013] [Accepted: 12/05/2013] [Indexed: 11/30/2022]
Abstract
We developed novel methodology for investigating the use of quantitative relaxometry (T1 and T2) and diffusion tensor imaging (DTI) for lateralization in temporal lobe epilepsy. Patients with mesial temporal sclerosis confirmed by pathology (N=8) and non-MTS unilateral temporal lobe epilepsy (N=6) were compared against healthy controls (N=19) using voxel-based analysis restricted to the anterior temporal lobes, and laterality indices for each MRI metric (T1, T2, fractional anisotropy (FA), mean diffusivity, axial and radial diffusivities) were computed based on the proportion of significant voxels on each side. The diffusivity metrics were the most lateralizing MRI metrics in MTS and non-MTS subsets, with significant differences also seen with FA, T1 and T2. Patient-specific multi-modal laterality indices were also computed and were shown to clearly separate the left-onset and right-onset patients. Marked differences between left-onset and right-onset patients were also observed, with left-onset patients exhibiting stronger laterality indices. Finally, neocortical abnormalities were found to be more common in the non-MTS patients. These preliminary results on a small sample size support the further investigation of quantitative MRI and multi-modal image analysis in clinical determination of seizure onset. The presence of more neocortical abnormalities in the non-MTS group suggests a role in seizure onset or propagation and motivates the investigation of more sensitive histopathological analysis to detect and delineate potentially subtle neocortical pathology.
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Affiliation(s)
- Ali R Khan
- Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada.
| | - Maged Goubran
- Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada
| | - Sandrine de Ribaupierre
- Department of Medical Biophysics, Western University, London, Ontario, Canada; Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada; Epilepsy Program, Department of Clinical Neurological Sciences, Western University & London Health Science Centre, London, Ontario, Canada
| | - Robert R Hammond
- Department of Pathology, Division of Neuropathology, Western University & London Health Science Centre, London, Ontario, Canada
| | - Jorge G Burneo
- Epilepsy Program, Department of Clinical Neurological Sciences, Western University & London Health Science Centre, London, Ontario, Canada
| | - Andrew G Parrent
- Epilepsy Program, Department of Clinical Neurological Sciences, Western University & London Health Science Centre, London, Ontario, Canada
| | - Terry M Peters
- Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; Department of Medical Biophysics, Western University, London, Ontario, Canada; Biomedical Engineering Graduate Program, Western University, London, Ontario, Canada
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Mesial temporal lobe epilepsy with no specific histological abnormality: a distinct surgically remediable syndrome. Epilepsy Behav 2013; 29:542-7. [PMID: 24207132 DOI: 10.1016/j.yebeh.2013.09.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 09/07/2013] [Accepted: 09/17/2013] [Indexed: 11/20/2022]
Abstract
PURPOSE The purposes of the study were twofold: to clarify the clinical features and surgical outcome of mesial temporal lobe epilepsy (MTLE) with no specific histological abnormality and to determine the optimal surgical strategy. METHODS Twelve patients who met the following criteria were included: (1) normal preoperative MRI; (2) intracranial EEG findings consistent with mesial temporal onset of seizures; (3) selective amygdalohippocampectomy (AHE) was performed, and the patient was followed for more than 2years postoperatively; and (4) hippocampal histopathology was nonspecific. Clinical characteristics, intracranial EEG findings, and postoperative seizure outcome were examined. These twelve patients were compared with twenty-one patients with MTLE with unilateral hippocampal sclerosis (HS) on MRI who underwent intracranial EEG before resection (control group). RESULTS In patients with MTLE with no specific histological abnormality, the age at onset was significantly higher, the history of febrile seizures was significantly less frequent, and preoperative IQ score was significantly higher than that in the control group. The proportion of patients with bitemporal independent and/or nonlateralizing seizure onset on intracranial EEG was 50% in patients with MTLE with nonspecific histopathology and was significantly higher than that in the control group. Seizure outcome was classified as Engel class I in seven patients, class II in three, class III in one, and class IV in one. Seizure outcome was favorable even in three patients with seizures originating more frequently from the side contralateral to the resected side. CONCLUSIONS Mesial temporal lobe epilepsy with no specific histological abnormality is a clinical entity distinctly different from MTLE with HS. Bitemporal independent and/or nonlateralizing seizure onset on intracranial EEG is very common. Although the presence of lateral temporal and/or extratemporal epileptogenicity should always be kept in mind, postoperative seizure outcome after AHE is favorable even in cases with bitemporal independent and/or nonlateralizing seizure onset.
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Uda T, Morino M, Ito H, Minami N, Hosono A, Nagai T, Matsumoto T. Transsylvian hippocampal transection for mesial temporal lobe epilepsy: surgical indications, procedure, and postoperative seizure and memory outcomes. J Neurosurg 2013; 119:1098-104. [DOI: 10.3171/2013.6.jns13244] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Amygdalohippocampectomy is a well-established, standard surgery for medically intractable mesial temporal lobe epilepsy (MTLE). However, in the case of MTLE without hippocampal atrophy or sclerosis, amygdalohippocampectomy is associated with decreased postoperative memory function. Hippocampal transection (HT) has been developed to overcome this problem. In HT the hippocampus is not removed; rather, the longitudinal hippocampal circuits of epileptic activities are disrupted by transection of the pyramidal layer of the hippocampus. The present study describes a less invasive modification of HT (transsylvian HT) and presents the seizure and memory outcomes for this procedure.
Methods
Thirty-seven patients with MTLE (18 men and 19 women; age range 9–63 years; 19 with surgery on the right side and 18 with surgery on the left side; seizure onset from 3 to 34 years) who were treated with transsylvian HT were retrospectively analyzed. All patients had left-side language dominance, and follow-up periods ranged from 12 to 94 months (median 49 months). Seizure outcomes were evaluated for all patients by using the Engel classification. Memory function was evaluated for 22 patients based on 3 indices (verbal memory, nonverbal memory, and delayed recall), with those scores obtained using the Wechsler Memory Scale–Revised. Patients underwent evaluation of the memory function before and after surgery (6 months–1 year).
Results
Engel Class I (completely seizure free) was achieved in 25 patients (67.6%). Class II and Class III designation was achieved in 10 (27%) and 2 patients (5.4%), respectively. There were differences in memory outcome between the sides of operation. On the right side, verbal memory significantly increased postoperatively (p = 0.003) but nonverbal memory and delayed recall showed no significant change after the operation (p = 0.718 and p = 0.210, respectively). On the left side, all 3 indices (verbal memory, nonverbal memory, and delayed recall) showed no significant change (p = 0.331, p = 0.458, and p = 0.366, respectively).
Conclusions
Favorable seizure outcome and preservation of verbal memory were achieved with transsylvian HT for the treatment of MTLE without hippocampal atrophy or sclerosis.
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Long-term surgical outcomes in patients with drug-resistant temporal lobe epilepsy and no histological abnormalities. NEUROLOGÍA (ENGLISH EDITION) 2013. [DOI: 10.1016/j.nrleng.2013.10.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Unnwongse K, Alexopoulos AV, Busch RM, Wehner T, Nair D, Bingaman WE, Najm IM. Nonlesional atypical mesial temporal epilepsy: electroclinical and intracranial EEG findings. Neurology 2013; 81:1848-55. [PMID: 24174582 DOI: 10.1212/01.wnl.0000436061.05266.dc] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Misleading manifestations of common epilepsy syndromes might account for some epilepsy surgery failures, thus we sought to characterize patients with difficult to diagnose (atypical) mesial temporal lobe epilepsy (mTLE). METHODS We retrospectively reviewed our surgical database over 12 years to identify patients who underwent a standard anterior temporal lobectomy after undergoing intracranial EEG (ICEEG) evaluation with a combination of depth and subdural electrodes. We carefully studied electroclinical manifestations, neuroimaging data, neuropsychological findings, and indications for ICEEG. RESULTS Of 835 patients who underwent anterior temporal lobectomy, 55 were investigated with ICEEG. Ten of these had atypical mTLE features and were not considered to have mTLE preoperatively. All of them had Engel class I outcome for 3 to 7 years (median 3.85). Five reported uncommon auras, and 3 had no auras. Scalp-EEG and nuclear imaging studies failed to provide adequate localization. None had MRI evidence of hippocampal sclerosis. However, ICEEG demonstrated exclusive mesial temporal seizure onset in all patients. Clues suggesting the possibility of mTLE were typical auras when present, anterior temporal epileptiform discharges or ictal patterns, small hippocampi, asymmetrical or ipsilateral temporal hypometabolism on PET, anterior temporal hyperperfusion on ictal SPECT, and asymmetry of memory scores. Histopathology revealed hippocampal sclerosis in 6 patients and gliosis in 2. CONCLUSIONS Atypical electroclinical presentation may be deceptive in some patients with mTLE. We emphasize the importance of searching for typical mTLE features to guide ICEEG study of mesial temporal structures in such patients, who may otherwise mistakenly undergo extramesial temporal resections or be denied surgery.
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Affiliation(s)
- Kanjana Unnwongse
- From the Cleveland Clinic Epilepsy Center (K.U., A.V.A., R.M.B., T.W., D.N., W.E.B., I.M.N.), Neurological Institute, Cleveland, OH; Department of Neurology (K.U.), Prasat Neurological Institute, Bangkok, Thailand; and Institute of Neurology (T.W.), University College London, UK
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Coan AC, Morita ME, de Campos BM, Yasuda CL, Cendes F. Amygdala Enlargement in Patients with Mesial Temporal Lobe Epilepsy without Hippocampal Sclerosis. Front Neurol 2013; 4:166. [PMID: 24298266 PMCID: PMC3829468 DOI: 10.3389/fneur.2013.00166] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 10/12/2013] [Indexed: 11/17/2022] Open
Abstract
Purpose: Patients with mesial temporal lobe epilepsy (MTLE) without MRI abnormalities (MTLE-NL) represent a challenge for definition of underlying pathology and for presurgical evaluation. In a recent study we observed significant amygdala enlargement (AE) in 14% of MTLE patients with MRI signs of hippocampal sclerosis. Areas of gray matter volume (GMV) increase could represent structural abnormalities related to the epileptogenic zone or part of a developmental abnormality. Our objective was to look for undetected areas of increased GMV in MTLE-NL using post processing MRI techniques to better understand the pathophysiology of this condition. Methods: We evaluated 66 patients with MTLE-NL on visual analysis and 82 controls. Voxel-based morphometry (VBM) group analysis was performed with VBM8/SPM8 looking for areas of increased GMV. We then performed automatic amygdala volumetry using FreeSurfer software and T2 relaxometry to confirm VBM findings. Results: Voxel-based morphometry group-analysis demonstrated increased amygdala volume in the MTLE-NL group compared to controls. Individual volumetric analysis confirmed AE in eight (12%) patients. Overall, from all patients with AE and defined epileptic focus, four (57%) had the predominant increased volume ipsilateral to the epileptic focus. These results were cross-validated by a secondary VBM analysis including subgroups of patients according to the volumetric data. T2 relaxometry demonstrated no amygdala hyperintense signal in any individual with significant AE. There were no clinical differences between patients with and without AE. Discussion: This exploratory study demonstrates the occurrence of AE in 12% of patients with MTLE-NL. This finding supports the hypothesis that there might be a subgroup of patients with MTLE-NL in which the enlarged amygdala could be related to the epileptogenic process. Further studies are necessary but this finding could be of great importance in the understanding of MTLE-NL.
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Affiliation(s)
- Ana Carolina Coan
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas , Campinas , Brazil
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Ver Hoef LW, Williams FB, Kennedy RE, Szaflarski JP, Knowlton RC. Predictive value of hippocampal internal architecture asymmetry in temporal lobe epilepsy. Epilepsy Res 2013; 106:155-63. [PMID: 23911210 DOI: 10.1016/j.eplepsyres.2013.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 04/13/2013] [Accepted: 05/13/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Asymmetry of hippocampal internal architecture (HIA) clarity has been suggested to be a sign of hippocampal sclerosis (HS) and is frequently associated with other MRI findings of HS. The goal of this work is to use a previously developed HIA visual scoring system (Ver Hoef et al., 2013) to quantify HIA asymmetry in a retrospective series of consecutive temporal lobe epilepsy (TLE) patients and evaluate its value in predicting laterality of seizure onset both in patients with other signs of HS (HS+) and those without (HS-). METHODS The HIA scoring system was used to rate hippocampal asymmetry and to assess the agreement between HIA and seizure lateralization. The median values of the average HIA scores for each hippocampus were compared for HS+ epileptogenic hippocampi, HS- epileptogenic hippocampi, and non-epileptogenic hippocampi with a Kruskal-Wallis one-way analysis of variance by ranks. Pair-wise differences between groups were evaluated with the two-tailed Mann-Whitney U test. A logistic regression model examined the utility of average HIA asymmetry score in predicting the true laterality of seizure onset as determined by video-EEG. Sensitivity and specificity are calculated using various asymmetry thresholds in each patient group. RESULTS Fifty-five patients were identified who met inclusion criteria. Thirteen patients (24%) were found to have hippocampal atrophy and/or signal abnormality indicative of HS (HS+) and 42 did not (HS-). Significant differences were observed in the distribution of individual and average HIA scores between each of the groups of hippocampi, with HS+ hippocampi having the lowest HIA scores and non-epileptogenic hippocampi having the highest. Logistic regression analysis showed that the average HIA asymmetry score was a strong predictor of the laterality of seizure onset (β=3.93508, p<0.001). HIA asymmetry remained significant even after adjustment for HS+/HS- status (β=3.8854, p<0.001). Among HS- patients, when the average HIA asymmetry score was equal to or exceeded a threshold value of 0.5, the specificity for correctly predicting the side of seizure onset was between 95% and 100% with a sensitivity of 40-45%. Among HS+ patients, a threshold of 0.3 yielded a sensitivity of 85% and specificity of 100%. CONCLUSIONS In this report we show for the first time that HIA asymmetry is a significant predictor of the laterality of seizure onset in TLE patients with otherwise normal MRI findings, and that the proposed HIA scoring system has high specificity and moderate sensitivity for lateralizing seizure onset in patients with TLE.
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Affiliation(s)
- Lawrence W Ver Hoef
- UAB Epilepsy Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States.
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Benedetti-Isaac JC, Torres-Zambrano M, Fandiño-Franky J, Dussán-Ordóñez J, Herrera-Trujillo A, Guerra-Olivares R, Alcalá-Cerra G. Long-term surgical outcomes in patients with drug-resistant temporal lobe epilepsy and no histological abnormalities. Neurologia 2013; 28:543-9. [PMID: 23623700 DOI: 10.1016/j.nrl.2013.01.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 10/30/2012] [Accepted: 01/22/2013] [Indexed: 11/29/2022] Open
Abstract
INTRODUCTION Reports on surgical outcomes in patients with drug-resistant temporal lobe epilepsy without histological abnormalities are scarce. METHODS Retrospective review of data from patients with drug-resistant temporal lobe epilepsy and no histopathological alterations who underwent anterior mesial temporal lobectomy. We analysed the following variables: age, sex, age at seizure onset, age at surgery, time elapsed between diagnosis and the date of the surgery, follow-up time, and classification according to the Engel rating scale. RESULTS From a database of 256 temporal lobectomies, 21 were identified as meeting the inclusion criteria. The average age upon diagnosis of epilepsy was 8.3 years and average age at time of surgery was 28.6 years. The mean time elapsed between diagnosis and surgery was 20.2 years. After a mean follow-up of 6.5 years, 90.5% of the patients showed favourable outcomes (classes i and ii) and 42.9% were seizure-free (class IA). Comparative analysis of the variables revealed that average age at seizure onset was the only statistically significant difference between groups, with age at onset being lower in patients with favourable outcomes. CONCLUSION Although long-term surgical outcomes were favourable for a large majority of patients, the percentage of seizure-free patients is lower than in patients with lesional epilepsy and comparable to that previously reported in the literature.
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Affiliation(s)
- J C Benedetti-Isaac
- Departamento de Investigación, Centro Latinoamericano de Investigación en Epilepsia (CLIE), Cartagena de Indias, Colombia.
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Wu XT, Rampp S, Buchfelder M, Kuwert T, Blümcke I, Dörfler A, Zhou D, Stefan H. Interictal magnetoencephalography used in magnetic resonance imaging-negative patients with epilepsy. Acta Neurol Scand 2013; 127:274-80. [PMID: 22882005 DOI: 10.1111/j.1600-0404.2012.01712.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2012] [Indexed: 02/05/2023]
Abstract
PURPOSE This study aims to investigate the contributions of magnetoencephalography (MEG) in magnetic resonance imaging (MRI)-negative patients. METHODS A total of 18 MRI-negative patients diagnosed with refractory epilepsy, subjected to MEG investigation, and subsequently underwent surgery were selected for retrospective analysis. A 1.5-tesla Magnetom Sonata with an eight-channel head array coil was used. MEG data were obtained using a 74/248-channel system. RESULTS A total of 16 patients (16/18) had positive MEG results, comprising 12 patients with monofocal localizations, five with multifocal localizations, and one with unremarkable results in MEG. In addition, 12 patients had indicative single photon-emission computed tomography (SPECT), five had indicative fluorodeoxyglucose positron emission tomography (FDG-PET), and all the patients had intracranial electroencephalography (EEG) (14 with subdural electrodes and four with electrocorticography). The intracranial EEG recordings of nine patients were guided by MEG informative results. Among these 18 patients, 10 exhibited good postoperative outcomes (Engel I and II), four of which were completely seizure-free. All these ten patients had clear monofocal localization in MEG, including nine with accordant indicative metabolic changes in either SPECT or FDG-PET, or both. None of the five patients with multifocal localizations achieved good postoperative outcomes. CONCLUSION For cases with negative MRI findings, epilepsy surgery may be an alternative option for pharmaco-resistant patients if epileptogenic focus localizations by MEG are present in multimodal evaluation.
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Affiliation(s)
| | - S. Rampp
- Neurological Clinic; University Hospital Erlangen; Erlangen; Germany
| | - M. Buchfelder
- Department of Neurosurgery; University Hospital Erlangen; Erlangen; Germany
| | - T. Kuwert
- Department of Nuclear medicine; University Hospital Erlangen; Erlangen; Germany
| | - I. Blümcke
- Department of Neuropathology; University Hospital Erlangen; Erlangen; Germany
| | - A. Dörfler
- Department of Neuroradiology; University Hospital Erlangen; Erlangen; Germany
| | - D. Zhou
- Department of Neurology; West China Hospital; Sichuan University; Chengdu; Sichuan; China
| | - H. Stefan
- Neurological Clinic; University Hospital Erlangen; Erlangen; Germany
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Matsubara T, Ayuzawa S, Aoki T, Fujiomto A, Osuka S, Matsumura A. The patient had a normal magnetic resonance imaging and temporal lobe epilepsy secondary to a porencephalic cyst but showed structural lesions (hippocampal sclerosis). EPILEPSY & BEHAVIOR CASE REPORTS 2013; 1:153-6. [PMID: 25667851 PMCID: PMC4150633 DOI: 10.1016/j.ebcr.2013.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 08/30/2013] [Accepted: 08/30/2013] [Indexed: 11/27/2022]
Abstract
Patients with a porencephalic cyst frequently develop intractable temporal lobe epilepsy (TLE). We report a surgically-treated male patient with intractable mesial TLE (mTLE) secondary to a porencephalic cyst. Although magnetic resonance imaging showed no hippocampal abnormalities, long-term video-electrocorticography revealed seizure onset discharges in the hippocampus. Temporal lobectomy brought an end to the patient's seizures. Hippocampal sclerosis was histopathologically confirmed (dual pathology). Careful evaluation of hippocampal epileptogenicity is required, and temporal lobectomy, which is less invasive than hemispherectomy, can be a treatment of choice for patients with mTLE secondary to a porencephalic cyst.
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Affiliation(s)
| | - Satoshi Ayuzawa
- Department of Neurosurgery, Tsukuba University Hospital, Japan ; Department of Neurosurgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan
| | - Tsukasa Aoki
- Department of Neurosurgery, Ryugasaki Saiseikai Hospital, Japan
| | - Ayataka Fujiomto
- Department of Neurosurgery, Seirei Hamamatsu General Hospital, Japan
| | - Satoru Osuka
- Department of Neurosurgery, Tsukuba University Hospital, Japan
| | - Akira Matsumura
- Department of Neurosurgery, Tsukuba University Hospital, Japan ; Department of Neurosurgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan
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Gomes WA, Shinnar S. Prospects for imaging-related biomarkers of human epileptogenesis: a critical review. Biomark Med 2012; 5:599-606. [PMID: 22003908 DOI: 10.2217/bmm.11.66] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
To facilitate the study of epileptogenesis in humans, noninvasive biomarkers of epileptogenesis are required. No validated biomarker is currently available, but brain imaging techniques provide many attractive candidates. In this article we examine the imaging features of temporal lobe epilepsy, focusing on those that may precede the onset of epilepsy and correlate with epileptogenesis. Hippocampal volumetry and T(2) relaxometry are proposed as candidate biomarkers of epileptogenesis in temporal lobe epilepsy following febrile status epilepticus. Preliminary data suggest that these have promise, and the ongoing Consequences of Prolonged Febrile Seizures in Childhood (FEBSTAT) study will provide more conclusive evidence as to their validity. At this time there are no other clear candidates for imaging-related biomarkers of epileptogenesis in human studies.
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Affiliation(s)
- William A Gomes
- Comprehensive Epilepsy Management Center, Montefiore Medical Center, 111 E. 210th St, Bronx, NY 10467, USA
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Vale FL, Effio E, Arredondo N, Bozorg A, Wong K, Martinez C, Downes K, Tatum WO, Benbadis SR. Efficacy of temporal lobe surgery for epilepsy in patients with negative MRI for mesial temporal lobe sclerosis. J Clin Neurosci 2012; 19:101-6. [DOI: 10.1016/j.jocn.2011.08.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 08/01/2011] [Accepted: 08/13/2011] [Indexed: 10/14/2022]
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Tang Y, Li Y, Luo D, Rong X, Ye J, Peng Y. Epilepsy related to radiotherapy in patients with nasopharyngeal carcinoma. Epilepsy Res 2011; 96:24-8. [DOI: 10.1016/j.eplepsyres.2011.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Revised: 04/10/2011] [Accepted: 04/24/2011] [Indexed: 10/18/2022]
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Luther N, Rubens E, Sethi N, Kandula P, Labar DR, Harden C, Perrine K, Christos PJ, Iorgulescu JB, Lancman G, Schaul NS, Kolesnik DV, Nouri S, Dawson A, Tsiouris AJ, Schwartz TH. The value of intraoperative electrocorticography in surgical decision making for temporal lobe epilepsy with normal MRI. Epilepsia 2011; 52:941-8. [PMID: 21480886 DOI: 10.1111/j.1528-1167.2011.03061.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE We hypothesized that acute intraoperative electrocorticography (ECoG) might identify a subset of patients with magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE) who could proceed directly to standard anteromesial resection (SAMR), obviating the need for chronic electrode implantation to guide resection. METHODS Patients with TLE and a normal MRI who underwent acute ECoG prior to chronic electrode recording of ictal onsets were evaluated. Intraoperative interictal spikes were classified as mesial (M), lateral (L), or mesial/lateral (ML). Results of the acute ECoG were correlated with the ictal-onset zone following chronic ECoG. Onsets were also classified as "M,""L," or "ML." Positron emission tomography (PET), scalp-EEG (electroencephalography), and Wada were evaluated as adjuncts. KEY FINDINGS Sixteen patients fit criteria for inclusion. Outcomes were Engel class I in nine patients, Engel II in two, Engel III in four, and Engel IV in one. Mean postoperative follow-up was 45.2 months. Scalp EEG and PET correlated with ictal onsets in 69% and 64% of patients, respectively. Wada correlated with onsets in 47% of patients. Acute intraoperative ECoG correlated with seizure onsets on chronic ECoG in all 16 patients. All eight patients with "M" pattern ECoG underwent SAMR, and six (75%) experienced Engel class I outcomes. Three of eight patients with "L" or "ML" onsets (38%) had Engel class I outcomes. SIGNIFICANCE Intraoperative ECoG may be useful in identifying a subset of patients with MRI-negative TLE who will benefit from SAMR without chronic implantation of electrodes. These patients have uniquely mesial interictal spikes and can go on to have improved postoperative seizure-free outcomes.
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Affiliation(s)
- Neal Luther
- Department of Neurological Surgery, Weill Cornell Medical College, New York, New York 10065, USA
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Velasco TR, Wichert-Ana L, Mathern GW, Araújo D, Walz R, Bianchin MM, Dalmagro CL, Leite JP, Santos AC, Assirati JA, Carlotti CG, Sakamoto AC. Utility of Ictal Single Photon Emission Computed Tomography in Mesial Temporal Lobe Epilepsy With Hippocampal Atrophy. Neurosurgery 2011; 68:431-6; discussion 436. [DOI: 10.1227/neu.0b013e318201c293] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
BACKGROUND:
The development of newer diagnostic technologies has reduced the need for invasive electroencephalographic (EEG) studies in identifying the epileptogenic zone, especially in adult patients with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS).
OBJECTIVE:
To evaluate ictal single photon emission computed tomography (SPECT) in the evaluation and treatment of patients with MTLE-HS.
METHODS:
MTLE patients were randomly assigned to those with (SPECT, n = 124) and without ictal SPECT (non-SPECT, n = 116) in an intent-to-treat protocol. Primary end points were the proportion of patients with invasive EEG studies, and those offered surgery. Secondary end points were the length of hospital stay and the proportion of patients with secondarily generalized seizures (SGS) during video-EEG, postsurgical seizure outcome, and hospital cost.
RESULTS:
The proportion of patients offered surgery was similar in the SPECT (85%) and non-SPECT groups (81%), as well as the proportion that had invasive EEG studies (27% vs 23%). The mean duration of hospital stay was 1 day longer for the SPECT group (P < 0.001). SGS occurred in 51% of the SPECT and 26% of the non-SPECT group (P < 0.001). The cost of the presurgical evaluation was 35% higher for the SPECT compared with the non-SPECT group (P < 0.001). The proportion of patients seizure-free after surgery was similar in the SPECT (59%) compared with non-SPECT group (54%).
CONCLUSION:
Ictal-SPECT did not add localizing value beyond what was provided by EEG-video telemetry and structural MRI that altered the surgical decision and outcome for MTLE-HS patients. Ictal-SPECT increased hospital stay was associated with increased costs and a higher chance of SGS during video-EEG monitoring. These findings support the notion that a protocol including ictal SPECT is equivalent to one without SPECT in the presurgical evaluation of adult patients with MTLE-HS.
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Affiliation(s)
| | - Lauro Wichert-Ana
- Department of Nuclear Medicine, University of São Paulo, Ribeirao Preto, Brazil
| | - Gary W. Mathern
- Department of Neurosurgery, The Intellectual and Developmental Disabilities Research Center, and The Brain Research Institute
| | - David Araújo
- Department of Radiology, University of São Paulo, Ribeirao Preto, Brazil
| | - Roger Walz
- Department of Neurology, University of São Paulo, Ribeirao Preto, Brazil
| | - Marino M. Bianchin
- Department of Neurology, University of São Paulo, Ribeirao Preto, Brazil
| | - Charles L. Dalmagro
- Department of David Geffen School of Medicine, University of California, Los Angeles, California
| | - Joao P. Leite
- Department of Neurology, University of São Paulo, Ribeirao Preto, Brazil
| | - Antonio C. Santos
- Department of Radiology, University of São Paulo, Ribeirao Preto, Brazil
| | - Joao A. Assirati
- Department of Neurosurgery, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Brazil
| | - Carlos G. Carlotti
- Department of Neurosurgery, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Brazil
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Widespread extrahippocampal NAA/(Cr+Cho) abnormalities in TLE with and without mesial temporal sclerosis. J Neurol 2010; 258:603-12. [PMID: 20976465 PMCID: PMC3065637 DOI: 10.1007/s00415-010-5799-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 09/29/2010] [Accepted: 10/07/2010] [Indexed: 12/11/2022]
Abstract
MR spectroscopy has demonstrated extrahippocampal NAA/(Cr+Cho) reductions in medial temporal lobe epilepsy with (TLE-MTS) and without (TLE-no) mesial temporal sclerosis. Because of the limited brain coverage of those previous studies, it was, however, not possible to assess differences in the distribution and extent of these abnormalities between TLE-MTS and TLE-no. This study used a 3D whole brain echoplanar spectroscopic imaging (EPSI) sequence to address the following questions: (1) Do TLE-MTS and TLE-no differ regarding severity and distribution of extrahippocampal NAA/(Cr+Cho) reductions? (2) Do extrahippocampal NAA/(Cr+Cho) reductions provide additional information for focus lateralization? Forty-three subjects (12 TLE-MTS, 13 TLE-no, 18 controls) were studied with 3D EPSI. Statistical parametric mapping (SPM2) was used to identify regions of significantly decreased NAA/(Cr+Cho) in TLE groups and in individual patients. TLE-MTS and TLE-no had widespread extrahippocampal NAA/(Cr+Cho) reductions. NAA/(Cr+Cho) reductions had a bilateral fronto-temporal distribution in TLE-MTS and a more diffuse, less well defined distribution in TLE-no. Extrahippocampal NAA/(Cr+Cho) decreases in the single subject analysis showed a large inter-individual variability and did not provide additional focus lateralizing information. Extrahippocampal NAA/(Cr+Cho) reductions in TLE-MTS and TLE-no are neither focal nor homogeneous. This reduces their value for focus lateralization and suggests a heterogeneous etiology of extrahippocampal spectroscopic metabolic abnormalities in TLE.
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Kang JQ, Shen W, Lee M, Gallagher MJ, Macdonald RL. Slow degradation and aggregation in vitro of mutant GABAA receptor gamma2(Q351X) subunits associated with epilepsy. J Neurosci 2010; 30:13895-905. [PMID: 20943930 PMCID: PMC2976503 DOI: 10.1523/jneurosci.2320-10.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Revised: 07/29/2010] [Accepted: 08/04/2010] [Indexed: 12/29/2022] Open
Abstract
The GABA(A) receptor γ2 subunit nonsense mutation Q351X has been associated with the genetic epilepsy syndrome generalized epilepsy with febrile seizures plus, which includes a spectrum of seizures types from febrile seizures to Dravet syndrome. Although most genetic epilepsy syndromes are mild and remit with age, Dravet syndrome has a more severe clinical course with refractory seizures associated with developmental delay and cognitive impairment. The basis for the broad spectrum of seizure phenotypes is uncertain. We demonstrated previously that the GABA(A) receptor γ2 subunit gene Q351X mutation suppressed biogenesis of wild-type partnering α1 and β2 subunits in addition to its loss of function. Here we show that γ2S(Q351X) subunits have an additional impairment of biogenesis. Mutant γ2(Q351X) subunits were degraded more slowly than wild-type γ2 subunits and formed SDS-resistant, high-molecular-mass complexes or aggregates in multiple cell types, including neurons. The half-life of γ2S(Q351X) subunits was ∼4 h, whereas that of γ2S subunits was ∼2 h. Mutant subunits formed complexes rapidly after synthesis onset. Using multiple truncated subunits, we demonstrated that aggregate formation was a general phenomenon for truncated γ2S subunits and that their Cys-loop cysteines were involved in aggregate formation. Protein aggregation is a hallmark of neurodegenerative diseases, but the effects of the mutant γ2S(Q351X) subunit aggregates on neuronal function and survival are unclear. Additional validation of the mutant subunit aggregation in vivo and determination of the involved signaling pathways will help reveal the pathological effects of these mutant subunit aggregates in the pathogenesis of genetic epilepsy syndromes.
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Affiliation(s)
- Jing-Qiong Kang
- Department of Neurology, Vanderbilt University Medical Center, Nashville, Tennessee 37212-8552, USA.
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Howe KL, Dimitri D, Heyn C, Kiehl TR, Mikulis D, Valiante T. Histologically confirmed hippocampal structural features revealed by 3T MR imaging: potential to increase diagnostic specificity of mesial temporal sclerosis. AJNR Am J Neuroradiol 2010; 31:1682-9. [PMID: 20538822 DOI: 10.3174/ajnr.a2154] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE With appropriate selection, temporal lobe epilepsy is potentially curable with surgical intervention achieving seizure freedom in ~80% of individuals. MR imaging-based identification of MTS remains central to the selection process but currently relies on qualitative visual analysis. We sought to determine if new ultrastructural hippocampal details seen on 3T MR imaging had histopathologic correlates and whether these could serve as a useful tool in MTS identification. MATERIALS AND METHODS Patients undergoing selective anterior temporal lobectomy (n = 5) were scanned using 3T MR imaging preoperatively. En bloc resections were rescanned and subsequently prepared for histopathologic analysis of all hippocampal layers in the CA1-3 regions. Using a newly identified landmark from 3T FSTIR coronal images in 20 patients with histologically confirmed MTS, blinded studies compared ipsilateral and contralateral sides to generate threshold measurements for application in a fast quantitative analysis tool. RESULTS Histopathologic analysis and correlation with 3T imaging of en bloc resections identified the low-intensity signal as the stratum lacunosum. MTS was associated with extensive gliosis throughout the CA1-3 regions, with loss of tissue thickness in the stratum pyramidale most pronounced in CA1. Fast quantitative analysis by using the stratum lacunosum as a landmark provided a test that identifies MTS with a SN of 70% and SP of 85%. CONCLUSIONS Here we delineated ultrastructural hippocampal details seen on 3T MR imaging in both the in vivo and ex vivo setting, correlating these with histopathologic features consistent with MTS, and provided preliminary data suggesting their utility in the development of a quantitative analysis assessment tool for application in surgical-candidate selection.
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Affiliation(s)
- K L Howe
- Department of Neurosurgery, University Health Network, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario, Canada
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Liu X, Wen F, Yang J, Chen L, Wei YQ. A review of current applications of mass spectrometry for neuroproteomics in epilepsy. MASS SPECTROMETRY REVIEWS 2010; 29:197-246. [PMID: 19598206 DOI: 10.1002/mas.20243] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The brain is unquestionably the most fascinating organ, and the hippocampus is crucial in memory storage and retrieval and plays an important role in stress response. In temporal lobe epilepsy (TLE), the seizure origin typically involves the hippocampal formation. Despite tremendous progress, current knowledge falls short of being able to explain its function. An emerging approach toward an improved understanding of the complex molecular mechanisms that underlie functions of the brain and hippocampus is neuroproteomics. Mass spectrometry has been widely used to analyze biological samples, and has evolved into an indispensable tool for proteomics research. In this review, we present a general overview of the application of mass spectrometry in proteomics, summarize neuroproteomics and systems biology-based discovery of protein biomarkers for epilepsy, discuss the methodology needed to explore the epileptic hippocampus proteome, and also focus on applications of ingenuity pathway analysis (IPA) in disease research. This neuroproteomics survey presents a framework for large-scale protein research in epilepsy that can be applied for immediate epileptic biomarker discovery and the far-reaching systems biology understanding of the protein regulatory networks. Ultimately, knowledge attained through neuroproteomics could lead to clinical diagnostics and therapeutics to lessen the burden of epilepsy on society.
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Affiliation(s)
- Xinyu Liu
- National Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, China
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Bell ML, Rao S, So EL, Trenerry M, Kazemi N, Stead SM, Cascino G, Marsh R, Meyer FB, Watson RE, Giannini C, Worrell GA. Epilepsy surgery outcomes in temporal lobe epilepsy with a normal MRI. Epilepsia 2009; 50:2053-60. [PMID: 19389144 PMCID: PMC2841514 DOI: 10.1111/j.1528-1167.2009.02079.x] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To determine the long-term efficacy of anterior temporal lobectomy for medically refractory temporal lobe epilepsy in patients with nonlesional magnetic resonance imaging (MRI). METHODS We identified a retrospective cohort of 44 patients with a nonlesional modern "seizure protocol" MRI who underwent anterior temporal lobectomy for treatment of medically refractory partial epilepsy. Postoperative seizure freedom was determined by Kaplan-Meyer survival analysis. Noninvasive preoperative diagnostic factors potentially associated with excellent surgical outcome were examined by univariate analysis in the 40 patients with follow-up of >1 year. RESULTS Engel class I outcomes (free of disabling seizures) were observed in 60% (24 of 40) patients. Preoperative factors associated with Engel class I outcome were: (1) absence of contralateral or extratemporal interictal epileptiform discharges, (2) subtraction ictal single photon emission computed tomography (SPECT) Coregistered to MRI (SISCOM) abnormality localized to the resection site, and (3) subtle nonspecific MRI findings in the mesial temporal lobe concordant to the resection. DISCUSSION In carefully selected patients with temporal lobe epilepsy and a nonlesional MRI, anterior temporal lobectomy can often render patients free of disabling seizures. This favorable rate of surgical success is likely due to the detection of concordant abnormalities that indicate unilateral temporal lobe epilepsy in patients with nonlesional MRI.
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Affiliation(s)
- Michael L. Bell
- Department of Neurology and Division of Epilepsy and Electroencephalography, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Satish Rao
- Department of Neurology and Division of Epilepsy and Electroencephalography, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Elson L. So
- Department of Neurology and Division of Epilepsy and Electroencephalography, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Max Trenerry
- Department of Neuropsychology, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Noojan Kazemi
- Department of Neurology and Division of Epilepsy and Electroencephalography, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - S. Matt Stead
- Department of Neurology and Division of Epilepsy and Electroencephalography, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Gregory Cascino
- Department of Neurology and Division of Epilepsy and Electroencephalography, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Richard Marsh
- Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Fredric B. Meyer
- Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Robert E. Watson
- Department of Radiology, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Caterina Giannini
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Gregory A. Worrell
- Department of Neurology and Division of Epilepsy and Electroencephalography, Mayo Clinic, Rochester, Minnesota, U.S.A
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Chernov MF, Ochiai T, Ono Y, Muragaki Y, Yamane F, Taira T, Maruyama T, Tanaka M, Iseki H, Kubo O, Okada Y, Hori T, Takakura K. Role of proton magnetic resonance spectroscopy in preoperative evaluation of patients with mesial temporal lobe epilepsy. J Neurol Sci 2009; 285:212-9. [PMID: 19647269 DOI: 10.1016/j.jns.2009.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 07/01/2009] [Accepted: 07/06/2009] [Indexed: 11/18/2022]
Abstract
A retrospective study was conducted for evaluation of the role of single-voxel proton magnetic resonance spectroscopy (1H-MRS) in preoperative investigation of patients with mesial temporal lobe epilepsy (MTLE). Eighteen cases, including both non-lesional and lesional MTLE, were analyzed. Selective amygdalohippocampectomy was performed in 8 cases, selective amygdalohippocampectomy combined with lesionectomy in 6 cases, lesionectomy in 3 cases, and anterior temporal lobe resection in one case. The length of follow-up varied from 24 to 71 months (median, 35 months). Before surgery, (1)H-MRS disclosed decrease of N-acetylaspartate (NAA) content (P=0.01) and more frequent (P=0.07) presence of lactate (Lac) on the side of the epileptogenic zone. Decrease of NAA content below 0.75 and/or unilateral presence of Lac provided 86% (95% CI: 68%-100%) lateralization accuracy. Metabolic parameters did not differ in subgroups with hippocampal sclerosis and brain tumors. On the long-term follow-up 12 patients (67%) were free of disabling seizures. There was a trend (P=0.05) for worse seizure outcome in cases with significant bilateral metabolic alterations characterized by predominance of choline-containing compounds' peak on 1H-MR spectra on both sides. In conclusion, 1H-MRS-detected reduction of NAA content and unilateral presence of Lac in the mesial temporal lobe structures may serve as additional diagnostic clues for lateralization of the epileptogenic zone in MTLE. Metabolic imaging has limited usefulness for differentiation of the hippocampal sclerosis and low-grade intraaxial brain tumor. Presence of significant bilateral metabolic alterations in the mesial temporal lobe structures is associated with worse postoperative seizure control.
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Affiliation(s)
- Mikhail F Chernov
- International Research and Educational Institute for Integrated Medical Sciences (IREIIMS), Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
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Morino M, Ichinose T, Uda T, Kondo K, Ohfuji S, Ohata K. Memory outcome following transsylvian selective amygdalohippocampectomy in 62 patients with hippocampal sclerosis. J Neurosurg 2009; 110:1164-9. [PMID: 19119880 DOI: 10.3171/2008.9.jns08247] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT It remains unclear whether selective amygdalohippocampectomy, an operative technique developed for use in epilepsy surgery to spare unaffected brain tissue and thus minimize the cognitive consequences of temporal lobe surgery, actually leads to a better memory outcome. The present study was performed to determine the effects of selective surgery on memory outcome in patients with intractable mesial temporal lobe epilepsy due to hippocampal sclerosis treated using transsylvian selective amygdalohippocampectomy (TSA). METHODS The study population consisted of 62 patients with left hemisphere language dominance who underwent left-(31 patients) or right-sided (31 patients) TSA. All patients underwent comprehensive neuropsychological testing before and 1 month and 1 year after unilateral TSA. Verbal Memory I, Nonverbal Memory I, Total Memory, Attention, and Delayed Recall were assessed using the Wechsler Memory Scale-Revised, whereas Verbal Memory II was assessed using the Miyake Verbal Retention Test (MVRT), and Nonverbal Memory II was assessed using the Benton Visual Retention Test. Separate repeated-measures multivariate analysis of variance (MANOVA) were performed for these intervals with memory scores. RESULTS The results of MANOVA indicated that patients who underwent right-sided TSA showed significant improvements in Verbal Memory I (preoperatively vs 1 month postoperatively, p < 0.0001; and preoperatively vs 1 year postoperatively, p = 0.0002), Nonverbal Memory I (preoperatively vs 1 month postoperatively, p = 0.0003; and preoperatively vs 1 year postoperatively, p = 0.006), and Delayed Recall (preoperatively vs 1 month postoperatively, p = 0.028) at both 1-month and 1-year follow-ups. In addition, Verbal Memory II (MVRT) was also significantly improved 1 year after surgery (p = 0.001). In the group of patients who underwent left-sided TSA, both Verbal Memory I and II were maintained at the same level 1 month after surgery, whereas the Verbal Memory I score 1 year after surgery increased with marginal significance (p = 0.074). In addition, Verbal Memory II showed significant improvement 1 year after surgery (p = 0.049). There were no significant changes in Nonverbal Memory I and II, Attention, or Delayed Recall at either the 1-month or 1-year follow-up. CONCLUSIONS Results of the present study indicated that left-sided TSA for hippocampal sclerosis tends to improve verbal memory function with the preservation of other types of memory function. Moreover, right-sided TSA for hippocampal sclerosis can lead to significant improvement in memory function, with memory improvement observed 1 month after right-sided TSA and persisting 1 year after surgery.
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Affiliation(s)
- Michiharu Morino
- Departments of Neurosurgery, Osaka City University Graduate School of Medicine, Osaka, Japan.
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Iwasaki M, Nakasato N, Suzuki H, Tominaga T. Endfolium sclerosis in temporal lobe epilepsy diagnosed preoperatively by 3-tesla magnetic resonance imaging. J Neurosurg 2009; 110:1124-6. [DOI: 10.3171/2008.11.jns081109] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A 34-year-old man presented with intractable temporal lobe epilepsy. Three-tesla magnetic resonance imaging revealed increased T2 signal intensity and volume loss limited to the CA4 region of the right hippocampus. A right anterior temporal lobectomy and amygdalohippocampectomy were performed. Histological examination of the hippocampus disclosed severe neuron loss limited to the CA4 region, consistent with the preoperative imaging, which is a pattern known as endfolium sclerosis. Close inspection of the internal hippocampal anatomy with high-field MR imaging is useful in patients with temporal lobe epilepsy, because endfolium sclerosis may be associated with less chance of seizure freedom after temporal lobectomy.
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Affiliation(s)
- Masaki Iwasaki
- 1Department of Neurosurgery and Ryogo Center, Kohnan Hospital
| | | | - Hiroyoshi Suzuki
- 2Department of Pathology and Laboratory Medicine, National Hospital Organization Sendai Medical Center; and
| | - Teiji Tominaga
- 3Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
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Hanamiya M, Korogi Y, Kakeda S, Ohnari N, Kamada K, Moriya J, Sato T, Kitajima M, Akamatsu N, Tsuji S. Partial loss of hippocampal striation in medial temporal lobe epilepsy: pilot evaluation with high-spatial-resolution T2-weighted MR imaging at 3.0 T. Radiology 2009; 251:873-81. [PMID: 19346512 DOI: 10.1148/radiol.2513080445] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To determine whether partial loss of the hippocampal striation (PLHS) at 3.0 T is more accurate than the currently accepted methods of using conventional magnetic resonance (MR) imaging to detect hippocampal sclerosis in medial temporal lobe epilepsy (MTLE). MATERIALS AND METHODS This retrospective study had institutional review board approval, and informed consent was waived. Fluid-attenuated inversion-recovery (FLAIR) MR images and T2-weighted MR images in the oblique coronal plane in 22 consecutive patients (10 men, 12 female patients; mean age, 41.0 years; range, 14-76 years) (25 hemispheres) with a clinical diagnosis of MTLE were retrospectively evaluated. Twenty-five hippocampi in 15 subjects without epilepsy were evaluated as age-matched controls. The volumes and thicknesses of the four anatomic sections of the hippocampi were quantitatively measured on the T2-weighted images. Two radiologists independently reviewed the MR imaging findings of the hippocampus regarding atrophy, abnormal signal intensity, and PLHS on each side separately, without comparing both sides. Sensitivity and specificity were calculated among the MR imaging findings. RESULTS Signal intensity abnormality on FLAIR images had a sensitivity of 36%, a specificity of 96%, and an accuracy of 66% for the diagnosis of hippocampal sclerosis. PLHS on T2-weighted MR images had a sensitivity of 76% and a specificity of 80% for the diagnosis of hippocampal sclerosis. The sensitivity for PLHS was higher than that for atrophy (44%) and abnormal signal intensity (48%) of the hippocampus on T2-weighted MR images. Although the mean volume of the hippocampus and the thickness of the hippocampal body were significantly smaller for patients with MTLE than for control subjects (P < .001 for both), there was no clear distinguishing threshold value between abnormal and normal hippocampi. CONCLUSION PLHS showed the highest sensitivity for MTLE. This MR imaging feature might improve the accuracy of the diagnosis of bilateral hippocampal sclerosis, although further research is required.
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Affiliation(s)
- Mai Hanamiya
- Department of Radiology, University of Occupational and Environmental Health School of Medicine, Iseigaoka 1-1, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
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The mortality and morbidity of febrile seizures. ACTA ACUST UNITED AC 2009; 4:610-21. [PMID: 18978801 DOI: 10.1038/ncpneuro0922] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Accepted: 09/04/2008] [Indexed: 11/08/2022]
Abstract
Approaches to the treatment and investigation of febrile seizures have changed since the main reference studies on outcomes were conducted in the 1960s and 1970s. We have, therefore, conducted a systematic review of literature from the past 15 years to see whether outcomes have also changed. We found that simple febrile seizures do not carry a risk of death, but there is a very small risk of death after complex febrile seizures (CFSs), particularly febrile status epilepticus. There is no evidence that SUDEP (sudden unexpected death in epilepsy) occurs in association with febrile seizures. The risk of later epilepsy after a febrile seizure lies between 2.0% and 7.5%, and the risk of developing epilepsy after CFSs is estimated at around 10-20%. There is no evidence of any risk of hippocampal or mesial temporal sclerosis (HS/MTS) in association with simple febrile seizures. Serial imaging has shown that HS/MTS develops in 0-25% of patients over time after prolonged febrile seizures; the range in prevalence reflects selection bias in different studies. The overall risk of HS/MTS associated with CFSs is around 3%. Approximately 40% of patients with medically refractory temporal lobe epilepsy and HS/MTS on neuroimaging have a history of febrile seizures.
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Badawy RAB, Harvey AS, Macdonell RAL. Cortical hyperexcitability and epileptogenesis: Understanding the mechanisms of epilepsy - part 2. J Clin Neurosci 2009; 16:485-500. [PMID: 19230676 DOI: 10.1016/j.jocn.2008.10.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 10/03/2008] [Indexed: 12/19/2022]
Abstract
Epilepsy encompasses a diverse group of seizure disorders caused by a variety of structural, cellular and molecular alterations of the brain primarily affecting the cerebral cortex, leading to recurrent unprovoked epileptic seizures. In this two-part review we examine the mechanisms underlying normal neuronal function and those predisposing to recurrent epileptic seizures starting at the most basic cellular derangements (Part 1, Volume 16, Issue 3) and working up to the highly complex epileptic networks and factors that modulate the predisposition to seizures (Part 2). We attempt to show that multiple factors can modify the epileptic process and that different mechanisms underlie different types of epilepsy, and in most situations there is an interplay between multiple genetic and environmental factors.
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Affiliation(s)
- Radwa A B Badawy
- Department of Neurology, Austin Health, Heidelberg, Victoria, Australia
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Blount JP, Cormier J, Kim H, Kankirawatana P, Riley KO, Knowlton RC. Advances in intracranial monitoring. Neurosurg Focus 2008; 25:E18. [DOI: 10.3171/foc/2008/25/9/e18] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Intracranial monitoring using electroencephalography (IC-EEG) continues to play a critical role in the assessment of patients with medically intractable localization-related epilepsy. There has been minimal change in grid or electrode design in the last 15–20 years, and the surgical approaches for implantation are unchanged. Intracranial monitoring using EEG allows detailed definition of the region of ictal onset and defines the epileptogenic zone, particularly with regard to adjacent potentially eloquent tissue. Recent developments of IC-EEG include the coregistration of functional imaging data such as magnetoencephalography to the frameless navigation systems. Despite significant inherent limitations that are often overlooked, IC-EEG remains the gold standard for localization of the epileptogenic cortex. Intracranial electrodes take a variety of different forms and may be placed either in the subdural (subdural strips and grids, depth electrodes) or extradural spaces (sphenoidal, peg, and epidural electrodes). Each form has its own advantages and shortcomings but extensive subdural implantation of electrodes is most common and is most comprehensively discussed. The indications for intracranial electrodes are reviewed.
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Affiliation(s)
| | | | - Hyunmi Kim
- 1Comprehensive Epilepsy Center,
- 3Pediatric Neurology, and
| | | | | | - Robert C. Knowlton
- 1Comprehensive Epilepsy Center,
- 4Department of Neurology, University of Alabama at Birmingham, Alabama
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Bartolomei F, Chauvel P, Wendling F. Epileptogenicity of brain structures in human temporal lobe epilepsy: a quantified study from intracerebral EEG. Brain 2008; 131:1818-30. [PMID: 18556663 DOI: 10.1093/brain/awn111] [Citation(s) in RCA: 445] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Williamson A, Patrylo PR. Physiological studies of human dentate granule cells. PROGRESS IN BRAIN RESEARCH 2008; 163:183-98. [PMID: 17765719 DOI: 10.1016/s0079-6123(07)63011-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The availability of human hippocampi obtained through surgery (usually for treatment of temporal lobe epilepsy) has allowed us to investigate the properties of the human dentate in a way that cannot be done with other brain regions. The dentate has been the primary focus of these studies because of its relative preservation in all patient specimens. Moreover, there is extensive synaptic reorganization of numerous neurotransmitter systems in this the fascia dentate (dentate gyrus and the hilus) in humans with specific forms of TLE. These changes are not evident in tissue from patients with seizure that begin outside the hippocampus, and, as a result, this tissue provides an invaluable resource for comparisons. Physiological data using both slices and acutely dissociated cells demonstrate that the granule cells have membrane properties similar to those of rodents although there are specific changes that appear to be associated with seizures. Similarly, in the non-sclerotic hippocampi, the synaptic properties are similar to those reported in rodents. There are also a number of parallels between the findings in humans and in status animal models of temporal lobe epilepsy. This review will cover analyses of membrane properties as well as of glutamatergic, GABAergic, and neuromodulatory systems. Thus, while there are a number of issues that invariably arise with studies of pathological human tissue, this tissue is ideally suited to verify and refine animal models of temporal lobe epilepsy. In addition, one can argue that human tissue provides the only resource to evaluate the ways that granule cells recorded from laboratory animals approximate human granule cell physiology.
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Affiliation(s)
- Anne Williamson
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT 06518, USA.
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