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Siadat MR, Elisevich K, Soltanian-Zadeh H, Eetemadi A, Smith B. Curvature analysis of perisylvian epilepsy. Acta Neurol Belg 2023; 123:2303-2313. [PMID: 37368146 DOI: 10.1007/s13760-023-02238-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 03/10/2023] [Indexed: 06/28/2023]
Abstract
PURPOSE We assess whether alterations in the convolutional anatomy of the deep perisylvian area (DPSA) might indicate focal epileptogenicity. MATERIALS AND METHODS The DPSA of each hemisphere was segmented on MRI and a 3D gray-white matter interface (GWMI) geometrical model was constructed. Comparative visual and quantitative assessment of the convolutional anatomy of both the left and right DPSA models was performed. Both the density of thorn-like contours (peak percentage) and coarse interface curvatures was computed using Gaussian curvature and shape index, respectively. The proposed method was applied to a total of 14 subjects; 7 patients with an epileptogenic DPSA and 7 non-epileptic subjects. RESULTS A high peak percentage correlated well with the epileptogenic DPSA. It distinguished between patients and non-epileptic subjects (P = 0.029) and identified laterality of the epileptic focus in all but one case. A diminished regional curvature also identified epileptogenicity (P = 0.016) and, moreover, its laterality (P = 0.001). CONCLUSION An increased peak percentage from a global view of the GWMI of the DPSA provides some indication of a propensity toward a focal or regional DPSA epileptogenicity. A diminished convolutional anatomy (i.e., smoothing effect) appears also to coincide with the epileptogenic site in the DPSA and to distinguish laterality.
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Affiliation(s)
- Mohammad-Reza Siadat
- Department of Computer Science and Engineering, Oakland University, 115 Library Dr., #540, Rochester, MI, 48309, USA.
| | - Kost Elisevich
- Department of Surgery, Michigan State University, East Lansing, MI, 48824, USA
| | - Hamid Soltanian-Zadeh
- Department of Diagnostic Radiology, Henry Ford Health System, Detroit, MI, 48202, USA
| | - Ameen Eetemadi
- Department of Computer Science, University of California, Davis, CA, 95616, USA
| | - Brien Smith
- Department of Neurosurgery, Ohio Health, Columbus, OH, 43228, USA
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2
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Achiriloaie A, Deisch J, Boling W, Bannout F. Striking MRI Changes of Focal Cortical Dysplasia Over Time: A Case Series and Literature Review. Neurol Clin Pract 2021; 11:445-451. [PMID: 34840871 DOI: 10.1212/cpj.0000000000001019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 10/28/2020] [Indexed: 11/15/2022]
Abstract
Purpose of Review Brain MRI findings of focal cortical dysplasia (FCD) can undergo dramatic changes over time, which may be related to long-term epilepsy or a combination of histopathologic changes that necessitate further investigation. Recent Findings We describe 2 cases of FCD type IIb that initially displayed inconspicuous findings on MRI, however progressed to obvious signal changes on subsequent MRI 10-17 years later. Pathologic analysis indicates that the interval changes are likely attributed to reactive astrogliosis and diffuse parenchymal rarefaction. A few case reports and case series showing similar MRI changes have been described in the literature, the majority in pediatric patients. The adult cases we present add to the scientific evidence of these changes occurring in the adult population. Summary Our observations lead to several clinical suggestions, including closer interval follow-up imaging for nonlesional cases, the addition of postprocessing imaging methods, earlier surgical intervention, and meticulous surgical planning.
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Affiliation(s)
- Adina Achiriloaie
- Loma Linda University Medical Center (AA), Department of Radiology, Loma Linda, CA; Loma Linda University Medical Center (JD), Department of Pathology, Loma Linda, CA; Loma Linda University Medical Center (WB), Department of Neurosurgery, Loma Linda, CA; and Loma Linda University Medical Center (FB), Department of Neurology, Loma Linda, CA
| | - Jeremy Deisch
- Loma Linda University Medical Center (AA), Department of Radiology, Loma Linda, CA; Loma Linda University Medical Center (JD), Department of Pathology, Loma Linda, CA; Loma Linda University Medical Center (WB), Department of Neurosurgery, Loma Linda, CA; and Loma Linda University Medical Center (FB), Department of Neurology, Loma Linda, CA
| | - Warren Boling
- Loma Linda University Medical Center (AA), Department of Radiology, Loma Linda, CA; Loma Linda University Medical Center (JD), Department of Pathology, Loma Linda, CA; Loma Linda University Medical Center (WB), Department of Neurosurgery, Loma Linda, CA; and Loma Linda University Medical Center (FB), Department of Neurology, Loma Linda, CA
| | - Firas Bannout
- Loma Linda University Medical Center (AA), Department of Radiology, Loma Linda, CA; Loma Linda University Medical Center (JD), Department of Pathology, Loma Linda, CA; Loma Linda University Medical Center (WB), Department of Neurosurgery, Loma Linda, CA; and Loma Linda University Medical Center (FB), Department of Neurology, Loma Linda, CA
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3
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Surgical Outcome in Extratemporal Epilepsies Based on Multimodal Pre-Surgical Evaluation and Sequential Intraoperative Electrocorticography. Behav Sci (Basel) 2021; 11:bs11030030. [PMID: 33806277 PMCID: PMC7998314 DOI: 10.3390/bs11030030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 01/28/2023] Open
Abstract
Objective: to present the postsurgical outcome of extratemporal epilepsy (ExTLE) patients submitted to preoperative multimodal evaluation and intraoperative sequential electrocorticography (ECoG). Subjects and methods: thirty-four pharmaco-resistant patients with lesional and non-lesional ExTLE underwent comprehensive pre-surgical evaluation including multimodal neuroimaging such as ictal and interictal perfusion single photon emission computed tomography (SPECT) scans, subtraction of ictal and interictal SPECT co-registered with magnetic resonance imaging (SISCOM) and electroencephalography (EEG) source imaging (ESI) of ictal epileptic activity. Surgical procedures were tailored by sequential intraoperative ECoG, and absolute spike frequency (ASF) was calculated in the pre- and post-resection ECoG. Postoperative clinical outcome assessment for each patient was carried out one year after surgery using Engel scores. Results: frontal and occipital resection were the most common surgical techniques applied. In addition, surgical resection encroaching upon eloquent cortex was accomplished in 41% of the ExTLE patients. Pre-surgical magnetic resonance imaging (MRI) did not indicate a distinct lesion in 47% of the cases. In the latter number of subjects, SISCOM and ESI of ictal epileptic activity made it possible to estimate the epileptogenic zone. After one- year follow up, 55.8% of the patients was categorized as Engel class I–II. In this study, there was no difference in the clinical outcome between lesional and non lesional ExTLE patients. About 43.7% of patients without lesion were also seizure- free, p = 0.15 (Fischer exact test). Patients with satisfactory seizure outcome showed lower absolute spike frequency in the pre-resection intraoperative ECoG than those with unsatisfactory seizure outcome, (Mann– Whitney U test, p = 0.005). Conclusions: this study has shown that multimodal pre-surgical evaluation based, particularly, on data from SISCOM and ESI alongside sequential intraoperative ECoG, allow seizure control to be achieved in patients with pharmacoresistant ExTLE epilepsy.
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Arévalo-Astrada M, McLachlan RS, Suller-Marti A, Parrent AG, MacDougall KW, Mirsattari SM, Diosy D, Steven DA, Burneo JG. All that glitters: Contribution of stereo-EEG in patients with lesional epilepsy. Epilepsy Res 2021; 170:106546. [PMID: 33422972 DOI: 10.1016/j.eplepsyres.2020.106546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 12/05/2020] [Accepted: 12/28/2020] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To determine the contribution of stereo-EEG for localization purpose in patients with a visible lesion on MRI. BACKGROUND Intracranial EEG is often used to localize the epileptogenic focus in patients with non-lesional focal epilepsy. Its role in cases where a lesion is visible on MRI can be even more complex and the relationship between the lesion and the seizure onset has rarely been addressed. METHODS All consecutive patients between February 2013 and May 2018 who underwent stereo-EEG and had a lesion visible on MRI were included. We assessed the localization of the seizure onset and its relationship with the lesion. Clinical, radiological, and electrographic analyses were performed. RESULTS Stereo-EEG revealed a seizure onset with either partial or no overlap with the lesion seen on MRI in 42 (56 %) of the 75 lesions included. Mesial temporal sclerosis was the only lesion type associated with an exclusively lesional seizure onset (p = 0.003). CONCLUSION Epilepsy surgery in MRI-positive cases should rely not only the results of lesions seen on MRI, which might be potentially misleading; SEEG is a gold standard method in these cases to define resective borders.
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Affiliation(s)
- Miguel Arévalo-Astrada
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Richard S McLachlan
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Ana Suller-Marti
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Andrew G Parrent
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Keith W MacDougall
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Seyed M Mirsattari
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - David Diosy
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - David A Steven
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Jorge G Burneo
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Neuro-Epidemiology Unit, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
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5
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Bonini F, McGonigal A, Scavarda D, Carron R, Régis J, Dufour H, Péragut JC, Laguitton V, Villeneuve N, Chauvel P, Giusiano B, Trébuchon A, Bartolomei F. Predictive Factors of Surgical Outcome in Frontal Lobe Epilepsy Explored with Stereoelectroencephalography. Neurosurgery 2019; 83:217-225. [PMID: 28673029 DOI: 10.1093/neuros/nyx342] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 05/20/2017] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Resective surgery established treatment for pharmacoresistant frontal lobe epilepsy (FLE), but seizure outcome and prognostic indicators are poorly characterized and vary between studies. OBJECTIVE To study long-term seizure outcome and identify prognostic factors. METHODS We retrospectively analyzed 42 FLE patients having undergone surgical resection, mostly preceded by invasive recordings with stereoelectroencephalography (SEEG). Postsurgical outcome up to 10-yr follow-up and prognostic indicators were analyzed using Kaplan-Meier analysis and multivariate and conditional inference procedures. RESULTS At the time of last follow-up, 57.1% of patients were seizure-free. The estimated chance of seizure freedom was 67% (95% confidence interval [CI]: 54-83) at 6 mo, 59% (95% CI: 46-76) at 1 yr, 53% (95% CI: 40-71) at 2 yr, and 46% (95% CI: 32-66) at 5 yr. Most relapses (83%) occurred within the first 12 mo. Multivariate analysis showed that completeness of resection of the epileptogenic zone (EZ) as defined by SEEG was the main predictor of seizure outcome. According to conditional inference trees, in patients with complete resection of the EZ, focal cortical dysplasia as etiology and focal EZ were positive prognostic indicators. No difference in outcome was found in patients with positive vs negative magnetic resonance imaging. CONCLUSION Surgical resection in drug-resistant FLE can be a successful therapeutic approach, even in the absence of neuroradiologically visible lesions. SEEG may be highly useful in both nonlesional and lesional FLE cases, because complete resection of the EZ as defined by SEEG is associated with better prognosis.
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Affiliation(s)
- Francesca Bonini
- APHM, Timone Hospital, Clinical Ne-urophysiology and Epileptology De-partment, Marseille, France.,Aix-Mar-seille Université, Institut de Neuroscience des Systèmes, INSERM UMR_S 1106, Marseille, France
| | - Aileen McGonigal
- APHM, Timone Hospital, Clinical Ne-urophysiology and Epileptology De-partment, Marseille, France.,Aix-Mar-seille Université, Institut de Neuroscience des Systèmes, INSERM UMR_S 1106, Marseille, France
| | - Didier Scavarda
- APHM, Timone Hospital, Paedia-tric Neurosurgery Department, Marse-ille, France
| | - Romain Carron
- APHM, Timone Hospital, Functional and Stereotactical Neuro-surgery Department, Marseille, France
| | - Jean Régis
- APHM, Timone Hospital, Functional and Stereotactical Neuro-surgery Department, Marseille, France
| | - Henry Dufour
- APHM, Timone Hospital, Neurosurgery Department, Marseille, France
| | - Jean-Claude Péragut
- APHM, Timone Hospital, Functional and Stereotactical Neuro-surgery Department, Marseille, France
| | | | - Nathalie Villeneuve
- Hôpital Henri Gastaut, Marseille, France.,Service de Neuropédiatrie, Assistance Publique des Hôpitaux de Marseille, Marseille, France
| | - Patrick Chauvel
- APHM, Timone Hospital, Clinical Ne-urophysiology and Epileptology De-partment, Marseille, France.,Aix-Mar-seille Université, Institut de Neuroscience des Systèmes, INSERM UMR_S 1106, Marseille, France
| | - Bernard Giusiano
- Aix-Mar-seille Université, Institut de Neuroscience des Systèmes, INSERM UMR_S 1106, Marseille, France
| | - Agnès Trébuchon
- APHM, Timone Hospital, Clinical Ne-urophysiology and Epileptology De-partment, Marseille, France.,Aix-Mar-seille Université, Institut de Neuroscience des Systèmes, INSERM UMR_S 1106, Marseille, France
| | - Fabrice Bartolomei
- APHM, Timone Hospital, Clinical Ne-urophysiology and Epileptology De-partment, Marseille, France.,Aix-Mar-seille Université, Institut de Neuroscience des Systèmes, INSERM UMR_S 1106, Marseille, France
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6
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Kasper BS, Rössler K, Hamer HM, Dörfler A, Blümcke I, Coras R, Roesch J, Mennecke A, Wellmer J, Sommer B, Lorber B, Lang JD, Graf W, Stefan H, Schwab S, Buchfelder M, Rampp S. Coregistrating magnetic source and magnetic resonance imaging for epilepsy surgery in focal cortical dysplasia. Neuroimage Clin 2018; 19:487-496. [PMID: 29984157 PMCID: PMC6029564 DOI: 10.1016/j.nicl.2018.04.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 04/18/2018] [Accepted: 04/28/2018] [Indexed: 11/29/2022]
Abstract
Background Epilepsy surgery for focal cortical dysplasia type II (FCD II) offers good chances for seizure freedom, but remains a challenge with respect to lesion detection, defining the epileptogenic zone and the optimal resection strategy. Integrating results from magnetic source imaging from magnetoencephalography (MEG) with magnetic resonance imaging (MRI) including MRI postprocessing may be useful for optimizing these goals. Methods We here present data from 21 adult FCD II patients, investigated during a 10 year period and evaluated including magnetic source imaging. 16 patients had epilepsy surgery, i.e. histopathologically verified FCD II, and a long follow up. We present our analysis of epileptogenic zones including MEG in relation to structural data according to MRI data and relate these results to surgical outcomes. Results FCD II in our cohort was characterized by high MEG yield and localization accuracy and MEG showed impact on surgical success-rates. MEG source localizations were detected in 95.2% of patients and were as close as 12.3 ± 8,1 mm to the MRI-lesion. After a mean follow up of >3 years, we saw >80% Engel I outcomes, with more favourable outcomes when the MEG source was completely resected (Fishers exact test 0,033). Conclusion We argue for a high value of conducting a combined MEG-MRI approach in the presurgical workup and the resection strategy in patients with FCD II related epilepsy.
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Affiliation(s)
- Burkhard S Kasper
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Karl Rössler
- Department of Neurosurgery, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Hajo M Hamer
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Arnd Dörfler
- Department of Neuroradiology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Ingmar Blümcke
- Department of Neuropathology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Roland Coras
- Department of Neuropathology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Julie Roesch
- Department of Neuroradiology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Angelika Mennecke
- Department of Neuroradiology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Jörg Wellmer
- Ruhr-Epileptology, University Hospital Knappschaftskrankenhaus, Ruhr-University Bochum, In der Schornau 23-25, Germany.
| | - Björn Sommer
- Department of Neurosurgery, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Bogdan Lorber
- Department of Neurology, University Medical Centre Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia.
| | - Johannes D Lang
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Wolfgang Graf
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Hermann Stefan
- Epilepsy Center, Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Stefan Schwab
- Department of Neurology, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Michael Buchfelder
- Department of Neurosurgery, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
| | - Stefan Rampp
- Department of Neurosurgery, Friedrich Alexander-University Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen, Germany.
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Abstract
INTRODUCTION There is growing awareness that reflex epileptic seizures offer unique insight into natural seizure generation in humans. In the last years, focus has mostly been on reflex seizures in generalized epilepsies whereas a comprehensive review of their role in focal epilepsies has been missing. Areas covered: This paper reviews reflex seizures strictly in focal epilepsies, not including focal reflex seizures in system epilepsies that also exist. They were categorized according to their triggers which can be sensory or cognitive, simple or complex. Numerous diverse conditions exist some of which are much better investigated than others. They required separate individual literature search in PubMed. Where recent review papers exist, it refers to these, but several conditions have never been reviewed, and here it refer to and discusses original reports. Miscellaneous case reports were only exceptionally included when they contributed aspects otherwise missing. Expert commentary: Research on focal reflex seizures with advanced methods of imaging and neurophysiology to elucidate mechanisms of focal ictogenesis will probably be rapidly increasing and will soon provide much new insight. Sensory and cognitive inhibition, i.e. the counterpart of reflex ictogenesis, is promising but needs more structured and controlled research to establish robust therapeutic approaches.
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Affiliation(s)
- Rūta Mameniškienė
- a Department of Neurology, Institute of Clinical Medicine , Center for Neurology, Vilnius University , Vilnius , Lithuania
| | - Peter Wolf
- b Danish Epilepsy Centre , Dianalund , Denmark.,c Serviço de Neurologia, Departamento de Clínica Médica , Hospital Universitário, Universidade Federal de Santa Catarina (UFSC) , Florianópolis , SC , Brazil
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8
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Maillard LG, Tassi L, Bartolomei F, Catenoix H, Dubeau F, Szurhaj W, Kahane P, Nica A, Marusic P, Mindruta I, Chassoux F, Ramantani G. Stereoelectroencephalography and surgical outcome in polymicrogyria-related epilepsy: A multicentric study. Ann Neurol 2017; 82:781-794. [PMID: 29059488 DOI: 10.1002/ana.25081] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 12/22/2022]
Abstract
OBJECTIVE We aimed to (1) assess the concordance between various polymicrogyria (PMG) types and the associated epileptogenic zone (EZ), as defined by stereoelectroencephalography (SEEG), and (2) determine the postsurgical seizure outcome in PMG-related drug-resistant epilepsy. METHODS We retrospectively analyzed 58 cases: 49 had SEEG and 39 corticectomy or hemispherotomy. RESULTS Mean age at SEEG or surgery was 28.3 years (range, 2-50). PMG was bilateral in 9 (16%) patients and unilateral in 49, including 17 (29%) unilobar, 12 (21%) multilobar, 15 (26%) perisylvian, and only 5 (9%) hemispheric. Twenty-eight (48%) patients additionally had schizencephaly, heterotopia, or focal cortical dysplasia. The SEEG-determined EZ was fully concordant with the PMG in only 8 (16%) cases, partially concordant in 74%, and discordant in 10%. The EZ included remote cortical areas in 21 (43%) cases and was primarily localized in those in 5 (10%), all related to the mesial temporal structures. All but 1 PMG patient with corticectomy or hemispherotomy had a unilateral PMG. At last follow-up (mean, 4.6 years; range, 1-16), 28 (72%) patients remained seizure free. Shorter epilepsy duration to surgery was an independent predictor of seizure freedom. INTERPRETATION PMG-related drug-resistant epilepsy warrants a comprehensive presurgical evaluation, including SEEG investigations in most cases, given that the EZ may only partially overlap with the PMG or include solely remote cortical areas. Seizure freedom is feasible in a large proportion of patients. PMG extent should not deter from exploring the possibility of epilepsy surgery. Our data support the early consideration of epilepsy surgery in this patient group. Ann Neurol 2017;82:781-794.
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Affiliation(s)
- Louis Georges Maillard
- Research Center for Automatic Control of Nancy (CRAN), University of Lorraine, CNRS, UMR 7039, Vandoeuvre, France.,Department of Neurology, Central University Hospital (CHU) Nancy, Nancy, France.,Medical Faculty, University of Lorraine, Nancy, France
| | - Laura Tassi
- "Claudio Munari" Epilepsy Surgery Centre, Niguarda Hospital, Milan, Italy
| | - Fabrice Bartolomei
- Aix Marseille University, Institute of Systems Neuroscience, Marseille, France.,AP-HM, Hospital de la Timone, Department of Clinical Neurophysiology, Marseille, France
| | - Hélène Catenoix
- Functional Neurology and Epileptology Department, Pierre Wertheimer Neurological Hospital, Lyon, France
| | - François Dubeau
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Québec, Canada
| | - William Szurhaj
- Epilepsy Unit, Lille University Medical Centre, Lille, France.,INSERM U1171, University of Lille, France
| | - Philippe Kahane
- Department of Neurology, Central University Hospital, Grenoble, France.,INSERM U1216, Grenoble Neuroscience Institute, Grenoble, France.,University Grenoble Alpes, Grenoble, France
| | - Anca Nica
- Neurology Department, CHU, Rennes, France.,INSERM, U1099, Rennes, France
| | - Petr Marusic
- Department of Neurology, 2nd Faculty of Medicine, Charles University, Motol University Hospital, Prague, Czech Republic
| | - Ioana Mindruta
- Department of Neurology, University Emergency Hospital, Bucharest, Romania.,Department of Neurology, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | | | - Georgia Ramantani
- Research Center for Automatic Control of Nancy (CRAN), University of Lorraine, CNRS, UMR 7039, Vandoeuvre, France.,Child Neurology, University Children's Hospital, Zurich, Switzerland.,Swiss Epilepsy Center, Zurich, Switzerland
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9
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Pizzo F, Roehri N, Catenoix H, Medina S, McGonigal A, Giusiano B, Carron R, Scavarda D, Ostrowsky K, Lepine A, Boulogne S, Scholly J, Hirsch E, Rheims S, Bénar CG, Bartolomei F. Epileptogenic networks in nodular heterotopia: A stereoelectroencephalography study. Epilepsia 2017; 58:2112-2123. [DOI: 10.1111/epi.13919] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2017] [Indexed: 01/06/2023]
Affiliation(s)
- Francesca Pizzo
- Inserm; Institut de Neurosciences des Systèmes (INS); Aix Marseille Univ; Marseille France
| | - Nicolas Roehri
- Inserm; Institut de Neurosciences des Systèmes (INS); Aix Marseille Univ; Marseille France
| | - Hélène Catenoix
- Department of Functional Neurology and Epileptology; Hospices Civils de Lyon (Lyon University Hospital); Hospital for Neurology and Neurosurgery Pierre Wertheimer; Lyon France
| | - Samuel Medina
- Inserm; Institut de Neurosciences des Systèmes (INS); Aix Marseille Univ; Marseille France
| | - Aileen McGonigal
- Inserm; Institut de Neurosciences des Systèmes (INS); Aix Marseille Univ; Marseille France
- Clinical Neurophysiology; APHM; Timone Hospital; Marseille France
| | - Bernard Giusiano
- Inserm; Institut de Neurosciences des Systèmes (INS); Aix Marseille Univ; Marseille France
| | - Romain Carron
- Inserm; Institut de Neurosciences des Systèmes (INS); Aix Marseille Univ; Marseille France
- Functional and Stereotactic Neurosurgery; APHM; Timone Hospital; Marseille France
| | - Didier Scavarda
- Inserm; Institut de Neurosciences des Systèmes (INS); Aix Marseille Univ; Marseille France
- Functional and Stereotactic Neurosurgery; APHM; Timone Hospital; Marseille France
| | - Karine Ostrowsky
- Department of Functional Neurology and Epileptology; Hospices Civils de Lyon (Lyon University Hospital); Hospital for Neurology and Neurosurgery Pierre Wertheimer; Lyon France
| | - Anne Lepine
- Pediatric Neurology Department; Timone Hospital; APHM; Marseille France
| | - Sébastien Boulogne
- Department of Functional Neurology and Epileptology; Hospices Civils de Lyon (Lyon University Hospital); Hospital for Neurology and Neurosurgery Pierre Wertheimer; Lyon France
| | - Julia Scholly
- Medical and Surgical Epilepsy Unit; Hautepierre Hospital; University of Strasbourg; Strasbourg France
| | - Edouard Hirsch
- Medical and Surgical Epilepsy Unit; Hautepierre Hospital; University of Strasbourg; Strasbourg France
| | - Sylvain Rheims
- Department of Functional Neurology and Epileptology; Hospices Civils de Lyon (Lyon University Hospital); Hospital for Neurology and Neurosurgery Pierre Wertheimer; Lyon France
| | - Christian-George Bénar
- Inserm; Institut de Neurosciences des Systèmes (INS); Aix Marseille Univ; Marseille France
| | - Fabrice Bartolomei
- Inserm; Institut de Neurosciences des Systèmes (INS); Aix Marseille Univ; Marseille France
- Clinical Neurophysiology; APHM; Timone Hospital; Marseille France
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The relationship between morphological lesion, magnetic source imaging, and intracranial stereo-electroencephalography in focal cortical dysplasia. NEUROIMAGE-CLINICAL 2017; 15:71-79. [PMID: 28491494 PMCID: PMC5412109 DOI: 10.1016/j.nicl.2017.04.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 04/14/2017] [Accepted: 04/18/2017] [Indexed: 02/08/2023]
Abstract
Magnetoencephalography (MEG) is a useful non-invasive technique for presurgical evaluation of focal cortical dysplasia patients. We aimed at clarifying the precise spatial relationship between the spiking volume determined with MEG, the seizure onset zone and the lesional volume in patients with focal cortical dysplasia. We studied the spatial relationships between the MEG spiking volume determined with a recent analysis pipeline, the seizure-onset zone location determined with a quantitative index calculated from intracranial EEG signals (‘Epileptogenicity Index’) and the lesional volume delineated on brain MRI in 11 patients with Focal Cortical Dysplasia explored with Stereo-electroencephalography (SEEG). A significant correlation between the MEG spiking activity and the Epileptogenicity Index was found in 8/11 patients. 7/8 patients were operated upon and had good surgical outcome. For three patients, no correlation between Epileptogenicity Index and spiking activity was observed; only one of those three patients had good surgical outcome. The lesion was at least partially overlapping with the seizure-onset zone in 8/9 patients with a lesion clearly identifiable by MRI. However, 57% of the SEEG epileptogenic contacts were located outside of the lesional volume. Lastly 44% of the highly epileptogenic SEEG contacts were located within the spiking volume and 22% of them were located exclusively in the spiking volume and not in the lesion. For 7/9 patients with a lesion, < 50% of epileptogenic SEEG contacts were included within the lesion: for 5/7 patients MEG provided an added value for targeting the epileptogenic region through intracranial electrodes, while for two of seven patients MEG detected only a few extralesional epileptogenic contacts. Our study suggests that modeling of the spiking volume with MEG is a promising tool to localize non-invasively the seizure-onset zone in patients with focal cortical dysplasia. Combined with brain MRI, MEG modeling of the spiking volume contributes to delineate the spatial extent of the seizure-onset zone. This study investigates the relationship between the seizure focus, the lesion and the MEG spikes in Focal Cortical Dysplasia (FCD). The lesion, the seizure-onset zone and the MEG spiking volumes in FCD patients are largely co-extensive brain regions. MEG is helpful to disclose epileptogenic areas remote from the lesion. MEG is complementary to MRI to estimate the full extent of the SOZ in patients with FCD.
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Abdijadid S, Mathern GW, Levine MS, Cepeda C. Basic mechanisms of epileptogenesis in pediatric cortical dysplasia. CNS Neurosci Ther 2014; 21:92-103. [PMID: 25404064 DOI: 10.1111/cns.12345] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/29/2014] [Accepted: 10/03/2014] [Indexed: 12/25/2022] Open
Abstract
Cortical dysplasia (CD) is a neurodevelopmental disorder due to aberrant cell proliferation and differentiation. Advances in neuroimaging have proven effective in early identification of the more severe lesions and timely surgical removal to treat epilepsy. However, the exact mechanisms of epileptogenesis are not well understood. This review examines possible mechanisms based on anatomical and electrophysiological studies. CD can be classified as CD type I consisting of architectural abnormalities, CD type II with the presence of dysmorphic cytomegalic neurons and balloon cells, and CD type III which occurs in association with other pathologies. Use of freshly resected brain tissue has allowed a better understanding of basic mechanisms of epileptogenesis and has delineated the role of abnormal cells and synaptic activity. In CD type II, it was demonstrated that balloon cells do not initiate epileptic activity, whereas dysmorphic cytomegalic and immature neurons play an important role in generation and propagation of epileptic discharges. An unexpected finding in pediatric CD was that GABA synaptic activity is not reduced, and in fact, it may facilitate the occurrence of epileptic activity. This could be because neuronal circuits display morphological and functional signs of dysmaturity. In consequence, drugs that increase GABA function may prove ineffective in pediatric CD. In contrast, drugs that counteract depolarizing actions of GABA or drugs that inhibit the mammalian target of rapamycin (mTOR) pathway could be more effective.
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Affiliation(s)
- Sara Abdijadid
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA, USA
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12
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Widespread pH abnormalities in patients with malformations of cortical development and epilepsy: a phosphorus-31 brain MR spectroscopy study. Brain Dev 2014; 36:899-906. [PMID: 24485900 DOI: 10.1016/j.braindev.2013.12.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 12/26/2013] [Accepted: 12/27/2013] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Neuroimaging studies demonstrate that not only the lesions of malformations of cortical development (MCD) but also the normal-appearing parenchyma (NAP) present metabolic impairments, as revealed with (1)H-MRS. We have previously detected biochemical disturbances in MCD lesions with phosphorus-31 magnetic resonance spectroscopy (31P-MRS). Our hypothesis is that pH abnormalities extend beyond the visible lesions. METHODS Three-dimensional 31P-MRS at 3.0 T was performed in 37 patients with epilepsy and MCD, and in 31 matched-control subjects. The patients were assigned into three main MCD subgroups: cortical dysplasia (n=10); heterotopia (n=14); schizencephaly/polymicrogyria (n=13). Voxels (12.5 cm3) were selected in five homologous regions containing NAP: right putamen; left putamen; frontoparietal parasagittal cortex; right centrum semiovale; and left centrum semiovale. Robust methods of quantification were applied, and the intracellular pH was calculated with the chemical shifts of inorganic phosphate (Pi) relative to phosphocreatine (PCr). RESULTS In comparison to controls and considering a Bonferroni adjusted p-value <0.01, MCD patients presented significant reduction in intracellular pH in the frontoparietal parasagittal cortex (6.985±0.022), right centrum semiovale (7.004±0.029), and left centrum semiovale (6.995±0.030), compared to controls (mean values±standard deviations of 7.087±0.048, 7.096±0.042, 7.088±0.045, respectively). Dunnet and Dunn tests demonstrated that the differences in pH values remained statistically significant in all MCD subgroups. No significant differences were found for the putamina. CONCLUSION The present study demonstrates widespread acidosis in the NAP, and reinforces the idea that MCD visible lesions are only the tip of the iceberg.
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13
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Clinical characteristics, pathological features and surgical outcomes of focal cortical dysplasia (FCD) type II: correlation with pathological subtypes. Neurol Sci 2014; 35:1519-26. [DOI: 10.1007/s10072-014-1782-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 03/27/2014] [Indexed: 10/25/2022]
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14
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Battaglia G, Colciaghi F, Finardi A, Nobili P. Intrinsic epileptogenicity of dysplastic cortex: converging data from experimental models and human patients. Epilepsia 2013; 54 Suppl 6:33-6. [PMID: 24001068 DOI: 10.1111/epi.12272] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Focal cortical dysplasia (FCD) is a brain malformation associated with particularly severe drug-resistant epilepsy that often requires surgery for seizure control. The molecular basis for such enhanced propensity to seizure generation in FCD is not as yet elucidated. To investigate cellular and molecular bases of epileptogenic mechanisms and possible effect of severe epilepsy on the malformed cortex we have here performed a parallel analysis of a rat model of acquired cortical dysplasia previously established in our laboratory, i.e., the methylazoxymethanol/pilocarpine (MAM-PILO) rats, and surgical samples from patients with type IIB FCD. Data from the MAM-PILO rat model and human FCD samples reveal in both conditions: (1) that status epilepticus (SE) and/or seizures can further modify the cellular and molecular settings of the malformed cortex; (2) excitation/inhibition imbalance, and dysregulation of the N-methyl-d-aspartate/ membrane-associated guanylate kinase (NMDA/MAGUK) expression; (3) activation of cell death in neurons and glia. The data therefore highlight the mechanistic relevance of glutamate/NMDA hyperactivation in FCD epileptogenesis and suggest that epilepsy is a pathologic process capable of affecting structure and function of both neurons and glia.
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Affiliation(s)
- Giorgio Battaglia
- Molecular Neuroanatomy and Pathogenesis Unit, IRCCS Foundation Neurological Institute Carlo Besta, Via Libero Temolo 4, Milan, Italy.
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15
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Finardi A, Colciaghi F, Castana L, Locatelli D, Marras CE, Nobili P, Fratelli M, Bramerio MA, Lorusso G, Battaglia GS. Long-duration epilepsy affects cell morphology and glutamatergic synapses in type IIB focal cortical dysplasia. Acta Neuropathol 2013; 126:219-35. [PMID: 23793416 DOI: 10.1007/s00401-013-1143-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/30/2013] [Accepted: 06/11/2013] [Indexed: 11/24/2022]
Abstract
To investigate hypothesized effects of severe epilepsy on malformed cortex, we analyzed surgical samples from eight patients with type IIB focal cortical dysplasia (FCD) in comparison with samples from nine non-dysplastic controls. We investigated, using stereological quantification methods, where appropriate, dysplastic neurons, neuronal density, balloon cells, glia, glutamatergic synaptic input, and the expression of N-methyl-D-aspartate (NMDA) receptor subunits and associated membrane-associated guanylate kinase (MAGUK). In all FCD patients, the dysplastic areas giving rise to epileptic discharges were characterized by larger dysmorphic neurons, reduced neuronal density, and increased glutamatergic inputs, compared to adjacent areas with normal cytology. The duration of epilepsy was found to correlate directly (a) with dysmorphic neuron size, (b) reduced neuronal cell density, and (c) extent of reactive gliosis in epileptogenic/dysplastic areas. Consistent with increased glutamatergic input, western blot revealed that NMDA regulatory subunits and related MAGUK proteins were up-regulated in epileptogenic/dysplastic areas of all FCD patients examined. Taken together, these results support the hypothesis that epilepsy itself alters morphology-and probably also function-in the malformed epileptic brain. They also suggest that glutamate/NMDA/MAGUK dysregulation might be the intracellular trigger that modifies brain morphology and induces cell death.
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Affiliation(s)
- Adele Finardi
- Experimental Neurophysiology and Epileptology Department, Molecular Neuroanatomy and Pathogenesis Unit, Neurological Institute C. Besta, Via Temolo 4, 20126, Milan, Italy
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Abstract
Structural abnormalities of the brain are increasingly recognized in patients that suffer from pharmacoresistant focal epilepsies by applying high-resolution imaging techniques. In many of these patients, epilepsy surgery results in control of seizures. Neuropathologically, a broad spectrum of malformations of cortical development (MCD) is observed in respective surgical brain samples. These samples provide a unique basis to further understand underlying pathomechanisms by molecular approaches and develop improved diagnostics and entirely new therapeutic perspectives. Here we provide a comprehensive description of neuropathological findings, available classification systems as well as molecular mechanisms of MCDs. We emphasize the recently published ILEA classification system for focal cortical dysplasias (FCDs), which are now histopathologically distinguished as types I to III. However, this revised classification system represents a major challenge for molecular neuropathologists, as the underlying pathomechanisms in virtually all FCD entities will need to be specified in detail. The fact that only recently, the mammalian target of rapamycin (mTOR)-antagonist Everolimus has been introduced as a treatment of epilepsies in the context of tuberous sclerosis-associated brain lesions is a striking example of a successful translational "bedside to bench and back" approach. Hopefully, the exciting clinico-pathological developments in the field of MCDs will in short term foster further therapeutic breakthroughs for the frequently associated medically refractory epilepsies.
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Affiliation(s)
- Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam
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Rowland NC, Englot DJ, Cage TA, Sughrue ME, Barbaro NM, Chang EF. A meta-analysis of predictors of seizure freedom in the surgical management of focal cortical dysplasia. J Neurosurg 2012; 116:1035-41. [DOI: 10.3171/2012.1.jns111105] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Focal cortical dysplasia (FCD) is one of the most common causes of medically refractory epilepsy leading to surgery. However, seizure control outcomes reported in isolated surgical series are highly variable. As a result, it is not clear which variables are most crucial in predicting seizure freedom following surgery for FCD. The authors' aim was to determine the prognostic factors for seizure control in FCD by performing a meta-analysis of the published literature.
Methods
A MEDLINE search of the published literature yielded 37 studies that met inclusion and exclusion criteria. Seven potential prognostic variables were determined from these studies and were dichotomized for analysis. For each variable, individual studies were weighted by inverse variance and combined to generate an odds ratio favoring seizure freedom. The methods complied with a standardized meta-analysis reporting protocol.
Results
Two thousand fourteen patients were included in the analysis. The overall rate of seizure freedom (Engel Class I) among patients undergoing surgery for FCD in the cohort of studies was 55.8% ± 16.2%. Partial seizures, a temporal location, detection with MRI, and a Type II Palmini histological classification were associated with higher rates of postoperative seizure control. As a treatment-related factor, complete resection of the anatomical or electrographic abnormality was the most important predictor overall of seizure freedom. Neither age nor electroencephalographic localization of the ictal onset significantly affected seizure freedom after surgery.
Conclusions
Using a large population cohort pooled from the published literature, an analysis identified important factors that are prognostic in patients with epilepsy due to FCD. The most important of these factors—diagnostic imaging and resection—provide modalities through which improvements in the impact of FCD can be effected.
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18
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Neuropathology of temporal lobe epilepsy. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:624519. [PMID: 22957233 PMCID: PMC3420738 DOI: 10.1155/2012/624519] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 01/20/2012] [Accepted: 02/07/2012] [Indexed: 12/31/2022]
Abstract
Pathologic findings in surgical resections from patients with temporal lobe epilepsy include a wide range of diagnostic possibilities that can be categorized into different groups on the basis of etiology. This paper outlines the various pathologic entities described in temporal lobe epilepsy, including some newly recognized epilepsy-associated tumors, and briefly touch on the recent classification of focal cortical dysplasia. This classification takes into account coexistent pathologic lesions in focal cortical dysplasia.
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Affiliation(s)
- Roberto Spreafico
- Department of Research and Diagnostics, IRCCS Foundation Istituto Neurologico C. Besta, Milan, Italy.
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20
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González-Martínez JA, Ying Z, Prayson R, Bingaman W, Najm I. Glutamate clearance mechanisms in resected cortical dysplasia. J Neurosurg 2011; 114:1195-202. [DOI: 10.3171/2010.10.jns10715] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Changes in the expression of glutamate transporters (GLTs) may play a role in the expression of epileptogenicity. Previous studies have shown an increased number of neuronal GLTs in human dysplastic neurons. The expression of glial and neuronal GLTs and glutamine synthetase (GS) in balloon cells (BCs) and BC-containing cortical dysplasia has not been studied.
Methods
The authors analyzed neocortical samples that were resected in 5 patients who had cortical dysplasia–induced medically intractable focal epilepsy and who underwent extraoperative prolonged electrocorticographic (ECoG) recordings. The expressions of glial (GLT1/EAAT2) and neuronal (EAAT3, EAAC1) GLTs and GS proteins were immunohistochemically studied in all 5 resected samples. The authors also assessed in situ colocalization of GLTs and GS with neuronal and glial markers.
Results
Balloon cell–containing cortical dysplasia lesions did not exhibit ictal patterns on prolonged extraoperative ECoG recordings. There was a differential expression of glial and neuronal GLTs in BCs and dysplastic neurons: the majority of BCs highly expressed glial but not neuronal GLTs. Dysplastic neurons showed increased immunohistochemical staining with neuronal EAAT3 but not with EAAT2/GLT1. Moreover, only glial fibrillary acidic protein–positive BCs also expressed GS.
Conclusions
There is a differential GLT expression in dysplastic and balloon cells. The presence of glial GLTs and GS in balloon cell cortical dysplasia suggests a possible antiepileptic role for BCs and is consistent with the reported increased epileptogenicity in GLT1-deficient animals.
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Affiliation(s)
| | | | - Richard Prayson
- 2Department of Surgical Pathology, Cleveland Clinic, Cleveland, Ohio
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21
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Chern JJ, Patel AJ, Jea A, Curry DJ, Comair YG. Surgical outcome for focal cortical dysplasia: an analysis of recent surgical series. J Neurosurg Pediatr 2010; 6:452-8. [PMID: 21039168 DOI: 10.3171/2010.8.peds10145] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Focal cortical dysplasia (FCD) is an important cause of intractable epilepsy and is at times treatable by resection. The now widespread use of MR imaging and recent advancement of functional imaging have increased the number of patients undergoing surgical treatment for FCD. The objective of this review is to critically examine and to provide a summary of surgical series on FCD published since 2000. METHODS Studies concerning surgery for FCD were identified from MEDLINE and references of selected articles and book chapters. Data from these included studies were summarized and analyzed to identify factors correlated with seizure outcome. RESULTS Sixteen studies were identified, and 469 patients met our selection criteria. Seizure-free outcome at 1-year postoperatively was achieved in 59.7% of the patients. Children and adults were equally likely to benefit from the surgery. Complete resection (OR 13.7, 95% CI 6.68-28.1; p < 0.0001) and temporal location (OR 2.15, 95% CI 1.26-3.69; p = 0.0073) were two positive prognostic indicators of seizure-free outcome. Utilization of invasive monitoring did not affect the chance of seizure remission, but firm conclusions could not be drawn because patients were not randomized. CONCLUSIONS The advancement of modern imaging has transformed the process of surgical candidate selection for partial epilepsy due to FCD. Patients from recent surgical series were more homogeneous in their clinical presentations and might represent FCD as an independent pathological entity. This likely explained the improved surgical outcome for this group of patients. These reports also documented the increased utilization of functional imaging, but their efficacy needs to be verified with further studies.
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Affiliation(s)
- Joshua J Chern
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA.
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22
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Han CW, Min BW, Kim Y, Jeong EH, Park CS, Woo YJ, Kim HS, Lee MC. Immunohistochemical analysis of developmental neural antigen expression in the balloon cells of focal cortical dysplasia. J Clin Neurosci 2010; 18:114-8. [PMID: 20719515 DOI: 10.1016/j.jocn.2010.05.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 05/28/2010] [Accepted: 05/31/2010] [Indexed: 12/25/2022]
Abstract
Balloon cells (BC) are the histological hallmarks of focal cortical dysplasia (FCD). Expression of the neural stem cell surface marker CD133 and other developmental markers was studied in the BC of FCD using formalin-fixed paraffin-embedded tissue from nine patients with FCD. Labeling indexes were calculated for all antibodies. BC were easily identified at the gray-white matter junction and they extended into the white matter. Immunoreactivity in BC was found for the following antigens in nine patients: CD133 (six patients; 22.2 ± 7.7%), CD34 (two patients; 0.4 ± 0.3%), nestin (nine patients; 37.6 ± 8.5%), vimentin (eight patients; 59.2 ± 8.7%), glial fibrillary acid protein (six patients; 34.3 ± 10.4%), microtubule-associated protein 2 (four patients; 8.3 ± 5.0%), neurofilament-middle/high (five patients; 10.2 ± 4.6%) and synaptophysin (three patients; 4.2 ± 3.3%). Neuronal nuclei (NeuN, neuron specific nuclear protein) was not expressed in BC of any patient. The results of this study suggest that BC in patients with FCD originate from glioneuronal precursor cells and that developmental defects of neuronal and glial specifications are important in the histogenesis of FCD.
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Affiliation(s)
- Chang-Woo Han
- Department of Pathology, Chonnam National University Medical School, Gwangju, Republic of Korea
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23
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Labudda K, Brand M, Mertens M, Ebner A, Markowitsch HJ, Woermann FG. Alterations of decision making and underlying neural correlates after resection of a mediofrontal cortical dysplasia: A single case study. Neurocase 2010; 16:59-73. [PMID: 20391186 DOI: 10.1080/13554790903329125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
We investigated the impact of a congenital prefrontal lesion and its resection on decision making under risk and under ambiguity in a patient with right mediofrontal cortical dysplasia. Both kinds of decision making are normally associated with the medial prefrontal cortex. We additionally studied pre- and postsurgical fMRI activations when processing information relevant for risky decision making. Results indicate selective impairments of ambiguous decision making pre- and postsurgically. Decision making under risk was intact. In contrast to healthy subjects the patient exhibited no activation within the dysplastic anterior cingulate cortex but left-sided orbitofrontal activation on the fMRI task suggesting early reorganization processes.
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Affiliation(s)
- Kirsten Labudda
- Mara Hospital, Bethel Epilepsy Center, MRI Unit, Bielefeld, Germany.
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24
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Aubert S, Wendling F, Regis J, McGonigal A, Figarella-Branger D, Peragut JC, Girard N, Chauvel P, Bartolomei F. Local and remote epileptogenicity in focal cortical dysplasias and neurodevelopmental tumours. ACTA ACUST UNITED AC 2009; 132:3072-86. [PMID: 19770216 DOI: 10.1093/brain/awp242] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
During the pre-surgical evaluation of drug-resistant epilepsy, the assessment of the extent of the epileptogenic zone and its organization is a crucial objective. Indeed, the epileptogenic zone may be organized as a simple focal lesional site or as a more complex network (often referred to as the 'epileptogenic network') extending beyond the lesion. This distinction is particularly relevant in developmental lesions such as focal cortical dysplasias or dysembryoplastic neuroepithelial tumours and may determine both the surgical strategy and the prognosis. In this study, we have quantified the epileptogenic characteristic of brain structures explored by depth electrodes in 36 patients investigated by stereoelectroencephalography and suffering from focal drug-resistant epilepsy associated with focal cortical dysplasias or dysembryoplastic neuroepithelial tumours. This quantification was performed using the 'Epileptogenicity Index' method that accounts for both the propensity of a brain area to generate rapid discharges and the time for this area to get involved in the seizure. Epileptogenicity Index values range from 0 (no epileptogenicity) to 1 (maximal epileptogenicity). We determined Epileptogenicity Index from signals recorded in distinct brain structures including the lesional site. We studied the type of epileptogenic zone organization (focal versus network) and looked for a correlation with clinical data and post-surgical outcome. Mean Epileptogenicity Index in lesional regions was 0.87 (+/-0.25), and 0.29 (+/-0.30) in 'non-lesional' structures. The number of highly epileptogenic structures (defined by Epileptogenicity Index value >or=0.4) was 3.14 (+/-1.87) in the whole population. We found that 31% of patients had only one epileptogenic structure (N(EI>or=0.4) = 1), therefore disclosing a strictly focal epileptogenic zone organization while 25 patients had more than one epileptogenic region, disclosing a network (61%) or bilateral (8%) epileptogenic zone organization. We observed a trend for a difference in seizure outcome according to the type of epileptogenic zone organization. Indeed, 57% of patients with network organization and 87% with focal organization were seizure-free while none of those with bilateral organization became seizure-free. The determination of Epileptogenicity Index computed from electrophysiological signals recorded according to the stereoelectroencephalography technique is a novel tool. Results suggest that it can help in the delineation of the epileptogenic zone associated with brain lesions and that it could be used in the definition of the subsequent surgical resection.
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Affiliation(s)
- Sandrine Aubert
- Service de Neurophysiologie Clinique, CHU Timone-264 Rue st Pierre, 13005-Marseille, France
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Jacobs J, Levan P, Châtillon CE, Olivier A, Dubeau F, Gotman J. High frequency oscillations in intracranial EEGs mark epileptogenicity rather than lesion type. ACTA ACUST UNITED AC 2009; 132:1022-37. [PMID: 19297507 DOI: 10.1093/brain/awn351] [Citation(s) in RCA: 251] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
High frequency oscillations (HFOs) called ripples (80-250 Hz) and fast ripples (FR, 250-500 Hz) can be recorded from intracerebral EEG macroelectrodes in patients with intractable epilepsy. HFOs occur predominantly in the seizure onset zone (SOZ) but their relationship to the underlying pathology is unknown. It was the aim of this study to investigate whether HFOs are specific to the SOZ or result from pathologically changed tissue, whether or not it is epileptogenic. Patients with different lesion types, namely mesial temporal atrophy (MTA), focal cortical dysplasia (FCD) and nodular heterotopias (NH) were investigated. Intracranial EEG was recorded from depth macroelectrodes with a sampling rate of 2000 Hz. Ripples (80-250 Hz) and Fast Ripples (250-500 Hz) were visually marked in 12 patients: five with MTA, four with FCD and three with NH. Rates of events were statistically compared in channels in four areas: lesional SOZ, non-lesional SOZ, lesional non-SOZ and non-lesional non-SOZ. HFO rates were clearly more linked to the SOZ than to the lesion. They were highest in areas in which lesion and SOZ overlap, but in patients with a SOZ outside the lesion, such as in NHs, HFO rates were clearly higher in the non-lesional SOZ than in the inactive lesions. No specific HFO pattern could be identified for the different lesion types. The findings suggest that HFOs represent a marker for SOZ areas independent of the underlying pathology and that pathologic tissue changes alone do not lead to high rates of HFOs.
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Affiliation(s)
- Julia Jacobs
- Montreal Neurological Institute and Hospital, McGill University, Montreal, Québec, Canada.
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Krsek P, Pieper T, Karlmeier A, Hildebrandt M, Kolodziejczyk D, Winkler P, Pauli E, Blümcke I, Holthausen H. Different presurgical characteristics and seizure outcomes in children with focal cortical dysplasia type I or II. Epilepsia 2009; 50:125-37. [DOI: 10.1111/j.1528-1167.2008.01682.x] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lin WC, Sandberg DI, Bhatia S, Johnson M, Morrison G, Ragheb J. Optical spectroscopy for in-vitro differentiation of pediatric neoplastic and epileptogenic brain lesions. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:014028. [PMID: 19256716 DOI: 10.1117/1.3080144] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The objective of this in vitro tissue study is to investigate the feasibility of using optical spectroscopy to differentiate pediatric neoplastic and epileptogenic brain from normal brain. Specimens are collected from 17 patients with brain tumors, and from 26 patients with intractable epilepsy during surgical resection of epileptogenic cerebral cortex. Fluorescence spectra are measured at excitations of 337, 360, and 440 nm; diffuse reflectance spectra are measured between 400 and 900 nm from each specimen. Pathological analysis is performed to classify abnormalities in brain specimens, and its findings are correlated with spectral data. Statistically significant differences (p<0.01) are found for both raw and normalized diffuse reflectance and fluorescence spectra between 1. neoplastic brain and normal gray matter, 2. epileptogenic brain and normal gray matter, and 3. neoplastic brain and normal white matter. However, no distinct spectral features are identified that effectively separate epileptogenic brain from normal white matter. The outcomes of the study suggest that certain unique compositional and structural characteristics of pediatric neoplastic and epileptogenic brain can be detected using optical spectroscopy in vitro.
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Affiliation(s)
- Wei-Chiang Lin
- Miami Children's Hospital, Brain Institute and Florida International University, Department of Biomedical Engineering, 10555 West Flagler St, EAS 2673 Miami, Florida 33131, USA.
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Juhász C, Asano E, Shah A, Chugani DC, Batista CEA, Muzik O, Sood S, Chugani HT. Focal decreases of cortical GABAA receptor binding remote from the primary seizure focus: what do they indicate? Epilepsia 2008; 50:240-50. [PMID: 18637829 DOI: 10.1111/j.1528-1167.2008.01721.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To determine the electroclinical significance and histopathological correlates of cortical gamma-aminobutyric acid(A)(GABA(A)) receptor abnormalities detected in and remote from human neocortical epileptic foci. METHODS Cortical areas with decreased(11)C-flumazenil (FMZ) binding were objectively identified on positron emission tomography (PET) images and correlated to intracranial electroencephalography (EEG) findings, clinical seizure variables, histology findings, and surgical outcome in 20 patients (mean age, 9.9 years) with intractable partial epilepsy of neocortical origin and nonlocalizing magnetic resonance imaging (MRI). RESULTS Focal decrease of cortical FMZ binding was detected in the lobe of seizure onset in 17 (85%) patients. Eleven patients (55%) had 17 remote cortical areas with decreased FMZ binding outside the lobe of seizure onset. Thirteen of those 16 (81%) of the 17 remote cortical regions that were covered by subdural EEG were around cortex showing rapid seizure spread on intracranial EEG. Remote FMZ PET abnormalities were associated with high seizure frequency and, when resected, showed gliosis in all six cases where material was available. Higher number of unresected cortical regions with decreased FMZ binding was associated with poorer surgical outcome. CONCLUSIONS Focal decreases of cortical GABA(A) receptor binding on PET may include cortical regions remote from the primary focus, particularly in patients with high seizure frequency, and these regions are commonly involved in rapid seizure propagation. Although these regions may not always need to be resected to achieve seizure freedom, a careful evaluation of cortex with decreased GABA(A) receptor binding prior to resection using intracranial EEG may facilitate optimal surgical outcome in patients with intractable neocortical epilepsy.
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Affiliation(s)
- Csaba Juhász
- Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan and Harper University Hospital, Detroit Medical Center, Wayne State University School of Medcine, Detroit, Michigan, USA.
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Trottier S, Landré E, Biraben A, Chassoux F, Pasnicu A, Scarabin JM, Turak B, Devaux B. [On the best strategies on the best results for surgery of frontal epilepsy]. Neurochirurgie 2008; 54:388-98. [PMID: 18462763 DOI: 10.1016/j.neuchi.2008.02.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 02/25/2008] [Indexed: 12/26/2022]
Abstract
Frontal lobe epilepsy surgery is the second most common surgery performed for drug-resistant partial epilepsy. We investigated the longitudinal outcome in a cohort of patients investigated since 1990 with SEEG and modern diagnostic techniques. We reviewed 105 patients who underwent surgery between 1990 and 2005 (mean follow-up, six years; range: one to 17 years) and analyzed the year-per-year follow-up according to Engel's classification. Favorable outcome (Class I) was observed for 70% and this result was stable at least five years after surgery. More than 90% of patients with lesion-related epilepsies (focal cortical dysplasia and dysembryoplastic neuroepithelial tumors) became seizure-free. Less than 50% of patients classified as having cryptogenic epilepsy (defined as normal imaging and neuropathology on surgical specimen) had a favorable outcome. Permanent neurological sequelae were subtle and rare, especially after surgery for dysplasia in eloquent cortex (primary motor cortex). Our data indicate that frontal surgery is a successful treatment in patients when electrophysiological and morphological investigations demonstrate a well-defined epileptogenic zone or lesion to be surgically resected. Progress in electrophysiological and brain-imaging techniques will further improve the selection of frontal lobe epilepsy surgery candidates.
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Affiliation(s)
- S Trottier
- Service de neurochirurgie, hôpital Sainte-Anne, 1, rue Cabanis, 75014 Paris, France. suzanne.trottier.fr
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Noachtar S, Bilgin O, Rémi J, Chang N, Midi I, Vollmar C, Feddersen B. Interictal regional polyspikes in noninvasive EEG suggest cortical dysplasia as etiology of focal epilepsies. Epilepsia 2008; 49:1011-7. [PMID: 18363706 DOI: 10.1111/j.1528-1167.2008.01583.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the clinical significance of interictal regional polyspikes in focal epilepsies secondary to cortical dysplasia. METHODS We performed a data search for the term "regional polyspikes" in the database of our epilepsy-monitoring unit. Patients with generalized epilepsies including Lennox-Gastaut syndrome were excluded. Regional interictal epileptiform discharges were recorded in 513 patients with noninvasive EEG. RESULTS We identified 29 patients with interictal regional polyspikes and focal epilepsies. Another 484 patients showed regional epileptiform discharges other than polyspikes. The etiology of the epilepsy was significantly more frequently cortical dysplasia in the group of patients with regional polyspikes (35%, 10 of 29 patients) than in the patients with other regional epileptiform discharges (5%, 24 of 484 patients) (p < 0.01). The polyspikes were significantly more frequently localized to the extratemporal (72%; n = 21) than temporal (28%; n = 8) regions (p < 0.01). In contrast, regional epileptiform discharges other than polyspikes were significantly more frequently localized to the temporal lobe (75%; n = 362) than extratemporal regions (25%; n = 122) (p < 0.01). Eight of the 10 patients with focal cortical dysplasia had extratemporal polyspikes. DISCUSSION Noninvasively recorded regional polyspikes suggest cortical dysplasias as etiology of predominantly extratemporal epilepsies.
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Affiliation(s)
- Soheyl Noachtar
- Department of Neurology, Epilepsy Center, University of Munich, Munich, Germany.
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Ictal technetium-99 m ethyl cysteinate dimer single-photon emission tomographic findings in epileptic patients with polymicrogyria syndromes: A Subtraction of ictal–interictal SPECT coregistered to MRI study. Eur J Nucl Med Mol Imaging 2007; 35:1159-70. [DOI: 10.1007/s00259-007-0655-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Accepted: 11/04/2007] [Indexed: 11/30/2022]
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Bruggemann JM, Wilke M, Som SS, Bye AM, Bleasel A, Lawson JA. Voxel-based morphometry in the detection of dysplasia and neoplasia in childhood epilepsy: Combined grey/white matter analysis augments detection. Epilepsy Res 2007; 77:93-101. [DOI: 10.1016/j.eplepsyres.2007.09.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2007] [Revised: 07/21/2007] [Accepted: 09/13/2007] [Indexed: 01/18/2023]
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Najm IM, Tilelli CQ, Oghlakian R. Pathophysiological mechanisms of focal cortical dysplasia: a critical review of human tissue studies and animal models. Epilepsia 2007; 48 Suppl 2:21-32. [PMID: 17571350 DOI: 10.1111/j.1528-1167.2007.01064.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Cortical dysplasia (CD, also known as malformations of cortical development) are the pathological substrates in a large percentage of patients with pharmacoresistant epilepsy who may be amenable to surgical treatment. Therefore, research on the mechanisms of dysplastic lesion formation and epileptogenicity is of paramount importance for the prevention, detection, and treatment of CD-induced epilepsy. The purpose of this review is to discuss and critically evaluate the current state and results of human tissue experimentation (focusing on reported results of studies done on neocortical dysplastic tissue resected from patients with pharmacoresistant epilepsy), and to discuss some of the concerns related to research that uses surgically resected epileptic human tissue. The use of better animal models of CD as a tool toward the better understanding of the mechanisms of pathogenesis, epileptogenesis, and epileptogenicity of dysplastic lesions will be reviewed from the perspective of their usefulness in a model of translational research that should ultimately result in better diagnostic and therapeutic techniques of CD.
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Affiliation(s)
- Imad M Najm
- Cleveland Clinic Epilepsy Center Head, Section of Adult Epilepsy and Clinical Neurophysiology, 9500 Euclid Avenue, S51, Cleveland, OH 44195, USA.
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Abstract
INTRODUCTION Malformations of the cerebral cortex are a frequent cause of pharmacoresistant epilepsies and developmental disorders. EPIDEMIOLOGY AND GENETICS The incidence of cortical dysplasias in epilepsy surgical series varies from 12 to 40% and focal cortical dysplasias (FCD) are one of the most common neuropathological findings in resection specimens from pediatric patients undergoing cortical resections for the treatment of refractory epilepsy. MACROSCOPY AND HISTOPATHOLOGY Surgical specimens in FCD may appear normal macroscopically, but in some cases, widening of the cortex with poor demarcation from the underlying white matter is noted. In milder dysplasias, the main pathological feature is disorganization of the cortical architecture ("dislamination") with less striking neuronal and glial cytopathology. Histopathology shows an excess of neurons in layer I, including Cajal-Retzius cells, clusters of neurons, marginal glioneuronal heterotopias, and a persistent subpial granule cell layer. The hallmarks of FCD are disorganization of the laminar architecture and of the cytology of individual neurons. In many cases, layer I remains hypocellular and distinct from deeper laminae, but lower cortical layers may be ill-defined or broken up by the presence of many large and randomly located abnormal and cytomegalic neurons; depending on their morphology, referred to as "giant neurons," "immature neurons," or "dysmorphic neurons." The other pathognomonic cell type associated with FCD is the "balloon cell." These cells were originally considered to be of astrocytic lineage; however, there is evidence that they are in effect "balloon neurons." IMMUNOHISTOCHEMISTRY AND STRUCTURAL FINDINGS Immunohistochemistry is not essential in making the diagnosis of FCD or microdysgenesis but allows further characterization of cell types.
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Affiliation(s)
- Christian H Rickert
- Department of Anatomical Pathology, Royal Children's Hospital, Flemington Road, 3052, Parkville Vic, Australia.
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Abstract
Focal cortical dysplasia (FCD) is a common cause of pharmacoresistant epilepsy that is amenable to surgical resective treatment. The identification of structural FCD by magnetic resonance imaging (MRI) can contribute to the detection of the epileptogenic zone and improve the outcome of epilepsy surgery. MR epilepsy protocols that include specific T1 and T2 weighted, and fluid-attenuated inversion recovery (FLAIR) sequences give complementary information about the characteristic imaging features of FCD; focal cortical thickening, blurring of the gray-white junction, high FLAIR signal, and gyral anatomical abnormalities. Novel imaging techniques such as magnetic resonance spectroscopy (MRS), magnetization transfer imaging (MTI), and diffusion tensor imaging (DTI) can improve the sensitivity of MR to localize the anatomical lesion. Functional/metabolic techniques such as positron emission tomography (PET), ictal subtraction single photon emission computed tomography (SPECT), functional MRI (fMRI), and magnetic source imaging (MSI) have the potential to visualize the metabolic, vascular, and epileptogenic properties of the FCD lesion, respectively. Identification of eloquent areas of cortex, to assist in the surgical resection plan, can be obtained non-invasively through the use of fMRI and MSI. Although a significant number of FCD lesions remain unidentified using current neuroimaging techniques, future advances should result in the identification of an increasing number of these cortical malformations.
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Affiliation(s)
- Peter Widdess-Walsh
- Section of Adult Epilepsy and Clinical Neurophysiology, The Cleveland Clinic Epilepsy Center, Cleveland, OH 44195, USA
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Park CK, Kim SK, Wang KC, Hwang YS, Kim KJ, Chae JH, Chi JG, Choe GY, Kim NR, Cho BK. Surgical outcome and prognostic factors of pediatric epilepsy caused by cortical dysplasia. Childs Nerv Syst 2006; 22:586-92. [PMID: 16541293 DOI: 10.1007/s00381-006-0085-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2003] [Indexed: 11/29/2022]
Abstract
OBJECTS We analyzed 30 patients with cortical dysplasia (CD) and epilepsy to evaluate the clinical characteristics and surgical outcome of both epilepsy control and neurocognition. MATERIALS AND METHODS The mean ages at seizure onset and at the time of the operation were 3.6 years (range, 1 month-12.6 years) and 10.3 years (range, 1.5-18.3 years), respectively. The mean follow-up period was 3.2 years (range, 1-5.3 years). (18)FDG-positron emission tomography was the most sensitive and magnetic resonance imaging was the most specific in localizing the lesion. Developmental/intellectual delay was predominant in the early-onset group (n=18, seizure onset <3 years), with intelligence tending to be normal in the late-onset group (n=12, seizure onset >or=3 years). Mild CD predominated in the late-onset epilepsy group and moderate or severe CD in the early-onset group (p=0.005). The surgical success rate of epilepsy control was 87%. A better outcome was obtained if the lesion was confined to the temporal lobe. School performance was favorable in 43%. The age at seizure onset and preoperative developmental/intellectual delay were the important prognostic factors in school performance as well as the epilepsy control. A total of 77% of patients had relatively good social adaptation. Successful epilepsy control and good school performance were affirmative conditions precedent to social adaptation. CONCLUSIONS Due to the favorable control of epilepsy and its effect on school performance and social adaptation, surgical treatment is strongly recommended for cortical dysplasia and intractable epilepsy.
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Affiliation(s)
- Chul-Kee Park
- Division of Pediatric Neurosurgery and Laboratory of Neuro-Oncology in Cancer Research Institute, Seoul National University Children's Hospital and Neurological Research Institute, SNUMRC, Seoul, South Korea
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Abstract
This review addresses the main neuropathologic advances that have been made over recent years in the study of focal lesions in patients with epilepsy undergoing surgical treatment. There have been revisions and simplifications to the classification of focal cortical dysplasias. Hippocampal sclerosis is a well-characterized lesion but further pathologic studies have explored its possible relationship to temporal lobe developmental lesions, ongoing neurogenesis and mechanisms of its epileptogenicity. The important contribution of astrocytes to epileptogenesis is also unfolding and is briefly discussed, as are the possible cellular mechanisms of drug resistance.
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Affiliation(s)
- Maria Thom
- National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
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Crino PB, Miyata H, Vinters HV. Neurodevelopmental disorders as a cause of seizures: neuropathologic, genetic, and mechanistic considerations. Brain Pathol 2006; 12:212-33. [PMID: 11958376 PMCID: PMC8095994 DOI: 10.1111/j.1750-3639.2002.tb00437.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
This review will consider patterns of developmental neuropathologic abnormalities-malformations of cortical development (MCD)--encountered in infants (often with infantile spasms), children, and adults with intractable epilepsy. Treatment of epilepsy associated with some MCD, such as focal cortical dysplasia and tubers of tuberous sclerosis, may include cortical resection performed to remove the "dysplastic" region of cortex. In extreme situations (eg, hemimegalencephaly), hemispherectomy may be carried out on selected patients. Neuropathologic (including immunohistochemical) findings within these lesions will be considered. Other conditions that cause intractable epilepsy and often mental retardation, yet are not necessarily amenable to surgical treatment (eg, lissencephaly, periventricular nodular heterotopia, double cortex syndrome) will be discussed. Over the past 10 years there has been an explosion of information on the genetics of MCD. The genes responsible for many MCD (eg, TSC1, TSC2, LIS-1, DCX, FLN1) have been cloned and permit important mechanistic studies to be carried out with the purpose of understanding how mutations within these genes result in abnormal cortical cytoarchitecture and anomalous neuroglial differentiation. Finally, novel techniques allowing for analysis of patterns of gene expression within single cells, including neurons, is likely to provide answers to the most vexing and important question about these lesions: Why are they epileptogenic?
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Affiliation(s)
- Peter B Crino
- PENN Epilepsy Center, Department of Neurology, University of Pennsylvania, Philadelphia 19104, USA.
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Avoli M, Louvel J, Pumain R, Köhling R. Cellular and molecular mechanisms of epilepsy in the human brain. Prog Neurobiol 2006; 77:166-200. [PMID: 16307840 DOI: 10.1016/j.pneurobio.2005.09.006] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 07/27/2005] [Accepted: 09/20/2005] [Indexed: 12/20/2022]
Abstract
Animal models have provided invaluable data for identifying the pathogenesis of epileptic disorders. Clearly, the relevance of these experimental findings would be strengthened by the demonstration that similar fundamental mechanisms are at work in the human epileptic brain. Epilepsy surgery has indeed opened the possibility to directly study the functional properties of human brain tissue in vitro, and to analyze the mechanisms underlying seizures and epileptogenesis. Here, we summarize the findings obtained over the last 40 years from electrophysiological, histochemical and molecular experiments made with the human brain tissue. In particular, this review will focus on (i) the synaptic and non-synaptic properties of neocortical neurons along with their ability to produce synchronous activity; (ii) the anatomical and functional alterations that characterize limbic structures in patients presenting with mesial temporal lobe epilepsy; (iii) the issue of antiepileptic drug action and resistance; and (iv) the pathophysiology of seizure genesis in Taylor's type focal cortical dysplasia. Finally, we will address some of the problems that are inherent to this type of experimental approach, in particular the lack of proper controls and possible strategies to obviate this limitation.
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Affiliation(s)
- Massimo Avoli
- Montreal Neurological Institute and Departments of Neurology and Neurosurgery, and of Physiology, McGill University, Montreal, Canada.
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40
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Wang VY, Chang EF, Barbaro NM. Focal cortical dysplasia: a review of pathological features, genetics, and surgical outcome. Neurosurg Focus 2006; 20:E7. [PMID: 16459997 DOI: 10.3171/foc.2006.20.1.8] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Focal cortical dysplasia (FCD) is found in approximately one-half of patients with medically refractory epilepsy. These lesions may involve only mild disorganization of the cortex, but they may also contain abnormal neuronal elements such as balloon cells. Advances in neuroimaging have allowed better identification of these lesions, and thus more patients have become surgical candidates. Molecular biology techniques have been used to explore the genetics and pathophysiological characteristics of FCD. Data from surgical series have shown that surgery often results in significant reduction or cessation of seizures, especially if the entire lesion is resected.
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Affiliation(s)
- Vincent Y Wang
- Department of Neurological Surgery, University of California, San Francisco, California 94130, USA
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Thom M, Martinian L, Sisodiya SM, Cross JH, Williams G, Stoeber K, Harkness W, Harding BN. Mcm2 labelling of balloon cells in focal cortical dysplasia. Neuropathol Appl Neurobiol 2006; 31:580-8. [PMID: 16281906 DOI: 10.1111/j.1365-2990.2005.00651.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Balloon cells (BC) are the prominent and defining cellular component of type IIB Focal Cortical Dysplasia (FCD), a common cause of focal epilepsy in patients undergoing surgical treatment. BC are considered immature cells of uncommitted cellular differentiation having immunophenotypical characteristics of both neurones and glia. They are often located in the lower cortical layers and white matter underlying the dysplastic cortex, suggesting migratory arrest during development. We investigated the proliferative potential of BC in 15 cases of FCD from patients with a wide range of ages using immunohistochemistry for Mcm2 (mini chromosome maintenance protein) and Ki67. In the majority of cases, BC showed Mcm2 nuclear positivity. In addition, cells with intermediate neuronal-glial characteristics were labelled whilst the dysmorphic or hypertrophic pyramidal neuronal components of FCD were not. Ki67 labelled only occasional BC. These findings support the view that BC cells represent a pool of less differentiated glial cells with proliferative capacity which may have potential for delayed neuronal differentiation. Furthermore, as Mcm2 specifically identifies BC populations, this marker may be of diagnostic value in the subtyping of FCD lesions in patients with epilepsy.
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Affiliation(s)
- M Thom
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, London, UK.
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42
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Ying Z, Gonzalez-Martinez J, Tilelli C, Bingaman W, Najm I. Expression of neural stem cell surface marker CD133 in balloon cells of human focal cortical dysplasia. Epilepsia 2005; 46:1716-23. [PMID: 16302851 DOI: 10.1111/j.1528-1167.2005.00276.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE Focal cortical dysplasia (CD) is characterized by the presence of dysmorphic neurons, laminar and columnar disorganization. A few patients with CD have balloon cells intermixed with dysmorphic neurons. The cellular characteristics of balloon cells remain unknown. This study was intended to determine further the cellular characteristics of balloon cells. METHODS Neocortical tissue resected from five patients with medically intractable focal epilepsy due to CD was studied. The presence of balloon cells (large opalescent cells with eccentric nuclei) was confirmed in all five patients by using cresylecht violet staining. Immunocytochemistry used antibodies against markers of pluripotential stem cells (CD133), multipotential progenitor cells (nestin), antiapoptotic gene products (Bcl-2), immature neurons (beta-tubulin 3, TUJ1), immature glia (vimentin), mature neurons (MAP2 and NeuN), and astrocytes (glial fibrillary acidic protein; GFAP). RESULTS Balloon cells (BCs) were found to be immunoreactive to Bcl-2 (46%), vimentin (41%), Nestin (28%), CD133 (28%), MAP2 (27%), GFAP (14%), and TUJ1 (10%). An extremely small number of BCs were immunopositive for NeuN. Confocal double labeling showed that balloon cells were dually immunopositive for CD133/nestin; CD133/GFAP; CD133/Bcl-2, and nestin/GFAP. CONCLUSIONS These results show that balloon cells are heterogeneous cell populations expressing cell-surface markers for pluripotential stem cells and proteins for multipotent progenitors, or immature neurons/glia. The presence of stem cell/progenitor markers in the balloon cells could be due to a persistent postnatal neurogenesis or early embryonic insult that resulted in arrest of proliferation/differentiation at their early stages. Additionally, the coexpression of Bcl-2 in CD133-positive balloon cells suggests that a resistance to programmed cell death may be involved in the pathogenesis of cortical dysplasia.
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Affiliation(s)
- Zhong Ying
- Department of Neurology, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Colliot O, Bernasconi N, Khalili N, Antel SB, Naessens V, Bernasconi A. Individual voxel-based analysis of gray matter in focal cortical dysplasia. Neuroimage 2005; 29:162-71. [PMID: 16099679 DOI: 10.1016/j.neuroimage.2005.07.021] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Revised: 06/29/2005] [Accepted: 07/05/2005] [Indexed: 10/25/2022] Open
Abstract
High-resolution MRI of the brain has made it possible to identify focal cortical dysplasia (FCD) in an increasing number of patients. There is evidence for structural abnormalities extending beyond the visually identified FCD lesion. Voxel-based morphometry (VBM) has the potential of detecting both lesions and extra-lesional abnormalities because it performs a whole brain voxel-wise comparison. However, on T1-weighted MRI, FCD lesions are characterized by a wide spectrum of signal hyperintensity that may compromise the results of the segmentation step in VBM. Our purpose was to investigate gray matter (GM) changes in individual FCD patients using voxel-based morphometry (VBM). In addition, we sought to assess the performance of this technique for FCD detection with respect to lesion intensity using an operator designed to emphasize areas of hyperintense T1 signal. We studied 27 patients with known FCD and focal epilepsy and 39 healthy controls. We compared the GM map of each subject (controls and patients) with the average GM map of all controls and obtained a GM z-score map for each individual. The protocol being designed to achieve a maximal specificity, no differences in GM concentration were found in the control group. The z-score maps showed an increase in GM that coincided with the lesion in 21/27 (78%) patients. Five of the six remaining patients whose lesions were not detected by VBM presented with a strong lesion hyperintensity, and a significant part of their lesion was misclassified as white matter. In 16/27 (59%) patients, there were additional areas of GM increase distant from the primary lesion. Areas of GM decrease were found in 8/27 (30%) patients. In conclusion, individual voxel-based analysis was able to detect FCD in a majority of patients. Moreover, FCD was often associated with widespread GM changes extending beyond the visible lesion. In its current form, however, individual VBM may be unable to detect lesions characterized by strong signal intensity abnormalities.
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Affiliation(s)
- O Colliot
- Department of Neurology and Neurosurgery and McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec, Canada H3A 2B4
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Cepeda C, André VM, Flores-Hernández J, Nguyen OK, Wu N, Klapstein GJ, Nguyen S, Koh S, Vinters HV, Levine MS, Mathern GW. Pediatric Cortical Dysplasia: Correlations between Neuroimaging, Electrophysiology and Location of Cytomegalic Neurons and Balloon Cells and Glutamate/GABA Synaptic Circuits. Dev Neurosci 2005; 27:59-76. [PMID: 15886485 DOI: 10.1159/000084533] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Accepted: 11/08/2004] [Indexed: 11/19/2022] Open
Abstract
Seizures in cortical dysplasia (CD) could be from cytomegalic neurons and balloon cells acting as epileptic 'pacemakers', or abnormal neurotransmission. This study examined these hypotheses using in vitro electrophysiological techniques to determine intrinsic membrane properties and spontaneous glutamatergic and GABAergic synaptic activity for normal-pyramidal neurons, cytomegalic neurons and balloon cells from 67 neocortical sites originating from 43 CD patients (ages 0.2-14 years). Magnetic resonance imaging (MRI), (18)fluoro-2-deoxyglucose positron emission tomography (FDG-PET) and electrocorticography graded cortical sample sites from least to worst CD abnormality. Results found that cytomegalic neurons and balloon cells were observed more frequently in areas of severe CD compared with mild or normal CD regions as assessed by FDG-PET/MRI. Cytomegalic neurons (but not balloon cells) correlated with the worst electrocorticography scores. Electrophysiological recordings demonstrated that cytomegalic and normal-pyramidal neurons displayed similar firing properties without intrinsic bursting. By contrast, balloon cells were electrically silent. Normal-pyramidal and cytomegalic neurons displayed decreased spontaneous glutamatergic synaptic activity in areas of severe FDG-PET/MRI abnormalities compared with normal regions, while GABAergic activity was unaltered. In CD, these findings indicate that cytomegalic neurons (but not balloon cells) might contribute to epileptogenesis, but are not likely to be 'pacemaker' cells capable of spontaneous paroxysmal depolarizations. Furthermore, there was more GABA relative to glutamate synaptic neurotransmission in areas of severe CD. Thus, in CD tissue alternate mechanisms of epileptogenesis should be considered, and we suggest that GABAergic synaptic circuits interacting with cytomegalic and normal-pyramidal neurons with immature receptor properties might contribute to seizure generation.
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Affiliation(s)
- C Cepeda
- Division of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
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Englund C, Folkerth RD, Born D, Lacy JM, Hevner RF. Aberrant neuronal-glial differentiation in Taylor-type focal cortical dysplasia (type IIA/B). Acta Neuropathol 2005; 109:519-33. [PMID: 15877232 DOI: 10.1007/s00401-005-1005-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2004] [Revised: 02/18/2005] [Accepted: 02/18/2005] [Indexed: 11/26/2022]
Abstract
Focal cortical dysplasia (FCD) type IIA/B (Taylor type) is a malformation of cortical development characterized by laminar disorganization and dysplastic neurons. FCD IIA and FCD IIB denote subtypes in which balloon cells are absent or present, respectively. The etiology of FCD IIA/B is unknown, but previous studies suggest that its pathogenesis may involve aberrant, mixed neuronal-glial differentiation. To investigate whether aberrant differentiation is a consistent phenotype in FCD IIA/B, we studied a panel of neuronal and glial marker antigens in a series of 15 FCD IIB cases, and 2 FCD IIA cases. Double-labeling immunofluorescence and confocal imaging revealed that different combinations of neuronal and glial antigens were co-expressed by individual cells in all cases of FCD IIA/B, but not in control cases of epilepsy due to other causes. Co-expression of neuronal and glial markers was most common in balloon cells, but was also observed in dysplastic neurons. The relative expression of neuronal and glial antigens varied over a broad range. Microtubule-associated protein 1B, an immature neuronal marker, was more frequently co-expressed with glial antigens than were mature neuronal markers, such as neuronal nuclear antigen. Our results indicate that aberrant neuronal-glial differentiation is a consistent and robust phenotype in FCD IIA/B, and support the hypothesis that developmental defects of neuronal and glial fate specification play an important role in its pathogenesis.
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Affiliation(s)
- Chris Englund
- Department of Pathology, Box 359791, Harborview Medical Center, University of Washington School of Medicine, 325 Ninth Ave., Seattle, WA 98104, USA
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Mueller SG, Laxer KD, Barakos JA, Cashdollar N, Flenniken DL, Vermathen P, Matson GB, Weiner MW. Metabolic characteristics of cortical malformations causing epilepsy. J Neurol 2005; 252:1082-92. [PMID: 15868069 PMCID: PMC2709485 DOI: 10.1007/s00415-005-0819-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Revised: 12/16/2004] [Accepted: 01/12/2005] [Indexed: 12/21/2022]
Abstract
PURPOSE Cortical malformations (CMs) are increasingly recognized as the epileptogenic substrate in patients with medically refractory neocortical epilepsy (NE). The aim of this study was to test the hypotheses that: 1. CMs are metabolically heterogeneous. 2. The structurally normal appearing perilesional zone is characterized by similar metabolic abnormalities as the CM. METHODS Magnetic resonance spectroscopic imaging (MRSI) in combination with tissue segmentation was performed on eight patients with NE and CMs and 19 age matched controls. In controls, NAA, Cr, Cho,NAA/Cr and NAA/Cho of all voxels of a given lobe were expressed as a function of white matter content and thresholds for pathological values determined by calculating the 95% prediction intervals. These thresholds were used to identify metabolically abnormal voxels within the CM and in the perilesional zone. RESULTS 30% of all voxels in the CMs were abnormal, most frequently because of decreases of NAA or increases of Cho. Abnormal voxels tended to form metabolically heterogeneous clusters interspersed in metabolically normal regions. Furthermore, 15% of all voxels in the perilesional zone were abnormal, the most frequent being decreases of NAA and Cr. CONCLUSION In CMs metabolically normal regions are interspersed with metabolically heterogeneous abnormal regions. Metabolic abnormalities in the perilesional zone share several characteristics of CMs and might therefore represent areas with microscopic malformations and/or intrinsic epileptogenicity.
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Affiliation(s)
- Susanne G. Mueller
- Dept. of Veterans Affairs (DVA), Medical Center, Magnetic Resonance Spectroscopy Unit, San Francisco (CA), USA
- Dept. of Radiology, University of California, San Francisco (CA), USA
| | - Kenneth D. Laxer
- Pacific Epilepsy Program, California Pacific Medical Center, 2100 Webster Street, Suite 115, San Francisco (CA) 94115, USA, Tel.: +1-415/600-7880, Fax: +1-415/600-7885
| | - Jerome A. Barakos
- Pacific Epilepsy Program, California Pacific Medical Center, 2100 Webster Street, Suite 115, San Francisco (CA) 94115, USA, Tel.: +1-415/600-7880, Fax: +1-415/600-7885
| | - Nathan Cashdollar
- Dept. of Veterans Affairs (DVA), Medical Center, Magnetic Resonance Spectroscopy Unit, San Francisco (CA), USA
| | - Derek L. Flenniken
- Dept. of Veterans Affairs (DVA), Medical Center, Magnetic Resonance Spectroscopy Unit, San Francisco (CA), USA
| | - Peter Vermathen
- Dept. of Veterans Affairs (DVA), Medical Center, Magnetic Resonance Spectroscopy Unit, San Francisco (CA), USA
| | - Gerald B. Matson
- Dept. of Veterans Affairs (DVA), Medical Center, Magnetic Resonance Spectroscopy Unit, San Francisco (CA), USA
- Dept. of Pharmaceutical Chemistry, University of California, San Francisco (CA), USA
| | - Michael W. Weiner
- Dept. of Veterans Affairs (DVA), Medical Center, Magnetic Resonance Spectroscopy Unit, San Francisco (CA), USA
- Dept. of Radiology, University of California, San Francisco (CA), USA
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Otsubo H, Iida K, Oishi M, Okuda C, Ochi A, Pang E, Weiss SK, Rutka JT, Chuang SH, Snead OC. Neurophysiologic findings of neuronal migration disorders: intrinsic epileptogenicity of focal cortical dysplasia on electroencephalography, electrocorticography, and magnetoencephalography. J Child Neurol 2005; 20:357-63. [PMID: 15921239 DOI: 10.1177/08830738050200041501] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We define specific neurophysiologic characteristics for focal cortical dysplasia, a neuronal migration disorder. We reviewed data from published reports and our patients with focal cortical dysplasia. Our patients underwent preoperative scalp video-electroencephalography (EEG), magnetic resonance imaging (MRI), magnetoencephalography, and intraoperative or extraoperative electrocorticography monitoring. Scalp EEG showed trains of rhythmic epileptiform spike or sharp waves. Positive spikes correlated with early seizure onset, MRI lesion around the rolandic fissure, hemiparesis, and a less favorable outcome. Interictal electrocorticography showed continuous epileptogenic discharges: repetitive electrographic seizures and bursting discharges or continuous or quasicontinuous rhythmic spiking. Ictal electrocorticography showed paroxysmal fast and/or repetitive spiking. Magnetoencephalography showed clustered spike sources within and extending from the lesion. Cortical stimulation gave more frequent, lower-threshold afterdischarges and higher-threshold primary motor function. Focal cortical dysplasias are highly and intrinsically epileptogenic. For surgical seizure control, EEG, electrocorticography, and magnetoencephalography must delineate the intrinsic epileptogenic zone within and extending from the focal cortical dysplasia identified by MRI.
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Affiliation(s)
- Hiroshi Otsubo
- Division of Neurology, The Hospital for Sick Children, Toronto, ON, Canada.
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Sakuta R, Otsubo H, Nolan MA, Weiss SK, Hawkins C, Rutka JT, Chuang NA, Chuang SH, Snead OC. Recurrent intractable seizures in children with cortical dysplasia adjacent to dysembryoplastic neuroepithelial tumor. J Child Neurol 2005; 20:377-84. [PMID: 15921242 DOI: 10.1177/08830738050200041801] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The purpose of this study was to identify the pathologic features that predict postoperative outcome in children with cortical dysplasia adjacent to dysembryoplastic neuroepithelial tumors. We reviewed the records of children with dysembryoplastic neuroepithelial tumor who underwent epilepsy surgery and who had at least 1 year of surgical follow-up. We divided the dysembryoplastic neuroepithelial tumors into three pathology classes (simple, complex, and nonspecific), categorized adjunctive cortical dysplasia into four types, and compared histopathology with seizure outcomes. We identified 26 children with dysembryoplastic neuroepithelial tumors. Dysembryoplastic neuroepithelial tumors were complex in 19 patients (73%), simple in 6 (23%), and nonspecific in 1 (4%). Cortical dysplasia was adjacent to dysembryoplastic neuroepithelial tumors in 18 patients. Six patients had type IA cortical dysplasia, 5 had type IB, 3 had type IIA, and 1 had type IIB. The 3 remaining patients had repeated surgeries; of these, 2 patients had cortical dysplasias of type IA/IB and 1 was type IIA/IIB. Eight (39%) of 18 patients with dysembryoplastic neuroepithelial tumors and cortical dysplasia required further surgery for recurrent intractable seizures (P < .05), whereas none of 8 patients without cortical dysplasia required additional surgery. Of 13 patients with type I cortical dysplasia, only 4 had a poor seizure outcome, whereas all 5 patients with type II had a poor seizure outcome postoperatively (P < .05). Children with dysembryoplastic neuroepithelial tumor and cortical dysplasia often had recurrent intractable seizures postoperatively and required further epilepsy surgery. Cortical dysplasia adjacent to dysembryoplastic neuroepithelial tumor can play a role in the epileptogenicity of dysembryoplastic neuroepithelial tumor. Complete resection of a dysembryoplastic neuroepithelial tumor and its adjacent cortical dysplasia should be considered.
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Affiliation(s)
- Ryoichi Sakuta
- Division of Pathology, The Hospital for Sick Children, University of Toronto, ON, Canada.
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Cohen-Gadol AA, Ozduman K, Bronen RA, Kim JH, Spencer DD. Long-term outcome after epilepsy surgery for focal cortical dysplasia. J Neurosurg 2004; 101:55-65. [PMID: 15255252 DOI: 10.3171/jns.2004.101.1.0055] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Reports of outcomes for surgical treatment of cortical dysplasia associated with epilepsy are conflicting due to the inclusion of patients with a wide range of malformations of cortical development. The authors report their experience and the long-term outcome for a subgroup of patients with the histopathological diagnosis of focal cortical dysplasia of Taylor. METHODS The records of 22 patients with focal cortical dysplasia of Taylor (15 with the balloon-cell type and seven with the nonballoon-cell type) were reviewed. There were 11 female and 11 male patients whose mean age was 26 +/- 17.6 years (mean +/- standard deviation [SD]) at surgery. The details of their epilepsy evaluation and resection were analyzed. Extent of resection was preoperatively planned using information obtained from long-term intracranial monitoring (15 patients) and/or more definitively determined by histopathologically proven clear margins during resection when feasible (12 patients). The mean duration of follow up was 6.3 +/- 5.1 years (mean +/- SD, range 0.5-15.6 years). Risk factors for epilepsy were trauma (seven patients) or meningoencephalitis (one patient); 14 patients (64%) had no obvious risk factors. The mean age at seizure onset was 9.2 years and the mean duration of their epilepsy was 16.1 +/- 9 years. In two patients there were no adverse findings on magnetic resonance (MR) imaging. In 15 patients (68%), the epileptogenic zone identified on long-term intracranial monitoring extended beyond the abnormality observed on MR images. Focal resection (lesion plus margins) was performed in 14 patients (64%), whereas eight (36%) underwent partial/tailored lobectomy. Two patients underwent multiple subpial transections in addition to partial lesionectomy because their lesions involved the sensorimotor cortex. In these two, functional MR imaging confirmed a normal functional anatomy despite the presence of the cortical dysplasia. Eleven (92%) of 12 patients who underwent resection guided by histopathologically proven clear margins and three (43%) of seven patients who underwent histopathologically proven subtotal resection have remained seizure free. Evidence of clear margins was significantly associated with an improved seizure outcome (p = 0.003). Postoperatively, expected deficits included nondisabling visual field defects, which occurred in three patients (14%), and transient sensorimotor deficits, which appeared in five (23%). Two patients had meningitis, which was successfully treated with antibiotics. Overall, 16 patients (73%) are either seizure free (13 patients), have rare nondisabling partial seizures (one patient), or had one seizure after their medication was changed (two patients). Thirteen patients (59%) have discontinued anticonvulsant medications or are being maintained on monotherapy. Of five patients (23%), two have had rare disabling seizures or significant reduction in their seizure frequency (three patients). One patient's seizures have remained the same. CONCLUSIONS Focal cortical dysplasias are a distinct subgroup of malformations of cortical development and have a favorable outcome after resection. The epileptogenic zone often extends beyond the abnormality found on neuroimaging. Resection of the epileptogenic zone guided by histopathologically proven clear margins is associated with an improved seizure outcome.
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Affiliation(s)
- Aaron A Cohen-Gadol
- Department of Neurosurgery, Yale Universityv School of Medicine, New Haven, Connecticut 55905, USA.
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Crino PB. Malformations of cortical development: molecular pathogenesis and experimental strategies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 548:175-91. [PMID: 15250594 DOI: 10.1007/978-1-4757-6376-8_13] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Malformations of cortical development (MCD) are developmental brain lesions characterized by abnormal formation of the cerebral cortex and a high clinical association with epilepsy in infants, children, and adults. Despite multiple anti-epileptic drugs (AEDs), treatment of epilepsy associated with MCD may require cortical resection performed to remove the cytoarchitecturally abnormal region of cortex. Single genes responsible for distinct MCD including lissencephaly, subcortical band heterotopia, and tuberous sclerosis, have been identified and permit important mechanistic insights into how gene mutations result in abnormal cortical cytoarchitecture. The pathogenesis of MCD such as focal cortical dysplasia, hemimegalencephaly, and polymicrogyria, remains unknown. A variety of new techniques including cDNA array analysis now allow for analysis of gene expression within MCD.
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Affiliation(s)
- Peter B Crino
- Penn Epilespsy Center, Department of Neurology, University of Pennsylvania Medical Center, Philadelphia, USA
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