1
|
Roy A, Murphy RM, Deng M, MacDonald JW, Bammler TK, Aldinger KA, Glass IA, Millen KJ. PI3K-Yap activity drives cortical gyrification and hydrocephalus in mice. eLife 2019; 8:45961. [PMID: 31094678 PMCID: PMC6544437 DOI: 10.7554/elife.45961] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/15/2019] [Indexed: 01/07/2023] Open
Abstract
Mechanisms driving the initiation of brain folding are incompletely understood. We have previously characterized mouse models recapitulating human PIK3CA-related brain overgrowth, epilepsy, dysplastic gyrification and hydrocephalus (Roy et al., 2015). Using the same, highly regulatable brain-specific model, here we report PI3K-dependent mechanisms underlying gyrification of the normally smooth mouse cortex, and hydrocephalus. We demonstrate that a brief embryonic Pik3ca activation was sufficient to drive subtle changes in apical cell adhesion and subcellular Yap translocation, causing focal proliferation and subsequent initiation of the stereotypic ‘gyrification sequence’, seen in naturally gyrencephalic mammals. Treatment with verteporfin, a nuclear Yap inhibitor, restored apical surface integrity, normalized proliferation, attenuated gyrification and rescued the associated hydrocephalus, highlighting the interrelated role of regulated PI3K-Yap signaling in normal neural-ependymal development. Our data defines apical cell-adhesion as the earliest known substrate for cortical gyrification. In addition, our preclinical results support the testing of Yap-related small-molecule therapeutics for developmental hydrocephalus.
Collapse
Affiliation(s)
- Achira Roy
- Center for Integrative Brain Research, Seattle Children's Research Institute, Washington, United States
| | - Rory M Murphy
- Center for Integrative Brain Research, Seattle Children's Research Institute, Washington, United States
| | - Mei Deng
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Washington, United States
| | - James W MacDonald
- Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Washington, United States
| | - Theo K Bammler
- Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Washington, United States
| | - Kimberly A Aldinger
- Center for Integrative Brain Research, Seattle Children's Research Institute, Washington, United States.,Division of Genetic Medicine, Department of Pediatrics, University of Washington, Washington, United States
| | - Ian A Glass
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Washington, United States
| | - Kathleen J Millen
- Center for Integrative Brain Research, Seattle Children's Research Institute, Washington, United States.,Division of Genetic Medicine, Department of Pediatrics, University of Washington, Washington, United States
| |
Collapse
|
2
|
Mühlebner A, Bongaarts A, Sarnat HB, Scholl T, Aronica E. New insights into a spectrum of developmental malformations related to mTOR dysregulations: challenges and perspectives. J Anat 2019; 235:521-542. [PMID: 30901081 DOI: 10.1111/joa.12956] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2019] [Indexed: 12/20/2022] Open
Abstract
In recent years the role of the mammalian target of rapamycin (mTOR) pathway has emerged as crucial for normal cortical development. Therefore, it is not surprising that aberrant activation of mTOR is associated with developmental malformations and epileptogenesis. A broad spectrum of malformations of cortical development, such as focal cortical dysplasia (FCD) and tuberous sclerosis complex (TSC), have been linked to either germline or somatic mutations in mTOR pathway-related genes, commonly summarised under the umbrella term 'mTORopathies'. However, there are still a number of unanswered questions regarding the involvement of mTOR in the pathophysiology of these abnormalities. Therefore, a monogenetic disease, such as TSC, can be more easily applied as a model to study the mechanisms of epileptogenesis and identify potential new targets of therapy. Developmental neuropathology and genetics demonstrate that FCD IIb and hemimegalencephaly are the same diseases. Constitutive activation of mTOR signalling represents a shared pathogenic mechanism in a group of developmental malformations that have histopathological and clinical features in common, such as epilepsy, autism and other comorbidities. We seek to understand the effect of mTOR dysregulation in a developing cortex with the propensity to generate seizures as well as the aftermath of the surrounding environment, including the white matter.
Collapse
Affiliation(s)
- A Mühlebner
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - A Bongaarts
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - H B Sarnat
- Departments of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute (Owerko Centre), Calgary, AB, Canada
| | - T Scholl
- Department of Paediatric and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - E Aronica
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Amsterdam, The Netherlands
| |
Collapse
|
3
|
Curatolo P, Moavero R, van Scheppingen J, Aronica E. mTOR dysregulation and tuberous sclerosis-related epilepsy. Expert Rev Neurother 2018; 18:185-201. [DOI: 10.1080/14737175.2018.1428562] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Paolo Curatolo
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University Hospital, Rome, Italy
| | - Romina Moavero
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University Hospital, Rome, Italy
- Child Neurology Unit, Neuroscience and Neurorehabilitation Department, “Bambino Gesù” Children’s Hospital, IRCCS, Rome, Italy
| | - Jackelien van Scheppingen
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), The Netherlands
| |
Collapse
|
4
|
Abstract
Epilepsy is one of the most common neurologic disorders, affecting about 50 million people worldwide. The disease is characterized by recurrent seizures, which are due to aberrant neuronal networks resulting in synchronous discharges. The term epilepsy encompasses a large spectrum of syndromes and diseases with different etiopathogenesis. The recent development of imaging and epilepsy surgery techniques is now enabling the identification of structural abnormalities that are part of the epileptic network, and the removal of these lesions may result in control of seizures. Access of this clinically well-characterized neurosurgical material has provided neuropathologists with the opportunity to study a variety of structural brain abnormalities associated with epilepsy, by combining traditional routine histopathologic methods with molecular genetics and functional analysis of the resected tissue. This approach has contributed greatly to a better diagnosis and classification of these structural lesions, and has provided important new insights into their pathogenesis and epileptogenesis. The present chapter provides a detailed description of the large spectrum of histopathologic findings encountered in epilepsy surgery patients, addressing in particular the nonneoplastic pathologies, including hippocampal sclerosis, malformations of cortical development, Sturge-Weber syndrome, and Rasmussen encephalitis, and reviews current knowledge regarding the underlying molecular pathomechanisms and cellular mechanisms mediating hyperexcitability.
Collapse
Affiliation(s)
- Eleonora Aronica
- Department of Neuropathology, Academic Medical Center and Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands; Stichting Epilepsie Instellingen Nederland, the Netherlands.
| | - Angelika Mühlebner
- Department of Neuropathology, Academic Medical Center and Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands
| |
Collapse
|
5
|
Ono Y, Saito Y, Maegaki Y, Tohyama J, Montassir H, Fujii S, Sugai K, Ohno K. Three cases of right frontal megalencephaly: Clinical characteristics and long-term outcome. Brain Dev 2016; 38:302-9. [PMID: 26415548 DOI: 10.1016/j.braindev.2015.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 09/08/2015] [Accepted: 09/11/2015] [Indexed: 11/30/2022]
Abstract
AIM To delineate the clinical and neuroimaging characteristics of localized megalencephaly involving the right frontal lobe. METHOD Data from three patients aged 14-16 years at the last follow-up were retrospectively reviewed. RESULTS All the patients were normal on neurological examination with no signs of hemiparesis. Enlargement of the right frontal lobe with increased volume of subcortical and deep white matter, as well as thickening of the ipsilateral genu of the corpus callosum was common. The onset of epilepsy was 4-7 years of age, with seizure types of massive myoclonus in two and generalized tonic-clonic in two, which could be eventually controlled by antiepileptics. Interictal electroencephalography showed frontal alpha-like activity in one, and abundant spike-wave complexes resulting in diffuse continuous spike-wave activity during sleep in two patients even after suppression of clinical seizures. Psychomotor development appeared unaffected or slightly delayed before the onset of epilepsy, but became mildly disturbed during follow-up period of 7-11 years. CONCLUSION Certain patients with right frontal megalencephaly can present with a milder epileptic and intellectual phenotype among those with localized megalencephaly and holohemispheric hemimegalencephaly, whose characteristic as epileptic encephalopathy was assumed from this study.
Collapse
Affiliation(s)
- Yoichi Ono
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Yoshiaki Saito
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan.
| | - Yoshihiro Maegaki
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Jun Tohyama
- Department of Pediatrics, Epilepsy Center, Nishi-Niigata Chuo National Hospital, Niigata, Japan
| | - Hesham Montassir
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Shinya Fujii
- Division of Radiology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Kenji Sugai
- Department of Child Neurology, National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Kousaku Ohno
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, Yonago, Japan
| |
Collapse
|
6
|
Roy A, Skibo J, Kalume F, Ni J, Rankin S, Lu Y, Dobyns WB, Mills GB, Zhao JJ, Baker SJ, Millen KJ. Mouse models of human PIK3CA-related brain overgrowth have acutely treatable epilepsy. eLife 2015; 4. [PMID: 26633882 PMCID: PMC4744197 DOI: 10.7554/elife.12703] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 11/26/2015] [Indexed: 12/12/2022] Open
Abstract
Mutations in the catalytic subunit of phosphoinositide 3-kinase (PIK3CA) and other PI3K-AKT pathway components have been associated with cancer and a wide spectrum of brain and body overgrowth. In the brain, the phenotypic spectrum of PIK3CA-related segmental overgrowth includes bilateral dysplastic megalencephaly, hemimegalencephaly and focal cortical dysplasia, the most common cause of intractable pediatric epilepsy. We generated mouse models expressing the most common activating Pik3ca mutations (H1047R and E545K) in developing neural progenitors. These accurately recapitulate all the key human pathological features including brain enlargement, cortical malformation, hydrocephalus and epilepsy, with phenotypic severity dependent on the mutant allele and its time of activation. Underlying mechanisms include increased proliferation, cell size and altered white matter. Notably, we demonstrate that acute 1 hr-suppression of PI3K signaling despite the ongoing presence of dysplasia has dramatic anti-epileptic benefit. Thus PI3K inhibitors offer a promising new avenue for effective anti-epileptic therapy for intractable pediatric epilepsy patients. DOI:http://dx.doi.org/10.7554/eLife.12703.001 An enzyme called PI3K is involved in a major signaling pathway that controls cell growth. Mutations in this pathway have devastating consequences. When such mutations happen in adults, they can lead to cancer. Mutations that occur in embryos can cause major developmental birth defects, including abnormally large brains. After birth, these developmental problems can cause intellectual disabilities, autism and epilepsy. Children with this kind of epilepsy often do not respond to currently available seizure medications. There are several outstanding questions that if answered could help efforts to develop treatments for children with brain growth disorders. Firstly, how do the developmental abnormalities happen? Do the abnormalities themselves cause epilepsy? And can drugs that target this pathway, and are already in clinical trials for cancer, control seizures? Now, Roy et al. have made mouse models of these human developmental brain disorders and used them to answer these questions. The mice were genetically engineered to have various mutations in the gene that encodes the catalytic subunit of the PI3K enzyme. The mutations were the same as those found in people with brain overgrowth disorders, and were activated only in the developing brain of the mice. These mutations caused enlarged brain size, fluid accumulation in the brain, brain malformations and epilepsy in developing mice – thus mimicking the human birth defects. The severity of these symptoms depended on the specific mutation and when the mutant genes were turned on during development. Next, Roy et al. studied these mice to see if the seizures could be treated using a drug, that has already been developed for brain cancer. This drug specifically targets and reduces the activity of PI3K. Adult mutant mice with brain malformations were treated for just one hour; this dramatically reduced their seizures. These experiments prove that seizures associated with this kind of brain overgrowth disorder are driven by ongoing abnormal PI3K activity and can be treated even when underlying brain abnormalities persist. Roy et al. suggest that drugs targeting PI3K might help treat seizures in children with these brain overgrowth disorders. DOI:http://dx.doi.org/10.7554/eLife.12703.002
Collapse
Affiliation(s)
- Achira Roy
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Jonathan Skibo
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Franck Kalume
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Jing Ni
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, United States
| | - Sherri Rankin
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, United States
| | - Yiling Lu
- The University of Texas MD Anderson Cancer Center, Houston, United States
| | - William B Dobyns
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| | - Gordon B Mills
- The University of Texas MD Anderson Cancer Center, Houston, United States
| | - Jean J Zhao
- Department of Cancer Biology, Dana Farber Cancer Institute, Boston, United States
| | - Suzanne J Baker
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, United States
| | - Kathleen J Millen
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, United States
| |
Collapse
|
7
|
Ma L, Yang F, Zhao R, Li L, Kang X, Xiao L, Jiang W. Quetiapine attenuates cognitive impairment and decreases seizure susceptibility possibly through promoting myelin development in a rat model of malformations of cortical development. Brain Res 2015; 1622:443-51. [PMID: 26188240 DOI: 10.1016/j.brainres.2015.07.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 06/19/2015] [Accepted: 07/09/2015] [Indexed: 10/23/2022]
Abstract
Developmental delay, cognitive impairment, and refractory epilepsy are the most frequent consequences found in patients suffering from malformations of cortical development (MCD). However, therapeutic options for these psychiatric and neurological comorbidities are currently limited. The development of white matter undergoes dramatic changes during postnatal brain maturation, thus myelination deficits resulting from MCD contribute to its comorbid diseases. Consequently, drugs specifically targeting white matter are a promising therapeutic option for the treatment of MCD. We have used an in utero irradiation rat model of MCD to investigate the effects of postnatal quetiapine treatment on brain myelination as well as neuropsychological and cognitive performances and seizure susceptibility. Fatally irradiated rats were treated with quetiapine (10mg/kg, i.p.) or saline once daily from postnatal day 0 (P0) to P30. We found that postnatal administration of quetiapine attenuated object recognition memory impairment and improved long-term spatial memory in the irradiated rats. Quetiapine treatment also reduced the susceptibility and severity of pentylenetetrazol-induced seizures. Importantly, quetiapine treatment resulted in an inhibition of irradiation-induced myelin breakdown in the cerebral cortex and corpus callosum. These findings suggest that quetiapine may have beneficial, postnatal effects in the irradiated rats, strongly suggesting that improving MCD-derived white matter pathology is a possible underlying mechanism. Collectively, these results indicate that brain myelination represents an encouraging pharmacological target to improve the prognosis of patients with MCD.
Collapse
Affiliation(s)
- Lei Ma
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi׳an 710032, China
| | - Feng Yang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi׳an 710032, China
| | - Rui Zhao
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi׳an 710032, China; Department of Neurology, Shaanxi Provincial People׳s Hospital, Xi׳an 710068, China
| | - Li Li
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi׳an 710032, China
| | - Xiaogang Kang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi׳an 710032, China
| | - Lan Xiao
- Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
| | - Wen Jiang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi׳an 710032, China.
| |
Collapse
|
8
|
Hemispheric malformations of cortical development: surgical indications and approach. Childs Nerv Syst 2014; 30:1831-7. [PMID: 25296544 DOI: 10.1007/s00381-014-2483-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 06/27/2014] [Indexed: 10/24/2022]
Abstract
INTRODUCTION The term "hemispheric malformation of cortical development" (MCD) has come into the medical lexicon in the past 20 years as improvements and availability of advanced imaging techniques have permitted more precise diagnosis of a variety of brain developmental disorders that affect large regions of brain. These conditions are united by their propensity to elicit seizures that are difficult to control with medication in the children who suffer them. PURPOSE The goal of surgical intervention is always to achieve seizure freedom and thereby give the affected child the best possible hope for neurological development. Even when seizure freedom cannot be achieved, a reduction in seizure burden is necessary to permit the survival of the child in many cases of MCD. EVALUATION A presurgical evaluation of a patient presenting with severe epilepsy and a possible hemispheric malformation can be divided into three stages. The first includes an evaluation of available imaging, clinical, and genetic data to accurately diagnose the child and help determine if surgical intervention is an option. The next includes an evaluation of EEG and neurological data, although this has limited utility in many clinical circumstances. Finally, a clinical team must decide upon an appropriate surgical strategy among a variety of options. CONCLUSIONS In this review, we will examine the set of diagnoses and associated imaging characteristics that describe the set of conditions for which surgical intervention is a possibility. We include a discussion of available surgical options, describing our own experience with surgery for MCD and the associated postoperative considerations including rates of seizure freedom, considerations for reoperation, and hydrocephalus.
Collapse
|
9
|
Magnetic resonance diffusion tensor imaging metrics in perilesional white matter among children with periventricular nodular gray matter heterotopia. Pediatr Radiol 2013; 43:1196-203. [PMID: 23529629 DOI: 10.1007/s00247-013-2677-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 02/08/2013] [Accepted: 02/12/2013] [Indexed: 02/03/2023]
Abstract
BACKGROUND Despite pharmacological and surgical interventions, some children with periventricular nodular heterotopia (PNH) remain refractory to treatment, which suggests more diffuse pathology potentially involving perilesional white matter. OBJECTIVE The purpose of this study was to evaluate MR diffusion tensor imaging (MRDTI) metrics within perilesional white matter in children with PNH. MATERIALS AND METHODS Six children with PNH (four boys; average age 3.2 years, range 2 months to 6 years) were studied with MRDTI at 3 T. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) were quantified within perilesional white matter at distances of 5 mm, 10 mm, 15 mm, and 20 mm from focal areas of PNH and compared to location-matched ROIs in six healthy control patients (two boys, average age 3.3 years, range 2-6 years). Statistical significance was set at an overall level of α = 0.05, corrected for multiple comparisons. RESULTS Perilesional white matter showed significantly decreased fractional anisotropy and elevated mean and radial diffusivity at all evaluated distances. No significant differences in axial diffusivity were detected at any distance. CONCLUSION PNH is associated with microstructural white matter abnormalities as indicated by abnormal perilesional MRDTI metrics detectable at least 20 mm from visible nodular lesions.
Collapse
|
10
|
Tarsi A, Marliani AF, Bartiromo F, Giulioni M, Marucci G, Martinoni M, Volpi L, Leonardi M. MRI findings in low grade tumours associated with focal cortical dysplasia. Neuroradiol J 2012; 25:639-48. [PMID: 24029175 DOI: 10.1177/197140091202500601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 11/04/2012] [Indexed: 11/15/2022] Open
Abstract
Magnetic resonance imaging (MRI) is mandatory to identify the epileptogenic zone in refractory temporal lobe epilepsy (TLE). The correct identification of lesions is essential to obtain good post-surgery seizure control. Low grade tumours (LGT) and focal cortical dysplasia (FCD) are common findings in symptomatic TLE, and frequently coexist. The aim of this study was to identify the MRI characteristics in the diagnosis of FCD associated with LGT. We analyzed 24 subjects with TLE who underwent tailored surgery. They all had LGTs. Two expert neuroradiologists analyzed the imaging data and compared them with histological results, hypothesizing the causes of diagnostic errors in the identification of FCD. We selected three exemplary cases to report the most important causes of errors. In the diagnosis of FCD we reported false positives and false negatives due to different causes. An incomplete MRI protocol, the large dimensions of the tumour, infiltration and related oedema were the most important factors limiting MRI accuracy. MRI can be limited by an incomplete protocol. In addition, the presence of an LGT may limit the neuroradiological diagnosis of FCD in the temporal lobe. Advanced MRI techniques could help reveal subtle lesions that eluded a previous imaging inspection.
Collapse
Affiliation(s)
- A Tarsi
- Division of Neuroradiology, Department of Neurosciences, Bellaria Hospital, "IRCCS Istituto delle Scienze Neurologiche"; Bologna, Italy -
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Focal cortical dysplasia. Clinical-radiological-pathological associations. NEUROLOGÍA (ENGLISH EDITION) 2012. [DOI: 10.1016/j.nrleng.2011.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
12
|
Development and dysgenesis of the cerebral cortex: malformations of cortical development. Neuroimaging Clin N Am 2012; 21:483-543, vii. [PMID: 21807310 DOI: 10.1016/j.nic.2011.05.014] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The cerebral cortex develops in several stages from a pseudostratified epithelium at 5 weeks to an essentially complete cortex at 47 weeks. Cortical connectivity starts with thalamocortical connections in the 3rd trimester only and continues until well after birth. Vascularity adapts to proliferation and connectivity. Malformations of cortical development are classified into disorders of specification, proliferation/apoptosis, migration, and organization. However, all processes are intermingled, as for example a dysplastic cell may migrate incompletely and not connect appropriately. However, this classification is convenient for didactic purposes as long as the complex interactions between the different processes are kept in mind.
Collapse
|
13
|
Pascual-Castroviejo I, Hernández-Moneo JL, Gutiérrez-Molina ML, Viaño J, Pascual-Pascual SI, Velazquez-Fragua R, Morales C, Quiñones D. Focal cortical dysplasia. Clinical-radiological-pathological associations. Neurologia 2012; 27:472-80. [PMID: 22217526 DOI: 10.1016/j.nrl.2011.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 10/11/2011] [Accepted: 10/15/2011] [Indexed: 10/14/2022] Open
Abstract
INTRODUCTION The term focal cortical dysplasia (FCD) describes a particular migration disorder with a symptomatology mainly characterised by drug-resistant epileptic seizures, typical neuroradiological images, and histological characteristics, as well as a very positive response to surgical treatment in the majority of cases. MATERIAL AND METHODS A total of 7 patients were studied, comprising 6 children with a mean age of 34.3 months and one 25-year-old male with very persistent focal seizures and MRI images that showed FCD. RESULTS Three of the patients (all girls) were operated on while very young, with extirpation of the FCD and the surrounding area; with the histopathology study showed agreement between the MRI images and the macroscopic study of the slices. The histology study showed findings typical of a Taylor-type FCD (poor differentiation between the cortical grey matter and the subcortical white matter, and balloon cells). Three years after the FCD extirpation, the same 3 patients remained seizure-free with no anti-epilepsy medication. Two others have seizure control with medication, another (the adult) is on the surgical waiting list, and the remaining patient refused the operation. CONCLUSION Taylor-type FCD is associated with a high percentage of all drug-resistant focal seizures, and it needs to be identified and extirpated as soon as possible. Well planned and well-performed surgery that leaves no remains of dysplasia can cure the disease it in many cases.
Collapse
|
14
|
Jackson GD, Badawy RAB. Selecting patients for epilepsy surgery: identifying a structural lesion. Epilepsy Behav 2011; 20:182-9. [PMID: 21145290 DOI: 10.1016/j.yebeh.2010.09.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 09/19/2010] [Indexed: 11/20/2022]
Abstract
One of the most important components of presurgical evaluation of patients with epilepsy is structural imaging, predominantly using magnetic resonance imaging. This study is now part of the basic assessment of patients with epilepsy and is as important as the electroencephalogram. Epilepsy protocol magnetic resonance imaging studies must be part of the overall assessment of the patient. To understand the basis of the epileptic disorder, interpretation of these investigations relies on knowledge of the clinical details and features of the seizures, the functional abnormality in the brain as shown on the electroencephalogram, and structural assessment of the brain with a magnetic resonance imaging study optimized for epilepsy. This review considers the essential elements of this issue and gives a broad overview of what imaging options are available for the investigation of the patient with epilepsy from the perspective of the practicing epileptologist.
Collapse
Affiliation(s)
- Graeme D Jackson
- Brain Research Institute, Florey Neurosciences Institutes, Austin Repatriation Hospital, Heidelberg West, Victoria, Australia.
| | | |
Collapse
|
15
|
Abstract
The purpose of this article is to familiarize radiologists with the different aspects of severe drug resistant epilepsy. These result in three levels of disability: the disease itself (seizures and their impact, underlying cause), social impact (restrictions, safety and precautions, education, activities of daily life) and issues related to the medical treatment (long term medication intake, side effects, complications). First, clinical and EEG diagnosis will be reviewed to move on to MRI with attention to technical and protocol considerations followed by the imaging features of specific entities causing severe drug resistant epilepsy: migration and gyration disorders, Rasmussen's encephalitis, Sturge Weber disease and post-ischemic sequelae. Finally, current data and the imaging features of hemispherotomy, a radical treatment for epilepsy, will be presented.
Collapse
Affiliation(s)
- C Bordonne
- Service de radiologie, Hôtel Dieu, 4 Place du Parvis notre dame, 75004 Paris, France
| | | | | |
Collapse
|
16
|
Schmidlin E, Jouffrais C, Freund P, Wannier-Morino P, Beaud ML, Rouiller EM, Wannier T. A case of polymicrogyria in macaque monkey: impact on anatomy and function of the motor system. BMC Neurosci 2009; 10:155. [PMID: 20030837 PMCID: PMC2807873 DOI: 10.1186/1471-2202-10-155] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Accepted: 12/23/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Polymicrogyria is a malformation of the cerebral cortex often resulting in epilepsy or mental retardation. It remains unclear whether this pathology affects the structure and function of the corticospinal (CS) system. The anatomy and histology of the brain of one macaque monkey exhibiting a spontaneous polymicrogyria (PMG monkey) were examined and compared to the brain of normal monkeys. The CS tract was labelled by injecting a neuronal tracer (BDA) unilaterally in a region where low intensity electrical microstimulation elicited contralateral hand movements (presumably the primary motor cortex in the PMG monkey). RESULTS The examination of the brain showed a large number of microgyri at macro- and microscopic levels, covering mainly the frontoparietal regions. The layered cortical organization was locally disrupted and the number of SMI-32 stained pyramidal neurons in the cortical layer III of the presumed motor cortex was reduced. We compared the distribution of labelled CS axons in the PMG monkey at spinal cervical level C5. The cumulated length of CS axon arbors in the spinal grey matter was not significantly different in the PMG monkey. In the red nucleus, numerous neurons presented large vesicles. We also assessed its motor performances by comparing its capacity to execute a complex reach and grasp behavioral task. The PMG monkey exhibited an increase of reaction time without any modification of other motor parameters, an observation in line with a normal CS tract organisation. CONCLUSION In spite of substantial cortical malformations in the frontal and parietal lobes, the PMG monkey exhibits surprisingly normal structure and function of the corticospinal system.
Collapse
Affiliation(s)
- Eric Schmidlin
- Unit of Physiology and Program in Neurosciences, Department of Medicine, Faculty of Sciences, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland.
| | | | | | | | | | | | | |
Collapse
|
17
|
Widjaja E, Zarei Mahmoodabadi S, Otsubo H, Snead OC, Holowka S, Bells S, Raybaud C. Subcortical Alterations in Tissue Microstructure Adjacent to Focal Cortical Dysplasia: Detection at Diffusion-Tensor MR Imaging by Using Magnetoencephalographic Dipole Cluster Localization. Radiology 2009; 251:206-15. [DOI: 10.1148/radiol.2511081092] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
18
|
Badawy RAB, Harvey AS, Macdonell RAL. Cortical hyperexcitability and epileptogenesis: Understanding the mechanisms of epilepsy - part 2. J Clin Neurosci 2009; 16:485-500. [PMID: 19230676 DOI: 10.1016/j.jocn.2008.10.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 10/03/2008] [Indexed: 12/19/2022]
Abstract
Epilepsy encompasses a diverse group of seizure disorders caused by a variety of structural, cellular and molecular alterations of the brain primarily affecting the cerebral cortex, leading to recurrent unprovoked epileptic seizures. In this two-part review we examine the mechanisms underlying normal neuronal function and those predisposing to recurrent epileptic seizures starting at the most basic cellular derangements (Part 1, Volume 16, Issue 3) and working up to the highly complex epileptic networks and factors that modulate the predisposition to seizures (Part 2). We attempt to show that multiple factors can modify the epileptic process and that different mechanisms underlie different types of epilepsy, and in most situations there is an interplay between multiple genetic and environmental factors.
Collapse
Affiliation(s)
- Radwa A B Badawy
- Department of Neurology, Austin Health, Heidelberg, Victoria, Australia
| | | | | |
Collapse
|
19
|
Abdel Razek AAK, Kandell AY, Elsorogy LG, Elmongy A, Basett AA. Disorders of cortical formation: MR imaging features. AJNR Am J Neuroradiol 2009; 30:4-11. [PMID: 18687750 DOI: 10.3174/ajnr.a1223] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The purpose of this article was to review the embryologic stages of the cerebral cortex, illustrate the classification of disorders of cortical formation, and finally describe the main MR imaging features of these disorders. Disorders of cortical formation are classified according to the embryologic stage of the cerebral cortex at which the abnormality occurred. MR imaging shows diminished cortical thickness and sulcation in microcephaly, enlarged dysplastic cortex in hemimegalencephaly, and ipsilateral focal cortical thickening with radial hyperintense bands in focal cortical dysplasia. MR imaging detects smooth brain in classic lissencephaly, the nodular cortex with cobblestone cortex with congenital muscular dystrophy, and the ectopic position of the gray matter with heterotopias. MR imaging can detect polymicrogyria and related syndromes as well as the types of schizencephaly. We concluded that MR imaging is essential to demonstrate the morphology, distribution, and extent of different disorders of cortical formation as well as the associated anomalies and related syndromes.
Collapse
Affiliation(s)
- A A K Abdel Razek
- Department of Diagnostic Radiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
| | | | | | | | | |
Collapse
|
20
|
Abdel Razek AAK, Kandell AY, Elsorogy LG, Elmongy A, Basett AA. Disorders of cortical formation: MR imaging features. AJNR Am J Neuroradiol 2008; 31:1623-30. [PMID: 18687750 DOI: 10.3174/ajnr.a2135] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The purpose of this article was to review the embryologic stages of the cerebral cortex, illustrate the classification of disorders of cortical formation, and finally describe the main MR imaging features of these disorders. Disorders of cortical formation are classified according to the embryologic stage of the cerebral cortex at which the abnormality occurred. MR imaging shows diminished cortical thickness and sulcation in microcephaly, enlarged dysplastic cortex in hemimegalencephaly, and ipsilateral focal cortical thickening with radial hyperintense bands in focal cortical dysplasia. MR imaging detects smooth brain in classic lissencephaly, the nodular cortex with cobblestone cortex with congenital muscular dystrophy, and the ectopic position of the gray matter with heterotopias. MR imaging can detect polymicrogyria and related syndromes as well as the types of schizencephaly. We concluded that MR imaging is essential to demonstrate the morphology, distribution, and extent of different disorders of cortical formation as well as the associated anomalies and related syndromes.
Collapse
Affiliation(s)
- A A K Abdel Razek
- Department of Diagnostic Radiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
| | | | | | | | | |
Collapse
|
21
|
Winston KR, Kang J, Laoprasert P, Kleinschmidt-DeMasters BK. Hemispherectomy in a premature neonate with linear sebaceous nevus syndrome. Pediatr Neurosurg 2008; 44:159-64. [PMID: 18230933 DOI: 10.1159/000113121] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2006] [Accepted: 02/05/2007] [Indexed: 11/19/2022]
Abstract
A male neonate with seizures, linear sebaceous nevus syndrome and hemimegalencephaly underwent hemispherectomy at 36 weeks' gestational age. He has had no clinical seizures in the 13 months since surgery but continues to have sharp wave activity over some parts of the intact hemisphere. He has moderate developmental delay and a mild hemiparesis but is making developmental progress.
Collapse
Affiliation(s)
- Ken R Winston
- Department of Neurosurgery, The University of Colorado Health Sciences Center, Denver, CO 80218, USA.
| | | | | | | |
Collapse
|
22
|
Widjaja E, Blaser S, Miller E, Kassner A, Shannon P, Chuang SH, Snead OC, Raybaud CR. Evaluation of subcortical white matter and deep white matter tracts in malformations of cortical development. Epilepsia 2007; 48:1460-9. [PMID: 17441991 DOI: 10.1111/j.1528-1167.2007.01105.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Abnormal cortical development will lead to abnormal axons in white matter. The purpose was to investigate (1) the microstructural changes in subcortical white matter adjacent to malformations of cortical development (MCD) and (2) the deep white matter tracts using diffusion tensor imaging (DTI). METHODS Thirteen children with a variety of MCD were recruited. The fractional anisotropy (FA), trace, and eigenvalues (lambdamajor, lambdamedium, lambdaminor) of subcortical white matter of MCD were compared with contralateral normal side. The deep white matter tracts were graded based on the size, color hues and displacement of the tracts as visualized on color vector maps and tractography; grade 1 was normal tract size and color hue, grade 2 was reduced tract size but preserved color hue and grade 3 was loss of color hue or failure of tracking on tractography. RESULTS The subcortical white matter adjacent to abnormal cortex demonstrated reduced FA (p < 0.05) and tendency to increase trace (p = 0.06). There was a significant elevation in lambdamedium and lambdaminor (p < 0.05), but no significant change in lambdamajor (p > 0.05). Twelve cases demonstrated alteration in white matter tracts. Seven cases of focal cortical dysplasia and two cases of transmantle MCD demonstrated grade 3 pattern of white matter tract. CONCLUSION Reduced FA is a sensitive but nonspecific marker of alteration in microstructure of white matter. The elevated lambdamedium and lambdaminor may reflect a dominant effect of abnormal myelin. Alteration in white matter tracts was observed in most cases of MCD.
Collapse
Affiliation(s)
- Elysa Widjaja
- Diagnostic Imaging, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada.
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Hemimegalencephaly syndrome. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/s0072-9752(07)87010-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
24
|
Soufflet C, Bulteau C, Delalande O, Pinton F, Jalin C, Plouin P, Bahi-Buisson N, Dulac O, Chiron C. The Nonmalformed Hemisphere Is Secondarily Impaired in Young Children with Hemimegalencephaly: A Pre- and Postsurgery Study with SPECT and EEG. Epilepsia 2004; 45:1375-82. [PMID: 15509238 DOI: 10.1111/j.0013-9580.2004.66003.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To study separately the functional value of each cerebral hemisphere in hemimegalencephaly (HME). HME is a unique model of unilateral hemispheric lesion, but one suspects that the non-HME hemisphere also could be functionally impaired because the postsurgery outcome is less favorable than expected. METHODS We performed simultaneous prolonged EEG and 133-xenon SPECT (single-photon emission computed tomography); we measured the absolute values of cerebral blood flow (CBF) in both hemispheres and compared them with the normal values previously acquired. Thirteen patients (aged 5-38 months) underwent 31 examinations, 20 before surgery (hemispherotomy) and 11 after. RESULTS In the HME hemisphere, we confirmed the presurgical mixture of increased and decreased CBF due to intermittent ictal discharges. After surgery, CBF was decreased in most cases. In the non-HME hemisphere, presurgery CBF was abnormal in 60% of the patients, increased and related mostly to diffuse interictal spikes on the same side, whereas normal CBF cases had focal spikes. After surgery, CBF was normal in 82% of cases, corresponding to an EEG without diffuse spikes. In the six patients longitudinally studied, CBF dramatically decreased after surgery in the HME hemisphere, whereas in the non-HME hemisphere, CBF was mostly normal very early (three fourths before 2 months), increased as soon as 3 months, and normalized only after hemispherotomy, the more rapidly the child was operated on, the earlier it was. CONCLUSIONS This study shows that the function of the nonmalformed hemisphere is impaired as soon as the first months of the course of HME but can be restored after surgery. Our data support the recommendations to operate on the children as early as possible.
Collapse
Affiliation(s)
- Christine Soufflet
- Clinical Neurophysiology Department, Necker-Enfants Malades Hospital, Paris, France
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Broumandi DD, Hayward UM, Benzian JM, Gonzalez I, Nelson MD. Best cases from the AFIP: hemimegalencephaly. Radiographics 2004; 24:843-8. [PMID: 15143232 DOI: 10.1148/rg.243035135] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- David D Broumandi
- Department of Radiology, Santa Barbara Cottage Hospital, Pueblo at Bath St, 0689, Santa Barbara, CA 93102-0689, USA.
| | | | | | | | | |
Collapse
|
26
|
|
27
|
Flores-Sarnat L, Sarnat HB, Dávila-Gutiérrez G, Alvarez A. Hemimegalencephaly: part 2. Neuropathology suggests a disorder of cellular lineage. J Child Neurol 2003; 18:776-85. [PMID: 14696906 DOI: 10.1177/08830738030180111101] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cerebral tissue from hemispherectomy in three children (two 4-month-old girls and one 4-year-old boy) with hemimegalencephaly was studied using histochemical and immunocytochemical markers of neuronal and glial maturation and identity. Histologic abnormalities of cellular growth and cytomorphology, including "balloon cells," were present in both gray and white matter, in addition to disorganized tissue architecture. Cells in the mitotic cycle were absent. Many hypertrophic, atypical cells with enlarged processes exhibited mixed or ambiguous lineage, with immunoreactivity for both glial (glial fibrillary acidic protein [GFAP]; S-100beta) and neuronal proteins (microtubule-associated protein 2 [MAP2], neuronal nuclear antigen, chromogranin A, and neurofilament protein [NFP]). Strong vimentin reactivity was present in neurons, as well as glial cells and cells of mixed lineage, suggesting incomplete maturation. Synaptophysin-reactive axons terminated on a minority of balloon cells and on most heterotopic single neurons in white matter, confirmed by electron microscopy, demonstrating that single heterotopic neurons are not synaptically "isolated," as they may appear; thus, they are capable of contributing to epilepsy. Oligodendrocytes are the least affected cells, at least in some cases. The findings are reminiscent of the hamartomas of tuberous sclerosis. We conclude that hemimegalencephaly is a primary disorder of neuroepithelial lineage and cellular growth. A migratory disturbance contributes to disorderly tissue architecture but is secondary. No pathologic difference is detected between isolated and syndromic forms of hemimegalencephaly.
Collapse
Affiliation(s)
- Laura Flores-Sarnat
- Department of Pediatrics (Neurology), Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
| | | | | | | |
Collapse
|
28
|
Abstract
Hemimegalencephaly is a rare hamartomatous malformation of the brain, remarkable for its extreme asymmetry. It can be isolated or associated with several neurocutaneous syndromes; less frequently, it also involves the brain stem and cerebellum. Traditionally, hemimegalencephaly has been considered a primary neuroblast migratory disturbance. At present, genetic theories of pathogenesis and modern histopathology provide a basis for this complex malformation as a primary disturbance in cellular lineage, differentiation, and proliferation, interacting with a disturbance in gene expression of body symmetry, with earlier onset than radial neuroblast migration. From my personal experience with 10 patients with hemimegalencephaly and review of the literature, I have found the same clinical neurologic, neuroimaging, and neuropathologic features in isolated and syndromic hemimegalencephaly. Magnetic resonance imaging (MRI) reveals abnormal gyration, ventriculomegaly, colpocephaly, an "occipital sign" (displacement of the occipital lobe across the midline), and increased volume and T2 signal of white matter, in addition to the overall increased size of the involved hemisphere. Mild, moderate, and severe grades of severity can be recognized, providing a functional neurologic prognosis and therapeutic plan. Early diagnosis is crucial because despite neuroimaging and pathologic evidence, hemimegalencephaly sometimes still is unrecognized. Also, misdiagnosis of obstructive hydrocephalus or cerebral neoplasm can lead to unnecessary surgical procedures. Although hemispherectomy has a high morbidity, it is recommended early for patients with severe, intractable epilepsy. The mildest forms of hemimegalencephaly are infrequent and the least recognized.
Collapse
Affiliation(s)
- Laura Flores-Sarnat
- Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
| |
Collapse
|
29
|
Fohlen M, Jalin C, Bulteau C, Delalande O. [Surgical treatment of epilepsy in children less than 3 years of age]. Arch Pediatr 2002; 9 Suppl 2:87s-89s. [PMID: 12108303 DOI: 10.1016/s0929-693x(01)00913-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- M Fohlen
- Service de neurochirurgie pédiatrique, fondation A. de Rothschild, 25, rue Manin, 75019 Paris, France
| | | | | | | |
Collapse
|
30
|
Chapter 68 Malformations due to abnormal cortical development: expression and mechanisms of epileptogenicity. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1567-424x(09)70488-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
31
|
Prayson RA, Spreafico R, Vinters HV. Pathologic characteristics of the cortical dysplasias. Neurosurg Clin N Am 2002; 13:17-25, vii. [PMID: 11754313 DOI: 10.1016/s1042-3680(02)80003-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The gross and microscopic features of cortical dysplasia (malformations caused by abnormalities of cortical development) are reviewed and illustrated in this article. The pathologic associations of neurocutaneous disorders, neoplasms, and hippocampal sclerosis with cortical dysplasia also are discussed.
Collapse
Affiliation(s)
- Richard A Prayson
- Department of Anatomic Pathology, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
| | | | | |
Collapse
|
32
|
Palmini A, Lüders HO. Classification issues in malformations caused by abnormalities of cortical development. Neurosurg Clin N Am 2002; 13:1-16, vii. [PMID: 11754312 DOI: 10.1016/s1042-3680(02)80002-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Malformations caused by abnormalities of cortical development (MCDs) as a group are now widely recognized as a key cause of medically refractory epilepsies, often leading to a consideration of surgical treatment. A practical classification scheme including histopathologic, imaging, and, if possible, clinical-electrographic features of the various different types of MCDs, will be important to the delineation of surgical strategies and anticipation of medical and surgical prognoses. A proposal of such a scheme with emphasis on the focal cortical dysplasias is given in the hopes that it will reopen the debate on the best way to classify these disorders.
Collapse
Affiliation(s)
- André Palmini
- Porto Alegre Epilepsy Surgery Program, Neurology Service, Faculty of Medicine, and Hospital São Lucas, Pontificia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
| | | |
Collapse
|
33
|
Abstract
It is only a decade since the realization (facilitated by magnetic resonance imaging) in early 1990s that disorders of cortical development occupy an important place in the aetiologic categorization of epilepsy. Since then research has demonstrated the intrinsic epileptogenicity of disorders of cortical development, their genetic bases and their functional properties. Some of the key points of this most exciting medical and scientific enterprise are reviewed here, with an emphasis in the advances seen within the past 2 years.
Collapse
Affiliation(s)
- A Palmini
- Porto Alegre Epilepsy Surgery Program, Hospital São Lucas da Pontificia Universidade Católica do Rio Grande do Sul, Brazil
| |
Collapse
|