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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tumors and cortical dysplasia are associated with epilepsy, but few studies have examined the coexistence of neoplasia and dysplasia in these patients. We studied 13 patients (age 4-29 years) with recurrent seizures of 1 month to 21-year' duration (median 72 months). Ten patients were aged < 21 years. Imaging studies localized the lesion to the temporal lobe (10 patients), parietal lobe (2 patients), and frontal lobe (1 patient). Tumors included ganglioglioma (8 patients), dysembryoplastic neuroepithelial tumor (DNT) (3 patients), and low-grade astrocytoma (2 patients). Cortical dysplasia, including atypical aggregates of neurons (6 patients), multifocal loss of the cortical laminar architecture (7 patients), and neurons in the molecular layer of the cortex (3 patients) were observed near but separate from the tumor. Coexistence of certain tumors with cortical dysplasia, most frequently observed in the pediatric population, suggests a hamartomatous/dysplastic nature of the neoplasms.
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PMID:Coexistence of neoplasia and cortical dysplasia in patients presenting with seizures. 833 May 69

We retrospectively studied 32 patients who had cortical dysplasia and epilepsy. Cortical dysplasia was classified into diffuse cortical dysplasia (8 patients), bilateral localized cortical dysplasia (5), unilateral diffuse cortical dysplasia (2), and focal cortical dysplasia (17). The onset of epilepsy was younger in patients with more widespread lesions. At the onset, patients with bilateral lesions generally had symptomatic generalized epilepsy, while those with unilateral cortical dysplasia tended to have symptomatic localization-related epilepsy. In patients with focal cortical dysplasia, however, 4 patients had West syndrome, either at the onset of epilepsy or during the follow up period. Seizure outcome was poor in any type of cortical dysplasia. An evaluation of prognostic factors in patients with focal cortical dysplasia did not show any of statistical significance, including gender, age at onset of epilepsy, psychomotor delay and the presence of high intensity areas in T2-weighted MRI.
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PMID:[Neuronal migration disorders and epilepsy]. 907 Nov 90

Detailed neuropathologic examination was performed on a 47.5-year-old man with an unusual adult-onset dementing illness. His initial symptoms were those of depression, memory loss, and personality change. He developed progressive cognitive decline with prominent psychiatric symptoms. Seizures began approximately 11 months prior to death and he died 5.5 years after onset of symptoms. Pathologic examination of the brain at autopsy revealed organizing necrosis of the hippocampi, felt to be the result of his seizures. More significant was the finding of widespread microscopic nodular cortical dysplasia. The dysplastic nodules were composed of clusters of abnormal cells with enlarged, pleomorphic, vesicular nuclei, many of which contained nucleoli and had ballooned cytoplasm. There were no mitoses. Cortical dysplasia is most commonly associated with childhood-onset seizures. It has not, to our knowledge, been reported as a cause of dementia. Whether or not the dysplasia was the basis of the patient's dementia is difficult to say with certainty, but we discuss possible pathoetiologic mechanisms of dementia due to cortical dysplasia.
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PMID:Dementia associated with cortical dysplasia. 949 56

We report unusual MRI patterns in patients with grey matter heterotopia. Standard T1- and T2-weighted spin-echo and inversion-recovery sequences were used in 22 patients presenting with seizures or developmental delay. The images were reviewed for signal change surrounding white matter and for atypical size, morphology or topography. We found 10 cases of subependymal heterotopias 11 of focal subcortical heterotopia and of diffuse subcortical heterotopia. On clinical or MRI grounds, 8 cases were considered unusual: 2 of the subependymal type, 2 of focal subcortical heterotopia with white matter abnormalities, 2 of focal subcortical heterotopia with no clinicoradiological correlation 1 of extensive hemispheric subcortical heterotopia and 1 of diffuse subcortical heterotopia confined to the frontal lobe. The classical classification of heterotopia enables easy radiological diagnosis even in cases with unusual patterns. In some cases, heterogeneity and high signal in surrounding white matter can be found. Cortical dysplasia is the most frequent associated malformation.
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PMID:Unusual MRI findings in grey matter heterotopia. 954 17

Few epilepsy surgery outcome data are available from series of pediatric patients. We studied seizure outcome in 136 pediatric patients who had surgery for intractable epilepsy at The Cleveland Clinic between January 1990 and June 1996, with a postoperative follow-up of 1 to 7.5 years (mean, 3.6 years). Sixty-two children (3 months to 12 years old at time of surgery) were compared with 74 adolescents (13-20 years old). Extratemporal or multilobar resections and hemispherectomies were similarly frequent among children (50%) and adolescents (44%), but these procedures strongly predominated in infancy (90% of patients 0-2 years of age). The remaining patients had temporal resection. Cortical dysplasia and low-grade tumor were the most common causes and hippocampal sclerosis was rare. Seizure-free outcome was achieved for 69% of adolescents, 68% of children, and 60% of the infant subgroup, overall; for 23 (74%) of 31 children and 33 (80%) of 41 adolescents after temporal resection; for 11 (58%) of 19 children and 15 (52%) of 29 adolescents after extratemporal or multilobar resection; and for 8 (67%) of 12 children and 3 (75%) of 4 adolescents after functional hemispherectomy. Seizure-free outcome was more frequent after temporal resection (56 of 72, 78%) than after extratemporal or multilobar resection (26 of 48, 54%; 41 of 48 with a focal lesion on magnetic resonance imaging), and among patients with tumor (36 of 44, 82%) versus cortical dysplasia (16 of 31, 52%). The frequency of seizure-free outcome after epilepsy surgery was similar for infants, children, and adolescents, and comparable with results from adult series. Most patients in each age, surgery type, and causal group were free from seizures after surgery. These results suggest that children should be considered for surgical evaluation at whatever age they manifest with severe, intractable, disabling localization-related epilepsy.
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PMID:Seizure outcome after epilepsy surgery in children and adolescents. 1021 86

Bcl-2 and bcl-xL are proteins known to inhibit cell death (apoptosis). Expression of these proteins in gangliogliomas has not been extensively examined. This study retrospectively evaluates bcl-2 and bcl-x immunostaining in paraffin-embedded materials in gangliogliomas. Twenty-nine gangliogliomas in 17 males and 12 females, age 2.5 to 47 years (mean, 20.7 years), were studied. Nineteen tumors were situated primarily in the temporal lobe. All but three patients presented with seizures ranging from 3 months to 28 years' duration (mean, 11.1 years) before surgery. All tumors histologically were comprised of an atypical neuronal component and a glioma component, which most frequently resembled a low-grade astrocytoma. Cortical dysplasia was observed adjacent to eight tumors. MIB-1 (marker of cell proliferation) labeling indices (percentage of positively staining tumor cell nuclei) ranged from 0 to 7.7 (mean, 0.8). bcl-2 staining was observed in 25 tumors (86%); neuronal staining was present in 24 cases (83%), and glial cell staining in 21 tumors (72%). Bcl-xL staining was only observed in eight gangliogliomas (28%); in all eight tumors (28%), neuronal staining was seen, and focal glial cell staining was present in two cases (7%). Four tumors (14%) did not stain with either bcl-2 or bcl-xL. There appeared to be no relationship between MIB-1 immunostaining and staining with bcl-2 or bcl-xL. bcl-2 expression by immunohistochemistry was observed more frequently than bcl-xL in gangliogliomas. Expression of these proteins may reflect abnormalities of apoptosis, which could play a role in the survival of cells that may be involved in the development of gangliogliomas.
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PMID:Bcl-2 and Bcl-X expression in gangliogliomas. 1037 80

Cortical dysplasia (CD) represents a common neuropathologic substrate of pediatric epilepsy, one frequently encountered in surgical resection specimens from infants and children with intractable seizure disorders, including infantile spasms. Severe CD shows similarities to structural features noted in tubers from individuals with tuberous sclerosis (TSC). The latter disorder, one with neurocutaneous and visceral manifestations, results from mutations in one of two recently cloned genes, TSC1 or TSC2, which encode (respectively) the proteins hamartin and tuberin. There is circumstantial evidence that both proteins may influence cell growth and differentiation, specifically that they may represent growth suppressors. Neither protein has a defined role in brain development. We discuss and illustrate neuropathologic features of both CD and TSC, and discuss the patterns and time course of hamartin/tuberin expression in normal brain, CD and TSC. Other recently cloned genes associated with cortical malformations encompassed by the term CD are briefly described.
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PMID:Cortical dysplasia, genetic abnormalities and neurocutaneous syndromes. 1057 48

Cortical dysplasia (CD) is now recognized as one of the major causes of pediatric focal neocortical epilepsy, and surgical procedures have been considered early in life. However, the mechanisms involved in seizure generation and intractability in these patients are still unknown. We analyzed with immunocytochemistry for various antibodies the brain tissue from 4 children (10 months to 6 years old) with focal epilepsy due to focal CD in order to study the inhibitory and excitatory circuits in dysplastic areas. Our group had similar histopathological and clinical characteristics. In all patients we found areas of cortical disorganization with dysplastic neurons and balloon cells. We studied distributions of glial cells with glial fibrillary acidic protein (GFAP) and neurons with microtubule-associated protein 2 (MAP-2). Gliosis was present in all cases, and GFAP stained also some balloon cells. Dysplastic neurons were darkly stained by MAP-2, and we also found balloon cells weakly stained with MAP-2 in the same areas where GFAP was positive, suggesting coexpression of neuronal and glial markers in some of these cells. There was an increased expression of glutamate receptors, especially GluR2/3, but also N-methyl-D-aspartate receptors in dysplastic cortex. The inhibitory circuit does not seem to be decreased, rather we notice an increased amount of glutamate-decarboxylase-positive terminals around some of the big neurons. We discuss the possible role of these findings as mechanisms of epilepsy.
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PMID:Focal cortical dysplasia in children. 1057 50

Since the nineteenth century, various abnormalities of cortical development resulting from migration defect, disorders of maturation, and disorders of cortical organization were described in brains at autopsy. Cortical dysplasia then was recognized in tissue resected during surgical treatment of patients with intractable epilepsy, but this finding remained largely unappreciated until the development of modern imaging. CT allowed glimpses of the more obvious malformations, but it was the advent of MRI that enabled the recognition and classification of the different types of lesions. In the Taylor type of cortical dysplasia, it became clear that there was a wide range in the severity and, above all, in the extent of the abnormality. The lesions range from small areas, often difficult to identify, to extensive lesions surrounded by a halo or penumbra of presumably less severe, but still clinically significant, structural abnormality. Functional imaging (SPECT, PET, and MRS) have provided additional insights and led to strategies for surgical treatment. Even lesions involving the central strip may at times be successfully resected, but in such patients much depends on the preoperative neurologic status. Recognition of the fact that dysplastic lesions are in themselves epileptogenic has been another milestone in our understanding of these abnormalities. Subcortical heterotopias, in particular periventricular nodular heterotopias, have been recognized as causing intractable epilepsy in some but not in all patients. Surgical approaches to these lesions are now being planned. The hereditary nature of the lesions in some patients has explained the familial occurrence of epilepsy in a number of instances. Generalized epileptic abnormalities and generalized disorders of migration and maturation have been described as band heterotopia or the double-cortex syndrome. Here, too, sex-linked dominant inheritance may occur, and progress has been made in our understanding of the mechanisms of these genetically determined lesions. Focal resection in patients with band heterotopia, however, has been of little value in the small number of patients in whom it has been carried out. Cortical malformations due to disorganization, occurring later in intrauterine life, are represented by micropolygyria. These lesions are often bilateral and perisylvian, but at times they are unilateral and in some patients may be occipital or frontal. Several syndromes have emerged, the most common being the one characterized by severe pseudobulbar palsy and mild pyramidal deficit (31). In some patients with such cortical abnormalities, particularly those with micropolygyria, the epilepsy may not be intractable, and full control may be obtained by medical treatment (32). Interesting and important clinical features of patients with bilateral perisylvian polymicrogyria were described by Guerrini et al. (33) and Caraballo et al. (34). In some patients who develop a secondary generalized electrographic abnormality and drop attacks early in the first decade, there is eventual improvement and cessation of the epileptic abnormality toward the end of the first decade or somewhat later. These investigators stressed that callosotomy should be considered with caution in patients with micropolygyria and this electroclinical pattern. Hypothalamic hamartomata and the associated epileptic syndrome have been better understood in recent years. Despite the risks of surgery, resection of the lesion offers hope of improvement in seizure control and of the often extremely severe behavioral abnormalities. On the other hand, patients with small lesions leading only to a "need to laugh" without more overt epileptic or behavioral manifestations are now being recognized. Finally, initial investigations have begun to uncover the transmitter abnormalities in patients with cortical dysplasia. (ABSTRACT TRUNCATED)
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PMID:Cortical dysplasias and epilepsy: a review of the architectonic, clinical, and seizure patterns. 1109 90

Cortical dysplasia is a major cause of intractable epilepsy in children. However, the precise mechanisms linking cortical malformations to epileptogenesis remain elusive. The neuronal-specific activator of cyclin-dependent kinase 5, p35, has been recognized as a key factor in proper neuronal migration in the neocortex. Deletion of p35 leads to severe neocortical lamination defects associated with sporadic lethality and seizures. Here we demonstrate that p35-deficient mice also exhibit dysplasia/ heterotopia of principal neurons in the hippocampal formation, as well as spontaneous behavioral and electrographic seizures. Morphological analyses using immunocytochemistry, electron microscopy, and intracellular labeling reveal a high degree of abnormality in dentate granule cells, including heterotopic localization of granule cells in the molecular layer and hilus, aberrant dendritic orientation, occurrence of basal dendrites, and abnormal axon origination sites. Dentate granule cells of p35-deficient mice also demonstrate aberrant mossy fiber sprouting. Field potential laminar analysis through the dentate molecular layer reflects the dispersion of granule cells and the structural reorganization of this region. Similar patterns of cortical disorganization have been linked to epileptogenesis in animal models of chronic seizures and in human temporal lobe epilepsy. The p35-deficient mouse may therefore offer an experimental system in which we can dissect out the key morphological features that are causally related to epileptogenesis.
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PMID:Abnormal morphological and functional organization of the hippocampus in a p35 mutant model of cortical dysplasia associated with spontaneous seizures. 1115 84


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