The Experts below are selected from a list of 693 Experts worldwide ranked by ideXlab platform
J.p. Pruvo - One of the best experts on this subject based on the ideXlab platform.
-
Neuropathologic and MR imaging correlation in a neonatal case of cerebellar cortical dysplasia.
AJNR. American journal of neuroradiology, 2002Co-Authors: Gustavo Soto-ares, J.p. Pruvo, Louise Devisme, Sylvie Jorriot, Berengere Deries, Marie M. RuchouxAbstract:Little documentation of the correlation between MR imaging findings in isolated cerebellar cortical dysplasia (CCD) and its neuropathologic characteristics exists in the recent literature. We documented a postmortem neuropathologic study of a clinically and radiologically well-documented case of CCD in a neonate with severe hypotonia and status epilepticus. MR imaging revealed a global vermian hypoplasia with marked cortical dysplasia. CCD was associated with a voluminous heterotopic mass. The postmortem neuropathologic study confirmed vermian hypoplasia and CCD, which consisted of right cerebellar cortical polymicrogyria with Subcortical Heterotopia. CCD is a pathologic entity that could be well diagnosed with MR imaging even in the neonatal period.
-
Unusual MRI findings in grey matter Heterotopia.
Neuroradiology, 1998Co-Authors: G. Soto Ares, Michèle Hamon-kérautret, C. Houlette, Olivier Godefroy, Xavier Leclerc, J.p. PruvoAbstract: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.
-
Unusual MRI findings in grey matter heteropia
Neuroradiology, 1998Co-Authors: G. Soto Ares, Michèle Hamon-kérautret, C. Houlette, Olivier Godefroy, Xavier Leclerc, J.p. PruvoAbstract: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.
A. J. Barkovich - One of the best experts on this subject based on the ideXlab platform.
-
Morphologic characteristics of Subcortical Heterotopia: MR imaging study.
AJNR. American journal of neuroradiology, 2000Co-Authors: A. J. BarkovichAbstract:BACKGROUND AND PURPOSE: Gray matter Heterotopia have been divided into three groups based on clinical and imaging characteristics: subependymal, Subcortical, and band Heterotopia. Nonetheless, Subcortical Heterotopia can have variable morphologic findings. The purpose of this study was to perform a morphologic analysis of a series of cases of Subcortical Heterotopia based on MR images, to correlate the morphologic appearance with clinical characteristics, and to speculate about the embryologic implications of our results. METHODS: The MR imaging studies and clinical records of 24 patients with Subcortical Heterotopia were retrospectively reviewed. The morphologic findings of the Heterotopia were recorded along with presence and type of associated malformations. These results were correlated with available data on development and neurologic status. RESULTS: Analysis revealed that, in six cases, the Heterotopia were composed exclusively of multiple nodules, in 13, they appeared primarily as curvilinear ribbons of cortex extending into the white matter, and in five, they had deep nodular regions with curvilinear areas more peripherally. All of the curvilinear regions were contiguous with the cerebral cortex in at least two locations. In eight cases, curvilinear Heterotopia contained curvilinear areas of flow void that were thought to be blood vessels; in 10, they contained fluid resembling CSF. No difference in developmental or neurologic manifestations was noted among patients with Heterotopia of different morphologic appearances. CONCLUSION: Subcortical Heterotopia can have nodular or curvilinear morphologic appearances. Although no difference was found in the clinical conditions of the patients with differing morphologic appearances, additional analysis of these patients or studies of animal models of these malformations may further our understanding of normal and abnormal brain development.
-
Subcortical Heterotopia: a distinct clinicoradiologic entity.
AJNR. American journal of neuroradiology, 1996Co-Authors: A. J. BarkovichAbstract:PURPOSE: To investigate the clinical syndrome and associated brain anomalies in a group of patients with Subcortical Heterotopia. METHODS: The seizure history, developmental history, family history, electroencephalographic results, imaging studies, and pathologic results (where available) of 13 patients with Subcortical Heterotopia were reviewed retrospectively. The patients ranged in age from 1 month to 39 years (mean, 11 years; median, 3 years) at the time of the most recent update of their records. RESULTS: Fifteen hemispheres were involved in 13 patients. The cerebral cortex overlying the Heterotopia was thin with shallow sulci and the affected part of the hemisphere was small as compared with the contralateral hemisphere. The corpus callosum was hypogenetic or agenetic in nine patients and the basal nuclei were dysplastic or hypoplastic in 11 patients. Most patients were developmentally delayed as children, had mild hemiplegia or hemihypesthesia contralateral to the affected hemisphere(s), and had partial epilepsy, most commonly evidenced by partial motor seizures in the body half contralateral to the malformation. Age at seizure onset varied from infancy to the second decade. Electroencephalographic results showed slow wave background with spike and spike wave complexes in the affected hemisphere. CONCLUSION:Subcortical Heterotopia seems to have characteristic clinical, electrophysiological, and imaging manifestations. These results suggest that affected patients may be conveniently grouped together to study treatment outcomes.
Qin Shen - One of the best experts on this subject based on the ideXlab platform.
-
ZEB1 Represses Neural Differentiation and Cooperates with CTBP2 to Dynamically Regulate Cell Migration during Neocortex Development.
Cell reports, 2019Co-Authors: Huanhuan Wang, Zhengtao Xiao, Jiangli Zheng, Xuerui Yang, Qin ShenAbstract:Zinc-finger E-box binding homeobox 1 (Zeb1) is a key regulator of epithelial-mesenchymal transition and cancer metastasis. Mutation of ZEB1 is associated with human diseases and defective brain development. Here we show that downregulation of Zeb1 expression in embryonic cortical neural progenitor cells (NPCs) is necessary for proper neuronal differentiation and migration. Overexpression of Zeb1 during neuronal differentiation, when its expression normally declines, blocks NPC lineage progression and disrupts multipolar-to-bipolar transition of differentiating neurons, leading to severe migration defects and Subcortical Heterotopia bands at postnatal stages. ZEB1 regulates a cohort of genes involved in cell differentiation and migration, including Neurod1 and Pard6b. The interaction between ZEB1 and CTBP2 in the embryonic cerebral cortex is required for ZEB1 to elicit its effect on the multipolar-to-bipolar transition, but not its suppression of Neurod1. These findings provide insights into understanding the complexity of transcriptional regulation during neuronal differentiation.
-
ZEB1 Represses Neural Differentiation and Cooperates with CTBP2 to Dynamically Regulate Cell Migration during Neocortex Development
Elsevier, 2019Co-Authors: Huanhuan Wang, Zhengtao Xiao, Jiangli Zheng, Xuerui Yang, Qin ShenAbstract:Summary: Zinc-finger E-box binding homeobox 1 (Zeb1) is a key regulator of epithelial-mesenchymal transition and cancer metastasis. Mutation of ZEB1 is associated with human diseases and defective brain development. Here we show that downregulation of Zeb1 expression in embryonic cortical neural progenitor cells (NPCs) is necessary for proper neuronal differentiation and migration. Overexpression of Zeb1 during neuronal differentiation, when its expression normally declines, blocks NPC lineage progression and disrupts multipolar-to-bipolar transition of differentiating neurons, leading to severe migration defects and Subcortical Heterotopia bands at postnatal stages. ZEB1 regulates a cohort of genes involved in cell differentiation and migration, including Neurod1 and Pard6b. The interaction between ZEB1 and CTBP2 in the embryonic cerebral cortex is required for ZEB1 to elicit its effect on the multipolar-to-bipolar transition, but not its suppression of Neurod1. These findings provide insights into understanding the complexity of transcriptional regulation during neuronal differentiation. : Neural progenitor cells in the developing brain undergo a precisely controlled transition from proliferation to differentiation. Wang et al. report that ZEB1 expression is restricted to neural progenitor cells to ensure the transition to neuronal generation. Forced expression of ZEB1 blocks neuronal migration through interaction with CTBP2, leading to cortical abnormalities. Keywords: neural stem cells, neurogenesis, cell migration, neocortex, cortical development, Zeb1, zinc finger protein, Ctbp
James A. Barkovich - One of the best experts on this subject based on the ideXlab platform.
-
Morphologic characteristics of Subcortical Heterotopia: MR imaging study
2015Co-Authors: James A. BarkovichAbstract:BACKGROUND AND PURPOSE: Gray matter Heterotopia have been divided into three groups based on clinical and imaging characteristics: subependymal, Subcortical, and band Heterotopia. Nonetheless, Subcortical Heterotopia can have variable morphologic findings. The purpose of this study was to perform a morphologic analysis of a series of cases of Subcortical Heterotopia based on MR images, to correlate the morphologic appearance with clinical char-acteristics, and to speculate about the embryologic implications of our results. METHODS: The MR imaging studies and clinical records of 24 patients with Subcortical Heterotopia were retrospectively reviewed. The morphologic findings of the Heterotopia were recorded along with presence and type of associated malformations. These results were cor-related with available data on development and neurologic status. RESULTS: Analysis revealed that, in six cases, the Heterotopia were composed exclusively of multiple nodules, in 13, they appeared primarily as curvilinear ribbons of cortex extending into the white matter, and in five, they had deep nodular regions with curvilinear areas more peripherally. All of the curvilinear regions were contiguous with the cerebral cortex in at least two locations. In eight cases, curvilinear Heterotopia contained curvilinear areas of flow voi
-
CME Callosal agenesis with cyst A better understanding and new classification
2015Co-Authors: James A. Barkovich, Md Erin, M. Simon, Christopher A. WalshAbstract:Article abstract—Objective: To analyze imaging studies of 25 cases of agenesis of the corpus callosum with interhemi-spheric cyst to assess this malformation itself and associated anomalies. Methods: CT (6 patients) and MRI (19 patients) were retrospectively reviewed. The patients were categorized according to morphologic and clinical characteristics. Re-sults: Based on morphology, the patients were separated into two major types, each with subtypes. Type 1 cysts appear to be an extension or diverticulation of the third or lateral ventricles, whereas Type 2 are loculated and do not communicate with the ventricular system. Type 1a were associated with presumed communicating hydrocephalus but no other cerebral malformations. Type 1b were associated with hydrocephalus secondary to diencephalic malformations prohibiting egress of CSF from the third ventricle into the aqueduct of Sylvius. Type 1c were associated with small head size and apparent cerebral hemispheric dysplasia or hypoplasia. Type 2a (multiloculated cysts) were associated with no abnormalities other than callosal agenesis/hypogenesis. Type 2b were associated with deficiencies of the falx cerebri, subependymal heteroto-pia, and polymicrogyria (and were almost all in patients diagnosed with Aicardi syndrome). Type 2c were associated with Subcortical Heterotopia. Type 2d consists of interhemispheric arachnoid cysts. Other than those with Type 2b cysts, gender predominance was overwhelmingly male. Conclusion: Agenesis of the corpus callosum with interhemispheric cyst appears to consist of a heterogeneous group of disorders that have in common callosal agenesis and extraparenchymal cysts, both of which are among the commonest CNS malformations. This article proposes a classification system, based primarily o
-
Analysis of the Cerebral Cortex in Holoprosencephaly with Attention to the
2015Co-Authors: Sylvian Fissures, James A. Barkovich, Erin M. Simon, Nancy J. Clegg, Steven L. Kinsman, Jin S. HahnAbstract:BACKGROUND AND PURPOSE: Analysis of specific features in the brain of patients with holoprosencephaly (HPE) may clarify normal and abnormal brain development and help predict outcomes for specific children. We assessed sulcal and gyral patterns of cerebral cortex in patients with HPE and developed a method of grading brain development. METHODS: Neuroimaging studies (75 MR imaging, 21 CT) of 96 patients with HPE were retrospectively reviewed, with specific attention paid to the cerebral cortex. Thickness of cortex, width of gyri, and depth of sulci were assessed subjectively and by measurement. The angle between lines drawn tangential to the sylvian fissures (“sylvian angle”) was measured in each patient with HPE and in 20 control patients. RESULTS: Thickness of cortex was normal in all 96 patients. Gyral shape and width and sulcal depth were normal in 80 patients. Twelve patients, all with very severe HPE and microcephaly, had reduced sulcal depth, diffusely in eight and limited to the anteromedial cortex in four with lobar HPE. Four patients had Subcortical Heterotopia, located anterior to the interhemispheric fissure, associated with shallow sulci in the overlying cortex. Sylvian fissures were displaced further anteriorly and medially as HPE became more severe, until, in the mos
-
the middle interhemispheric variant of holoprosencephaly
American Journal of Neuroradiology, 2002Co-Authors: Erin M. Simon, Nancy J. Clegg, Jin S. Hahn, Robert F Hevner, Joseph D Pinter, Mauricio R Delgado, Stephen L Kinsman, James A. BarkovichAbstract:BACKGROUND AND PURPOSE: The middle interhemispheric variant of holoprosencephaly (MIH) is a rare malformation in which the cerebral hemispheres fail to divide in the posterior frontal and parietal regions. We herein describe the structural abnormalities of the brain in a large group of patients with MIH, compare these features with those of classic holoprosencephaly (HPE), and propose a developmental mechanism, based on current knowledge of developmental neurogenetics, by which MIH develops. METHODS: Brain images obtained in 21 patients with MIH (MR images in 16 patients and high-quality X-ray CT scans in five patients) were retrospectively reviewed to classify cerebral abnormalities. The cerebral parenchyma, hypothalami, caudate nuclei, lentiform nuclei, thalami, and mesencephalon were examined for the degree of midline separation (cleavage) of the two hemispheres. The orbits, olfactory apparati, and presence or absence of a dorsal cyst were also assessed. RESULTS: In all patients, by definition, midportions of the cerebral hemispheres were continuous across the midline, with an intervening interhemispheric fissure. The sylvian fissures were abnormally connected across the midline over the vertex in 18 (86%) of 21 patients. Two patients had relatively normal-appearing sylvian fissures; one had unilateral absence of a sylvian fissure owing to substantial Subcortical Heterotopia. Heterotopic gray matter or dysplastic cerebral cortex was also seen in 18 (86%) of 21 patients. MIH differed from classic HPE as follows. 1) In all subjects, the midline third ventricle separated the hypothalamus and lentiform nuclei. 2) The caudate nuclei were separated by the cerebral ventricles in 17 (89%) of the 17 patients in whom they could be assessed. 3) The most commonly affected basal nucleus was the thalamus (non-cleavage in seven [33%] of 21 cases, abnormal alignment in 1 [5%]). 4) Three (18%) of the 16 patients in whom the mesencephalon could be assessed showed some degree of mesencephalic non-cleavage. 5) No patients had hypotelorism (four had hypertelorism, the remainder manifested normal intraocular distances). Dorsal cysts were present in five (25%) of the 20 patients in whom they could be assessed (dorsal cysts could not be assessed after shunt surgery), and as in classic HPE, were associated with severe thalamic non-cleavage in three of these five patients. CONCLUSION: MIH appears to cause non-cleavage of midline structures in a completely different pattern than does classic HPE. In MIH, impaired induction or expression of genetic factors appears to influence the embryonic roof plate, whereas in classic HPE, induction or expression of the embryonic floor plate seems to be affected.
-
callosal agenesis with cyst a better understanding and new classification
Neurology, 2001Co-Authors: James A. Barkovich, Erin M. Simon, Christopher A. WalshAbstract:Objective: To analyze imaging studies of 25 cases of agenesis of the corpus callosum with interhemispheric cyst to assess this malformation itself and associated anomalies. Methods: CT (6 patients) and MRI (19 patients) were retrospectively reviewed. The patients were categorized according to morphologic and clinical characteristics. Results: Based on morphology, the patients were separated into two major types, each with subtypes. Type 1 cysts appear to be an extension or diverticulation of the third or lateral ventricles, whereas Type 2 are loculated and do not communicate with the ventricular system. Type 1a were associated with presumed communicating hydrocephalus but no other cerebral malformations. Type 1b were associated with hydrocephalus secondary to diencephalic malformations prohibiting egress of CSF from the third ventricle into the aqueduct of Sylvius. Type 1c were associated with small head size and apparent cerebral hemispheric dysplasia or hypoplasia. Type 2a (multiloculated cysts) were associated with no abnormalities other than callosal agenesis/hypogenesis. Type 2b were associated with deficiencies of the falx cerebri, subependymal Heterotopia, and polymicrogyria (and were almost all in patients diagnosed with Aicardi syndrome). Type 2c were associated with Subcortical Heterotopia. Type 2d consists of interhemispheric arachnoid cysts. Other than those with Type 2b cysts, gender predominance was overwhelmingly male. Conclusion: Agenesis of the corpus callosum with interhemispheric cyst appears to consist of a heterogeneous group of disorders that have in common callosal agenesis and extraparenchymal cysts, both of which are among the commonest CNS malformations. This article proposes a classification system, based primarily on morphology, by which this complex group of disorders might begin to be better understood.
Tingting Wang - One of the best experts on this subject based on the ideXlab platform.
-
Abnormal Rat Cortical Development Induced by Ventricular Injection of rHMGB1 Mimics the Pathophysiology of Human Cortical Dysplasia
Frontiers in cell and developmental biology, 2021Co-Authors: Xiaolin Yang, Zhongke Wang, Guolong Liu, Kaifeng Shen, Gang Zhu, Xiaoqing Zhang, Kaixuan Huang, Tingting WangAbstract:Cortical dysplasia (CD) is a common cause of drug-resistant epilepsy. Increasing studies have implicated innate immunity in CD with epilepsy. However, it is unclear whether innate immune factors induce epileptogenic CD. Here, we injected recombinant human High Mobility Group Box 1 (rHMGB1) into embryonic rat ventricles to determine whether rHMGB1 can induce epileptogenic CD with pathophysiological characteristics similar to those of human CD. Compared with controls and 0.1 μg rHMGB1-treated rats, the cortical organization was severely disrupted in the 0.2 μg rHMGB1-treated rats, and microgyria and Heterotopia also emerged; additionally, disoriented and deformed neurons were observed in the cortical lesions and Heterotopias. Subcortical Heterotopia appeared in the white matter and the gray-white junction of the 0.2μg rHMGB1-treated rats. Moreover, there was decreased number of neurons in layer Ⅴ-Ⅵ and an increased number of astrocytes in layer Ⅰ and Ⅴ of the cortical lesions. And the HMGB1 antagonist dexmedetomidine alleviated the changes induced by rHMGB1. Further, we found that TLR4 and NF-κB were increased after rHMGB1 administration. In addition, the excitatory receptors, N-methyl-D-aspartate receptor 1(NR1), 2A (NR2A), and 2B (NR2B) immunoreactivity were increased, and immunoreactivity of excitatory amino acid transporter 1 (EAAT1) and 2 (EAAT2) were reduced in 0.2 μg rHMGB1-treated rats compared with controls. While there were no differences in the glutamic acid decarboxylase 65/67 (GAD65/67) immunoreactivity between the two groups. These results indicate that the excitation of cortical lesions was significantly increased. Furthermore, electroencephalogram (EEG) showed a shorter latency of seizure onset and a higher incidence of status epilepticus in the 0.2 μg rHMGB1-treated rats; the frequency and amplitude of EEG were higher in the treated rats than controls. Intriguingly, spontaneous electrographic seizure discharges were detected in the 0.2 μg rHMGB1-treated rats after 5 months of age, and spike-wave discharges of approximately 8 Hz were the most significantly increased synchronous propagated waves throughout the general brain cortex. Taken together, these findings indicate that rHMGB1 exposure during pregnancy could contribute to the development of epileptogenic CD, which mimicked some pathophysiological characteristics of human CD.
-
Abnormal Rat Cortical Development Induced by Ventricular Injection of rHMGB1 Mimicked the Pathophysiology of Human Cortical Dysplasia
2020Co-Authors: Xiaolin Yang, Zhang Xiaoqing, Zhongke Wang, Guolong Liu, Kaifeng Shen, Gang Zhu, Tingting Wang, Chunqing Zhang, Hui YangAbstract:Abstract Background Cortical dysplasia (CD) is a common cause of drug-resistant epilepsy. Increasingly, innate immunity is involved in CD with epilepsy. However, it is unclear whether innate immune factors contribute to induce epileptogenic CD. Here, we injected recombinant human HMGB1 (rHMGB1) into the embryonic rat ventricle to determine whether rHMGB1 can induce epileptogenic CD with pathophysiological characteristics similar to those of human CD.Methods At gestational day 14.5, rHMGB1 was injected into the ventricles of Sprague Dawley (SD) rat embryos. At 2 months postnatal, the effects of rHMGB1 on cortex construction were examined by Nissl staining; the alterations of nerve tissue were detected using immunostaining. At 3 months postnatal, the susceptibility and severity of pilocarpine-induced seizures and the spontaneous epileptic discharges were evaluated by EEG. Open-field tests, novel object recognition tests, and Morris water maze tests were performed to observe the behavior of rHMGB1-treated rats.Results The results showed cortical organization was severely disrupted in the rHMGB1-treated rats, and microgyria and Heterotopia also emerged; additionally, disoriented neurons, dysmorphic neurons, and dysplastic neurons were found in the cortical lesions and Heterotopias. Subcortical Heterotopia also appeared in the white matter and the gray-white junction of the rHMGB1-treated rats. Moreover, the numbers of neurons and astrocytes were increased in the cortical lesions; the neuronal dendrites were thickened, randomly oriented, and frequently crossed each other. Moreover, the immunoreactivity of NR2A, NR2B, NR1, GAD65/67, EAAT1 and EAAT2 indicated that the excitation of cortical lesions and Heterotopia were significantly increased. Furthermore, EEG showed more susceptibility and severity of seizures in rHMGB1-treatment rats compared with the control rats. Intriguingly, spontaneous nonepileptic seizure discharges were also detected in the rHMGB1-treated rats after 5 months of age, and spike-wave discharges of approximately 8 Hz were the most significantly increased synchronously propagated waves throughout the general brain cortex.Conclusions These results indicated that rHMGB1 exposure during pregnancy can modify the cerebral structure of offspring, which results in increased susceptibility to seizures and mimics the pathophysiological characteristics of human CD. Those results suggested that HMGB1 upregulation resulting from various insults could contribute to the development of epileptogenic CD during pregnancy.
