Polymicrogyria: pathology, fetal origins and mechanisms

Squier, Waney; Jansen, Anna

doi:10.1186/s40478-014-0080-3

Cited by 94 publications

(37 citation statements)

References 94 publications

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“…Polymicrogyria (shown in Figure 1g) is a complex congenital malformation where the surface of the fetal brain normally has many ridges or folds, called gyri [23]. Friede et al [24] defined polymicrogyria as “an abnormally thick cortex formed by the piling upon each other of many small gyri with a fused surface”.…”

Section: Introductionmentioning

confidence: 99%

Fetal Brain Abnormality Classification from MRI Images of Different Gestational Age

2019

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Magnetic resonance imaging (MRI) is a common imaging technique used extensively to study human brain activities. Recently, it has been used for scanning the fetal brain. Amongst 1000 pregnant women, 3 of them have fetuses with brain abnormality. Hence, the primary detection and classification are important. Machine learning techniques have a large potential in aiding the early detection of these abnormalities, which correspondingly could enhance the diagnosis process and follow up plans. Most research focused on the classification of abnormal brains in a primary age has been for newborns and premature infants, with fewer studies focusing on images for fetuses. These studies associated fetal scans to scans after birth for the detection and classification of brain defects early in the neonatal age. This type of brain abnormality is named small for gestational age (SGA). This article proposes a novel framework for the classification of fetal brains at an early age (before the fetus is born). As far as we could know, this is the first study to classify brain abnormalities of fetuses of widespread gestational ages (GAs). The study incorporates several machine learning classifiers, such as diagonal quadratic discriminates analysis (DQDA), K-nearest neighbour (K-NN), random forest, naïve Bayes, and radial basis function (RBF) neural network classifiers. Moreover, several bagging and Adaboosting ensembles models have been constructed using random forest, naïve Bayes, and RBF network classifiers. The performances of these ensembles have been compared with their individual models. Our results show that our novel approach can successfully identify and classify numerous types of defects within MRI images of the fetal brain of various GAs. Using the KNN classifier, we were able to achieve the highest classification accuracy and area under receiving operating characteristics of 95.6% and 99% respectively. In addition, ensemble classifiers improved the results of their respective individual models.

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Section: Introductionmentioning

confidence: 99%

Fetal Brain Abnormality Classification from MRI Images of Different Gestational Age

2019

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“…The migration defect in KBP knockdown brains may be correlated to the PMG phenotype, characterized by numerous small, unfolded gyri, and disorganized lamination, in GOSHS patients (Valence et al, 2013; Squier and Jansen, 2014; Kato, 2015). Previous studies have shown that defects in neuronal migration caused MCDs, including lissencephaly and PMG (Tsai et al, 2005, 2007, 2016; Vallee and Tsai, 2006; Vallee et al, 2009; Jheng et al, 2018).…”

Section: Discussionmentioning

confidence: 99%

Multiple Functions of KBP in Neural Development Underlie Brain Anomalies in Goldberg-Shprintzen Syndrome

Chang

Cheng

Tsao

et al. 2019

Front. Mol. Neurosci.

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Kinesin-binding protein (KBP; KIF1BP; KIAA1279) functions as a regulator for a subset of kinesins, many of which play important roles in neural development. Previous studies have shown that KBP is expressed in nearly all tissue with cytoplasmic localization. Autosomal recessive mutations in KIAA1279 cause a rare neurological disorder, Goldberg-Shprintzen syndrome (GOSHS), characterized by microcephaly, polymicrogyria, intellectual disability, axonal neuropathy, thin corpus callosum and peripheral neuropathy. Most KIAA1279 mutations found in GOSHS patients are homozygous nonsense mutations that result in KBP loss-of-function. However, it is not fully understood how KBP dysfunction causes these defects. Here, we used in utero electroporation (IUE) to express KBP short hairpin RNA (shRNA) with green fluorescent protein (GFP) in neural progenitor cells of embryonic day (E) 14 mice, and collected brain slices at different developmental stages. By immunostaining of neuronal lineage markers, we found that KBP knockdown does not affect the neural differentiation process. However, at 4 days post IUE, many cells were located in the intermediate zone (IZ). Moreover, at postnatal day (P) 6, about one third of the cells, which have become mature neurons, remained ectopically in the white matter (WM), while cells that have reached Layer II/III of the cortex showed impaired dendritic outgrowth and axonal projection. We also found that KBP knockdown induces apoptosis during the postnatal period. Our findings indicate that loss of KBP function leads to defects in neuronal migration, morphogenesis, maturation, and survival, which may be responsible for brain phenotypes observed in GOSHS.

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“…The pathophysiology of AFs or cortical infoldings in PMG remains to be unknown. Some researchers have suggested that there is a failure in the attachment of glial radial fibers to the pial limiting membrane and gaps are formed in the membrane [15][16][17] . PMG is postulated to occur as a result of incomplete migration and accumulation of neuronal cells to form dysmorphic cortical layers and small gyri close to the germinal matrix.…”

Section: Discussionmentioning

confidence: 99%

Aberrant fissure in polymicrogyria

Öztoprak¹,

Atalar²

2016

Cumhuriyet Med J

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SUMMARYObjective: Polymicrogyria (PMG) is the most common malformation of the brain cortex. There is an impaired migration and proliferation of neuronal cells leading to a thickened cortex with multiple small (micro) gyri. It can be focal or diffuse. The aim of this study is to delineate the MRI properties of an aberrant fissure (AF) associated with PMG. Method: MR images of 34 patients were retrospectively investigated for the features of PMG, the presence of an AF and its properties along with the clinical findings. Results: Thirty-one patients (91.2%) showed focal PMG, whereas 3 patients (8.8%) had diffuse involvement of the brain. None of the diffuse PMGs showed an AF, whereas 30 patients (88%) with focal PMG showed an associated AF. Only one patient with a focal PMG did not display an AF, however, he had an arachnoid cyst adjacent to the PMG. AFs were related to or in continuity with major fissures of the brain in 27 subjects. Conclusions: An AF is present in the vast majority of patients with a focal PMG, however, there is no significant relation between the presence of AF and clinical findings. Keywords: Aberrant fissure, magnetic resonance imaging, polymicrogyria ÖZET Amaç: Polimikrogiri (PMG) beyin korteksinin en sık görülen malformasyonudur. Beyin gelişimi sırasında nöronal migrasyonun son evresinde ve migrasyon sonrası korteks organizasyonunda bozukluk mevcuttur. PMG fokal veya diffüz olabilir. Bu çalışmanın amacı PMG'de görülen aberran fissürün (AF) MR özelliklerini ortaya koymaktır. Yöntem: PMG tanısı alan 34 hastanın manyetik rezonans görüntüleme (MRG) bulguları ve dosya bilgileri PMG özellikleri, AF varlığı ve özellikleri ile klinik bulguları yönünden retrospektif olarak değerlendirildi. Bulgular: 34 hastanın 31'inde (% 91.2) fokal, 3'ünde (% 8.8) diffüz PMG görüldü. Diffüz PMG'li 3 olguda AF izlenmedi. Fokal PMG li 30 olguda AF saptandı. AF saptanmayan bir fokal PMG olgusunda PMG komşuluğunda araknoid kist mevcuttu. 27 hastada AF beynin bilinen majör fissürleri ile ilişkiliydi ya da onlarla devamlılık gösteriyordu. Sonuç: Fokal PMG li olguların büyük çoğunluğunda AF izlenmekle birlikte klinik bulgular ile anlamlı ilişkisi yoktur. Anahtar sözcükler: Aberran fissür, manyetik rezonas görüntüleme, polimikrogiri CMJ

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Polymicrogyria: pathology, fetal origins and mechanisms

Cited by 94 publications

References 94 publications

Fetal Brain Abnormality Classification from MRI Images of Different Gestational Age

Fetal Brain Abnormality Classification from MRI Images of Different Gestational Age

Multiple Functions of KBP in Neural Development Underlie Brain Anomalies in Goldberg-Shprintzen Syndrome

Aberrant fissure in polymicrogyria

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