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AJNR. American Journal of Neuroradiology Aug 2020Polymicrogyria and lissencephaly may be associated with abnormal organization of the undelying white matter tracts that have been rarely investigated so far. Our aim was...
BACKGROUND AND PURPOSE
Polymicrogyria and lissencephaly may be associated with abnormal organization of the undelying white matter tracts that have been rarely investigated so far. Our aim was to characterize white matter tract organization in polymicrogyria and lissencephaly using constrained spherical deconvolution, a multifiber diffusion MR imaging modeling technique for white matter tractography reconstruction.
MATERIALS AND METHODS
We retrospectively reviewed 50 patients (mean age, 8.3 ± 5.4 years; range, 1.4-21.2 years; 27 males) with different polymicrogyria ( = 42) and lissencephaly ( = 8) subtypes. The fiber direction-encoded color maps and 6 different white matter tracts reconstructed from each patient were visually compared with corresponding images reconstructed from 7 age-matched, healthy control WM templates. Each white matter tract was assessed by 2 experienced pediatric neuroradiologists and scored in consensus on the basis of the severity of the structural abnormality, ranging from the white matter tracts being absent to thickened. The results were summarized by different polymicrogyria and lissencephaly subgroups.
RESULTS
More abnormal-appearing white matter tracts were identified in patients with lissencephaly compared with those with polymicrogyria (79.2% versus 37.3%). In lissencephaly, structural abnormalities were identified in all studied white matter tracts. In polymicrogyria, the more frequently affected white matter tracts were the cingulum, superior longitudinal fasciculus, inferior longitudinal fasciculus, and optic radiation-posterior corona radiata. The severity of superior longitudinal fasciculus and cingulum abnormalities was associated with the polymicrogyria distribution and extent. A thickened superior fronto-occipital fasciculus was demonstrated in 3 patients.
CONCLUSIONS
We demonstrated a range of white matter tract structural abnormalities in patients with polymicrogyria and lissencephaly. The patterns of white matter tract involvement are related to polymicrogyria and lissencephaly subgroups, distribution, and, possibly, their underlying etiologies.
Topics: Adolescent; Brain; Child; Child, Preschool; Diffusion Tensor Imaging; Female; Humans; Infant; Lissencephaly; Male; Polymicrogyria; Retrospective Studies; White Matter; Young Adult
PubMed: 32732266
DOI: 10.3174/ajnr.A6646 -
Revue Neurologique Mar 2019Comparison studies between 7T and 1.5 or 3T magnetic resonance imaging (MRI) have demonstrated the added value of ultra-high field (UHF) MRI to better identify,... (Review)
Review
Comparison studies between 7T and 1.5 or 3T magnetic resonance imaging (MRI) have demonstrated the added value of ultra-high field (UHF) MRI to better identify, delineate and characterize malformations of cortical development (MCD), and to disambiguate doubtful findings observed at lower field strengths. High resolution structural sequences such as magnetization prepared two rapid acquisition gradient echoes (MP2RAGE), fluid and white matter suppression MP2RAGE (FLAWS), and susceptibility-weighted imaging (SWI) appear to be key to the improvement of MCD diagnosis in clinical practice. 7T MRI offers not only images of high resolution and contrast but also provides many quantitative approaches capable of acting as more efficient probes of microstructure and ameliorating the categorization of MCDs. Post-processing of multiparametric ultra-high resolution and quantitative data may also be used to improve automated detection of MCD via machine learning. Therefore, 7T MRI can be considered as a useful tool in the presurgical evaluation of drug-resistant partial epilepsies, particularly, but not exclusively, in cases of normal appearing conventional MRI. It also opens many perspectives in the fields of in vivo histology and computational anatomy.
Topics: Brain; Functional Neuroimaging; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Malformations of Cortical Development
PubMed: 30827579
DOI: 10.1016/j.neurol.2019.01.393 -
Seminars in Ultrasound, CT, and MR Dec 2015Fetal brain magnetic resonance imaging (MRI) is a powerful tool in the diagnosis of symptomatic congenital cytomegalovirus infection, requiring a detailed search for... (Comparative Study)
Comparative Study Review
Fetal brain magnetic resonance imaging (MRI) is a powerful tool in the diagnosis of symptomatic congenital cytomegalovirus infection, requiring a detailed search for specific features. A combination of anterior temporal lobe abnormalities, white matter lesions, and polymicrogyria is especially predictive. Fetal MRI may provide a unique opportunity to detect anterior temporal cysts and occipital horn septations, as dilation of these areas may decrease later in development. Cortical migration abnormalities, white matter abnormalities, cerebellar dysplasia, and periventricular calcifications are often better depicted on postnatal imaging but can also be detected on fetal MRI. We present the prenatal brain MRI findings seen in congenital cytomegalovirus infection and provide postnatal imaging correlation, highlighting the evolution of findings at different times in prenatal and postnatal developments.
Topics: Craniofacial Abnormalities; Cytomegalovirus Infections; Diagnosis, Differential; Female; Humans; Hydrocephalus; Infant, Newborn; Magnetic Resonance Imaging; Male; Prenatal Diagnosis; Statistics as Topic
PubMed: 26614131
DOI: 10.1053/j.sult.2015.04.001 -
Turkish Archives of Pediatrics Jul 2021The purpose of this study is to classify the malformations of cortical development in children according to the embryological formation, localization, and...
AIM
The purpose of this study is to classify the malformations of cortical development in children according to the embryological formation, localization, and neurodevelopmental findings. Seizure/epilepsy and electrophysiological findings have also been compared.
MATERIAL AND METHODS
Seventy-five children (age: 1 month-16.5 years; 56% male) followed with the diagnosis of malformation of cortical development, in Marmara University Pendik Research and Educational Hospital Department of Pediatric Neurology, were included in the study. Their epilepsy characteristics, electroencephalogram (EEG) findings, and prognosis were reported. Neurodevelopmental characteristics were evaluated by the Bayley Scales of Infant and Toddler Development (Bayley-III) for the ages of 0-42 months ( = 30); the Denver Developmental Screening Test-II (DDST-II) for ages 42 months-6 years ( = 11); and the Wechsler Intelligence Scales for Children (WISC-R), used for children 6 years and older ( = 34).
RESULTS
The patients were classified as 44% premigrational (14.6% microcephaly, 24% tuberous sclerosis, 2.7% focal cortical dysplasia, 1.3% hemimegalencephaly, and 1.3% diffuse cortical dysgenesis); 17.3% migrational (14.6% lissencephaly, 2.7% heterotopia); and 38.6% postmigrational (14.6% schizencephaly, 24% polymicrogyria) developmentally. According to involved area, the classification was 34.7% hemispheric/multilobar, 33.3% diffuse, and 32% focal. Seventy-five percent of the patients had a history of epilepsy, and 92% were resistant to treatment. The seizures started before the age of 12 months in diffuse malformations, and epileptic encephalopathy was more common in microcephaly with a rate of 80% and lissencephaly with a rate of 54.5% in the first EEGs. Ninety-five percent of patients had at least one level of neurodevelopmental delay detected by DDST/Bayley-III; this was more common in patients with accompanying epilepsy ( < .05). As seen more commonly in patients with diffuse pathologies and intractable frequent seizures, mental retardation was detected by WISC-R in 64.5% of patients ( < .05).
CONCLUSION
In cases with cortical developmental malformation, epilepsy/EEG features and neurodevelopmental prognosis can be predicted depending on the developmental process and type and extent of involvement. Patients should be followed up closely with EEG.
PubMed: 35005731
DOI: 10.5152/TurkArchPediatr.2021.20148 -
The Canadian Journal of Neurological... Nov 2020Megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome (OMIM #602501) is characterized by megalencephaly, midline capillary malformations, and cortical...
Megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome (OMIM #602501) is characterized by megalencephaly, midline capillary malformations, and cortical malformations. This genetic overgrowth syndrome is associated with mosaic gain-of-function pathogenic PIK3CA variants (OMIM #171834).
Topics: Capillaries; Humans; Megalencephaly; Mutation; Polymicrogyria; Vascular Malformations; Venous Thrombosis
PubMed: 32631464
DOI: 10.1017/cjn.2020.127 -
Zhurnal Nevrologii I Psikhiatrii Imeni... 2022This paper describes two cases of congenital bilateral perisylvian syndrome (CBPS), a rare disorder of late neuronal migration, which is characterized by language delay,...
This paper describes two cases of congenital bilateral perisylvian syndrome (CBPS), a rare disorder of late neuronal migration, which is characterized by language delay, intellectual disorders, epilepsy and bilateral perisylvian polymicrogyria. Pseudobulbar paralysis and orofacial muscles dyspraxia causing drooling and feeding difficulties are common for patients with CBPS. Communicational problems lead to low self-esteem and social maladaptation. Literature data regarding correlation between polymicrogyria topography and speech disorders and articulation impairment severity are presented. The results demonstrate the association of diffuse spreading of bilateral polymicrogyria and more severe speech disorders comparing to mild speech disorders in patients with more local polymicrogyria. Known etiology factors of this syndrome are bilateral cerebral hypoperfusion, brain damage while neuronal migration period, postmigrational vascular insults and gene mutations. Syndrome can be inherited in autosome dominant and X-linked manner. Speech apraxia with normal impressive speech, refractory epileptic seizures and status dysraphicus must be red flags for a physician regarding this syndrome. Overnight video-EEG monitoring and brain MRI confirm a thesis that this syndrome is underdiagnosed in everyday clinical practice.
Topics: Abnormalities, Multiple; Cerebral Cortex; Child; Humans; Intellectual Disability; Magnetic Resonance Imaging; Malformations of Cortical Development; Polymicrogyria; Speech Disorders; Syndrome
PubMed: 36170094
DOI: 10.17116/jnevro202212209221 -
Epileptic Disorders : International... Oct 2018Polymicrogyria (PMG) is one of the most common malformations of cortical development (MCDs), with epilepsy affecting most patients. PMG-related drug-resistant epilepsy... (Review)
Review
Polymicrogyria (PMG) is one of the most common malformations of cortical development (MCDs), with epilepsy affecting most patients. PMG-related drug-resistant epilepsy patients can be considered for epilepsy surgery in well-selected cases. In this context, a comprehensive presurgical evaluation, often including stereo-electroencephalography (SEEG), is warranted to accurately delineate the epileptogenic zone. The heterogeneity of intrinsic epileptogenicity in PMG, together with the additional or predominant involvement of remote cortical areas, calls for a different strategy in PMG compared to other MCDs, namely one that is not predominantly MRI- but rather SEEG-oriented. Favourable results in terms of seizure freedom and antiepileptic drug cessation are feasible in a large proportion of patients with unilateral PMG. PMG extent should not deter from exploring the possibility of epilepsy surgery. On the other hand, patients with hemispheric PMG can be excellent hemispherotomy candidates, particularly when presenting with contralateral hemiparesis. Recent findings support the early consideration of surgery in PMG-related drug-resistant epilepsy.
Topics: Drug Resistant Epilepsy; Electroencephalography; Humans; Polymicrogyria; Stereotaxic Techniques
PubMed: 30378553
DOI: 10.1684/epd.2018.1004 -
Neurology Jan 2019Hereditary hemorrhagic telangiectasia (HHT) is generally considered a disorder of endothelial dysfunction, characterized by the development of multiple systemic...
Hereditary hemorrhagic telangiectasia (HHT) is generally considered a disorder of endothelial dysfunction, characterized by the development of multiple systemic arteriovenous malformations (AVMs), including within the brain. However, there have recently been a number of reports correlating HHT with malformations of cortical development, of which polymicrogyria is the most common type. Here we present 7 new cases demonstrating polymicrogyria in HHT, 6 of which demonstrate a brain AVM (bAVM) in close spatial proximity, with the aim of providing a common origin for the association. Upon reviewing patient genetics and imaging data and comparing with previously reported findings, we form 2 new conclusions: (1) polymicrogyria in HHT appears exclusively associated with a subset of mutations in the transmembrane protein endoglin that is involved with blood flow-related mechanotransduction signaling during angiogenesis and (2) the polymicrogyria is characteristically unilateral, typically focal, and correlates with vascular regions experiencing low fluid shear stress during corticogenesis in utero. Integrating these with findings in the literature from genetics and molecular biology experiments, we propose a theory suggesting haploinsufficient endoglin mutations, especially those that are dominant-negative, may predispose focal, aberrant hypersprouting angiogenesis during corticogenesis that leads to the production of polymicrogyria. This hypoxic insult may further serve as the revealing trigger for later development of a spatially coincident bAVM. This hypothesis suggests an essential role for endoglin-mediated hemodynamic mechanotransduction in normal corticogenesis.
Topics: Adolescent; Adult; Arteriovenous Malformations; Brain; Child; Child, Preschool; Female; Humans; Infant; Male; Polymicrogyria; Telangiectasia, Hereditary Hemorrhagic
PubMed: 30584075
DOI: 10.1212/WNL.0000000000006686 -
Fukutin regulates tau phosphorylation and synaptic function: Novel properties of fukutin in neurons.Neuropathology : Official Journal of... Feb 2022Fukutin, a product of the causative gene of Fukuyama congenital muscular dystrophy (FCMD), is known to be responsible for basement membrane formation. Patients with FCMD...
Fukutin, a product of the causative gene of Fukuyama congenital muscular dystrophy (FCMD), is known to be responsible for basement membrane formation. Patients with FCMD exhibit not only muscular dystrophy but also central nervous system abnormalities, including polymicrogyria and neurofibrillary tangles (NFTs) in the cerebral cortex. The formation of NFTs cannot be explained by basement membrane disorganization. To determine the involvement of fukutin in the NFT formation, we performed molecular pathological investigations using autopsied human brains and cultured neurons of a cell line (SH-SY5Y). In human brains, NFTs, identified with an antibody against phosphorylated tau (p-tau), were observed in FCMD patients but not age-matched control subjects and were localized in cortical neurons lacking somatic immunoreactivity for glutamic acid decarboxylase (GAD), a marker of inhibitory neurons. In FCMD brains, NFTs were mainly distributed in lesions of polymicrogyria. Immunofluorescence staining revealed the colocalization of immunoreactivities for p-tau and phosphorylated glycogen synthase kinase-3β (GSK-3β), a potential tau kinase, in the somatic cytoplasm of SH-SY5Y cells; both the immunoreactivities were increased by fukutin knockdown and reduced by fukutin overexpression. Western blot analysis using SH-SY5Y cells revealed consistent results. Enzyme-linked immunosorbent assay (ELISA) confirmed the binding affinity of fukutin to tau and GSK-3β in SH-SY5Y cells. In the human brains, the density of GAD-immunoreactive neurons in the frontal cortex was significantly higher in the FCMD group than in the control group. GAD immunoreactivity on Western blots of SH-SY5Y cells was significantly increased by fukutin knockdown. On immunofluorescence staining, immunoreactivities for fukutin and GAD were colocalized in the somatic cytoplasm of the human brains and SH-SY5Y cells, whereas those for fukutin and synaptophysin were colocalized in the neuropil of the human brains and the cytoplasm of SH-SY5Y cells. ELISA confirmed the binding affinity of fukutin to GAD and synaptophysin in SH-SY5Y cells. The present results provide in vivo and in vitro evidence for novel properties of fukutin as follows: (i) there is an inverse relationship between fukutin expression and GSK-3β/tau phosphorylation in neurons; (ii) fukutin binds to GSK-3β and tau; (iii) tau phosphorylation occurs in non-GAD-immunoreactive neurons in FCMD brains; (iv) neuronal GAD expression is upregulated in the absence of fukutin; and (v) fukutin binds to GAD and synaptophysin in presynaptic vesicles of neurons.
Topics: Brain; Glycogen Synthase Kinase 3 beta; Humans; Neurofibrillary Tangles; Neurons; Phosphorylation; tau Proteins
PubMed: 35026860
DOI: 10.1111/neup.12797 -
Frontiers in Neuroscience 2022Congenital genetic disorders often present with neurological manifestations such as neurodevelopmental disorders, motor developmental retardation, epilepsy, and... (Review)
Review
Congenital genetic disorders often present with neurological manifestations such as neurodevelopmental disorders, motor developmental retardation, epilepsy, and involuntary movement. Through qualitative morphometric evaluation of neuroimaging studies, remarkable structural abnormalities, such as lissencephaly, polymicrogyria, white matter lesions, and cortical tubers, have been identified in these disorders, while no structural abnormalities were identified in clinical settings in a large population. Recent advances in data analysis programs have led to significant progress in the quantitative analysis of anatomical structural magnetic resonance imaging (MRI) and diffusion-weighted MRI tractography, and these approaches have been used to investigate psychological and congenital genetic disorders. Evaluation of morphometric brain characteristics may contribute to the identification of neuroimaging biomarkers for early diagnosis and response evaluation in patients with congenital genetic diseases. This mini-review focuses on the methodologies and attempts employed to study Rett syndrome using quantitative structural brain MRI analyses, including voxel- and surface-based morphometry and diffusion-weighted MRI tractography. The mini-review aims to deepen our understanding of how neuroimaging studies are used to examine congenital genetic disorders.
PubMed: 35450016
DOI: 10.3389/fnins.2022.835964