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Assessment of fetal brain abnormalities
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Schizencephaly is a disorder characterized by congenital clefts in the cerebral mantle, lined by pia-ependyma, with communication between the subarachnoid space laterally and the ventricular system medially. Of that 63% is unilateral and 37% bilateral. Frontal region is 44% and frontoparietal is 30% (43). Schizencephaly is associated with ventriculomegaly, microcephaly, polymicrogyria, gray matter heterotopias, dysgenesis of the corpus callosum, absence of the septum pellucidum, and optic nerve hypoplasia.
Developmental Diseases of the Nervous System
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
James H. Tonsgard, Nikolas Mata-Machado
The causes of schizencephaly are heterogeneous. Both genetic and nongenetic causes are postulated. There are some cases associated with chromosomal aneuploidy, single gene defects, and distinct syndromes, so it is likely that there is more than one genetic cause. The EMX2 gene was initially implicated, but more recent studies do not support that. Currently, another gene, LHX2, a gene expressed in the forebrain, has been suggested, as well as the genes HESX1 and SOX2. Pathology shows a deep cleft, either unilateral or bilateral, extending the full thickness of the brain. The walls of the cleft are usually widely separated, and the clefts are commonly in the perisylvian area. The cortex lining the clefts is polymicrogyric.
Central nervous system
Published in Dave Maudgil, Anthony Watkinson, The Essential Guide to the New FRCR Part 2A and Radiology Boards, 2017
Dave Maudgil, Anthony Watkinson
Are the following statements regarding cerebral malformations true or false? Lissencephaly presents with an abnormally thick grey matter.In incomplete lissencephaly the frontal lobes are most commonly affected.Polymicrogyria presents with thinned cortex.In open lip schizencephaly white matter lines the cleft.Schizencephaly is most commonly bilateral.
Schizencephaly accompanied by occipital encephalocele and deletion of chromosome 22q13.32: a case report
Published in Fetal and Pediatric Pathology, 2019
Cihan Inan, N. Cenk Sayin, Hakan Gurkan, Engin Atli, Selen Gursoy Erzincan, Isil Uzun, Havva Sutcu, Sumeyra Dogan, Emine Ikbal Atli, Fusun Varol
Schizencephaly is a cerebral cortical malformation with an estimated prevalence of 1.48/100.000 births. This congenital abnormality is characterized by a hemispheric cleft extending from the ventricles to the ipsilateral subarachnoid space [1]. There are two types, separated (open-lip) or fused (closed-lip) [2, 3]. The clefts are covered by heterotopic gray matter and may be present at any location in the brain [4]. Schizencephaly may coexist with various cerebral malformations including gray matter heterotopy, agenesis of the corpus callosum, polymicrogyria, microcephaly, and septo-optic dysplasia [5, 6]. Although the etiopathogenesis is still unclear, the most accepted hypothesis of the formation of cerebral cleft is a vascular damage in early gestation that results in ischemia in the germinal matrix [7, 8]. Alternatively, genetic alterations in the empty spiracles homeobox2 (EMX2), SIX homebox3 (SIX3), and sonic hedgehog (SHH) genes may also contribute to the development of schizencephaly because of their potential adverse effects on the brain development and neuronal migration processes [9–11]. We describe a female infant with schizencephaly with the unexpected findings of an occipital encephalocele and deletion of chromosome 22q13.32.
Congenital Visual Field Loss from a Schizencephalic Cleft Damaging Meyer’s Loop
Published in Neuro-Ophthalmology, 2021
Benyam Kinde, A. James Barkovich, Jonathan C. Horton
Recent evidence suggests that schizencephaly can be caused by destructive vascular events in the foetal brain.5 Gould and colleagues have shown that mutations in the Col4A1 gene, encoding procollagen type IV, can lead to intrauterine intracerebral haemorrhage.6 The resulting damage to the cortex can produce a typical schizencephalic cleft.7