Malformation Of Cortical Development: A Patient Of Schizencephaly And Heterotopia

Objection:The study was to investigate the characteristics of malformation of cortical development,analysis a rare case of schizencephaly accompanied by heterotopia, discuss the etiology and pathology of this cortical malformation.Methods:1,A rare case of schizencephaly accompanied by heterotopia is reported here. The case was obtained from the Department of Neurology.2,The related literatures in recent years are reviewed.Results:A 15-year-old girl presented with closed-lip schizencephaly around precentral sulcus manifesting as 3-year history of epilepsy.Magnetic resonance imaging demonstrated closed-lip schizencephaly around the right precentral sulcus,accompanied by subcortical heterotopia,polymicrogyria,Corpus Callosum hypogenesis and enlarged cisterna magna.EEG suggested that the epileptogenic zone located in the central of the right frontal lobe.Schizencephalu and heterotopia are disorders of neuronal migration, caused by genetic,infective,toxic,radiative factors in the gestation.Schizencephaly is frequently accompanied by polymicrogyria,because they are occurred both due to abnormal neuronal organization.Affected patients may have epilepsy,locomotion deficiency and developmental delay.Two main mechanisms are described concerning the pathogenesis of schizencephaly:the first mechanism is essentially a process of dysgenesis with a localized failure of induction of neuronal migration from the neural cells lining the primitive ventricle.In cases of cortical dysgenesis,the defect might be familial or hereditary and associated with the EMX2 germ line mutation and with septo-optic dysplasia.The second mechanism involves an early fetal destructive lesion occurring before the fifth month of gestation.In many cases,such a lesion might be vascular,whether vascular anomaly,or caused by hypoperfusion and hemorrhagic or thrombotic events.However,schizencephaly was also reported in association with cytomegalovirus infection and trauma.So far,it is controversial that the epileptogenic zone locates in the polymicrogyric or heterotopic cortex around the cleft.Of the few cases reported in the literature,the epileptogenic zone of schizencephaly is extralesional or adjacent to the cleft.While in another case,excision the lips of the cleft improved seizure control.Conclusion:Schizencephaly is frequently accompanied by polymicrogyria,because they are occurred both due to abnormal neuronal organization.Affected patients often have epilepsy.To these patients,excision of the epileptogenic zone is an effective way to control seizure.