ABSTRACT
Background: Lissencephaly is a rare developmental disorder characterized by absence of cerebral convolutions.Pachygyria (broad gyri) or agyria (no gyri) are terms used to describe appearance of cerebral surface. Togetherthese associated conditions are a part of congenital cortical malformations and may result due to arrest ofbrain development before third or fourth month of gestation. Patients suffering from these conditions presentswith significant developmental delays which further depends on the degree of malformation. Results: We reporta case of bilateral symmetrical extensive lissencephaly with pachygyria. The major MRI findings during evaluationof our case were smooth gyral pattern with thickened cortex, thinning of periventricular white matter andprominent VR (Ventricular) spaces.Conclusion: These defects can be idiopathic, associated with chromosomal abnormalities LIS 1 (chromosome 17)or can be to environmental factors (prenatal drugs or intrauterine perfusion failures). In our case Chromosome17 defect was suspected as the parieto-occipital regions were more involved.