MR Features of Lissencephaly with Clinical Correlations

Abstract

We aimed to demonstrate the MRI features of lissencephaly and to correlate these features with associated anomalies and clinical features in an attempt to classify them. This study included eight infants with lissencephaly. They presented with seizures, hypotonia, microcephaly, large head or failure to thrive. They were examined using a 1.5 Tesla scanner. Both T1 and T2 weighted scan were done.

Our patients showed a smooth surface of both cerebral hemispheres with complete loss of gyri and sulci (agyria) (n=5) or agyria with areas of pachygyria (n=3). The cortex was thickened with thinning of the underlying white matter and loss of normal grey-white matter interdigitations (n=8). A shallow Sylvian fissure with hourglass or oval configuration of the brain was also noted (n=8). A linear cortical band of low SI on T1 WI and high SI on T2WI was noted in five cases. Other associated findings included: Dandy-Walker malformations (n=5), hydrocephalus (n=4), microcephaly (n=2), callosal agenesis (n=2), occipital encephalocele (n=1), microphalamia with retinal dysplasia (n=1), absent septum pellucidum (n?1) and colpocephaly (n=1). MR imaging is the imaging modality of choice for the demonstration of the pathognomonic features of lissencephaly. It helps the classification of lissencephaly into different types according to their MR appearance, associated anomalies and clinical features.