MRI images at ages 1 and 10 years. (A) Sagittal T2 weighted image at age 1 year showed a small cerebellar vermis (black arrows) and abnormal posterior arch of C1 (white arrow) causing compression of the posterior aspect of the upper cervical spinal cord. (B) Parasagittal T1 weighted image at age 10 years showed subtle irregularity of the cortical-white matter junction and the surface of the cortex in the left frontal lobe (arrows), consistent with polymicrogyria or similar dysgenesis. (C) Coronal T2 weighted image at age 10 years showed ventriculomegaly and malrotated hippocampi. (D) Coronal T2 weighted image at age 10 years at the level of the ventricular trigones showed periventricular nodular heterotopia of moderate (black arrow) and small (white arrow) sizes.