Left frontoparietal parenchymal cleft lined by grey matter and extending from the cortical surface to the lateral ventricle. The latter shows enlargement, a small ependymal defect at its lateral border and a large defect of the septum pellucidum. The corpus callosum is intact. There are severeal areas of polymicrogyria, not only at the borders of the defect but also at the superior left frontal lobe surface. Hetereotopic islands of grey matter can be found as well (supero-lateral to left ventricle). Also note the marked atrophy of the left cortico-spinal tract.