Illustration comparing a normal cerebral cortex to two types of cortical malformations. The left panel shows the normal brain surface with smooth folds. The upper right panel shows “Bottom of Sulcus Dysplasia,” where abnormal tissue is located deep in the groove of a brain fold. The lower right panel shows “Focal Cortical Dysplasia,” where the abnormal area affects a larger portion of the cortex. Arrows point from the normal cortex to each dysplasia type, showing where the abnormalities occur.