Figure 1: Pathologic classification of cortical lesions. (a) Type 1 “Leukocortical” lesions involve the deeper layers of gray matter and underlying white matter. Arrow head demonstrates the portion of the lesion extending into the white matter. (b) Type 2 “Intracortical” lesions are small lesions completely contained within the cortex, typically centered around small blood vessels. (c) Type 3 “Subpial” lesions extend from the pial surface into the superficial cortical layers, not reaching the white matter. (d) Type 4 “Subpial” lesions involve all layers of the gray matter but do not involve underlying white matter.