Polymicrogyria

**Definition:** Polymicrogyria (PMG) is a cerebral cortical malformation characterised by excessive cortical folding and by shallow sulci. Microscopic examination reveals abnormal cortical layering. Topographic distribution of PMG is variable, but bilateral symmetrical perisylvian PMG (BPP) is the most frequent form. PMG is manifested by mild intellectual deficit, epilepsy, and pseudobulbar palsy, which causes difficulties with speech learning and feeding. The severity of PMG is highly dependent on the location and size of the affected area.