Cortical dysplasia
Cortical dysplasia is a benign tumor which occurs when the infant brain is developing in the womb. Occasionally neurons will develop that are larger than normal in certain areas. This causes the signals sent through the neurons in these areas to misfire, which sends an incorrect signal. It is commonly found near the cerebral cortex and is associated with seizures and often some level of mental retardation. Instead of using medication to suppress the seizures, surgery is increasingly becoming a popular solution for the problem.