Cortical dysplasia is the most common brain malformation seen in an epilepsy surgery facility. There are many different types of cortical dysplasias. Cortical dysplasia can be limited to one area of the brain, one lobe, or be located in several different lobes.
Neuroimaging such as magnetic resonance imaging (MRI) should be performed at an advanced pediatric epilepsy facility because the brain malformation can be very subtle and missed by an inexperienced neuro-radiologist or if imaged on a low resolution machine. Sometimes, the cortical dysplasia is not always apparent on MRI because it is too small, but may show up several years later in imaging when the brain grows. Also, the extent of the cortical dysplasia can be more than what the MRI is capable of viewing.
Completely removing the entire area of cortical dysplasia is associated with the best post-surgery seizure control.
Cross, H. et al. Proposed criteria for referral and evaluation of children for epilepsy surgery: recommendations of the sub commission for pediatric epilepsy surgery. Epilepsy, 47(6): 952-959 (2006).