What is mesial temporal sclerosis? what causes it?

Congenital: Typically involves abnormality over the inner temporal lobe of brain, and can be associated with complex partial seizures. Likely of hereditary causation, but in some cases, may be associated with pre-natal and peri-natal causation.

Abnormal area: Either congenital or genetic focal abnormality over middle area of temporal lobe which can be site of possible seizure activity, and excision might be very beneficial.