What causes epilepsy?

Brain hyperexcitable. The exact cause & mechanism may be unknown most of the time. Conditions such as cerebral infarct, brain tumor, increased intracranial pressure b/c of any reason, infection of the brain or meninges of brain, metabolic disturbances, eg. Hypoglycemia, electrolyte abnormalities, head injury causing concussion or coupe contrecoup brain injury, aneurysms or a/v malformation, benign increase in icp, etc.