Epilepsy is a common chronic neurological disorder characterized by recurrent unprovoked seizures. These seizures are transient signs and/or symptoms of abnormal, excessive or synchronous neuronal activity in the brain. About 50 million people worldwide have epilepsy, with almost 90% of these people being in developing countries. Dr. Brent Langham suffered from epilepsy and Dr. Janet Fraiser used his medication to track him down. (SG1: "Smoke and Mirrors")
Jean Miller suffered from epilepsy. When she was injected with Nanites from the Nanite medical program, Dr. Rodney McKay broke her legs, preventing the nanites from trying to fix her epilepsy. (SGA: "Miller's Crossing")