A seizure is a disturbance in the electrical activity of the brain. About 2.7 million people in the United States have some form of epilepsy. Thirty percent are under age 18. Many more children and adults have undetected or untreated epilepsy. There are about 200,000 newly diagnosed cases each year. Twice as many Americans have epilepsy than have cerebral palsy, muscular dystrophy, multiple sclero
sis, and cystic fibrosis combined. Anyone can develop epilepsy at any time. Twenty percent of cases develop before age five. Fifty percent develop before age 25. Epilepsy is also increasingly associated with older adults: there are as many cases of epilepsy in those age 60 and older as there are in children age 10 and younger.