Kennedy hospitalized after seizure; not a stroke

Seizures are little electrical storms in the brain. They tend to be brief; an occasional one can happen to anyone even without a prior history of seizures, especially if there has been some prior brain trauma.

A stroke is either ischemic -a clog in a blood vessel -or hemorrhagic, bleeding in the brain. Hemorrhagic ones are very rare. Kennedy had the carotid artery surgery to try to prevent the ischemic type. A stroke kills brain tissue; how much depends on how big it is and how long it lasts. Some people show no lasting effects; others can be partly paralyzed on one side or somewhere in-between.

"Sen. Kennedy was at high risk because he had surgery for an artery in his neck," said Dr. Wendy Wright, The Emory Clinic, Assistant Professor, Departments of Neurology and Nuerosurgery,

But she said there are a lot of things that can cause seizures, such as an infection or medication.

"Certain medications are known to cause seizures. A stroke can cause a seizure, a brain tumor or a head injury, or something in the brain itself," Wright said. "Common symptoms that we know about are falling on the ground, shaking and having confusion."

Kennedy, the second-longest serving member of the Senate and a dominant figure in national Democratic Party politics, was elected in 1962, filling out the term won by his brother, John F. Kennedy.

Kennedy eldest brother, Joseph, was killed in a World War II airplane crash. President John Kennedy was assassinated in 1963 and his brother Robert was assassinated in 1968.

Kennedy is active for his age, maintaining an aggressive schedule on Capitol Hill and across Massachusetts.

He has been vocal in both his opposition to the Iraq war and support for Democratic presidential contender Barack Obama, who is trying to become the first senator elected to the White House since John F. Kennedy.

Kennedy made several campaign appearances for the Illinois senator in February, and most recently another in April.