The Supreme Court was mum on whether Roberts would need anti-seizure medication. But specialists say his doctor would have raised that possibility because someone who has had two seizures is at high risk of having another.
Roberts, 52, cheerfully waved to onlookers outside the Penobscot Bay Medical Center in Rockport, Maine, before heading by pontoon boat to his summer home on Hupper Island, off Maine's middle coast. Hours earlier, he had assured President Bush by phone that he felt fine.
Roberts joins millions of adults who have had seizures for no apparent reason. The court said doctors had found no tumor, stroke or any other explanation.
Seizures are essentially little electrical storms in the brain. The resulting symptoms can range from a muscle twitch to loss of consciousness. They generally last 30 seconds to two minutes, and most people report feeling back to normal just minutes after that.
While they're most commonly associated with children, one in 10 adults will have one at some point, according to the Epilepsy Foundation. Roberts' first was in 1993.
Officials would give no details on the chief justice's diagnosis or treatment.
But the definition of epilepsy is having two or more seizures without any other cause. About 3 million Americans meet that definition.
And brain specialists said Tuesday that regardless of whether that term is officially used with Roberts, his highly publicized episode offers a teachable moment about a stigmatized disorder.
"There's nothing about epilepsy that should interfere with him continuing to function at the very highest level," stressed Dr. Orrin Devinsky, chief of New York University's epilepsy center.
Former Supreme Court clerk Ed Lazarus still expects Roberts to serve for many years — comparing him to Justices William Rehnquist and Sandra Day O'Connor, both of whom battled cancer and stayed on the job, reports CBS News chief White House correspondent Jim Axelrod. Cancer survivor Justice Ruth Bader Ginsburg continues to serve, Justice William Brennan served more than a decade after his stroke, and Justice William O. Douglas fought mental illness.
"He's at the extreme low end of the scale of ailments that the Supreme Court justices have persevered with," says Lazarus. "You're talking about people who have had to go through chemotherapy, people who've had to go through surgeries — all kinds of things much more serious than this."
Devinsky has patients for whom seizures are a much bigger concern than a high-court judge — namely, surgeons — who successfully control them with medication.
"There's unfortunately a terrible, terrible stigma in America that maybe this will go a small way to erase," he added. "Epilepsy needs to be thought of as just another disorder."
Indeed, Roberts' prior seizure in 1993 didn't raise concerns at the White House when Bush nominated him to the nation's highest court — or at the Senate Judiciary Committee, which reviewed his health records as part of Roberts' confirmation hearing in 2005.
"Look, it's something that you will take seriously, but obviously upon examining it, they also believed that he would be competent to continue — and still do believe so," White House press secretary Tony Snow told reporters Tuesday.
Roberts was hospitalized after he fell on a dock near his home on Monday. Supreme Court spokeswoman Kathy Arberg said doctors found.
"Idiopathic means they really don't know what caused it," Dr. Emily Senay told CBS' The Early Show, and added that the seizures could have a genetic component to them.
The big question, left unanswered, is whether Roberts will take a daily pill to prevent another seizure.
Once someone has had two seizures, chances of a third can reach as high as 80 percent, said Dr. Gholam Motamedi, epilepsy director at Georgetown University Hospital. Whether someone is on the high or low end of that risk scale depends in part on results of tests, including a measure of brain activity called an EEG.
There are numerous medications to choose from, and while all can cause side effects, they're generally mild in the low dose that would be expected for someone with just two seizures 14 years apart, Motamedi said.
"If you ask 10 neurologists, at least eight would agree he's better off on medication."
But Devinsky offered an example of how to weigh that decision: Say someone with Roberts' two-seizure history always took a bus or walked and hated pills. They might be OK skipping medication. But say that person was required to drive 500 miles a week for a sales job. Devinsky would strongly advise medication as a safety precaution, and because state laws vary widely on the driving restrictions imposed after a seizure.
Roberts has a driver to shuttle him to the Supreme Court. His home state of Maryland decides driving restrictions based on individual circumstances, while Washington, D.C., generally imposes a 12-month seizure-free period.
Are there seizure triggers? Stress "doesn't create seizures in people," Motamedi said. "If you have a stressful life, it doesn't mean you're more likely to become epileptic."
But sleep deprivation is a well-known trigger of seizures in certain people, and stress can lead to poor sleep, Motamedi added. Patients with what he calls "low seizure thresholds" — they have them often — also tell doctors they're more susceptible when stressed.