Senator Edward M. Kennedy was hospitalized yesterday after suffering a seizure, triggering shock in the political world and drawing an outpouring of support from across the nation and the ideological spectrum.
The 76-year-old Democrat was talkative and joking with family members yesterday afternoon, friends and associates said. His condition was considered serious, they said, but he did not appear to be in imminent danger.
"Senator Kennedy was admitted to Massachusetts General today after experiencing a seizure at his home," Kennedy's personal physician, Dr. Larry Ronan, said in a statement released last night. "Preliminary tests have determined that he has not suffered a stroke and is not in any immediate danger. He's resting comfortably and watching the Red Sox game with his family.
"Over the next couple of days, Senator Kennedy will undergo further evaluation to determine the cause of the seizure, and a course of treatment will be determined at that time," Ronan said.
By last evening, the mood of Kennedy family and friends contrasted markedly to that of the morning, when he was stricken at his Hyannis Port compound at about 8:15 a.m., rushed first to Cape Cod Hospital, and then transported by helicopter to Massachusetts General Hospital in Boston.
His children were urgently summoned to Boston. Telephone lines buzzed with politicians in Washington and Boston exchanging scraps of information, and television crews rushed to set up in the front drive of the hospital.
Kennedy, who underwent surgery in October to prevent a stroke but had appeared to rebound quickly, was undergoing a battery of tests at Mass. General to determine what caused the seizure and what the longer-term impact of the episode might be.
But one family associate said yesterday evening that Kennedy was alert and joking with family and was watching the Red Sox play the Milwaukee Brewers. They planned to dine on takeout from Legal Sea Foods in his room last night, the associate said.
The senator was stricken by what was initially believed to be strokelike symptoms at his Cape house, but Kennedy's Senate office released a statement around 2 p.m. that confirmed he had experienced a seizure.
A government official said he was believed to have suffered a second seizure on the flight to Boston. Dr. Ronan's statement made no mention of a second seizure.
"He is undergoing a battery of tests at Massachusetts General Hospital to determine the cause of the seizure," a brief statement from his Senate office read. "It is unlikely we will know anything more for the next 48 hours."
A seizure is an electrical disturbance in the brain that usually lasts no longer than a couple of minutes, and it can have multiple causes, including a fever, infection, dehydration, a stroke, a tumor, or an old head injury.
During the course of the day, members of his famous family, including his niece Caroline Kennedy, the daughter of assassinated President John F. Kennedy, and all three of his children - Patrick, a congressman from Rhode Island, Edward M. Kennedy Jr., and Kara - rushed to his side, either pushing through throngs of reporters gathered outside the hospital or slipping into a side entrance by Storrow Drive. Kennedy's sister Jean Kennedy Smith and nephew, former Massachusetts congressman Joseph P. Kennedy II, were also among the visitors.
It was the second time in seven months that Kennedy had been hospitalized. In October, doctors performed surgery to clean out a partially blocked neck artery they said had put him at risk of a stroke.
The chief of vascular surgery at the hospital described it at the time as "routine, uneventful, and successful," and days afterward Kennedy friends were privately laughing over how quickly the senator demanded his release.
But doctors also described the buildup in Kennedy's artery as "a very high-grade blockage" and said there was a slight chance it could recur in the next few years.
Reports of Kennedy's hospitalization prompted a media frenzy and statements of sympathy from all three presidential candidates, who are Kennedy's colleagues in the US Senate.
Democratic presidential candidate Barack Obama, beginning a tour of hospitals in Eugene, Ore., ahead of next week's primary, told reporters he had been in touch with Kennedy's family.
"Ted Kennedy is a giant in American political history," Obama said. "He's done more for healthcare than just about anybody in history. We are going to be rooting for him. I insist on being optimistic about how it's going to turn out."
Kennedy gave Obama's presidential campaign a major boost this year with his endorsement and has campaigned actively for the Illinois senator.
The other Democratic contender for president, Senator Hillary Clinton, said: "My thoughts and prayers are with Senator Ted Kennedy and his family today. We all wish him well and a quick recovery."
John McCain, the presumptive Republican nominee, said Kennedy's role in the US Senate could not be overstated.
"He is a legendary lawmaker, and I have the highest respect for him," McCain said. "When we have worked together, he has been a skillful, fair, and generous partner."
US Senator John F. Kerry, the state's junior senator, also visited Kennedy at the hospital. "Teresa and I are praying for Teddy, Vicki, and all of his family, and we know that everyone in Massachusetts and people throughout the nation pray for a full and speedy recovery for a man whose life's work has touched millions upon millions of lives," Kerry said in a written statement.
Kennedy, arguably the best known member of the US Senate, is an icon to those on the left and a scourge to conservatives nationwide. He was first elected in 1962 to fill the seat left open when his brother, John F. Kennedy, was elected president.
He has been reelected to eight full terms and is now the second most senior member of the Senate.
He was hospitalized yesterday as the Kennedy family was involved in a charity bicycle ride that began yesterday at the John F. Kennedy Library in Dorchester and was scheduled to conclude at a Hyannis Port beach with a concert and a lobster bake.
"Massachusetts General is one of the best hospitals in the world; I'm 100 percent confident he'll be fine," Kennedy nephew Anthony Shriver, founder and chairman of the nonprofit Best Buddies, said as riders arrived this afternoon at the event.
At Mass. General, dozens of reporters stood outside the entrance waiting for word on Kennedy's condition, with more than a dozen television cameras from local stations and national networks.
When Kennedy underwent surgery in October, his doctors said the blockage found in his left carotid artery could have triggered a stroke by choking off blood flow and preventing oxygen from getting to the brain or by breaking off and lodging in the brain.
About a quarter of strokes are due to carotid artery disease. Such surgery is typically performed on patients who have had a stroke or have an artery that is at least 70 percent blocked.
Kennedy felt no symptoms from the blockage, which was discovered during a routine MRI conducted to check on his spine, which was injured in a 1964 plane crash. At the time, his personal physician deemed his overall health excellent and said he exercised daily and ate well. After a short period of rest, Kennedy returned to the Senate floor Oct. 30.
Before the surgery, Kennedy's only serious hospitalization is believed to have been after the crash of a small private plane more than 40 years ago. Kennedy suffered several fractured bones in his back, broken ribs, and internal bleeding in the crash, which killed two people.
Also joining Kennedy and his second wife, Victoria Reggie Kennedy, at the hospital were Kennedy's two stepchildren, Curran and Caroline Raclin, as well as several of Kennedy's grandchildren and grandnephews.
Kennedy's other surviving sister is Eunice Kennedy Shriver. Two other sisters, Rosemary Kennedy and Patricia Kennedy Lawford, died within the past three years.
Tania deLuzuriaga, Jamie Vaznis, and Martin Finucane of the Globe staff contributed to this report.