Kennedy taken to hospital

Senator Edward M. Kennedy was briefly hospitalized Friday after suffering a seizure, sending a jolt through the political world as the iconic figure publicly battles a malignant brain tumor.

Kennedy was rushed to Cape Cod Hospital after authorities received an emergency 911 call at 5:12 p.m. from the Kennedy Compound in Hyannis Port reporting he was feeling ill, said Barnstable police Sergeant Ben Baxter. He said Kennedy was alert and conscious when crews arrived.

Kennedy's representatives released a statement Friday night, saying, "Doctors believe the incident was triggered by a change in medication. Senator Kennedy will return home tonight and looks forward to watching the debate."

Kennedy was adamant in the hospital about returning home in time to see Friday night's presidential debate, which began at 9 p.m., said a Kennedy associate who asked for anonymity because of the sensitivity of Kennedy's illness. He returned back home by 8 p.m., according to family spokeswoman Melissa Wagoner.

The associate said Kennedy received a brief phone call last night from Senator John F. Kerry expressing concern, and that they discussed the debate and its preparations in Mississippi. Kennedy was one of the first high-profile figures to publicly endorse Senator Barack Obama for the Democratic nomination.

Friday night, Republican presidential hopeful Senator John McCain mentioned Kennedy during the debate, saying, "Our thoughts and prayers go out to the lion of the Senate."

The associate said doctors told Kennedy that seizures will become more common as he battles his brain tumor, and that they were adjusting his anti-seizure medication.

The associate said Kennedy was OK, and "everything was mild."

It is not uncommon for patients with brain cancer to suffer seizures intermittently, said Dr. Deepa Subramaniam, director of the Brain Tumor Center at Georgetown University'ss Lombardi Comprehensive Cancer Center in Washington.

"Even for those patients whose tumors have been completely taken out, you still have an area of their brain that remains abnormal for the rest of their lifetime," Subramaniam said.

The region of the brain where Kennedy's tumor was located — pivotal to speech and movement — is especially prone to seizures.

Subramaniam, who does not have direct knowledge of Kennedy's condition, said seizures can be triggered by a number of factors. After surgery, the brain can be left irritable and, thus, susceptible to the electrical malfunctioning that is the hallmark of a seizure.

Additionally, changes in medication can spark a seizure.

When it happens, a seizure most often manifests as trembling of the hands and legs; in other cases, it can result in a sensation of blinking lights or cause an abnormal smell sensation.

"The seizure by itself in the brain doesn’t cause permanent damage,’’ Subramaniam said. "They are usually temporary events."

Once the immediate medical problem has subsided, doctors typically adjust a patient’s medication to reduce the prospect of future seizures.

The 76-year-old senator, who championed for reforms in healthcare and education in his 46 years in the Senate, has been more visible recently. Although he has completed radiation treatments, Kennedy is still being treated with chemotherapy. He was diagnosed in May after suffering a seizure, and has been seen as a heroic figure as he publicly battles his cancer.

He made a grand, poignant public appearance last month at the Democratic National Convention in Denver while he was undergoing treatment, fighting off kidney stones to deliver a dramatic address.

On Tuesday, Kennedy welcomed Chilean President Michelle Bachelet to his compound to receive Chile’s highest honor bestowed upon a foreign citizen for his work to restore democracy to her country, helping to cut off US aid to the dictatorial Pinochet regime in the 1970s.

During the visit, Kennedy looked well-rested and relaxed but was somewhat unsteady on his feet and later needed assistance up the porch stairs. It was his first public appearance since his speech at the Democratic National Convention on Aug. 25.

Several of Kennedy’s friends in Congress who have seen him recently have said in the last week that he looked great. He participated in a teleconference call with Democratic members of the Health, Education, Labor and Pensions Committee for about a half-hour.

Yesterday, the Senate unanimously passed legislation -- which Kennedy had championed -- giving aid to state and local law enforcement to help address the needs of nonviolent mentally ill offenders. The law authorizes $50 million in grants to law enforcement agencies.

In July, in the middle of his treatment, Kennedy stunned the nation when he flew to the Capital for a critical vote to battle scheduled cuts in Medicare payments to doctors.

Kennedy underwent a three-hour operation on June 2 by a hand-picked surgeon, Dr.Allan H. Friedman, at the Duke University Medical Center. A week later, he returned to his Cape Cod compound, and within hours went for a sail with his wife, Vicki and their two dogs. He has since been since by doctors at Massachusetts General Hospital.

His aides have said that he has been in daily contact with colleagues in the Senate, and that he plans to return to Washington in January. Susan Milligan of the Globe Staff contributed to this report.