Sen. Edward M. Kennedy is visited by family members

A glioma is a brain tumor that arises from glial cells, the structural cells that surround and support the neurons that do the actual work of the brain. Aggressive gliomas, also called glioblastomas, of the type suffered by Sen. Edward M. Kennedy strike about 9,000 Americans every year, accounting for about a third of all primary brain tumors.

With standard treatments, the median survival is 15 months, according to Dr. Keith L. Black, chairman of the department of neurosurgery at Cedars-Sinai Medical Center in Los Angeles. Two years after diagnosis, about 8% of patients are still alive.

"Age is a very strong predictor of prognosis," Black said, and because Kennedy is 76, his outlook is not as good as that of someone younger.

Unlike most other types of cancer, brain tumors do not metastasize and spread to other organs. But the most aggressive ones, like Kennedy's, spread rapidly throughout the brain, taking up substantial space inside the skull, squeezing other tissue in the brain and impairing its function.

One common course of therapy is administering steroids to reduce swelling and ease the pressure on neurons. But those steroids have many side effects that produce behavioral problems and make sleep difficult, said Dr. Behnam Badie, head of the brain tumor program at City of Hope Comprehensive Cancer Center in Duarte.

Standard treatment involves surgery, radiation and chemotherapy. Surgery entails removing the tumor, but that may not be a good option for Kennedy because his tumor is in the left parietal lobe, which controls language functions, such as the ability to comprehend speech.

This type of tumor sometimes crosses the corpus callosum, which connects the hemispheres of the brain. Surgery is even more difficult in such cases, Black said.

If the tumor is in the language areas of the brain, he said, surgeons will sometimes try to remove it while the patient is conscious so that they can monitor speech function during the procedure.

Dr. Lynne Taylor, a neuro-oncologist at the University of Washington and a spokeswoman for the American Academy of Neurology, noted that surgical resection of brain tumors was usually done in conjunction with the needle biopsy like that performed on Kennedy. The fact that they did not do so suggested that surgery is not possible, she said.

BOSTON -- Sen. Edward M. Kennedy is being released from the hospital, one day after being diagnosed with a cancerous brain tumor that experts say is almost certainly fatal.

Doctors said Wednesday the Massachusetts Democrat "has recovered remarkably quickly" from a biopsy conducted after he suffered a seizure last weekend at his home on Cape Cod.

The doctors say he will await further test results and treatment options while convalescing at his home over the Memorial Day weekend.

Kennedy has been treated at Massachusetts General Hospital for what doctors now say is a malignant glioma in his left parietal lobe. Malignant gliomas are diagnosed in about 9,000 Americans a year; in general, half of all patients die within a year.

Seizures, like the one Sen. Edward M. Kennedy reportedly suffered yesterday, are a fairly common occurence affecting about 10 percent of the population and often are precipitated by a stroke, according to a stroke expert.

“Stroke is probably the most common cause of seizure in American adults,” said Dr. David Thaler, director of Tufts Medical Center Comprehensive Stroke Center.

According to Epilepsy Foundation figures, 22 percent of stroke survivors will have seizures. Two or more after a stroke is labeled a seizure disorder or epilepsy.

Last October, Kennedy underwent an hourlong procedure to remove a blockage from his left carotid artery. The procedure often is performed to prevent stroke.

Seizures are divided into two major categories: generalized and partial, Thaler said.

A partial seizure is an electrical discharge that affects one part of the brain. A generalized seizure is caused by an electrical discharge that affects both sides of the brain simultaneously. It’s a more serious condition that causes convulsions.

Patients can undergo an MRI, CAT scan or electroencephalogram (EEG) to determine the cause of the seizure, Thaler said.

He described anti-seizure medications as “safe and effective.”

WASHINGTON -- Sen. Edward M. Kennedy, hospitalized Saturday after apparently suffering a seizure at his home on Cape Cod, Mass., was awake and joking with family members later in the day, a spokeswoman said. The Democratic senator is undergoing tests at Massachusetts General Hospital in Boston to determine the cause of the seizure. The 76-year-old Kennedy, leader of a storied political dynasty and a liberal icon, was rushed from the family compound at Hyannis Port, Mass., to Cape Cod Hospital at 9 a.m. He was evaluated there, then airlifted to Massachusetts General. Kennedy suffered what first appeared to be "stroke-like symptoms," a Democratic Party aide said. The longtime senator experienced one seizure in Cape Cod and a second while aboard the helicopter flight to Boston, the Boston Globe reported. By the end of the day, however, Kennedy was "conscious, talking, joking with family," said Kennedy's spokeswoman, Stephanie Cutter. Nonetheless, news of his illness sent shudders through the Democratic establishment and commanded wide national attention, in part because he so vividly embodies the Kennedy legacy, with even his voice and appearance potently reminiscent of his two slain brothers. Family members said they remained "guardedly optimistic" that he would recover soon, and hospital officials said he was resting comfortably. Relatives gathered at the hospital, joined by Kennedy's Massachusetts colleague, Sen. John F. Kerry. The 76-year-old Kennedy, leader of a storied political dynasty and a liberal icon, was rushed from the family compound at Hyannis Port, Mass., to Cape Cod Hospital at 9 a.m. He was evaluated there, then airlifted to Massachusetts General. Kennedy suffered what first appeared to be "stroke-like symptoms," a Democratic Party aide said. The longtime senator experienced one seizure in Cape Cod and a second while aboard the helicopter flight to Boston, the Boston Globe reported. By the end of the day, however, Kennedy was "conscious, talking, joking with family," said Kennedy's spokeswoman, Stephanie Cutter. Nonetheless, news of his illness sent shudders through the Democratic establishment and commanded wide national attention, in part because he so vividly embodies the Kennedy legacy, with even his voice and appearance potently reminiscent of his two slain brothers. Family members said they remained "guardedly optimistic" that he would recover soon, and hospital officials said he was resting comfortably. Relatives gathered at the hospital, joined by Kennedy's Massachusetts colleague, Sen. John F. Kerry. The hospital canceled plans for a news briefing. Experts said a seizure is caused by the abnormal firing of neurons in the brain, producing an excess of electrical activity. Although frequently thought to lead to a loss of consciousness or convulsions, seizures can produce symptoms as mild as numbness, nausea or a sensation of fear. Many of those symptoms also are associated with stroke, making it difficult at times to distinguish between the two. Nearly everybody is at some risk of seizures, according to Dr. Marc R. Nuwer of UCLA's David Geffen School of Medicine. They can be triggered by sleep deprivation, stress, alcohol consumption or medications. It is unlikely that Kennedy will suffer any long-lasting aftereffects. But Nuwer said he would probably have a headache and a sore body for several days, "like he ran a marathon."