Doctors Know Little of Cause of Arteritis : Medical: Disease that may have caused stroke from which Killum died is rare. Expert says there are no good treatments for it.

Arteritis, the condition that doctors say might have killed basketball player Earnest Killum, is an inflammation of the artery walls that, in rare cases, can trigger a massive stroke by blocking a critical vessel and cutting off blood flow to the brain.

The disease has many forms, nearly all of them extremely uncommon. Some run in families, but little is known about their causes. The condition often goes undetected, is difficult to treat and, in unusual cases such as Killum’s, can prove fatal.

“There are no good treatments,” Dr. John Glaspy, a hematologist-oncologist and director of the Bowyer Oncology Center at UCLA, said Monday. “You can put people on blood thinners to thin the blood. But that doesn’t solve the (underlying) problem.”

Killum, 20, from Lynwood and a basketball player at Oregon State, was found lying on the deck of a hotel Jacuzzi Friday, unable to speak or move his right side. He was taken to Daniel Freeman Memorial Hospital in Inglewood, where it was determined he had an acute stroke affecting the left frontal area of his brain.

Early Sunday, his condition began to deteriorate dramatically because of brain swelling precipitated by the stroke, his doctors said. Over the next 24 hours, he lost all brain function and was pronounced dead at about 3 p.m. Monday.

At a news conference Monday evening, physicians said Killum had been suffering from a congenital form of arteritis that already had caused two deaths in his family. They said his carotid artery, the main vessel supplying blood to the brain, was blocked.

Little is known about the causes of large-vessel arteritis, though some suspect it may be a disease in which the immune system attacks the blood vessels. Symptoms of its many forms range from skin rashes to death from blockage of blood flow to vital organs.

Large-vessel arteritis can cause a stroke, such as Killum’s, in either of two ways: It can cause the lining of the artery to swell to a point where it simply swells shut; or, it can damage the lining and thus trigger clotting, causing a clot to shut off blood flow.

Under normal conditions, blood flowing through arteries will not clot. But if the inner lining of the vessel is exposed as a result of damage, it stimulates clotting. A clot could block the vessel there, or smaller clots could be sent downstream.

If blood flowing through the carotid artery is blocked, cutting off flow to the brain, it can rapidly damage areas of the brain essential to what Glaspy referred to as the basic “housekeeping” of the body.

Once that happens, brain swelling may occur as damaged cells soak up water and are unable to pump it out. Pressure in the skull rises. Because the only escape route is the hole carrying the spinal cord, it can push the bottom part of the brain into that hole.

That part of the brain is essential to breathing.

It is extremely uncommon for people to survive that experience, called herniation, particularly without major brain damage, Glaspy said. Once such a stroke occurs, he said, there is nothing that can be done to minimize the damage.

According to Glaspy, large-vessel arteritis rarely is detected before symptoms occur, because examination of the lining of the blood vessels is not part of a routine physical. In young people, it is usually recognized as a result of a stroke or stroke-like symptoms.

There are no really effective treatments for arteritis, Glaspy said. The principal approach is to put the patient on a blood-thinning drug. That reduces the risk of clotting, but it does not resolve the underlying condition.

Another possible approach is to replace part of the swollen artery with a graft, but that technique has not been very successful, said Glaspy.

Killum had been taking a blood thinner, Coumadin, since a first stroke suffered in July. He initially was ordered to give up basketball, but physicians changed their minds in late December and reduced his dosage to enable him to play without excessive risk of bleeding.

Killum’s doctors said Monday they had found no clot. An autopsy, to be done today, may shed further light on that. A clot in the artery would be visible through the tests done Monday, but clots showered into the brain would be apparent only through an autopsy.

It is possible that Killum’s stroke resulted simply from swelling of the artery. “People can go ahead and get strokes despite full-dose anti-coagulation,” noted Glaspy, who is not involved with Killum’s case. “. . . The artery wall can swell and block in the absence of clotting.”

Glaspy added: “There really aren’t any good ‘preventatives’ for what happened to him, assuming it wasn’t a clot.”