Mike Patterson diagnosed with AVM

BETHLEHEM, Pa. -- Philadelphia Eagles defensive tackle Mike Patterson has a brain condition that may require surgery, team trainer Rick Burkholder said.

Burkholder said Thursday morning that Patterson is undergoing further tests and is listed in stable condition. The 28-year-old player was hospitalized after suffering a seizure Wednesday morning at training camp at Lehigh University.

"In medicine today, there's tons of options," Burkholder said. "Everybody wants to jump right into surgery and I'm not saying for this particular case, I'm saying with everything, but there's so many other avenues out there. It would be foolish to speculate what's going to happen to Mike."

The 6-foot-1, 300-pound Patterson has been diagnosed with arteriovenous malformation (AVM), which is the tangling of blood vessels near the skull.

"We're pretty sure it's what caused the seizure and we're pretty sure it's not football-related," Burkholder said. "It just so happened at football practice. It could've happened anywhere."

AVMs are malformations or tangles of arteries and veins that alter blood flow. The cause isn't known, but they are usually present at birth. They can form anywhere, but are more common in the brain or spinal cord.

About 300,000 Americans are thought to be affected by AVMs of the brain or spinal cord. Most people don't experience any symptoms, and aren't aware of the malformation until symptoms arise, usually in their 20s, 30s and 40s. Common symptoms are headaches and seizures. The biggest risk is bleeding.

Treatments include medications, surgery or radiation and vary depending on the size and location.

Patterson's agent, J.R. Rickert, disputed the definite diagnosis of AVM. He said it's too early to say the 6-foot-1, 300-pound Patterson has the condition. Rickert spoke with Patterson and his wife, Bianca, Thursday morning. He had a conversation with Burkholder on Wednesday.

"Rick spoke to one doctor who evaluated Mike that's leaning toward the diagnosis of AVM," Rickert told The Associated Press. "Two other doctors are not leaning toward AVM. They haven't ruled it out, but they're not leaning in that direction at all. They're saying it's premature to diagnose him in that capacity.

"We're going to take Mike to a fourth specialist to get an opinion. After we get that opinion, Mike and Bianca will get together and make a decision about the best course of action based on which opinion they want to follow."

Burkholder said the Eagles are consulting with doctors at Philadelphia's Thomas Jefferson University Hospital who use a less-invasive procedure for treating AVM. The procedure, called endovascular coiling, involves the surgeon guiding a catheter though the arterial network until the tip of the catheter reaches the site of the AVM. The surgeon then introduces a substance that will plug the fistula, correcting the abnormal pattern of blood flow.

Burkholder said Patterson is on medication to prevent another seizure, and anticipates he'll be released from the hospital Thursday. It's unknown when or if Patterson will return to the Eagles.

"He's antsy to get out of the hospital and get to the next step," Burkholder said. "He's always upbeat and that's the way he is now."

On Wednesday, the player dropped to the ground between drills during a morning practice, and the player began violently shaking. He was immediately tended to by Burkholder and his staff, with assistance from rookie Danny Watkins, a trained firefighter, and taken by ambulance to Lehigh Valley Hospital.

Burkholder said Wednesday that the seizure lasted about four minutes, and Patterson lost consciousness at one point. As players kneeled nearby, holding hands and praying, an ambulance arrived and Patterson was placed on a stretcher and lifted into the ambulance.

Patterson was the Eagles' first-round pick out of USC in 2005. He has started 84 games and played in 95, the most of anybody on the current roster.

Players around the NFL expressed their concern for Patterson on Twitter.

"Prayers go out 2 Mike Patterson. Great college teammate n even better person!" wrote Green Bay Packers All-Pro linebacker Clay Matthews, who played with Patterson at USC.

Information from The Associated Press and ESPN national correspondent Sal Paolantonio was used in this report.