This week during training camp, defensive tackle Mike Patterson of the Philadelphia Eagles collapsed on the practice field, had a seizure and was taken to hospital. Given that the Minnesota Vikings recently remembered the 10 year anniversary of Korey Stringer dying from a heat stroke in training camp, needless to say it was a scary sight.
Since then, Patterson has being diagnosed with an arteriovenous malformation, or AVM, of the brain which likely caused his seizure. ESPN has an excellent article (and consequently does most of my work for me) here. I'll try not to repeat too much of what they say.
What is an AV malformation? Basically, it's a tangling of the arteries and veins in your head. Normally, your body's arteries carry oxygen-rich blood to tissue and organs to provide sustenance to your cells. The oxygen is delivered via tiny blood vessel beds, or capillaries. The blood vessels that carry blood with little oxygen left are the veins. So the sequence is artery --> capillary --> vein. With areas of AVM, you have some arteries feeding into veins, veins feeding into arteries, often no capillaries in between... it's just a giant mess. As a result, tissue that have these malformations don't get enough oxygen.
So then what happens? Smaller AVMs can cause hemorrhages (40-60%) because of the large pressure difference between arteries and veins (which should not be connected directly). Seizures, like in Patterson's case, are more common in larger AVMs (50%). Patients can also get localized headaches due to increased pressure in the brain, or other neurological symptoms like trouble with speech, eye movements, muscle weakness, etc.
Do I have it??? It's quite rare. 0.14% prevalence, more common in males than females, and it can only be inherited. The average age of diagnosis is ~33. People don't usually know they have it until they have some sort of event (i.e. seizure or intracranial bleed) that results in an MRI that picks it up.
Can it be fixed? The only definitive treatment is surgery, but this is only if the site of the AV malformation is accessible, if there has been a bleed, and if the benefits of the surgery outweigh the risks (think: a young strapping man like Patterson vs. a 95-year old man with severe heart and kidney failure). Many people who only experience seizures do well on anti-convulsant medication.
Surgery normally involves excision of the AVM. An alternative (which is what Patterson received) involves blocking the fistula (i.e. the direct pathway from artery-to-vein) which should normalize blood flow. There are other treatment options like endovascular embolization and stereotactic radiosurgery which kind of go above the scope of this blog and my interest level in the topic (haha).
Prognosis? Provided the doctors gave him a clean bill of health, Mike Patterson is a lucky guy. 10% of people die from each one of these bleeds, and 30-50% have some sort of neurological deficit as a result. Patients with AVM have a 2-4% chance of a major bleed each year.
Sources:
ESPN.com
Toronto Notes, 2010 edition
CURRENT Medical Diagnosis & Treatment, 2011
Does playing a high impact sport such as football put him at an increased risk in the future, even if his condition is controlled through medication?
ReplyDeletein what I read, I found no mention of any activities that put him at higher risk for future bleeds or seizures. With that said, repeated impacts to the head probably don't help (i.e. epidural, subdural bleeds)!
ReplyDelete