John Hamilton

Yeah. It's this malformed tangle of veins and arteries that can cause a stroke. So usually, you know, blood from the heart travels through the arteries and then through these tiny blood vessels called capillaries before it goes back to our veins and then back to the heart. Those capillaries act as a kind of a buffer.

They take this turbulent, high-pressure blood from the arteries and they smooth it out before it reaches the veins, which really aren't made to handle all that pressure and turbulence. In an AVM, Blood from the arteries goes directly back to the veins, and that can lead to a hemorrhage in the brain.

They take this turbulent, high-pressure blood from the arteries and they smooth it out before it reaches the veins, which really aren't made to handle all that pressure and turbulence. In an AVM, Blood from the arteries goes directly back to the veins, and that can lead to a hemorrhage in the brain.

They take this turbulent, high-pressure blood from the arteries and they smooth it out before it reaches the veins, which really aren't made to handle all that pressure and turbulence. In an AVM, Blood from the arteries goes directly back to the veins, and that can lead to a hemorrhage in the brain.

I did. And today I want to bring you a story just about AVMs. It's with Wilcox and another Marine, both of whom had this rare condition. I talked to them both about their experiences, which have some remarkable parallels. William Wilcox, I went to his house in Virginia, talked to him and his wife.

I did. And today I want to bring you a story just about AVMs. It's with Wilcox and another Marine, both of whom had this rare condition. I talked to them both about their experiences, which have some remarkable parallels. William Wilcox, I went to his house in Virginia, talked to him and his wife.

I did. And today I want to bring you a story just about AVMs. It's with Wilcox and another Marine, both of whom had this rare condition. I talked to them both about their experiences, which have some remarkable parallels. William Wilcox, I went to his house in Virginia, talked to him and his wife.

And then the other man, Michael Lozano, he lives in Colorado and runs the War Horse Ranch, which offers what's known as equine therapy to veterans and other people who are recovering from trauma. So today on the show, veterans and a rare brain condition called an AVM.

And then the other man, Michael Lozano, he lives in Colorado and runs the War Horse Ranch, which offers what's known as equine therapy to veterans and other people who are recovering from trauma. So today on the show, veterans and a rare brain condition called an AVM.

And then the other man, Michael Lozano, he lives in Colorado and runs the War Horse Ranch, which offers what's known as equine therapy to veterans and other people who are recovering from trauma. So today on the show, veterans and a rare brain condition called an AVM.

And I'm John Hamilton. And you're listening to Shortwave, the science podcast from NPR.

And I'm John Hamilton. And you're listening to Shortwave, the science podcast from NPR.

And I'm John Hamilton. And you're listening to Shortwave, the science podcast from NPR.

Michael Lozano and William Wilcox have a lot in common.

Michael Lozano and William Wilcox have a lot in common.

Michael Lozano and William Wilcox have a lot in common.

Each trained extensively with weapons like the tow, a missile system small enough to mount on a Humvee and potent enough to disable a tank. Wilcox says the most intimidating weapon was a shoulder-fired rocket launcher called the SMAW.

Each trained extensively with weapons like the tow, a missile system small enough to mount on a Humvee and potent enough to disable a tank. Wilcox says the most intimidating weapon was a shoulder-fired rocket launcher called the SMAW.

Each trained extensively with weapons like the tow, a missile system small enough to mount on a Humvee and potent enough to disable a tank. Wilcox says the most intimidating weapon was a shoulder-fired rocket launcher called the SMAW.

Also, your brain. Gunners like Wilcox and Lozano place their heads just inches from the explosion that propels a missile or rocket from its launch tube. The blast creates a pressure wave strong enough to kill anyone standing directly behind the weapon, and there's growing evidence that repeated exposure to these blast waves can damage the brain. Hi, I'm John. Ah!