John Hamilton
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She said, hey, the state police are here with a search warrant. She said, what am I supposed to do? I was like, well, you better let them search.
She said, hey, the state police are here with a search warrant. She said, what am I supposed to do? I was like, well, you better let them search.
Oh, I just couldn't believe it.
Oh, I just couldn't believe it.
Yeah, I just couldn't believe it. I'm just thinking, what is going on here?
Yeah, I just couldn't believe it. I'm just thinking, what is going on here?
And then I asked Natalie, how do you want to get him to the hospital? I said, you know, it's like, just however you want to take him, Mary. She said, well, no, I'm just going to let him sleep it off right now.
And then I asked Natalie, how do you want to get him to the hospital? I said, you know, it's like, just however you want to take him, Mary. She said, well, no, I'm just going to let him sleep it off right now.
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.
Hello, Regina Barber.
Hello, Regina Barber.
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.
I had a great time making fun of you. Not that I want you to go away again or anything.
I had a great time making fun of you. Not that I want you to go away again or anything.
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!
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!
Wilcox lives in southern Virginia with his wife Cynthia and their dog Leah. His mementos from the military include a single-use launch tube about three feet long.
Wilcox lives in southern Virginia with his wife Cynthia and their dog Leah. His mementos from the military include a single-use launch tube about three feet long.
Wilcox fired lots of anti-tank weapons after joining the Marines in 1992, especially during one training exercise at 29 Palms in the California desert.
Wilcox fired lots of anti-tank weapons after joining the Marines in 1992, especially during one training exercise at 29 Palms in the California desert.
The headaches began when Wilcox moved from Camp Lejeune to Quantico in Virginia. They kept getting worse even after he left the firing ranges to become a computer systems specialist.
The headaches began when Wilcox moved from Camp Lejeune to Quantico in Virginia. They kept getting worse even after he left the firing ranges to become a computer systems specialist.
In 2000, Wilcox moved to the private sector. Despite the headaches, he thrived. Fast forward to 2014. Wilcox and some friends go to Penn State for homecoming. They're watching a band. Wilcox feels a headache coming on.
In 2000, Wilcox moved to the private sector. Despite the headaches, he thrived. Fast forward to 2014. Wilcox and some friends go to Penn State for homecoming. They're watching a band. Wilcox feels a headache coming on.
His brain was bleeding. The cause? A tangle of abnormal blood vessels called an arteriovenous malformation, or AVM. The condition sends high-pressure blood from the arteries directly into fragile veins, which can leak or burst. Wilcox recalls an ambulance ride to a local hospital, then a helicopter ride to the medical center in Hershey.
His brain was bleeding. The cause? A tangle of abnormal blood vessels called an arteriovenous malformation, or AVM. The condition sends high-pressure blood from the arteries directly into fragile veins, which can leak or burst. Wilcox recalls an ambulance ride to a local hospital, then a helicopter ride to the medical center in Hershey.
Right, Gina. Back in August, we talked about how some people who fired powerful weapons in the military can end up with brain damage. We talked about concussions or maybe a more serious traumatic brain injury. And then there's this early research about arteriovenous malformations or AVMs.
Right, Gina. Back in August, we talked about how some people who fired powerful weapons in the military can end up with brain damage. We talked about concussions or maybe a more serious traumatic brain injury. And then there's this early research about arteriovenous malformations or AVMs.
Emergency surgery removed the AVM and probably saved his life.
Emergency surgery removed the AVM and probably saved his life.
Wilcox got better, but not enough to go back to his computer job. He has a big scar, several titanium screws in his skull, and memory lapses.
Wilcox got better, but not enough to go back to his computer job. He has a big scar, several titanium screws in his skull, and memory lapses.
But Wilcox says his biggest challenge is epilepsy.
But Wilcox says his biggest challenge is epilepsy.
For years, Wilcox did not connect his brain hemorrhage with his military service. Then a friend told him about another Marine gunner with an AVM. Michael Lozano and his wife Valerie run the War Horse Ranch near Steamboat Springs, Colorado. It's a place for people who've experienced trauma.
For years, Wilcox did not connect his brain hemorrhage with his military service. Then a friend told him about another Marine gunner with an AVM. Michael Lozano and his wife Valerie run the War Horse Ranch near Steamboat Springs, Colorado. It's a place for people who've experienced trauma.
Lozano grew up in Ventura, California, skating, surfing, a happy childhood.
Lozano grew up in Ventura, California, skating, surfing, a happy childhood.
That was in 1991. More than a decade later, after 9-11, he was sent to Iraq. Lozano shows me a video. His squad is rescuing a disabled tank on a bridge. Lozano is in a Humvee.
That was in 1991. More than a decade later, after 9-11, he was sent to Iraq. Lozano shows me a video. His squad is rescuing a disabled tank on a bridge. Lozano is in a Humvee.
Lozano left the Marines in 2004. Then came the hard part.
Lozano left the Marines in 2004. Then came the hard part.
Also anger and alcohol. Lozano's first marriage ended. He entered a law enforcement training program in Georgia, where he met Valerie. The headaches continued, though, and Valerie Lozano noticed other signs.
Also anger and alcohol. Lozano's first marriage ended. He entered a law enforcement training program in Georgia, where he met Valerie. The headaches continued, though, and Valerie Lozano noticed other signs.
She got her husband to the Barrow Neurological Institute in Phoenix.
She got her husband to the Barrow Neurological Institute in Phoenix.
Surgeons removed the AVM, but couldn't fix Lozano's memory. There's compelling evidence that the pressure waves from powerful weapons can cause concussion-like symptoms in the people who fire them. Those symptoms include the sort of headaches and memory problems experienced by both Lozano and Wilcox. But could all those blasts also have contributed to their AVMs?
Surgeons removed the AVM, but couldn't fix Lozano's memory. There's compelling evidence that the pressure waves from powerful weapons can cause concussion-like symptoms in the people who fire them. Those symptoms include the sort of headaches and memory problems experienced by both Lozano and Wilcox. But could all those blasts also have contributed to their AVMs?
Lozano leans toward trauma. Lozano's surgeon, Dr. Michael Lawton, has doubts.
Lozano leans toward trauma. Lozano's surgeon, Dr. Michael Lawton, has doubts.
Because most AVMs are caused by genetic changes that affect the growth of blood vessels. But Lawton, the president of Barrow Neurological Institute, says recent studies suggest that blast waves can alter genes in the brain.
Because most AVMs are caused by genetic changes that affect the growth of blood vessels. But Lawton, the president of Barrow Neurological Institute, says recent studies suggest that blast waves can alter genes in the brain.
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.
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.
The evidence is stronger for blood vessel changes less extreme than an AVM. Dr. Ibolya Chernak of Belmont University in Nashville has spent decades studying the health effects of blast waves.
The evidence is stronger for blood vessel changes less extreme than an AVM. Dr. Ibolya Chernak of Belmont University in Nashville has spent decades studying the health effects of blast waves.
Chernek says even a single blast can leave blood vessels in need of repair.
Chernek says even a single blast can leave blood vessels in need of repair.
In rats, this has led to malformed blood vessels that resemble AVMs. Much of the research on blast waves is supported by the military, which has taken steps to minimize blast exposure, especially in training. But that won't help veterans like Wilcox and Lozano. So they are learning to live with their disabilities. For Lozano, that often means assisting veterans in the corral at War Horse Ranch.
In rats, this has led to malformed blood vessels that resemble AVMs. Much of the research on blast waves is supported by the military, which has taken steps to minimize blast exposure, especially in training. But that won't help veterans like Wilcox and Lozano. So they are learning to live with their disabilities. For Lozano, that often means assisting veterans in the corral at War Horse Ranch.
Even if your brain is still recovering from blast waves. This episode was produced by Rebecca Ramirez, edited by Giselle Grayson, and fact-checked by me, John Hamilton.
Even if your brain is still recovering from blast waves. This episode was produced by Rebecca Ramirez, edited by Giselle Grayson, and fact-checked by me, John Hamilton.
I'm John Hamilton. Thanks for listening to Shortwave from NPR.
I'm John Hamilton. Thanks for listening to Shortwave from NPR.
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.
But you don't have to take my word for it. Here is Dr. Dev Manoli. He's a psychiatrist at the University of California, San Francisco. And he has spent a lot of time studying prairie voles.
But you don't have to take my word for it. Here is Dr. Dev Manoli. He's a psychiatrist at the University of California, San Francisco. And he has spent a lot of time studying prairie voles.
It's very sweet. And I got to say, it's a little bit like some human couples I have known. Yes. And that is probably why prairie voles get a lot of attention from researchers like Dave. You know, it turns out these rodents are really good models of certain human social behaviors, especially what scientists call pair bonding, which brings us to the brain science stuff.
It's very sweet. And I got to say, it's a little bit like some human couples I have known. Yes. And that is probably why prairie voles get a lot of attention from researchers like Dave. You know, it turns out these rodents are really good models of certain human social behaviors, especially what scientists call pair bonding, which brings us to the brain science stuff.
Exactly. So decades ago, Prairie Vols helped scientists show the importance of this protein in the brain called oxytocin. Yes, it plays a big role in pair bonding in both Prairie Vols and humans. And we've all heard about oxytocin because it is the... love hormone.
Exactly. So decades ago, Prairie Vols helped scientists show the importance of this protein in the brain called oxytocin. Yes, it plays a big role in pair bonding in both Prairie Vols and humans. And we've all heard about oxytocin because it is the... love hormone.
All of that. But there is a new study out that suggests love can prevail even without oxytocin, at least in prairie voles.
All of that. But there is a new study out that suggests love can prevail even without oxytocin, at least in prairie voles.
OK, so here's the reason. Humans and prairie voles are both sort of anomalies in terms of pair bonding and parenting. Of course, we know that lots of birds mate for life, but mammals tend to be, how shall I say this, pretty promiscuous. And that includes most rodents and including most voles. Prairie voles are the exception. And they actually choose the partner they're going to be with.
OK, so here's the reason. Humans and prairie voles are both sort of anomalies in terms of pair bonding and parenting. Of course, we know that lots of birds mate for life, but mammals tend to be, how shall I say this, pretty promiscuous. And that includes most rodents and including most voles. Prairie voles are the exception. And they actually choose the partner they're going to be with.
So it's not like, say, a duckling that just imprints on the first creature it sees after hatching. I actually called up one of the scientists who did a lot of the early work on prairie voles. Her name is Sue Carter, and she's on the faculty at both the University of Virginia and Indiana University.
So it's not like, say, a duckling that just imprints on the first creature it sees after hatching. I actually called up one of the scientists who did a lot of the early work on prairie voles. Her name is Sue Carter, and she's on the faculty at both the University of Virginia and Indiana University.
Swipe left or swipe right, you know, man.
Swipe left or swipe right, you know, man.
Well, so back in the 80s and 90s, Sue Carter helped show that oxytocin levels rise when a prairie vole meets that special someone. She and others did these lab experiments showing that if you give a prairie vole extra oxytocin, it increases their tendency to pair bond. But if you give a drug that blocks oxytocin, they won't pair bond at all.
Well, so back in the 80s and 90s, Sue Carter helped show that oxytocin levels rise when a prairie vole meets that special someone. She and others did these lab experiments showing that if you give a prairie vole extra oxytocin, it increases their tendency to pair bond. But if you give a drug that blocks oxytocin, they won't pair bond at all.
And oxytocin levels, by the way, also seem to predict a lot of human pair bonding behavior.
And oxytocin levels, by the way, also seem to predict a lot of human pair bonding behavior.
That is the conventional wisdom in popular culture and everything. There's even a Billie Eilish song called Oxytocin. Key lyric, you know I need you for the oxytocin.
That is the conventional wisdom in popular culture and everything. There's even a Billie Eilish song called Oxytocin. Key lyric, you know I need you for the oxytocin.
And speaking of scientists, you know that scientist Dave Minoli? Yeah. The one who was talking about how prairie vole couples like to huddle? He was a total believer in the love hormone idea until he wasn't, at least not so much.
And speaking of scientists, you know that scientist Dave Minoli? Yeah. The one who was talking about how prairie vole couples like to huddle? He was a total believer in the love hormone idea until he wasn't, at least not so much.
What happened was Dave was part of this team at UCSF and Stanford that did an experiment with prairie voles. What they did is they removed fertilized eggs from female voles. Then they used a technique called CRISPR to edit the genes in a way that got rid of the oxytocin receptors. Then they put the embryos back in female voles and waited for the pups to arrive.
What happened was Dave was part of this team at UCSF and Stanford that did an experiment with prairie voles. What they did is they removed fertilized eggs from female voles. Then they used a technique called CRISPR to edit the genes in a way that got rid of the oxytocin receptors. Then they put the embryos back in female voles and waited for the pups to arrive.
The idea here was that they were going to create baby voles whose cells wouldn't respond to the love hormone. You know, they would neutralize the effects of oxytocin. Got it. Dave figured that the result would affect pair bonding, not surprisingly. And at least that's what he thought until he got a visit from his postdoc who was doing the actual studying of these animals.
The idea here was that they were going to create baby voles whose cells wouldn't respond to the love hormone. You know, they would neutralize the effects of oxytocin. Got it. Dave figured that the result would affect pair bonding, not surprisingly. And at least that's what he thought until he got a visit from his postdoc who was doing the actual studying of these animals.
Well, to be precise here, we're talking about love without the love hormone receptor.
Well, to be precise here, we're talking about love without the love hormone receptor.
So you know the molecule that makes cells respond to oxytocin. One possibility here is that signals from oxytocin itself were still somehow, you know, getting through. Another possibility is that animals born without any oxytocin receptors are able to rely on other systems, you know, in their biology to make sure that they will find true love when they grow up.
So you know the molecule that makes cells respond to oxytocin. One possibility here is that signals from oxytocin itself were still somehow, you know, getting through. Another possibility is that animals born without any oxytocin receptors are able to rely on other systems, you know, in their biology to make sure that they will find true love when they grow up.
And Dev thinks it may have to do with the fact that prairie voles really can't survive without pair bonding. So they've evolved these redundant systems to produce that behavior.
And Dev thinks it may have to do with the fact that prairie voles really can't survive without pair bonding. So they've evolved these redundant systems to produce that behavior.
Hi, Emily, and way too casually dropped that AP vocabulary word. Respect. Thank you, thank you, thank you. But Valentine's Day, you know, it does give us a brilliant excuse to talk about a very special rodent, one that gives love a good name.
Hi, Emily, and way too casually dropped that AP vocabulary word. Respect. Thank you, thank you, thank you. But Valentine's Day, you know, it does give us a brilliant excuse to talk about a very special rodent, one that gives love a good name.
They know a little bit. Sue Carter actually has done a lot of the research on another molecule called vasopressin. She thinks it also affects social behavior, though not as much as oxytocin. And she says there may be other love hormones that just haven't been discovered yet.
They know a little bit. Sue Carter actually has done a lot of the research on another molecule called vasopressin. She thinks it also affects social behavior, though not as much as oxytocin. And she says there may be other love hormones that just haven't been discovered yet.
I should also note that Sue sounded kind of pleased when she found out that removing a single receptor wasn't enough to end a rodent's search for love.
I should also note that Sue sounded kind of pleased when she found out that removing a single receptor wasn't enough to end a rodent's search for love.
Well, Sue Carter thinks there is. She says the research on oxytocin and prairie voles is really kind of a reminder that even something as abstract as love can be found, I mean, at least in some form, in other mammals.
Well, Sue Carter thinks there is. She says the research on oxytocin and prairie voles is really kind of a reminder that even something as abstract as love can be found, I mean, at least in some form, in other mammals.
Yeah, I mean, at least when it comes to pair bonding.
Yeah, I mean, at least when it comes to pair bonding.
Well, of course, we are talking about the humble prairie vole. You've probably seen one, but you might not have realized it because you thought it was a mouse. Prairie voles, you can tell the difference, I am told, because they tend to be a little thicker, smaller ears, bigger eyes. But really, for today's purposes, looks are not important.
Well, of course, we are talking about the humble prairie vole. You've probably seen one, but you might not have realized it because you thought it was a mouse. Prairie voles, you can tell the difference, I am told, because they tend to be a little thicker, smaller ears, bigger eyes. But really, for today's purposes, looks are not important.
What counts about prairie voles is their social behavior, especially when it comes to love.
What counts about prairie voles is their social behavior, especially when it comes to love.
Well, you don't. I mean, obviously, there is no way to know exactly what some little furry creature is feeling in their heart of hearts. But scientists do know that prairie voles tend to mate for life. And once they do, these little vole couples also co-parent. They share a nest. And they spend lots of quality time snuggled up with their life partner.
Well, you don't. I mean, obviously, there is no way to know exactly what some little furry creature is feeling in their heart of hearts. But scientists do know that prairie voles tend to mate for life. And once they do, these little vole couples also co-parent. They share a nest. And they spend lots of quality time snuggled up with their life partner.
But you don't have to take my word for it. Here is Dr. Dev Manoli. He's a psychiatrist at the University of California, San Francisco. And he has spent a lot of time studying prairie voles.
It's very sweet. And I got to say, it's a little bit like some human couples I have known. Yes. And that is probably why prairie voles get a lot of attention from researchers like Dave. You know, it turns out these rodents are really good models of certain human social behaviors, especially what scientists call pair bonding, which brings us to the brain science stuff.
Exactly. So decades ago, Prairie Vols helped scientists show the importance of this protein in the brain called oxytocin. Yes, it plays a big role in pair bonding in both Prairie Vols and humans. And we've all heard about oxytocin because it is the... love hormone.
All of that. But there is a new study out that suggests love can prevail even without oxytocin, at least in prairie voles.
OK, so here's the reason. Humans and prairie voles are both sort of anomalies in terms of pair bonding and parenting. Of course, we know that lots of birds mate for life, but mammals tend to be, how shall I say this, pretty promiscuous. And that includes most rodents and including most voles. Prairie voles are the exception. And they actually choose the partner they're going to be with.
So it's not like, say, a duckling that just imprints on the first creature it sees after hatching. I actually called up one of the scientists who did a lot of the early work on prairie voles. Her name is Sue Carter, and she's on the faculty at both the University of Virginia and Indiana University.
Swipe left or swipe right, you know, man.
Well, so back in the 80s and 90s, Sue Carter helped show that oxytocin levels rise when a prairie vole meets that special someone. She and others did these lab experiments showing that if you give a prairie vole extra oxytocin, it increases their tendency to pair bond. But if you give a drug that blocks oxytocin, they won't pair bond at all.
And oxytocin levels, by the way, also seem to predict a lot of human pair bonding behavior.
That is the conventional wisdom in popular culture and everything. There's even a Billie Eilish song called Oxytocin. Key lyric, you know I need you for the oxytocin.
And speaking of scientists, you know that scientist Dave Minoli? Yeah. The one who was talking about how prairie vole couples like to huddle? He was a total believer in the love hormone idea until he wasn't, at least not so much.
What happened was Dave was part of this team at UCSF and Stanford that did an experiment with prairie voles. What they did is they removed fertilized eggs from female voles. Then they used a technique called CRISPR to edit the genes in a way that got rid of the oxytocin receptors. Then they put the embryos back in female voles and waited for the pups to arrive.
The idea here was that they were going to create baby voles whose cells wouldn't respond to the love hormone. You know, they would neutralize the effects of oxytocin. Got it. Dave figured that the result would affect pair bonding, not surprisingly. And at least that's what he thought until he got a visit from his postdoc who was doing the actual studying of these animals.
Well, to be precise here, we're talking about love without the love hormone receptor.
So you know the molecule that makes cells respond to oxytocin. One possibility here is that signals from oxytocin itself were still somehow, you know, getting through. Another possibility is that animals born without any oxytocin receptors are able to rely on other systems, you know, in their biology to make sure that they will find true love when they grow up.
And Dev thinks it may have to do with the fact that prairie voles really can't survive without pair bonding. So they've evolved these redundant systems to produce that behavior.
Hi, Emily, and way too casually dropped that AP vocabulary word. Respect. Thank you, thank you, thank you. But Valentine's Day, you know, it does give us a brilliant excuse to talk about a very special rodent, one that gives love a good name.
They know a little bit. Sue Carter actually has done a lot of the research on another molecule called vasopressin. She thinks it also affects social behavior, though not as much as oxytocin. And she says there may be other love hormones that just haven't been discovered yet.
I should also note that Sue sounded kind of pleased when she found out that removing a single receptor wasn't enough to end a rodent's search for love.
Well, Sue Carter thinks there is. She says the research on oxytocin and prairie voles is really kind of a reminder that even something as abstract as love can be found, I mean, at least in some form, in other mammals.
Yeah, I mean, at least when it comes to pair bonding.
Well, of course, we are talking about the humble prairie vole. You've probably seen one, but you might not have realized it because you thought it was a mouse. Prairie voles, you can tell the difference, I am told, because they tend to be a little thicker, smaller ears, bigger eyes. But really, for today's purposes, looks are not important.
What counts about prairie voles is their social behavior, especially when it comes to love.
Well, you don't. I mean, obviously, there is no way to know exactly what some little furry creature is feeling in their heart of hearts. But scientists do know that prairie voles tend to mate for life. And once they do, these little vole couples also co-parent. They share a nest. And they spend lots of quality time snuggled up with their life partner.
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.
Hello, Regina Barber.
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.
I had a great time making fun of you. Not that I want you to go away again or anything.
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!
Wilcox lives in southern Virginia with his wife Cynthia and their dog Leah. His mementos from the military include a single-use launch tube about three feet long.
Wilcox fired lots of anti-tank weapons after joining the Marines in 1992, especially during one training exercise at 29 Palms in the California desert.
The headaches began when Wilcox moved from Camp Lejeune to Quantico in Virginia. They kept getting worse even after he left the firing ranges to become a computer systems specialist.
In 2000, Wilcox moved to the private sector. Despite the headaches, he thrived. Fast forward to 2014. Wilcox and some friends go to Penn State for homecoming. They're watching a band. Wilcox feels a headache coming on.
His brain was bleeding. The cause? A tangle of abnormal blood vessels called an arteriovenous malformation, or AVM. The condition sends high-pressure blood from the arteries directly into fragile veins, which can leak or burst. Wilcox recalls an ambulance ride to a local hospital, then a helicopter ride to the medical center in Hershey.
Right, Gina. Back in August, we talked about how some people who fired powerful weapons in the military can end up with brain damage. We talked about concussions or maybe a more serious traumatic brain injury. And then there's this early research about arteriovenous malformations or AVMs.
Emergency surgery removed the AVM and probably saved his life.
Wilcox got better, but not enough to go back to his computer job. He has a big scar, several titanium screws in his skull, and memory lapses.
But Wilcox says his biggest challenge is epilepsy.
For years, Wilcox did not connect his brain hemorrhage with his military service. Then a friend told him about another Marine gunner with an AVM. Michael Lozano and his wife Valerie run the War Horse Ranch near Steamboat Springs, Colorado. It's a place for people who've experienced trauma.
Lozano grew up in Ventura, California, skating, surfing, a happy childhood.
That was in 1991. More than a decade later, after 9-11, he was sent to Iraq. Lozano shows me a video. His squad is rescuing a disabled tank on a bridge. Lozano is in a Humvee.
Lozano left the Marines in 2004. Then came the hard part.
Also anger and alcohol. Lozano's first marriage ended. He entered a law enforcement training program in Georgia, where he met Valerie. The headaches continued, though, and Valerie Lozano noticed other signs.
She got her husband to the Barrow Neurological Institute in Phoenix.
Surgeons removed the AVM, but couldn't fix Lozano's memory. There's compelling evidence that the pressure waves from powerful weapons can cause concussion-like symptoms in the people who fire them. Those symptoms include the sort of headaches and memory problems experienced by both Lozano and Wilcox. But could all those blasts also have contributed to their AVMs?
Lozano leans toward trauma. Lozano's surgeon, Dr. Michael Lawton, has doubts.
Because most AVMs are caused by genetic changes that affect the growth of blood vessels. But Lawton, the president of Barrow Neurological Institute, says recent studies suggest that blast waves can alter genes in the brain.
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.
The evidence is stronger for blood vessel changes less extreme than an AVM. Dr. Ibolya Chernak of Belmont University in Nashville has spent decades studying the health effects of blast waves.
Chernek says even a single blast can leave blood vessels in need of repair.
In rats, this has led to malformed blood vessels that resemble AVMs. Much of the research on blast waves is supported by the military, which has taken steps to minimize blast exposure, especially in training. But that won't help veterans like Wilcox and Lozano. So they are learning to live with their disabilities. For Lozano, that often means assisting veterans in the corral at War Horse Ranch.
Even if your brain is still recovering from blast waves. This episode was produced by Rebecca Ramirez, edited by Giselle Grayson, and fact-checked by me, John Hamilton.
I'm John Hamilton. Thanks for listening to Shortwave from NPR.
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.