A Navy SEAL’s last act of service: A search for the truth about brain disease and the military

On the afternoon of March 12, 2014, Jennifer Collins checked her phone and found a message from her husband, Dave Collins, a retired Navy SEAL. He’d texted to say that she should pick up their son from kindergarten, and then this: "So sorry baby. I love you all."

Hours later, two police officers showed up at their house in Virginia Beach with news that Dave, 45, had shot himself in his truck a few miles away. Although Jennifer had held out hope for any other explanation, she also knew the moment she read it what the text meant. For months, she’d watched Dave disintegrate into a man she hardly knew. She’d tried everything, but nothing had alleviated his severe insomnia, intense anxiety and worsening cognitive problems.

"I was so frustrated that I couldn't find the answers he needed," she remembers.

It was out of that frustration, she says, that the idea came to donate his brain to research. She was still answering a detective's questions in her living room that night when she blurted it out: Tell the medical examiner to do whatever is needed to preserve Dave's brain. She hoped the decision might help others struggling with what everyone believed explained Dave's afflictions – traumatic brain injury and PTSD, the most common wounds of the post-9/11 wars.

"That's what he’d been diagnosed with," Jennifer says. "I had no reason to think there was anything else to find."

In June, three months after Dave died, a letter came from the doctor who examined his brain. It left Jennifer stunned.

What had caused Dave's unraveling was chronic traumatic encephalopathy, the degenerative brain disease best known for affecting former professional football players. Associated with repeated head trauma, CTE causes neurological decay, has no known treatment and can be diagnosed only at autopsy. It is linked to memory loss, personality changes, depression, impulsivity, dementia and suicide.

While more attention has been paid to CTE among athletes, Dave is one of dozens of veterans who have been diagnosed with the disease in recent years. The cases, along with new research on the effects of exposure to blasts, suggest that CTE may be as directly linked to military service as it is to professional football.

"I’m positive that it's drastically underdiagnosed in the military," says Bennet Omalu, the forensic pathologist who first identified CTE in the brains of deceased former NFL players and is portrayed in the movie "Concussion." Omalu believes the disease is often misdiagnosed as PTSD and could be an underlying factor in homelessness among veterans.

The only reason more veterans have not been diagnosed, he and others say, is because the disease is not commonly looked for. In Dave's case, CTE would never have been identified if Jennifer had not thought to donate his brain.

"In my opinion," Omalu says, "this is more important than the NFL, because many more people are involved in the military."

The biggest question is whether exposure to blasts – even in training or when no injury is apparent – causes CTE in some individuals. The military's researchers recently found that blast exposure triggers the disease's pathology in rodents, and some scientists say a single explosion could be enough to do the same in certain people.

If CTE and neurodegeneration are indeed as linked to military service and blast exposure as some believe, the implications would be grim. More than 2.5 million service members have deployed to Iraq or Afghanistan since 2001, many more than once, and countless others have experienced blast exposure and head trauma during training.

"We know that a substantial number of individuals have had many exposures," says Lee Goldstein, a CTE researcher and professor at Boston University's medical school.

While veterans with PTSD and traumatic brain injury often improve with time, CTE is degenerative. Experts say that as it progresses, the disease can become as debilitating as Alzheimer's. In addition to the burden of caring for those who develop lasting problems, there are other financial implications: Based on Dave's CTE diagnosis, the Department of Veterans Affairs deemed his death service-related and awarded Jennifer benefits.

Debra Yourick, a spokeswoman for the Walter Reed Army Institute of Research, where the new research connecting CTE and blast exposure was done, says of the findings: "This is bad news for the Department of Defense and anyone who uses blast in their job. But it's something we need to know."

In the past three years, the Defense Department has spent at least $47 million on roughly a dozen research projects related to CTE, according to defense officials. Among efforts the military is either funding or conducting are projects exploring ways to diagnose CTE in the living and to stem neurodegeneration after brain injury, as well as studies that are enrolling thousands of service members and veterans for long-term neurological monitoring.

That Dave's brain might make even a small difference is of comfort to Jennifer.

"So many of our guys are coming back with these symptoms," she says.

"We need to find answers."

Dave grew up in Lock Haven, Pa., and joined the military less than a year after finishing high school. As a kid, he loved running and played baseball and basketball, but never football, maybe because he was on the small side. The only contact sport he tried was a couple of months of boxing at Lock Haven University, where he went for a semester before deciding college wasn't for him.

He signed up with the Marine Corps in the spring of 1988 but after doing well on entrance tests was rerouted to the Navy to attend the service's Nuclear Power School. He missed so much class because of a bad bout of colitis that he was unable to finish, so the Navy made him a boatswain's mate, assigning him to maintenance aboard the aircraft carrier Independence.

After a Middle East deployment with the ship during the first Gulf War, Dave landed a spot in 1991 to train to become a Navy diver. His first unit out of dive school was a SEAL delivery team at Little Creek Naval Amphibious Base in Virginia Beach, where he got a taste of special operations.

He met Jennifer on New Year's Eve in 1992. A Navy friend of his was seeing a friend of hers in Philadelphia, where Jennifer was living after finishing a bachelor's degree at Temple University. She and Dave started dating, and the following year, in 1994, he went to Coronado, Calif., to begin the Navy's legendary six-month test to become a SEAL.

He finished Basic Underwater Demolition/SEAL training, known as BUD/S, in February 1996 after a medical delay for sinus surgery to remedy lingering problems from a diving mishap. When he was assigned to SEAL Team 4 in Virginia Beach, Jennifer made the move south. She took a public relations job at a local foundation before joining the staff at Old Dominion University, where she would eventually become the assistant vice president for marketing and communications.

In some ways, Jennifer says, she and Dave were opposites. She jokes that while he was the kind of person who never met a stranger, she was "a typical Philly girl, so everyone was a stranger." And although he was always very together, he often flew by the seat of his pants – something she had to adjust to.

"He was the kindest person you’d ever meet, like, annoyingly kind," Jennifer says. Within a few days of moving somewhere new, Dave knew everyone on the block. On Veterans Day, he’d bring six-packs to the vets in their neighborhood. He loved old people and hearing their stories, and he loved making people feel good about themselves. He’d give anything away. One time, he loaned his Harley-Davidson to a friend but never asked for it back.

Ed Rasmussen, a retired SEAL who was in Dave's first platoon and was close with him until he died, once got a bad case of the stomach flu. He was a single dad at the time with twin 3-year-old daughters. Dave picked up the girls for a sleepover at his house.

"He did stuff like that all the time," Rasmussen says. "And he was so funny. He had the best sense of humor."

Dave also loved anything new – new places, new cultures, new people, new stuff. "He’d try anything," Jennifer says. "He wasn't afraid of looking like an idiot, which is the barrier for most of us." He’d buy the strangest things from infomercials: CDs of Charlton Heston reading the Bible, even though he wasn't overly religious. VHS tapes about how to be a magician.

"This was before we had kids," Jennifer says of the magician tapes. "It's not like he was immature. I think it was just that he loved life. He wanted to experience everything."

As a SEAL, Dave experienced plenty. With Team 4, which at the time covered Central and South America and carried out drug interdiction missions, he made three deployments between 1997 and 2001.

Dave always joked that at 5-foot-9 and 155 pounds, he was the world's smallest SEAL. His teammates called him Lucky Legs, teasing him that his legs were so skinny he was lucky they didn't snap off and stab him in the butt when he ran.

In spite of his size, "as an operator, Dave was extremely squared away," Rasmussen says. A communications guy, Dave prided himself on carrying his equipment's extra weight and always being able to get in touch with whoever was coming to get his teammates.

In the months after 9/11, Dave became a founding member of the Navy's newest SEAL team – Team 10, based in Virginia Beach. In 2003, he spent seven months in Afghanistan, where, by then, SEALs had begun dying in combat. In 2004, he went to Iraq, where he protected the country's then-interim prime minister, Ayad Allawi.

He deployed to Iraq at least twice more before retiring as a chief petty officer in September 2012 at age 43.

Jennifer doesn't know a lot about Dave's missions. He told her stories occasionally. Once she overheard him talking with other SEALs about a 48-hour firefight they’d been through in Afghanistan.

"A lot of people glorify war, but he wasn't one of those people," she says.

Typical of SEALs, he also wasn't one to complain, so many of his injuries went unmentioned. Yet the job's physical toll showed. He had neck, back and leg problems. Sometimes extremities went numb, and other times they quivered, which Jennifer would feel when Dave slept.

He luckily managed to avoid grave injury.

"There wasn't this one time when he was really blown up," Jennifer says. "It's very clear to me that it was over and over and over."

Indeed, special operations – which includes SEALs and Army Special Forces, Rangers and Delta Force – is among the military's most unforgiving jobs. These troops have carried out some of the hardest combat in the post-9/11 wars, deploying again and again, often with little downtime. Recent heads of U.S. Special Operations Command acknowledge that the demands have left many fighters broken.

"In the 18 months that I have been in command, frankly, the force has continued to fray at a fairly rapid pace," Adm. William McRaven, then-commander of Special Operations Command, told members of Congress in March 2013.

SEALs’ exposure to head trauma on missions includes everything from parachute jumps and hard landings in helicopters to explosions and hand-to-hand fighting. Their rigorous, realistic training can be just as dangerous. They practice with weapons such as Claymore mines, grenades and explosives used to blow through doors and walls to quickly get inside buildings, a tactic called breaching.

"Anything you’re using in combat, you’re also training with it, and it's over and over," says Jimmy Hatch, who sustained many injuries, including to his brain, when he was a SEAL from 1990 to 2011.

Another former SEAL, Cade Courtley, hadn't finished BUD/S yet when he suffered a major head injury; he was hit by a boat during training, fracturing his skull.

In the years that followed, Courtley says, firing certain larger weapons felt like getting punched. "I definitely got my bell rung," he says.

Around 2010, after 15 years as a SEAL, Dave's friend Rasmussen began experiencing cognitive and emotional problems. It wasn't until 2013, after a colleague suggested he might have brain damage, that he sought help.

He went to the National Intrepid Center of Excellence at Walter Reed, which treats TBI and psychological health problems and sees many SEALs. There, Rasmussen's doctors impressed upon him that he’d likely been exposed to more blasts than he realized; they helped him estimate and came up with 7,500.

While working up for a deployment, SEALs sometimes practiced with explosives six days a week, Rasmussen says.

He offers an example: shoulder-fired rockets. "In the instructions, it says you can only shoot two a day in training. But then you’re next to other guys shooting their two, and just think if you’re an instructor.

"The problem," he says, "is that you don't know you’re hurting your brain. But you are."

Although CTE entered the popular lexicon only after Omalu identified it in the brains of former NFL players in the 2000s, reports of the disease date to the early 1900s, when in boxers it was known as punch-drunk syndrome. The first published case was in 1954, and since then, according to a recent medical literature review, roughly 150 more have been documented. Yet it wasn't until last year that experts from around the world, at a conference in Boston, declared CTE a unique disease associated with repetitive head trauma. To diagnose CTE, the scientists agreed, one must find abnormal, telltale accumulations of a protein called tau in the depths of brain's valleys, specifically around blood vessels.

While many scientists argue it is still too soon to say with certainty that repetitive head trauma causes CTE, Robert Stern, director of clinical research at Boston University's CTE Center, sees it mostly as a matter of semantics. "What we know," he says, "is that every pathologically confirmed case of CTE has one thing in common: a history of repetitive hits to the head. And it has never been found in anyone without that history."

As for what happens in the brain, Stern explains it this way: CTE is not a residual injury; it's not that trauma accumulates and the brain becomes increasingly damaged. Instead, CTE is a disease that gets turned on in certain people as a result of repetitive brain trauma, causing a cascade of events that leads to changes in tau, a component of every nerve cell.

The tau becomes phosphorylated and toxic and destroys brain cells. Eventually, the brain atrophies.

The process begins years before the emergence of symptoms, which generally fall into three categories: changes in cognition, such as memory loss, confusion and difficulty with cognitive processes, including planning and multitasking; changes in mood, such as depression and hopelessness; and changes in behavior, such as aggression and impulsivity.

Given CTE's symptoms, it stands to reason that the disease increases a person's risk of ending his or her life, Stern says. "Put the two of those together," he says of depression and impulsivity, "and that's sadly a magic combination that can indeed lead to suicide."

Former NFL players diagnosed with CTE after committing suicide include Shane Dronett, Ray Easterling, Junior Seau and Dave Duerson, who shot himself in the chest and left a note asking that his brain be studied. The condition isn't limited to NFL players: As recently as last week, neuropathologists learned BMX star Dave Mirra, who killed himself in February, had CTE.

The degree of head trauma required to trigger CTE is among the biggest unknowns. While much attention is paid to concussions, many scientists believe lesser trauma matters more.

That's an especially troubling notion given that lesser or subconcussive trauma is far more common and tends to be thought of as harmless because it does not produce immediate symptoms.

Other big unknowns include CTE's prevalence; whether a genetic component explains why some people develop the disease while many others do not; how to stop the molecular cascade believed to be responsible for CTE; and how to diagnose CTE in the living. Much of the research underway is exploring blood biomarkers as a means for detection, as well as imaging technology.

Omalu was the chief medical examiner in San Joaquin County, Calif., when, in 2007, he first discovered CTE in the brain of a veteran – a heart attack victim who had served in Vietnam. What piqued Omalu's curiosity was the 61-year-old's history. After Vietnam, he’d begun abusing drugs and alcohol and exhibiting signs of a serious mental illness, which were attributed to PTSD. He’d received treatment but had only gotten worse.

"If it was psychological, why was it progressive?" Omalu says.

By then he’d identified CTE in the brains of several former NFL players, and he had a hunch he’d find the same thing in the veteran, so he spent his own money to analyze the man's brain.

In 2011, Omalu published the first case study of CTE in a veteran, Michael Smith, a Marine who deployed twice to Iraq and hanged himself in 2010 at age 27.

Married with two sons, Smith had been an amphibious assault vehicle crewman, had experienced combat in Fallujah and Ramadi, and was exposed to numerous blasts, although he’d also played football, hockey and rugby. After his second deployment, Smith developed "a progressive history of cognitive impairment, impaired memory, behavioral and mood disorders and alcohol abuse," according to the case study, which appeared in the medical journal Neurosurgical Focus. The VA diagnosed Smith with PTSD, according to his parents, Michael and Carol.

Although they knew their son was struggling, they never imagined he would commit suicide.

"I’d had a conversation with him earlier that day that was perfectly logical, positive and forward-looking," his father recalls, adding that the CTE diagnosis helped his family make sense of what happened. "It connected some of the dots. Not that you understand it, but at least there's some logic. There's a physical manifestation you can point to."

Omalu is among scientists who are critical of the military for having not done more to gauge how many veterans might have CTE. If it were up to him, Omalu says, there would be a national surveillance program; any time a veteran died by any cause anywhere in the country, the local medical examiner would send a brain sample to the military to be examined.

"We should be looking at as many as possible, and then we’d know," he says. "The truth will make things better for everybody."

While no published study has estimated the prevalence of CTE among veterans, Ann McKee, director of Boston University's CTE Center and a VA neuropathologist, decided with some colleagues in 2009 to look for the disease in the brains of all veterans autopsied by the Boston VA over the course of a year.

They found CTE in roughly 10 percent.

"That was very preliminary," McKee cautions, "but it suggested a couple of things: that it's not rare, and that when we look for it, we do find it."

McKee leads a VA-Boston University brain bank that has collected about 300 human brains since 2008, most of them from deceased athletes suspected of having CTE. As of late last year, the bank included the brains of 71 military veterans, 53 of which were found to have CTE, although McKee notes that all but eight of the vets had another primary exposure to head trauma, mostly contact sports.

There is plenty of evidence that explosions affect the brain, even when they cause no secondary fallout, such as banging one's head. Studies of breachers – soldiers who train to breach buildings and are routinely exposed to low-level blasts – have documented symptoms ranging from headaches and fatigue to memory problems and slowed thinking. The effects are common enough to have been given a nickname: breacher's brain.

But what mechanisms may be responsible for various kinds of damage and all the possible consequences are still largely matters of debate.

In a study by BU's Goldstein published in 2012 in the journal Science Translational Medicine, researchers presented a case series of four blast-exposed veterans and four athletes, all with CTE. They also conducted experiments on mice, subjecting them to explosions using a long aluminum blast tube. With a mouse secured at one end of the tube, the scientists used compressed gas to explode a membrane at the other end, creating force equal to a moderate-size improvised explosive device, or IED.

When Goldstein and his colleagues examined the animals’ brains two weeks later, they found early CTE pathology, and subsequent tests on other blast-exposed mice revealed short-term memory deficits and learning impairment.

What surprised the researchers most was that a single blast was enough to trigger changes.

Also notable, Goldstein says, is that the mice appeared perfectly healthy immediately after the simulations, eating and behaving normally.

"They looked fine," he says, "but they weren't fine at all."

The researchers also explored the mechanism responsible for the damage and concluded that blast shock waves were not the culprit. Rather, Goldstein says, the intense wind that follows a shock wave – at speeds faster than 300 mph – rapidly shakes the head back and forth in a matter of milliseconds, causing what the researchers termed a "bobblehead effect." When they immobilized the mice's heads to prevent the shaking, the animals did not develop the changes linked to CTE, which Goldstein believes proves the mechanism.

What happens to the brain because of blast wind is similar to what happens when a football player takes a hit, he says, except that because the head snaps back and forth repeatedly, "you’re essentially compressing a whole bunch of hits into a very short time."

To trigger CTE, he says, "my suspicion is that one hit on the ball field isn't enough, but for some people, one blast is."

For Dave, who was probably exposed to thousands of blasts, the fallout would be too great to bear.

Next: Dave's struggle deepens

Learn more

Resources for service members and veterans

To take part in military brain trauma research, visit CENC's website.

Learn more about donating brain tissue.

To get help

Military Crisis Line: 800-273-8255, press 1

Traumatic Brain Injury, Psychological Health Help: DCoE Outreach Center; 866-966-1020

Defense and Veterans Brain Injury Center

DVBIC Resources

Corinne Reilly is a former Virginian-Pilot military reporter. She was a finalist for a Pulitzer Prize for "A Chance in Hell," a series about NATO's hospital at Kandahar Airfield in Afghanistan.

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