From: hounddog23x@gmail.com   
      
   Vietnam Vets' Nightmares May Unlock Link to Dementia Risk   
      
      
   by Jason Gale   
   5:00 PM CDT May 10, 2015   
      
   The development of advanced PET scans, combined with new tracer dyes means   
   that doctors can now follow subtle biological routes in the brain and spinal   
   fluid. Photographer: Carla Gottgens/Bloomberg   
   David Hay was almost out of ammunition when a rocket-propelled grenade   
   exploded in the turret of his Centurion tank in the rubber plantation village   
   of Binh Ba, Vietnam, spraying shrapnel into the 21-year-old radio operator's   
   body.   
   That was 46 years ago, and while the flesh-wounds healed within weeks, Hay had   
   nightmares and bouts of depression for decades. Now, he and hundreds of other   
   Vietnam veterans are helping doctors try to trace pathways in the brain that   
   may connect the    
   trauma he suffered with the development later in life of one of the world's   
   fastest-growing and most debilitating diseases: Alzheimer's.   
   For decades, dementia-causing conditions like Alzheimer's were a mystery,   
   illnesses that couldn't be diagnosed for sure except at post-mortem. The   
   development of advanced PET scans, combined with new tracer dyes means that   
   doctors can now follow subtle    
   biological routes in the brain and spinal fluid. That could explain how and   
   why physical and psychological wartime traumas can double the risk of such   
   conditions.   
      
   "Vietnam veterans are getting to an age now where we should be picking up   
   changes in those people who are going to develop Alzheimer's," said   
   Christopher Rowe, director of molecular imaging research at the Austin   
   Hospital in Melbourne, who is leading the    
   Australian arm of the research.   
   Football Concussions   
   The findings will offer insights into what causes dementia, cases of which are   
   projected to almost double every 20 years. They could shed light on the   
   long-term effects of assaults on the brain -- whether sustained in battle, in   
   a car wreck or on the    
   football field, said Michael Weiner, professor of radiology at the University   
   of California, San Francisco School of Medicine, who's leading the study.   
   PET scanner   
   David Hay lies on a bed inside a PET, or positron emission tomography, scanner   
   at the Austin Hospital in Melbourne. Photographer: Carla Gottgens/Bloomberg   
   "It's long known that there's an association of head injury with Alzheimer's   
   disease," Weiner said. "But no study has been done with biomarkers to   
   establish the risk."   
   About 2 percent of Americans live with disabilities caused by a traumatic   
   brain injury, amounting to $77 billion in costs, according to the U.S. Centers   
   for Disease Control and Prevention. It was associated with about 2.5 million   
   emergency department    
   visits, hospitalizations, or deaths in the U.S. in 2010.   
   The new study, funded by the U.S. Department of Defense, is looking for early   
   signs of disease in healthy veterans who, like Hay, experienced post-traumatic   
   stress disorder, as well as those who suffered a physical brain injury. The   
   data is compared with    
   results from veterans who had neither form of injury. About 125 men have been   
   enrolled so far -- about a quarter of the number sought in the U.S., Canada   
   and Australia.   
   Diagnostic Tools   
   The tests are a sign of the growing demand in developed nations for advanced   
   equipment and medical techniques that can diagnose ailments before they become   
   difficult to treat.   
   The health-care business is the second most-profitable of the eight industrial   
   divisions of Munich-based Siemens AG, one of the world's top three makers of   
   PET, or positron emission tomography, scanners.   
   The study is also a new avenue for the radioactive liquids made by General   
   Electric Co., Eli Lilly & Co. and Piramal Enterprises Ltd. that are injected   
   into a vein and travel through the bloodstream to the brain. These help light   
   up deposits on the    
   scanner of a protein called beta-amyloid that may tip off doctors decades   
   before Alzheimer's dementia ensues.   
   By understanding the genesis of the disease, doctors hope to be able to   
   prevent it, or at least slow its progression. Results announced in March of   
   Biogen Inc.'s experimental drug for Alzheimer's provide the best evidence so   
   far that the memory-robbing    
   condition is caused by beta-amyloid.   
   Lilly, Roche   
   Studies underway with drug candidates made by Eli Lilly and Roche Holding AG   
   are testing if it's possible to stave off dementia in healthy people with an   
   inherited genetic mutation that causes Alzheimer's and whose PET scans reveal   
   early signs of the    
   disease.   
   That's encouraging for veterans like Hay.   
   David Hay   
   David Hay, now 67, was a laboratory technician looking for a change when he   
   volunteered for a two-year stint in the Australian military in 1968.   
   Photographer: Carla Gottgens/Bloomberg   
   The number of new cases of Alzheimer's among U.S. veterans is predicted to   
   jump by 423,000 by 2020, Weiner and colleagues estimated in 2013. Of those,   
   140,000 will be associated with factors specific to the military and lead to   
   as much as $7.8 billion in    
   costs.   
   Hay was a laboratory technician looking for a change when he volunteered for a   
   two-year stint in the Australian military in 1968. He ended up as a radio   
   operator in one of four tanks in Binh Ba during one of the fiercest street   
   battles of the war. Hay    
   was loading guns with some of the tank's dwindling stock of ammunition when   
   the RPG exploded, injuring him, the crew commander and gunner.   
   Not Superficial   
   "I had shrapnel in my face, my eyes, my chest and down my left arm, but that   
   was all superficial," Hay, now 67, said by telephone from his home in   
   Melbourne, recounting an event he resisted sharing with his wife for 20 years   
   and which "still raises    
   hackles on the back of my neck."   
   Flashbacks and nightmares haunted him for more than a decade. He suffered   
   depression, moodiness and sudden bursts of anger, and was diagnosed with   
   posttraumatic stress disorder about 25 years ago. The gunner in Hay's crew   
   killed himself after returning    
   to Australia.   
   "One thing that has always struck me is that, with normal trauma, you get over   
   it in time," said Hay, who earned a PhD in chemistry after his tour of duty   
   and still works part-time as a scientist with an Australian government   
   research organization. "   
   People can be in car accidents and they'll recover in time. But PTSD is   
   something that time by itself doesn't heal. There's got to be some part of the   
   brain, deep inside, that's affected permanently and doesn't recover the way   
   the other parts of the body    
   recover."   
      
      
      
      
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