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Headlines 5 studying concussion Helen remains acutely aware of the risk inherent in contact sport. Earlier this year she suffered a sub-concussive head knock – one of many she has sustained over the years – when she fell backwards during a hockey match, whacking her head on the ice. “I had my helmet on and I didn’t feel that bad, but I thought, ‘no, I'm not going to push this’. I sat on the bench, and I just watched my team play the rest of the game. I thought, ‘you know, this is why I do this work’. We don’t know what those small knocks do to our brains.” The science behind Helen’s study is to unravel the ‘tau tangles’ discovered in the brains of athletes diagnosed with CTE after death. “Tau tangles are the pathology, or the main change in the brain you see in CTE. That's the hallmark that something bad is happening,” Helen explains. “Tau is a normal protein found in the brain, but in CTE, AD, and some types of frontotemporal dementia, they tangle and clump inside cells, eventually causing those cells to die.” In AD the tau clumps in the hippocampus, where learning and memory happens. But what's different about CTE is the clumps form specifically in the frontal lobe. “We think repeated head injuries shake and stretch and warp the brain. All that force is concentrated deep in the folds of the frontal lobe which damages the blood vessels.” This means CTE and AD are likely to cause different symptoms. AD primarily affects memory and cognitive abilities, while CTE, in line with frontal lobe damage, is more likely to cause impulsivity, aggression, and mood swings. However, people with either disease can experience all these symptoms, and eventually the tau tangles spread across the entire brain, making the two diseases difficult to distinguish post-mortem. “When I talk to patients they just want to know what the future looks like for them. A diagnosis of CTE or Alzheimer’s are two very different things. We need to fill that gap in between, and that takes long-term research.” CTE expert and national ice hockey representative Dr Helen Murray is based at the Neurological Foundation Human Brain Bank.