Repetitive mild traumatic brain injury in sport can lead to a progressive neurodegenerative disorder called chronic traumatic encephalopathy (CTE). CTE has been reported in athletes from a range of sports including rugby, soccer, American football, boxing and ice hockey. CTE occurs many years after an athlete has endured repetitive head impacts and causes mood and behavioural changes that progressively develop into dementia. CTE pathology involves the accumulation of toxic clumps of tau protein but we know very little about the other brain changes that occur. This project will use novel anatomical methods to investigate a wide range of structural changes in brains donated from former athletes diagnosed with CTE in comparison to Alzheimer’s disease and neurologically normal brains. This research will highlight how sport-related brain injury contributes to dementia and will identify potential targets to detect and prevent CTE pathology during an athlete's life, to promote healthy ageing.