PUBLISHED: 02:15 EST, 4 December 2012 | UPDATED: 12:10 EST, 4 December 2012 An extensive study of the brains of dead NFL and CFL players showed that the majority of them had signs of brain damage after suffering repeated head injuries. The study, carried out by the Boston University School of Medicine, posthumously tested the brains of 50 footballers, 33 of whom played in the NFL. It found a link between head injuries suffered in the heavy-impact sport and degenerative brain disease. Brain study: Dr Ann McKee, professor of Neurology and Pathology of Boston University School of Medicine, inspects a brain in the Bedford Veteran Medical Center
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Dozens of athletes had donated their brains to be studied by Boston University School of Medicine
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Thirty-three of 50 subjects showing signs of CTE had played in the NFL
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New interest in brain injury effects after murder suicide involving Kansas City Chiefs player Javon Belcher
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