Frank Bruno is undergoing brain scans amid concerns of a “slow decline”. The 62-year-old former heavyweight champion – who won 40 of his 45 fights in the 1980s and 1990s – is being studied by doctors, who are trying to determine if the blows to the head he sustained during his 14-year career have caused long-term damage. Speaking in new documentary ‘Four Kings’, Frank’s daughter Rachel said: “We have learned recently that his brain might be on a slow decline. “They are just doing scans and tests at the moment. With the impact of his career and constant knocks to the head, it’s obviously probab…