美国有线新闻 CNN 2013-01-15（在线收听）

 Chronic Traumatic Encephalopathy is usually called CTE. It's a brain disease that can lead to dementia, memory lose or depression. Officials say it's sometime seen in people after they suffer multiple hits to the head. The National Institutes of Health says it's a disease that former NFL linebacker Junior Seau had. He played 20 years in the league. Last May, he took his own life. Seau's family donated his brain for research, that's how doctors discovered that he had CTE. Experts say being exposed to repeated head trauma doesn't necessarily mean that you will get this disease. But a recent study found signs of CTE in the brains of 34 out of 35 former pro-football players. Thousands of former players are suing the NFL. They say the league ignored and then denied the link between football and brain damage. NFL officials have changed several rules and made new policies to focus on head trauma and the possible dangers it might cause. This isn't just an issue at the professional level. It can happen to younger players too.