![science x network](/b98584f181.site.internapcdn.net/tmpl/v5/img/1x1.gif)
-
.
-
.
.
meet other global citizens who care about the same issues you do. keep updated on what they're doing to change the world. .
logout
chronic traumatic encephalopathy (cte), a degenerative brain disease, has been linked by medical researchers to the sort of hits football players endure. .
![](/cdn.cnn.com/cnn/.e1mo/img/4.0/logos/menu_health.png)