Is there a link between concussions and dementia?

Some types, yes: Yes, head injuries including those that cause concussions increase the risk of demenita. Dementia pugilistica is even named for this type of dementia.

Yes: There is more and more evidence about the effect of small craneoencephlic injuries or trauma to the brain and developing dementia. Athletes have 6%more changes of developing dementia ( not alzheimers ) comparing with other populations.Some recent epidemiologic studies have shown that head injury is a risk factor for the development of dementia/alzheimer disease, whereas others have not.