CTE is said to cause such symptoms as memory loss, aggression, depression and progressive dementia. But there is debate in the scientific community over this theory. "I don't think CTE exists," said Christopher Randolph, PhD, ABPP a professor in the Department of Neurology of Loyola University Chicago Stritch School of Medicine.

Two of the nation's leading sports concussion experts will debate the issue June 20 in Chicago during the annual meeting of the American Academy of Clinical Neuropsychology (AACN). The format will be similar to the Obama-Romney presidential debates.

Randolph will debate Robert Stern, PhD, a leading proponent of the theory that sports concussions and hits to the head cause CTE. Stern is co-director of the Center for the Study of Traumatic Encephalopathy at Boston University. The program will be hosted and moderated by Aaron Nelson, PhD, ABPP, president of the AACN.