**FILE** Dr. Robert Stern, right, and Chris Nowinski, left, confer before answering a reporter's question at the Boston University Center for the Study of Traumatic Encephalopathy news conference about the finding of Chronic Traumatic Encephalopathy in the brain of former NFL player Dave Duerson in Boston, Monday morning, May 2, 2011. Duerson committed suicide in February. Dr. Robert Cantu, MD, is at center. (AP Photo/Stephan Savoia)

Photo by: Stephan Savoia

**FILE** Dr. Robert Stern, right, and Chris Nowinski, left, confer before answering a reporter's question at the Boston University Center for the Study of Traumatic Encephalopathy news conference about the finding of Chronic Traumatic Encephalopathy in the brain of former NFL player Dave Duerson in Boston, Monday morning, May 2, 2011. Duerson committed suicide in February. Dr. Robert Cantu, MD, is at center. (AP Photo/Stephan Savoia)