Despite the devastating consequences of traumatic brain injury and the large number of athletes playing contact sports who are at risk, no method has been developed for early detection or tracking of the brain pathology associated with these injuries. Now, UCLA researchers have taken pictures of the abnormal tau proteins associated with such injuries in five living National Football League (NFL) retirees. Previously, confirmation of the presence of this protein, which is also associated with Alzheimer's disease, could only be established by an autopsy.
The preliminary findings of the study are reported in the American Journal of Geriatric Psychiatry. For the study, the researchers recruited five retired NFL players with a history of one or more concussions and cognitive or mood symptoms. They used positron emission tomography (PET) to view and identify the locations in the brain of amyloid beta "plaques" and neurofibrillary tau "tangles" that had been stained with a chemical marker, FDDNP, that binds to the deposits. When the researchers compared the scans to those of healthy men of comparable age, education, body mass index and family history of dementia, they found that the NFL players had more of the FDDNP in the amygdala and subcortical regions of their brains - regions that control learning, memory, behavior, emotions and other mental and physical functions. Those players who had experienced a greater number of concussions were found to have higher FDDNP levels.
The NFL players also had more depressive symptoms than the healthy men and demonstrated greater evidence of cognitive loss.
"Early detection of tau proteins may help us to understand what is happening sooner in the brains of these injured athletes," says Gary Small, MD, the Parlow-Solomon Professor on Aging and professor of psychiatry and biobehavioral sciences at the Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA. This non-invasive method also may be "a critical first step" in developing interventions to prevent symptom onset and progression of chronic traumatic encephalopathy - a degenerative condition caused by buildup of tau protein that is associated with memory loss, confusion, progressive dementia, depression, suicidal behavior, personality changes, abnormal gait and tremors.
"PET Scanning of Brain Tau in Retired National Football League Players: Preliminary Findings," American Journal of Geriatric Psychiatry, February 2013