Chronic traumatic encephalopathy (CTE), the neurodegenerative brain disease associated with repeat traumatic brain injuries, is currently only able to be diagnosed post-mortem, but a new method of neuroimaging may be able to identify it in living people.
A case study conducted by the Icahn School of Medicine at Mount Sinai and Molecular Neuroimaging (MNI) LLC says an experimental positron emission topography (PET) tracer is able to facilitate the diagnosis of the brain disease in living specimens. The report was published in the September 16 volume of the journal Translational Psychiatry.
The tracer, specifically an experimental radiolabeled compound known as [18 F]-T807, attaches itself onto a tau proteins which accumulate in the brain after repeated hits to the head. Using PET scanning to see this tracer makes it possible to diagnose CTE. Importantly, this method can also differentiate CTE and other forms of dementia or neurological disorders.
“Our data suggest that PET imaging using the [18F]-T807 tau tracer is an effective method of diagnosing or ruling out chronic traumatic encephalopathy in a living brain,” writes Samuel Gandy, MD, Director of the Center for Cognitive Health and NFL Neurological Care at the Icahn School of Medicine at Mount Sinai. “Estimates of the prevalence of CTE have varied wildly, with the most recent figure coming from the National Football League who predicts that one in three NFL players will suffer significant brain damage. We can now begin to test this while the players are still alive. Moreover, we are now equipped to tell prospective athletes of all ages some real data on the risks that accompany sports involving repeated traumatic brain injuries.”
CTE has long been associated with boxing, often being called “punch drunk syndrome” in earlier times thanks to the noticable symptoms such as memory loss, depression, and violent outbursts. It has recently become a hot issue as the NFL has been accused of attempting to hide information about the condition and it’s association with repeated hits to the head from players.
This study evaluated two living patients, a retired NFL football player with a history of multiple concussions and a patient with a single severe traumatic brain injury. Both showed signs of cognitive decline and suspected Alzheimer’s disease, which shares many symptoms of CTE. Despite the similarities between the conditions, both have a distinctive distribution which allows them to be individually identifiable.
During the study, both patients underwent neurological and neuropsycholgical assessments by a team of experts. At the end of these evaluations, the experts disagreed on whether the retire NFL player had Alzheimer’s.
The participants then underwent PET scans using a chemical approved for the detection of brain amyloid plaques characteristic of Alzheimer’s disease, which showed the condition was not present in the retired NFL player. However, [18F]-T807 showed signs of tau build up in his brain which suggests he is experiencing the symptoms of CTE.
“Although we are just now understanding the clinical impact of PET, our use of tauopathy PET imaging to evaluate the progressive alterations in brain proteins for CTE patients already offers us a powerful new tool for evaluation,” says Ken Marek, MD, President and Senior Scientist at Molecular Neuroimaging (MNI) LLC in New Haven, where the [18F]-T807 imaging was performed. “In particular, we can directly measure the accumulation of tau protein we believe associated with the devastating symptoms experienced by patients and their families and evaluate the disease during life in ways that were previously only available to the pathologist’s microscope.”