Amyloid and Tauopathy PET Imaging in Acute and Chronic Traumatic Brain Injury
Status:
Completed
Trial end date:
2017-12-21
Target enrollment:
Participant gender:
Summary
The potential long-term effects of Traumatic Brain Injury (TBI) are poorly understood.
Repeated concussions have been associated with an elevated incidence of Alzheimer's disease
(AD) along with a reduced age of onset. As repetitive TBI has been studied, a syndrome has
now been identified: chronic traumatic encephalopathy (CTE). There are growing concerns about
the long-term neurologic consequences of head impact exposure from routine participation in
contact sports (e.g., boxing, football). Brain autopsies of athletes with confirmed CTE have
demonstrated tau-immunoreactive neurofibrillary tangles and neuropil threads (known as
tauopathy). The relationship between exposure to repetitive head impact and the subsequent
development of chronic neurodegenerative disease has not been established. Further, as the
diagnosis of CTE (defined by the presence of tauopathy) is presently made after death at
autopsy, clinical tools and biomarkers for detecting it remain to be defined.
With the advent of FDA-approved PET amyloid imaging, clinicians and researchers are now able
to estimate plaque density in the brains of living patients. However, there are critical
limitations to amyloid imaging. Current evidence suggests that markers of the presence and
severity of tauopathy may be able to address these limitations. The study will utilize both
[18F] Florbetapir and [18F]-T807 PET imaging to investigate amyloid and tau accumulation in
subjects with a history of concussions. In order to determine whether problems with cognition
and memory are seen within the populations defined for the study, the researchers will
administer a core battery of neurocognitive testing. This battery will assess cognitive
abilities commonly affected by TBI, including processing speed, reaction time, new
problem-solving, executive functions, attention and concentration, and learning and memory.
These tests, in conjunction with the imaging, will be able to determine whether regional
brain activity is associated with specific cognitive problems. The researchers will obtain
PET and neurocognitive data in 3 cohorts: subjects with a history of TBIs, subjects with mild
cognitive impairment (MCI) and no TBI history, and healthy controls.
The investigators aim to determine whether individuals with TBI are on the same trajectory of
neurodegenerative disease seen in AD or in CTE. Because of the overlap in clinical/cognitive
and some behavioral symptoms in AD and CTE, an additional biomarker tool is needed to prevent
misdiagnosis. Accurate diagnosis is crucial in order to provide patients with appropriate
treatment.