Cerebral [18 F]T807/AV1451 retention pattern in clinically probable CTE resembles pathognomonic distribution of CTE tauopathy

Abstract

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder most commonly associated with repetitive traumatic brain injury (TBI) and characterized by the presence of neurofibrillary tangles of tau protein, known as a tauopathy. Currently, the diagnosis of CTE can only be definitively established postmortem. However, a new positron emission tomography (PET) ligand, [¹⁸F]T807/AV1451, may provide the antemortem detection of tau aggregates, and thus various tauopathies, including CTE. Our goal was to examine [¹⁸F]T807/AV1451 retention in athletes with neuropsychiatric symptoms associated with a history of multiple concussions. Here we report a 39-year-old retired National Football League player who suffered 22 concussions and manifested progressive neuropsychiatric symptoms. Emotional lability and irritability were the chief complaints. Serial neuropsychological exams revealed a decline in executive functioning, processing speed and fine motor skills. Naming was below average but other cognitive functions were preserved. Structural analysis of longitudinally acquired magenetic resonance imaging scans revealed cortical thinning in the left frontal and lateral temporal areas, as well as volume loss in the basal ganglia. PET with [¹⁸F]florbetapir was negative for amyloidosis. The [¹⁸F]T807/AV1451 PET showed multifocal areas of retention at the cortical gray matter-white matter junction, a distribution considered pathognomonic for CTE. [¹⁸F]T807/AV1451 standard uptake value (SUV) analysis showed increased uptake (SUVr⩾1.1) in bilateral cingulate, occipital, and orbitofrontal cortices, and several temporal areas. Although definitive identification of the neuropathological underpinnings basis for [¹⁸F]T807/AV1451 retention requires postmortem correlation, our data suggest that [¹⁸F]T807/AV1451 tauopathy imaging may be a promising tool to detect and diagnose CTE-related tauopathy in living subjects.

Figure 1

Total number of games played and recorded concussions by year. 1989–1994: high school football. 1995–1998: college football. 1999–2010: National Football League. The last concussion from the 2009 season was incurred in 2010.

Figure 2

Percent change in cortical thickness from 2011 to 2015. Map of cortical thinning across the brain hemispheres are presented with dark gray regions representing sulci and light gray regions representing gyri. The top panel displays changes in thickness from 0 to 5% with no cutoff. The bottom panel displays changes in thickness >2%. Color scales represent percent thickness change relative to 2011 from 0 to ±5%.

Figure 3

Percent change in subcortical volumes from 2011 to 2015.

Figure 4

PET Imaging from a 39-year-old retired NFL player. (a) structural MRI image, (b) [¹⁸F]florbetapir PET (c) [¹⁸F]T807/AV1451 PET, (d) [¹⁸F]T807/AV1451 PET from a healthy age-matched control subject. Note that the [¹⁸F]florbetapir image was negative for amyloid accumulation, while the [¹⁸F]T807/AV1451 image shows extensive cortical ligand retention, especially at the junction of the gray and white matter, as is characteristic of the distribution of tauopathy in CTE. The PET scales represent ligand uptake in Bq/ml. CTE, chronic traumatic encephalopathy; MRI, magnetic resonance imaging; PET, positron emission tomography.