Amyloid and Tauopathy PET Imaging in Acute and Chronic Traumatic Brain Injury

• Status: Completed
• Trial end date: 2017-12-21
• Target enrollment: 0
• Participant gender: Male

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.

• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Samuel Gandy

Criteria

Inclusion Criteria:

• males between 40 to 85 years of age

• individuals who participated in contact sports (e.g., active and retired NFL players, NHL players, boxers, NCAA athletes) and other individuals (including but not limited to veterans, breachers, or law enforcement officials with multiple blast exposures) who all have a history of one or more concussions and have a memory or cognitive complaint

• individuals with Mild Cognitive Impairment (MCI) and no history of concussion or TBI

• healthy controls with no history of head injury and no current cognitive or memory problems

• all participants require a study partner, who is well acquainted with the participant, to answer questions either in person or over the telephone about the individuals' activities of daily living, and to corroborate cognitive problems and past history of brain injury

Exclusion Criteria:

• any significant neurological disease, such as Alzheimer's disease, Parkinson's disease, vascular dementia, Huntington's disease, Pick's disease, Lewy Body Dementia, frontotemporal dementia, normal pressure hydrocephalus, brain tumor, progressive supranuclear palsy, seizure disorder, or multiple sclerosis

• any significant systemic illness or unstable medical condition, including:

uncontrolled diabetes mellitus, uncorrected hypothyroidism or hyperthyroidism, or systemic cancer

• a history of schizophrenia or psychosis, alcohol or substance abuse or dependence within the past 6 months

• clinically significant impairment of liver or renal function

• significant cerebrovascular disease

• impairment of visual or auditory acuity sufficient to interfere with completion of study procedures

• education level < 10 years

• any subjects with a history of risk factors for Torsades de Pointes, or subjects taking drugs known to prolong the QT interval

• subjects who have had 2 or more PET scans within the past year, or other significant exposure to radiation (i.e., radiation therapy)