Abstract World Trade Center (WTC) responders were exposed to a mix of tiny dust particles as they participated in rescue and recovery efforts at the WTC in the aftermath of 9/11/2001. A significant number continue to suffer from Post- Traumatic Stress Disorder (PTSD) as a result of their experiences. These may have changed their expectations of health as they age. Our team has interrogated the potential for early signs of cognitive aging and has identified higher than expected burden of mild cognitive impairment (MCI) and, surprisingly, changes to physical functional limitations (PFL) common in both physical disability and in neurodegenerative disease. Given the magnitude and scale of events surrounding 9/11 and the level of exposure within a young civilian population, prior studies are insufficient in determining the pathogenesis of MCI in the WTC responder cohort. We propose that MCI is arising early because PTSD causes a neuroinflammatory response resulting in increased activation of the pituitary gland resulting in increased Alzheimer’s disease neuropathology. We propose to conduct a large longitudinal PET/MRI study of 120 medically-healthy WTC responders using two well-validated positron emission tomography (PET) ligands ([11C]-PiB to measure β-amyloid, and [18F]-Flortaucipir to measure tauopathy). Detailed cognitive testing will help to determine the level of cognitive dysfunction. Simultaneous structural MRI will be used to measure the extent of neurodegeneration. Proteomic analyses will be completed to track changes and to validate a monitoring program for biomarkers in this population. This study is timely because we are in a critical period when neuropathology is still emerging.

Narrative World Trade Center (WTC) responders were exposed to a mix of tiny dust particles as they participated in rescue and recovery efforts at the WTC in the aftermath of 9/11/2001, and a large number may have developed cognitive impairment, a symptom consistent with some neurodegenerative diseases. Given the magnitude and scale of events surrounding 9/11 and the level of exposure within a young civilian population, prior studies are insufficient to identify the etiology of neurocognitive and neuromotor symptoms evident among responders with PTSD. The proposed study will examine Beta-Amyloid and Tau burden using positron emission tomography (PET) combined with magnetic resonance neuroimaging (MRI) on a subset of individuals recruited as part of an existing NIA- funded study of cognitive aging to measure in order to determine whether there is evidence of Alzheimer’s disease in the brains of WTC responders with symptoms consistent with Alzheimer’s disease.