Imaging Biomarkers of Delayed Sequelae in Trauma Brain Injury

This study is being done to learn if a new brain imaging technology called DaTscan can detect subtle changes in the brain ("biomarkers") that are similar to those seen in early Parkinson's disease (PD). The results of this study may provide more information about a potential link between mild to moderate traumatic brain injury (mTBI) and PD. We will compare findings from persons who experienced mTBI ("cases") to persons without history of brain injury (mTBI-or "controls"). This study may provide preliminary data that might be used to help design future long-term studies. The investigators propose scientific studies with one specific aim and two hypotheses: Specific aim: to determine if one year post emergency room (ER) visits, DaTscan uptake (Ioflupane I123 injection and single photon emission computerized tomography) is lower in subjects exposed to mTBI (defined as a closed head trauma that results in loss of consciousness or amnesia for less than 24 hours) than in subjects not exposed to mTBI (without closed head trauma; mTBI-). Hypotheses: Hypothesis #1: mTBI is a risk factor for Parkinson's disease (PD). Hypothesis #2: DaTscan is able to detect subclinical PD (as measured by a dopamine transporter deficiency) in mTBI subjects.