Clinical Characteristics of Dementias That Occur Remotely After Traumatic Brain Injury in Retired Military Personnel

Inclusion Criteria: Cases (with a history of TBI): 1. Ages 50-95 years 2. History of traumatic brain injury of sufficient severity to have resulted in medical attention (ascertained via the Ohio State University TBI Identification Questionnaire-OSU TBI-ID, and based on DoD/VA criteria) 3. Residence in AFRH-Washington D.C. or the Veterans Home of California-Yountville 4. MMSE score ≥ 20 5. Capacity to provide consent to participate in research (assessment made by study physician) 6. Ability to read and write English Controls (without a history of TBI): 1. Ages 50-95 years 2. No history of traumatic brain injury of sufficient severity to have resulted in medical attention (ascertained via the Ohio State University TBI Identification Questionnaire-OSU TBI-ID) 3. Residence in AFRH-Washington or the Veterans Home of California-Yountville 4. MMSE score ≥ 20 5. Capacity to provide consent or assent to participate in research 6. Ability to read and write English - Exclusion Criteria: Cases (with a history of TBI): 1. History of penetrating brain injury 2. History of disabling neurological or psychiatric condition such as epilepsy (besides posttraumatic epilepsy), multiple sclerosis, cortical stroke, hypoxic-ischemic encephalopathy, encephalitis, or schizophrenia Controls (without a history of TBI): History of disabling neurological or psychiatric condition such as epilepsy, multiple sclerosis, cortical stroke, hypoxic-ischemic encephalopathy, encephalitis, or schizophrenia \-