Mid Life Hypometabolism In The Precuneus May Be Associated With Prior History Of Traumatic Brain Injury (TBI) (P5.329)

OBJECTIVE: To investigate whether TBI severity is associated with AD like metabolic decline independent of age in a cohort of mid-life veterans BACKGROUND:There is increasing evidence suggesting that a history of TBI is increasing the risk for dementia and may fasten its onset. However, it is unclear to what extent there is a specific link between TBI and AD. DESIGN/METHODS:A convenience sample of mid-life veterans was selected from our study center. Diagnosis of TBI severity and Post-traumatic stress disorder (PTSD) was established using Alteration of Consciousness (AOC), Loss of Consciousness (LOC), Post-traumatic amnesia (PTA) and Clinician-Administered PTSD Scale (CAPS). All patients underwent FDG imaging within 1 week of the examination. FDG scans were spatially normalized to the MNI FDG template in SPM8 and smoothed with at 6mm kernel. Scans were then entered into a multiple regression analysis with TBI severity as variable of interest and age as nuisance variable. T-maps exploring negative correlations between TBI severity and metabolic decline where initially thresholded at p < .001 (uncorrected) followed by a volume-of-interest (VOI) analysis (30 mm sphere). RESULTS:The sample consisted of 57 veterans (7 females), mean age of 46.8 yrs. (median: 45.1), 31 mild TBI, 5 moderate TBI and 43 with PTSD. Glucose metabolism decreased significantly with increasing TBI severity in the right precuneus and left angular gyrus. VOI analyses with FWE multiple comparison correction at p < .05 confirmed the robustness of the effect. Conclusions:TBI severity is associated with AD like metabolic decline within the precuneus and angular gyrus, independent of age. Study Supported by: War Related Illness and Injury Study Center, California Disclosure: Dr. Soman has nothing to disclose. Dr. Cheng has nothing to disclose. Dr. Chao has nothing to disclose. Dr. Kong has nothing to disclose. Dr. Adamson has nothing to disclose. Dr. Ashford has nothing to disclose. Dr. Furst has nothing to disclose.