Longitudinal evaluation of ventricular volume changes associated with mild traumatic brain injury in military service members

Primary objective: To investigate differences in longitudinal trajectories of ventricle-brain ratio (VBR), a general measure of brain atrophy, between Veterans with and without history of mild traumatic brain injury (mTBI).Research design: Structural magnetic resonance imaging (MRI) was used to calculate VBR in 70 Veterans with a history of mTBI and 34 Veterans without such history at two time points approximately 3 and 8years after a combat deployment.Main outcomes and results: Both groups demonstrated a quadratic relationship between VBR and age that is consistent with normal developmental trajectories. Veterans with history of mTBI had larger total brain volume, but no interaction between mTBI and age was observed for brain volume, ventricular volume, or VBR.Conclusions: In our longitudinal sample of deployed Veterans, mTBI was not associated with gross brain atrophy as reflected by abnormally high VBR or abnormal increases in VBR over time.