Bidirectional Brain-Systemic Interactions and Outcomes After TBI

Traumatic brain injury (TBI) is a debilitating disorder associated with chronic progressive neurodegeneration and long-term neurological decline. Importantly, there is now substantial and increasing evidence that TBI can negatively impact systemic organs, including the pulmonary, gastrointestinal (GI), cardiovascular, renal, and immune system. Less well appreciated, until recently, is that such functional changes can affect both the response to subsequent insults or diseases, as well as contribute to chronic neurodegenerative processes and long-term neurological outcomes. In this review, we summarize evidence showing bidirectional interactions between the brain and systemic organs following TBI and critically assess potential underlying mechanisms. Traumatic brain injury (TBI) can cause significant changes in systemic organ function.Peripheral immune challenges following TBI can increase chronic neuroinflammation and exacerbate neurological dysfunction.Recognition of brain-systemic interactions after TBI provides important insights relating to the pathobiology and treatment of head injury.Targeting brain systemic changes after TBI may influence long-term morbidity and mortality.