Epidemiology, Pathogenesis and Diagnosis of Traumatic Brain Injury in Military Personnel - A Narrative Review

Major causes of Traumatic Brain Injury (TBI) in military cases include severe head trauma, exposure to explosives, and penetrating ballistic injuries. Military TBI may lead to a number of adverse consequences, including headache, dizziness, vomiting and impaired consciousness, PTSD, depression, irritability, the tendency to commit suicide. TBI may also reduce the quality of life of veterans and have a serious impact on their social functioning. In terms of pathophysiological mechanisms, blast damage and shock waves produced by explosive weapons are the most common damage mechanisms in military TBI. This explosive lesion manifests itself pathologically as vasospasm, axonal and microvascular damage, congestion, hemorrhage, and brain cell edema, and its pathological diagnosis focuses more on multifocal traumatic axonal injury and Tau protein hyperphosphorylation. In fact, Tau protein phosphorylation is thought to be the main mechanism leading to neurological symptoms after TBI, although the evidence is still insufficient. The next pathogenesis mechanism in military TBI is cerebral blood vessel damage, possibly associated with perivascular inflammation and autoimmune processes and oxidative damage, which increases cerebral blood vessel permeability and impairs energy metabolism in brain cells, as well as ion concentration balance within. It breaks down outside the brain tissue cells, eventually leading to vasogenic edema after TBI. Unpredictability of pathological changes and delay in post-injury assessment have been reported to be major factors limiting early detection of military TBI. However, advanced imaging techniques and biomarkers have been reported to be useful for early detection of military TBI. Today, immediate interventions in patients with TBI, despite various new technologies, remain a clinical challenge. To fully repair injuries to the nervous system and to enable military personnel to recover from their social functions, the development of technologies for appropriate diagnosis and treatment is essential.