Fig. 1

Relationship between concussion, blast injury, post-traumatic brain sequelae and chronic traumatic encephalopathy (CTE). The broad definition of military TBI can be divided into concussion, blast injury and traumatic sequelae. Among them, concussion can directly or indirectly cause damage of neuronal axon, congestion, haemorrhage, cell oedema and hyperphosphorylation of Tau protein. The blast injury mainly resulted in congestion, haemorrhage and cell oedema. Blast injuries can be the cause of concussion and traumatic sequelae. Concussions can also cause traumatic sequelae. The main cause of CTE is traumatic sequelae. Blast injury can also lead to CTE to a certain extent, while concussion has little relationship with CTE. The pathological manifestations of CTE are mainly congestion, haemorrhage, cell oedema, and hyperphosphorylation of Tau protein. Macroscopically, both military and civilian TBI can be the cause of CTE. Solid black and red arrows indicate associations of pathological mechanisms or clinical manifestations, dashed black arrows indicate relationships among subtypes, and dashed red arrows indicate possible aetiology of CTE. mTBI mild traumatic brain injury