Pathophysiology and management of mild traumatic brain injury

Mild traumatic brain injury (mTBI) is a common reason for visiting an emergency department. In the last decade, there has been increasing interest in the delayed-onset cognitive and behavioral impairments that occur after repetitive mTBI, also known as chronic traumatic encephalopathy (CTE), in athletes and military personnel. Because many patients with mTBI are adolescents and the increasing incidence of mTBI has a significant social impact, re-searchers are exploring the mechanism underlying mTBI and its management. Cerebral concussion, a common type of mTBI, is associated with physical symptoms such as headache, dizziness, nausea, and temporary consciousness disturbance and shows no structural abnormalities on imaging studies. Because there are no diagnostic criteria for concussion, its symptoms should be carefully observed using established assessment tools. There are three sequential conditions related to mTBI with concussion: CTE, second impact syndrome, and post-concussion syndrome. Al-though repetitive mTBI is thought to increase the risk of progression of these related conditions, the mechanism is unclear. Patients with mTBI should rest from physical and cognitive activities, and avoid activities that could cause repetitive injury. For athletes, to avoid missing signs of worsening, a return-to-play protocol should be used in which the patient’s physical and cognitive conditions are evaluated at each stage of recovery. Rest and supportive care are the only ways to manage mTBI. There are currently no effective treatments to prevent worsening or prolongation of symptoms. To minimize the adverse outcomes of mTBI, especially in children whose brains are immature, it is vital to educate supervisors to prevent repetitive mTBI and to manage patients appropriately. In particular, supervisors should have a clear understanding of mTBI and its management, including strict adherence to protocols. It is also important to establish new guidelines for the management of patients with mTBI.