Diagnostic imaging such as a CT scan or an MRI may also be required to rule out severe head injuries. Routine imaging is not required to diagnose concussion.Prevention of concussions includes the use of a helmet when bicycling or motorbiking. Treatment includes physical and cognitive rest for 1–2 days, with a gradual step-wise return to activities, school, and work. Prolonged periods of rest may slow recovery and result in greater depression and anxiety. Paracetamol (acetaminophen) or NSAIDs may be recommended to help with a headache. Physiotherapy may be useful for persistent balance problems; cognitive behavioral therapy may be useful for mood changes. Evidence to support the use of hyperbaric oxygen therapy and chiropractic therapy is lacking.Worldwide, concussions are estimated to affect more than 3.5 per 1,000 people a year. Concussions are classified as mild traumatic brain injuries and are the most common type of TBIs. Males and young adults are most commonly affected. Outcomes are generally good. Another concussion before the symptoms of a prior concussion have resolved is associated with worse outcomes. Repeated concussions may also increase the risk in later life of chronic traumatic encephalopathy, Parkinsons disease and depression. Signs and symptoms
Concussions symptoms vary between people and include physical, cognitive, and emotional symptoms. Symptoms may appear immediately or be delayed. Up to one-third of people with concussion experience prolonged or persistent concussion symptoms, also known as post concussion syndrome, which is defined as concussion symptoms lasting for 4-weeks or longer in children/adolescents and symptoms lasting for more than 14 days in an adult.
As of 2007, studies with athletes have shown that the amount of force and the location of the impact are not necessarily correlated with the severity of the concussion or its symptoms, and have called into question the threshold for concussion previously thought to exist at around 70–75 g.The parts of the brain most affected by rotational forces are the midbrain and diencephalon. It is thought that the forces from the injury disrupt the normal cellular activities in the reticular activating system located in these areas and that this disruption produces the loss of consciousness often seen in concussion. Other areas of the brain that may be affected include the upper part of the brain stem, the fornix, the corpus callosum, the temporal lobe, and the frontal lobe. Angular accelerations of 4600, 5900, or 7900 rad/s2 are estimated to have 25, 50, or 80% risk of mTBI respectively. Pathophysiology
In both animals and humans, mTBI can alter the brains physiology for hours to years, setting into motion a variety of pathological events. As one example, in animal models, after an initial increase in glucose metabolism, there is a subsequent reduced metabolic state which may persist for up to four weeks after injury.