About 10% to 20% of people have post-concussion syndrome for more than a month. Symptoms may include headaches, dizziness, fatigue, anxiety, memory and attention problems, sleep problems, and irritability. Rest, a previously recommended recovery technique, has limited effectiveness. A recommended treatment in both children and adults with symptoms beyond 4 weeks involves an active rehabilitation program with reintroduction of non-contact aerobic activity. Progressive physical exercise has been shown to reduce long-term post-concussive symptoms. Symptoms usually go away on their own within months but may last for years. The question of whether the syndrome is due to structural damage or other factors such as psychological ones, or a combination of these, has long been the subject of debate. Cumulative effects
As of 1999, cumulative effects of concussions were poorly understood, especially the effects on children. The severity of concussions and their symptoms may worsen with successive injuries, even if a subsequent injury occurs months or years after an initial one. Symptoms may be more severe and changes in neurophysiology can occur with the third and subsequent concussions. As of 2006, studies had conflicting findings on whether athletes have longer recovery times after repeat concussions and whether cumulative effects such as impairment in cognition and memory occur.Cumulative effects may include chronic traumatic encephalopathy, psychiatric disorders and loss of long-term memory. For example, the risk of developing clinical depression has been found to be significantly greater for retired American football players with a history of three or more concussions than for those with no concussion history.
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.