Concussion
A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning.[9] Symptoms may include loss of consciousness; memory loss; headaches; difficulty with thinking, concentration, or balance; nausea; blurred vision; dizziness; sleep disturbances, and mood changes.[1] Any of these symptoms may begin immediately, or appear days after the injury.[1] Concussion should be suspected if a person indirectly or directly hits their head and experiences any of the symptoms of concussion.[10] Symptoms of a concussion may be delayed by 1–2 days after the accident. It is not unusual for symptoms to last 2 weeks in adults and 4 weeks in children.[11][2] Fewer than 10% of sports-related concussions among children are associated with loss of consciousness.[12]
For concussion (mild traumatic brain injury) in children and adolescents, see Pediatric concussion.Concussion
Mild brain injury, mild traumatic brain injury (mTBI), mild head injury (MHI), minor head trauma
Headache; trouble with thinking, memory, or concentration; nausea; blurry vision; sleep disturbances; mood changes[1]
Up to 4 weeks[2]
Physical violences, drinking alcohol, playing contact sports such as American football, playing martial arts such as muay thai, previous history of concussion[5]
Based on symptoms[6]
Paracetamol (acetaminophen), NSAIDs[2]
6 per 1,000 people a year[3]
Common causes include motor vehicle collisions, falls, sports injuries, and bicycle accidents.[3][4] Risk factors include physical violence, drinking alcohol and a prior history of concussion.[13][5] The mechanism of injury involves either a direct blow to the head or forces elsewhere on the body that are transmitted to the head.[13] This is believed to result in neuron dysfunction, as there are increased glucose requirements, but not enough blood supply.[2] A thorough evaluation by a qualified medical provider working in their scope of practice (such as a physician or nurse practitioner) is required to rule out life-threatening head injuries, injuries to the cervical spine, and neurological conditions and to use information obtained from the medical evaluation to diagnose a concussion.[6][14][15] Glasgow coma scale score 13 to 15, loss of consciousness for less than 30 minutes, and memory loss for less than 24 hours may be used to rule out moderate or severe traumatic brain injuries.[6] Diagnostic imaging such as a CT scan or an MRI may be required to rule out severe head injuries.[14] Routine imaging is not required to diagnose concussion.[16]
Prevention of concussions includes the use of a helmet when bicycling or motorbiking.[3] Treatment includes physical and mental rest for 1–2 days, with a gradual step-wise return to activities, school, and work.[8][2][17] Prolonged periods of rest may slow recovery and result in greater depression and anxiety.[2] Paracetamol (acetaminophen) or NSAIDs may be recommended to help with a headache.[2] Prescribed aerobic exercise may improve recovery.[18] Physiotherapy may be useful for persisting balance problems, headache, or whiplash; cognitive behavioral therapy may be useful for mood changes.[2] Evidence to support the use of hyperbaric oxygen therapy and chiropractic therapy is lacking.[2]
Worldwide, concussions are estimated to affect more than 3.5 per 1,000 people a year.[19] Concussions are classified as mild traumatic brain injuries and are the most common type of TBIs.[3][19] Males and young adults are most commonly affected.[3][19] Outcomes are generally good.[20] Another concussion before the symptoms of a prior concussion have resolved is associated with worse outcomes.[21][22] Repeated concussions may also increase the risk in later life of chronic traumatic encephalopathy, Parkinson's disease and depression.[23]
Society and culture
Costs
Due to the lack of a consistent definition, the economic costs of mTBI are not known, but they are estimated to be very high.[139] These high costs are due in part to the large percentage of hospital admissions for head injury that is due to mild head trauma,[90] but indirect costs such as lost work time and early retirement account for the bulk of the costs.[139] These direct and indirect costs cause the expense of mild brain trauma to rival that of moderate and severe head injuries.[140]
Terminology
The terms mild brain injury, mild traumatic brain injury (mTBI), mild head injury (MHI), and concussion may be used interchangeably;[141][88] although the term "concussion" is still used in sports literature as interchangeable with "MHI" or "mTBI", the general clinical medical literature uses "mTBI" instead, since a 2003 CDC report outlined it as an important strategy.[76][38] In this article, "concussion" and "mTBI" are used interchangeably.
The term "concussion" is from Latin concutere, "to shake violently"[47] or concussus, "action of striking together".[142]
