A concussion is any trauma that causes a change in mental status, with confusion and amnesia (partial or total loss of memory), with or without a loss of consciousness. A concussion occurs when the head hits or is hit by an object, or when the brain is jarred against the skull, with enough force to cause temporary loss of function of parts of the brain. The injured person may remain conscious or lose consciousness briefly, and is confused for some time after the blow. Most concussions are caused by car accidents or sports injuries.
Symptoms of a concussion include: headache, confusion, dizziness, slurred speech, amnesia (unable to remember the events immediately before or during the accident), nausea or vomiting, double vision, and ringing in the ears. These symptoms may last from several minutes to several hours. The length of time that the patient was unconscious and the extent of confusion are very important in deciding the seriousness of the injury. In addition to a neurological exam, a computed tomography (CT) scan or a magnetic imaging resonance (MRI) scan may be required to look for brain injury. Concussion usually leaves no lasting brain problems. Nonetheless, symptoms of post-concussion syndrome such as headache, poor attention and concentration, memory difficulties, anxiety, depression, sleep disturbances, light and noise intolerance may last for weeks or even months.