Your brain is a soft organ that is surrounded by spinal fluid and protected by your hard skull. Normally, the fluid around your brain acts like a cushion that keeps your brain from banging into your skull. But if your head or your body is hit hard, your brain can crash into your skull, or be jolted, literally causing it to move around in your head. This force can injure the brain, causing bruising, damage to the blood vessels, and injury to the nerves. The result? Your brain doesn’t function normally. If you’ve suffered a concussion, vision may be disturbed, you may lose equilibrium, or you may fall unconscious. In short, the brain is confused.
There are many ways to get a concussion. Some common ways include fights, falls, playground injuries, car crashes, and bike accidents. Concussions can also happen while participating in any sport or activity such as football, boxing, hockey, soccer, skiing, or snowboarding. Blasts are an important cause of MTBI among military personnel in war zones.
However, concussions don’t always involve a loss of consciousness. Most people who have a concussion never pass out, but they may describe seeing all white, black, or stars. You can have a concussion and not realize it.
You don’t have to pass out (lose consciousness) to have a concussion. Some people will have obvious symptoms of a concussion, such as passing out or forgetting what happened right before the injury. But other people won’t. With rest, most people fully recover from a concussion within 7 to 10 days. Other people take a few weeks or months to recover. In rare cases, concussions cause more serious problems. Repeated concussions or a severe concussion may require surgery or lead to long-lasting problems with movement, learning, or speaking. Because of the small chance of permanent brain problems, it is important to contact a concussion specialist if you or someone you know has symptoms of a concussion.
Studies in basic neuroscience have demonstrated that mild traumatic brain injury (concussion) is followed by a complex cascade of ionic, metabolic, and physiological events that can adversely affect cerebral function for several days to weeks. Concussive brain injuries trigger a sequence of biochemical changes characterized earliest by an indiscriminate release of excitatory amino acids, massive ionic flux, and a brief period of hyperglycolysis, followed by persistent metabolic instability, mitochondrial dysfunction, diminished cerebral glucose metabolism, reduced cerebral blood flow, and altered neurotransmission. These events culminate in axonal injury and neuronal dysfunction. Clinically, concussion eventuates in neurological deficits, cognitive impairment, and somatic symptoms.
The terms concussion, mild brain injury, mild traumatic brain injury (MTBI), mild head injury (MHI), and minor head trauma may be used interchangeably. Head injury, closed head injury, head trauma, brain injury, diffuse axonal injury, goose-egg, bump on the head, postconcussive syndrome, “seeing stars”, and “getting your bell rung” are also terms commonly used interchangeably with concussion.