Sports-related traumatic brain injury
Rules exist within each sport to help prevent cerebral contusions and traumatic brain injuries. However, individual athletes are the best prevention against their own injuries. In a game, athletes notice when they have the symptoms of a cerebral contusion and should take themselves out of the game. It may be hard for medical personnel or coaches to notice when a player has a traumatic brain injury, so it is in the player’s best interest to be removed from play. In hockey, traumatic brain injuries constitute 10%-15% of all head injuries. With the high percent of injuries being traumatic, extensive design improvements have been made to helmets. These improvements reduce the risk of cerebral contusions by providing more padding around the skull and a chin strap that keeps the helmet snug. In baseball, major improvements to helmets have been made to protect batters from the impact a baseball can have when hitting their head. Helmets, before this major improvement, were designed to withstand a velocity of 70 mph from a pitch or foul ball. Since the company Rawlings’ new design, helmets can withstand a velocity of 100 mph and have further padding around the softer parts on the side of the skull.
Traumatic brain injury
Secondary injury events include damage to the blood–brain barrier, release of factors that cause inflammation, free radical overload, excessive release of the neurotransmitter glutamate (excitotoxicity), influx of calcium and sodium ions into neurons, and dysfunction of mitochondria. Injured axons in the brain's white matter may separate from their cell bodies as a result of secondary injury, potentially killing those neurons. Other factors in secondary injury are changes in the blood flow to the brain; ischemia (insufficient blood flow); cerebral hypoxia (insufficient oxygen in the brain); cerebral edema (swelling of the brain); and raised intracranial pressure (the pressure within the skull). Intracranial pressure may rise due to swelling or a mass effect from a lesion, such as a hemorrhage. As a result, cerebral perfusion pressure (the pressure of blood flow in the brain) is reduced; ischemia results. When the pressure within the skull rises too high, it can cause brain death or herniation, in which parts of the brain are squeezed by structures in the skull. A particularly weak part of the skull that is vulnerable to damage causing extradural haematoma is the pterion, deep in which lies the middle meningeal artery, which is easily damaged in fractures of the pterion. Since the pterion is so weak, this type of injury can easily occur and can be secondary due to trauma to other parts of the skull where the impact forces spreads to the pterion.