Crash! Bang! “What a hit!” On Sunday every weekend during the fall, football catches our attentions with big, powerful hits between opposing teams. On occasion, players are assisted off the field under suspicion of suffering a head injury from such a hit. More often than not, the announcer informs you that the player will not be returning to the game due to concussion-like symptoms. In the case of my grandpa, this generally prompts an angry outburst followed by a comment about how “in the old days” men use to play through such injuries. I do agree with my grandpa that it does seem like there was less concern about concussions in the past than today. So why are concussions such a hot topic in football today? Why are players not allowed to return to finish the game?
Before I begin to answer these questions, it is best to understand what a concussion is. Concussions are a type of traumatic injury caused by a hit to the head or body, a fall, or another injury which results in jarring or shaking of the brain inside the skull.1Some common symptoms include confusion, disorientation, dizziness, headaches, unsteadiness, and vision problems.2 Concussions are generally associated with sports, but they can occur in daily activities as well. You are probably saying, “but why are they so dangerous?”
First, we need to understand what happens to the brain immediately following a concussion. After receiving a concussion, there is an increased concentration of calcium ions due to increased signaling in the brain, leading to stress on the neurons. Increased calcium concentrations can lead to stress on neurons as a result of calcium accumulation. One downside of calcium accumulation is that it slows down energy production by interfering with mitochondria in the cells. Additionally, when a concussion occurs, there is a disruption in the brain’s ability to regulate potassium ions inside and outside the cell. Normally potassium ions have a high concentration in the nerve cells so after a concussion the brain tries to restore this concentration gradient by causing the ion pumps in the brain to work overtime. Therefore, the brain requires extra energy (ATP) to run these pumps longer, leading to an energy shortage. The increased potassium and calcium ion concentrations greatly limit the body’s ability to produce enough energy to support the brain cells. It takes many days until these ions return to their normal concentrations.
If enough time is given for the brain to return to normal, there seems to be little or no lasting neurological conditions from concussions. However, the lasting effects from concussions appear to occur when someone gets another concussion before the first one is fully healed. According to the research paper, the brain is most vulnerable to lasting damage when it is working overtime producing energy to recover from the first injury. When there is a second concussion, the brain may not be able to produce enough energy to support the repair process for both the first and second concussions. The result is irreversible damage to the brain. Therefore, the injured NFL players are not allowed to return to the game because the NFL is trying to protect the players from a second concussion and thus permanent brain damage.