Concussions seem like such a common thing. It happens because we fall off the jungle gym on the playground as kids or because we run into the walls during a basketball game. If we haven’t had a concussion ourselves, we know a handful of people who have had at least one. I understood that there was brain trauma, but I never stopped to think of the repercussions of that trauma. For instance, the immediate symptoms are dizziness, nausea, inability to concentrate, memory problems, and the obvious, headaches.
However, there are much greater long-term consequences to multiple traumas. Some high school and college athletes may rank up a handful of concussions. Professional athletes whose entire careers fall on the line whether they shake it off and get back on the field may have even more severe brain traumas. But for some reason, they go unreported. Professionals have the greatest risk of developing long-term health issues because of the severity and number of concussions they may accumulate. Very few people stop to think how their brain and their future health they are put at risk when they tell their coach to put them back in. For example, that college student may be putting their degree on the line if the cognitive issues may prevent them from finishing a semester or a year of classes. If the general public were more aware of the neurophysiological changes that occur to brains with head traumas, especially repeated and intense traumas, they may think twice about going out on the field or court too soon.
So what exactly happens to the brain after a concussion? Interestingly, a couple of the culprits are quite similar to Alzheimer’s disease discussed last week on our blog. First, the neurons in the brain are stretched and broken by the blunt impact with the inside of the skull. The neuron undergoes a rapid depolarization because without a membrane the Na+ and K+ are able to flow down their concentration gradients. Immediately following, certain biochemical processes, such as glycolysis and Na+/K+ pump, increase their activity and quickly deplete glucose and ATP. The brain is then left to try to replenish this ATP and restore ion balance over the next few weeks. The Alzheimer’s-like pathology happens during neuronal repair. Amyloid precursor protein (APP) is upregulated in the repair process, and once it is cleaved by b-secretase it forms the amyloid-b (Ab) plaques also found in Alzheimer’s. Another similar process is the hyperphosphorylation of tau protein, a protein that stabilized microtubules in axons, due to the trauma. Tau proteins and Ab aggregate to block the neuronal signal.
The question is when do concussions or acute brain traumas become more serious? The chronic brain injury, CTE, is a neurodegenerative disorder that has similar mental degradation because of the similar pathology. The symptoms in CTE vary greatly depending on the location of the trauma in the brain. Attention and memory deficits are commonly seen farther down the line as the disease progresses. There are no clinical tests to distinguish whether the neurological changes are due to Alzheimer’s and CTE because they are so similar, however age may be one distinguishing factor. There are very few tests that can definitively say whether an individual has a concussion. There is also a fine line between when concussed brain is fully healed and when it isn’t. Once an individual has a concussion, they are more likely to get another concussion and the damage due to the concussion increases.
It is important to protect our brains as much as we can. Certain things are sporadic or genetic, such as Alzheimer’s or ALS, but some things can be prevented. Limiting harmful behaviors which may lead to the neurodegeneration due to concussions is just one way. The athlete’s dreams may be crushed or a professional’s career may be shortened, but the long-term quality of their life will be increased. They won’t be plagued with memory issues, headaches, or behavioral issues because they took one hit too many. I’m not saying athletes need to step away completely from their sport, but they should really think about whether they had enough time to heal and can take a hit without affecting their future health.
Concussions: Not Always Worth Taking One for the Team
