What is concussion?

A concussion is a type of traumatic brain injury (TBI) that occurs when the brain is jolted or shaken within the skull, typically as a result of a blow to the head or a sudden acceleration or deceleration of the head. Concussions are commonly caused by sports injuries, motor vehicle accidents, falls, and physical assaults, among other causes.


What is the relationship between concussion and oxidative stress?

The relationship between concussion and oxidative stress is a topic of growing interest in the field of traumatic brain injury (TBI) research. Oxidative stress occurs when there’s an imbalance between the production of reactive oxygen species (ROS) and the body’s ability to neutralize them with antioxidants. Following a concussion, several factors can contribute to oxidative stress in the brain:


  • Mitochondrial Dysfunction: Concussions can disrupt mitochondrial function in brain cells. Mitochondria are responsible for generating energy in cells, but they are also a significant source of ROS production. When mitochondria are damaged or dysfunctional due to a concussion, they may produce excessive amounts of ROS, contributing to oxidative stress.


  • Inflammatory Response: Concussions trigger an inflammatory response in the brain, involving the activation of immune cells and the release of pro-inflammatory cytokines. While inflammation is a crucial part of the brain’s response to injury, it can also lead to the production of ROS by activated immune cells, exacerbating oxidative stress.


  • Excitotoxicity: Following a concussion, there can be an increase in the release of excitatory neurotransmitters such as glutamate. Excessive glutamate release can lead to overactivation of glutamate receptors, resulting in calcium influx and the generation of ROS within neurons, contributing to oxidative stress.


  • Blood-Brain Barrier Disruption: Concussions can cause damage to the blood-brain barrier, a specialized structure that regulates the passage of substances between the bloodstream and the brain. Disruption of the blood-brain barrier can allow entry of inflammatory cells and circulating toxins into the brain, further contributing to oxidative stress and inflammation.


  • Antioxidant Defense Mechanisms: Following a concussion, there may be alterations in antioxidant defense mechanisms in the brain. Antioxidants help neutralize ROS and protect cells from oxidative damage. However, in the acute phase of concussion, antioxidant levels may be depleted, leaving the brain more vulnerable to oxidative stress.


The consequences of oxidative stress following a concussion are not fully understood, but it is believed to contribute to secondary injury processes and neurodegenerative changes in the brain.