What is traumatic brain injury (TBI)?
TBI refers to any physical injury to the head or neck that causes chemical and/or structural changes inside the brain. It is different from head injury, and can be much more devastating or fatal. In general, TBI is characterized by a state of inflammation inside the brain, which leads to chemical damage that can cause permanent changes to personality and cognitive ability.
Around two million people each year in the United States alone sustain a traumatic brain injury from car accidents, contact sports, and even bad falls; of these cases, 275,000 involve hospitalization and over 50,000 are fatal.
The overwhelming majority of traumatic brain injuries are initiated with a blunt force trauma to the head or neck. This is the primary injury, and it can cause blood vessels to burst and sometimes physical reordering of nervous tissue. The secondary injury is often more serious than the primary injury, and it’s caused by the chemical changes that occur in the subsequent hours and days following a physical trauma to the head. This is where CBD, and for that matter any other non-surgical treatment method, exerts its therapeutic effect.
The brain is made up of neurons (cells that send chemical signals to one another) and glia (cells that provide structural support and maintenance for neurons). Glia are further broken down into several classes, one of which is called microglia. Microglia are the functional units of the immune system inside the blood-brain barrier; normal immune system cells cannot cross the BBB. When an injury to the brain is sustained, these microglia release the same inflammatory compounds and cytotoxic mediators (toxic to cells) that T-cells and macrophages release during an immune response in the rest of your body.
This has the purpose of attacking any infection and killing compromised brain cells. It causes a massive release of not only immune hormones, but also of reactive oxygen species (ROS), better known as free radicals, like hydrogen peroxide, that rapidly degrade cell membranes and DNA strands. While this is useful for reducing infection and killing both pathogens and infected cells, in cases of blunt force trauma, the good that it does is far outweighed by the negative.
What is the blood brain barrier?
When any of our cells experience injury or damage, they release warning chemicals that initiate an inflammatory response from the immune system. The brain is somewhat different, because it is separated from the rest of our body by a series of structures collectively known as the blood-brain barrier (BBB). The BBB is comprised of endothelial (barrier) cells that line the capillaries and blood vessels in the brain. Their primary purpose is to selectively allow only certain substances to pass from the blood into the brain and spinal cord. It physically won’t allow molecules larger than about 40 nanometers to pass through unless there are specific channels and receptors for it.
This is absolutely indispensable because many of the compounds produced by our own body are toxic to brain tissue, let alone things that we consume and are exposed to throughout the course of our life. In cases of inflammation and in the presence of free radicals and cytotoxic hormones, the BBB becomes more permeable, allowing T-cells and other peripheral mechanisms to enter the brain and help to mitigate whatever infection or damage was caused. However, this also allows these cells and hormones to attack healthy brain tissue, or to worsen the condition of injured brain tissue that still has the potential for recovery. Worst of all, it allows toxins and irritants to enter the brain as well. This can cause widespread destruction to entire sections of the brain, and can result in decreased cognition, coma, and death.
How can CBD help?
Thanks to the extensive research conducted by interested parties in all medical fields, we now understand how the therapeutic effects of CBD and other phytocannabinoids are mediated. We also know more about how TBI work and why they can be so deadly. This research has cultivated an understanding that it’s the brain’s response to blunt force, rather than the blunt force itself, which produces many of the “traumatic” problems associated with TBI. As the research crossed over, a trend developed that substantiated the anecdotal claims that cannabis and CBD products have significantly improved the condition of many who have experienced blunt force trauma to the head.
As mentioned above, it’s the inflammatory response of microglia that produces the destructive chemical environment that leads to long term brain damage. Inflammation and the subsequent presence of free radicals are the overwhelming specific mechanisms of the brain damage that occurs in roughly 90% of TBI cases. Inflammation inside the brain causes swelling and pressure, but also chemically degrades neurons and inhibits their firing. In addition, microglia produce massive quantities of hydrogen peroxide, nitrous oxide, and several other oxidizing agents that literally dissolve the neuron’s cell membrane. Furthermore, they cause the degradation of DNA so that cells are unable to reproduce.
CBD has shown immense efficacy in preventing the series of chemical reactions that produce an inflammatory response. It blocks the enzyme, cyclooxygenase (COX), that initiates the influx of immune system hormones and free radicals that degrade both damaged and healthy brain cells with impunity. More importantly, CBD is an incredibly powerful antioxidant, much like vitamins C and E. What this means is that it binds with free radicals and oxidizing agents, such as hydrogen peroxide, which destroy many different parts of the cell. These free radicals are released by cells as a precursor to apoptosis, also known as programmed cell death. They are toxic compounds that break down chains of fatty acids, namely the phospholipids that comprise our cell membranes and DNA strand “backbones”.
By binding with the oxygen atom found at the top of the CBD molecule, the reactive oxygen species like peroxide, which degrade cellular components, get turned into molecules of water. (Peroxide consists of 2 hydrogens and 2 oxygens. When one of the oxygens gets taken by CBD, the peroxide now has 2 hydrogens and 1 oxygen, the chemical formula of water.) After serving this vital purpose, the CBD molecule simply gets metabolized and excreted.
In these very real, chemically repeatable ways, CBD has shown promise in helping to attenuate many of the symptoms that accompany a traumatic brain injury, improving quality of life and saving precious brain tissue.