The idea that a brain injury is a chronic disease has only been with us for approximately 10 years, since the seminal paper by Dr. Brent Masel. Prior to that, it was felt that only recovery occurred as time went by, without any chance of further decline. Many things have changed, however.
The glia cells of the brain, ignored for 100 years by scientist, are now known to provide defenses against injury similar to what white blood cells do in the rest of the body. The brain and spinal cord are separated from the rest of the body by something called the brain blood barrier (BBB). If that barrier is broken by trauma, as it commonly is, large harmful molecules are able to enter into the CNS (Central Nervous System ). This causes disruption of brain activity and can also lead to seizures. When an injury occurs, the glia in the brain, which are the most common cells in the brain itself, are activated and go to the site of the injury to help scavenge dead cells and do repairs. However, in about a third of individuals the microglia do not stop their work and continue to scavenge healthy brain tissue over months or years. This leads to gradual cognitive decline following TBI. Beneficial microglia are termed M–1, and harmful microglia are known as M–2.
This helps explain several previously confusing concepts in the field of TBI injury. For example, having two concussions in succession is extraordinarily harmful to the brain, because the glia are already activated by the first injury and after a second injury prior to recovery, the microglia are turned into harmful glia in greater amounts. This also helps explain how two similar TBI’s can result in such different levels of recovery and outcome. Much like an auto – immune disease, certain individuals have microglia that are less likely to turn off and not attack the brain as in other individuals.
Many other chronic symptoms have been identified as possibly lasting for decades after injury, these include: temporary or permanent loss of human growth hormone because of injury to the pituitary gland. Braininjury.com has the most experience in dealing with pituitary injury than any other group of lawyers in the United States. These individuals have to undergo special testing, and if found to be missing human growth hormone, will need daily injections for decades. The treatment significantly improves the patient’s overall health, especially in getting rid of crippling fatigue. TBI also makes future mental illness far more likely, especially depression, anxiety, and obsessive-compulsive symptoms. The rate of brain atrophy accelerates after TBI. Persons with TBI have abnormal levels of amino acids in their blood.
TBI of any severity basically ages the person by 1 to 4 decades, especially the brain. The brain of a person with a moderate to severe TBI will look like the brain of a person 20 to 30 years older. TBI reduces the cognitive reserve of the brain by killing cells and thus places the individual closer to dementia over time.
Many medical trials are ongoing to develop drugs to control microglia after injury. One promising drug is PIF (Pre-Implantation Factor), which is a molecule created by all mammalian embryos. PIF has been shown to greatly reduce inflammation and degeneration in the brain following injury. Hopefully PIF will be approved by the FDA within the next few years.