Different Kinds of TBIs

 For this post, I am not talking about mild, moderate and/or severe. That post was already done. Nor am I talking about ways in which you could obtain an injury; I'm talking about the different kinds of traumatic brain injuries. There is SO much to try to explain, and so much background to understand! But let me try to break it down into smaller pieces. 

First there are closed brain injuries and penetrating head injuries. Penetrating head injuries are where something breaks through the skull, through the dura and all other meninges (brain protectors) to penetrate and physically damage the actual brain. This rare type of injury only occurs 1-2% of the time. However, this type of injury has been made famous by a man named Phineas Gage. He was working on a railroad when an iron rod shot straight up from beneath his left jaw out the top of his skull. It surprisingly did not kill him but left him with strange new behaviors. "Phineas' survival and rehabilitation demonstrated a theory of recovery which has influ­enced the treat­ment of frontal lobe damage today." 

Each of the primary injuries have many subcategories, if you will. For the sake of you readers, I’ll keep all of the complications out. The first is skull fractures. The next is contusions - or bruises on the brain. A similar but more vigorous category is called coup-countrecoup. This is essentially dramatic whiplash - where the impact throws your brain into one side of the skull and back to the opposite. Then we have 

hematomas and hemorrhages. A hematoma is a blood clot whereas hemorrhages are uncontrolled bleeding. Both cause problems for a few different reasons. As my neurosurgeon put it, “the skull holds 3 things: the brain, blood and cerebrospinal fluid, and if any one of those decides to take up more room it creates pressure which can surround the brainstem and kill you.” Additionally when blood outside of its vessels come in contact with neurons (brain cells) they die. Then we have the most severe and dangerous type of primary injuries; the diffuse axonal injury. Diffuse axonal injury is a twisting and tearing of the connections between the brain cells. The damage results in the inability to function.

Finally, I’ll give you a quick list of secondary injuries. (Especially because it’s late and I’ve been working on this post for hours). Hydrocephalus (increased cerebrospinal fluid in ventricles); Ischemia (insufficient blood flow); hypoxia (insufficient oxygen in the brain); hypo/hypertension (low/high blood pressure); cerebral edema (swelling of the brain); raised intracranial pressure (increased pressure within the skull), which can lead to herniation (parts of the brain are displaced); hypercapnia (excessive carbon dioxide levels in the blood); meningitis (infection of the meningeal layers) and brain abscess; biochemical changes (changes in levels of neurotransmitters, sodium, potassium, etc.); epilepsy.