Causes
It is hard to come up with an exact number of people suffering from Traumatic Brain Injury (TBI), but there are many more than you would think. According to records maintained by the United States Centers for Disease Control and Prevention, there are close to 1.5 million new victims of TBI every year. 50,000 people die as a result of TBI on an annual basis, and 85,000 are diagnosed with long-term disabilities. Only TBI patients who are treated in the hospital are included in this pool, but any who were cared for in the ER or doctor's office are omitted.
There are a variety of causes of TBI, but the three most prevalent are auto accidents, gunshot wounds, and falls. Nine out of ten shooting victims are fatally wounded. Teens and seniors are the two groups most prone to TBI. Since there isn't a cure for TBI, educating each other about how to prevent it is the best solution.
The following scenarios are notorious for leading to TBI:
Open head injury
- Commonly results from bullet penetration
- Primarily focal damage
- Intrusion of the skull
- Impact may be just as severe as closed head injury
Closed head injury
- Caused by falls, car crashes, etc.
- Focal damage and widespread harm to axons
- Effects are normally diffuse
- No skull infiltration
Diffuse axonal injury (Deceleration injury)
Everyone knows that our brains our housed inside the skull and that the skull is very hard and rigid, but not everyone is aware that the human brain has the texture of Jell-O. As a person's head moves through space (accelerates) and suddenly collides with a motionless object (decelerates), the brain's momentum forces it to shift inside the skull. The brain travels at a different speed compared to the skull because it has a lower density. Various sections of the brain do not move at the same rate because some are heavier than others. This difference in movement between the skull and brain when a person's head strikes an object is what causes diffuse axonal shearing, bruising, swelling, and ultimately, brain damage.
Diffuse axonal shearing occurs when the brain is rattled back and forth, compressing and stretching as it collides with the victim's skull. The elongated, delicate axons of the neurons, which are the single nerve cells found in the brain and spinal cord, are also compacted and expanded. If the blow is powerful enough, axons may be stretched until they tear, which is known as axonal shearing. This causes the neuron to die. In the case of a severe brain injury, substantial axonal shearing and neuron death occurs.
Chemical/Toxic
- Also called metabolic disorders
- Dangerous chemicals harm neurons
- Harmful chemicals or toxins may be found in pesticides, solvents, carbon monoxide, lead, etc.
Hypoxia (Oxygen shortage)
- If blood is lacking oxygen, permanent brain damage can happen due to anoxia (no oxygen) or hypoxia (reduced oxygen)
- Only requires a few minutes to take effect
- May be triggered by heart attacks, respiratory failure, low blood pressure, or an environment with oxygen saturation well below average
- Resulting brain damage can cause harsh cognitive and memory problems
Tumors
- Cancerous tumors can grow directly on or over the brain
- By occupying the crevices of the brain, tumors cause damage
- Large tumors can do damage by putting pressure on surrounding brain tissue
- Surgery to remove brain tumors can be risky and also result in brain damage
Infection
- The brain and its membranes are breeding grounds for infections if its unique blood-brain protective shield is invaded
- Viruses and bacteria have the potential to cause deadly diseases of the brain (encephalitis) and meninges (meningitis)
Stroke
- Causes cells to die in area of the brain where blockage of blood occurred
- If bleeding occurs inside (hemorrhage) or around the brain (hematoma) as a result of a torn artery or vein, stifled blood flow and injury to brain tissue from contact with the blood will cause brain damage