What are the Causes of Traumatic Brain Injury?

The number of people with Traumatic Brain Injury (TBI) is difficult to assess accurately but is much larger than most people would expect.  According to the CDC (United States Centers for Disease Control and Prevention), there are approximately 1.5 million people in the U.S. who suffer from a traumatic brain injury each year.  50,000 people die from TBI each year and 85,000 people suffer long term disabilities.  In the U.S., more than 5.3 million people live with disabilities caused by TBI.  Patients admitted to a hospital for TBI are included in this count, while those treated in an emergency room or doctor’s office are not counted.

The causes of TBI are diverse.  The top three causes are: car accident, firearms and falls.  Firearm injuries are often fatal: 9 out of 10 people die from their injuries.  Young adults and the elderly are the age groups at highest risk for TBI. Along with a traumatic brain injury, persons are also susceptible to spinal cord injuries which is another type of traumatic injury that can result out of vehicle crashes, firearms and falls. Prevention of TBI is the best approach since there is no cure.

Open Head Injury

  • Results from bullet wounds, etc.
  • Largely focal damage
  • Penetration of the skull
  • Effects can be just as serious as closed brain injury

 Closed Head Injury

  • Resulting from a slip and fall, motor vehicle crashes, etc.
  • Focal damage and diffuse damage to axons
  • Effects tend to be broad (diffuse)
  • No penetration to the skull

 Deceleration Injuries (Diffuse Axonal Injury)

The skull is hard and inflexible while the brain is soft with the consistency of gelatin.  The brain is encased inside the skull.  During the movement of the skull through space (acceleration) and the rapid discontinuation of this action when the skull meets a stationary object (deceleration) causes the brain to move inside the skull.  The brain moves at a different rate than the skull because it is soft.  Different parts of the brain move at different speeds because of their relative lightness or heaviness.  The differential movement of the skull and the brain when the head is struck results in direct brain injury, due to diffuse axonal shearing, contusion and brain swelling.

Diffuse axonal shearing: when the brain is slammed back and forth inside the skull it is alternately compressed and stretched because of the gelatinous consistency.  The long, fragile axons of the  neurons (single nerve cells in the brain and spinal cord) are also compressed and stretched.  If the impact is strong enough, axons can be stretched until they are torn.  This is called axonal shearing.  When this happens, the neuron dies.  After a severe brain injury, there is massive axonal shearing and neuron death.

As traumatic brain injury lawyers, we are often retained to represent individuals who have sustained brain injury trauma or closed head injury.

Certain traumatic brain injuries are easy to identify. For instance, a fractured skull, a brain bleed, or if an individual is in a coma due to an impact to the head, we can be certain they have suffered a traumatic brain injury or trauma to the brain. However, oftentimes an individual will suffer what is termed a “mild” or “moderate” brain injury (as if trauma to the brain could be considered “mild”) as a result of trauma.  The term “mild brain injury” often leads to misconceptions that the symptoms are not serious or that the injury is only temporary. This is dangerous as brain injury symptoms can often increase or intensify as time goes on. Such injuries are often more difficult to identify as they involve subtle problems with emotions, memory, thinking, and concentration among others.