The brain can be injured in a variety of ways. We will look at 3 ways in
particular:
skull fracture or skull penetration;
acceleration-deceleration injuries;
and
coup/contre-coup injuries.
1. Skull Fracture:
Let’s start with a basic understanding of the skull and traumatic
brain injury. Brain injury can occur when the skull is fractured, resulting
in brain swelling, brain contusion, or the entry point of bacteria and infection.
Brain injury can also occur without a skull fracture, such as “shaken
baby syndrome.” The skull is a very strong structure with rigid bones
on its inside. It takes significant force to break or crack the skull. The
brain, on the other hand, is a very soft gelatin-like tissue structure much
like jello. A force that passes through the skull and penetrates the brain
may cause severe injury. The skull is thinnest, and therefore the weakest,
at the temporal lobe which is near the ear. As a result, many skull fractures
occur in the area of the temporal lobe.
2. Acceleration-Deceleration Injuries:
The key to understanding the role of acceleration-deceleration forces in
causing traumatic brain injury is to discuss “inertia.” This
means that an object remains stationary or continues moving until acted upon
by some outside force. In traumatic brain injury, the brain has inertia.
For example, when a person falls backwards onto a hard floor, the back of
the person’s head hits the floor and stops. The brain, however, is
still moving until it strikes the inside of the skull. If the brain gets
bruised, there is bleeding, also called a hemorrhage. This bleeding causes
further damage to the brain. The skull does not need to strike an object
in order for the brain to get injured. There are many situations in motor
vehicle crashes where the forces are transmitted through the brain without
the skull hitting the dashboard, windshield, steering wheel or window. Let’s
look at acceleration-deceleration injuries in a rear-end motor vehicle collision.
When a car is rear-ended there is a certain amount of force that is transmitted
through the car. As a result, the occupants of the car begin to move forward.
The brain which is inside the skull floats in a bath of cerebral spinal fluid
and remains stationary by the membranes of the brain that attach to the skull.
When the neck reaches the end point of moving forward, there may be rapid
deceleration of the head, while the brain continues forward hitting into
the interior structure of the skull. Contusions of the brain are usually
more severe in parts of the brain closest to the skull, including the tips
of the frontal and temporal lobes. The undersurface of these lobes are quite
vulnerable because they are located next to the skull structures that are
rough and irregular.
3. Coup/Contre-Coup Injuries:
Related to acceleration-deceleration injuries are coup/contre-coup injuries.
These happen with a severe impact or after a fall when the head is struck.
After the brain hits the inside of the skull it might actual bounce back
and strike the opposite side of the skull, potentially resulting in two separate
injuries to the brain.
Let’s start with a basic understanding of the skull and traumatic
brain injury. Brain injury can occur when the skull is fractured, resulting
in brain swelling, brain contusion, or the entry point of bacteria and infection.
Brain injury can also occur without a skull fracture, such as “shaken
baby syndrome.” The skull is a very strong structure with rigid bones
on its inside. It takes significant force to break or crack the skull. The
brain, on the other hand, is a very soft gelatin-like tissue structure much
like jello. A force that passes through the skull and penetrates the brain
may cause severe injury. The skull is thinnest, and therefore the weakest,
at the temporal lobe which is near the ear. As a result, many skull fractures
occur in the area of the temporal lobe.
The key to understanding the role of acceleration-deceleration forces in
causing traumatic brain injury is to discuss “inertia.” This
means that an object remains stationary or continues moving until acted upon
by some outside force. In traumatic brain injury, the brain has inertia.
For example, when a person falls backwards onto a hard floor, the back of
the person’s head hits the floor and stops. The brain, however, is
still moving until it strikes the inside of the skull. If the brain gets
bruised, there is bleeding, also called a hemorrhage. This bleeding causes
further damage to the brain. The skull does not need to strike an object
in order for the brain to get injured. There are many situations in motor
vehicle crashes where the forces are transmitted through the brain without
the skull hitting the dashboard, windshield, steering wheel or window. Let’s
look at acceleration-deceleration injuries in a rear-end motor vehicle collision.
When a car is rear-ended there is a certain amount of force that is transmitted
through the car. As a result, the occupants of the car begin to move forward.
The brain which is inside the skull floats in a bath of cerebral spinal fluid
and remains stationary by the membranes of the brain that attach to the skull.
When the neck reaches the end point of moving forward, there may be rapid
deceleration of the head, while the brain continues forward hitting into
the interior structure of the skull. Contusions of the brain are usually
more severe in parts of the brain closest to the skull, including the tips
of the frontal and temporal lobes. The undersurface of these lobes are quite
vulnerable because they are located next to the skull structures that are
rough and irregular.
Related to acceleration-deceleration injuries are coup/contre-coup injuries.
These happen with a severe impact or after a fall when the head is struck.
After the brain hits the inside of the skull it might actual bounce back
and strike the opposite side of the skull, potentially resulting in two separate
injuries to the brain.