What Happens to the Brain?
Traumatic brain injury differs from other types of brain damage (genetic,
drug or alcohol included, degenerative
disease, strike, etc.) in a number of ways:
Damage is acquired in the course of what may well have been normal development.
It happens suddenly, bringing significant change immediately.
Damage is usually diffuse, widespread, not confined
to one area of the brain. Thus the effects are multiple.
TBI results from some trauma to the head, causing damage to the brain. The
head may be hit or strike a stationary object or be shaken violently.
Alternatiively, the brain may actually be penetrated from the outside.
Open Head Injury. The brain is penetrated from outside, as in a
Closed Head injury. The brain is damaged within the head, without
The brain is a soft mass of jelly-like constistency. Its volume cannot be
compressed, but it can shift and move when violently disturbed. It "floats"
in a bath of cerebral spinal fluid within a hard, unyielding skull. The
protuberances froming vaults and ridges. When, because of trauma to the
head, the brain moeseithin the skull, the camage prouces predictable
patients of TBI. While open head injuries cause destruction of the
penetrated brain tissue, closed head injuries may result in three other
types of damage:
- Widespread damage results from the strectching and tearing of nerve
fibers. When the brain mass twists and shifts, billions of thread-like
nerve connections are pulled and stretched. Some actually snap and never
function again. Some that are stretched may recover but others degenerate
and finally fall apart.
- The brain mass collides with the sharp ridges indside the skull. As
it bounces off hard bone, it is torn and bruised. Contusions (bruises)
are the most likely to occur at the tips and base of the frontal and
temporal lobes, because these areas are closest to sharp ridges of
- If the head is struck in a particular way, the skull may bend in,
bruising the brain, then diving the brain mass against the opposite wall of
the skull so that brain tissue on the other side is bruised as well.
There also may be secondary damage to the brain after injury.
Bleeding of the damaged vessels can cause an internal buildup of
blood, which can cause pressure and harm the tissue. The injured brain
may swell with fluid, causing intracranial pressure and herniation
or tissue death as a result of loss of oxygen. If surgery is
necessary, additional brain tissue may be destroyed in the process.
Very Thorough and Resourceful TBI Page