What is a Contusion?
When we hit our
shin or arm on a table, a black and blue mark appears which we call
a bruise. A contusion in the brain is essentially the same thing, a
bruise that forms when you hit your head. A contusion is a focal
injury (limited and localized) and consists of an area of hemorrhage
(bleeding), which can damage neurons and produce swelling within the
brain. The damage caused by the contusion depends on where the head
is impacted and the direction of the stress on the brain from the
impact. Most often, contusions are the result of differential
movement between the skull and the brain itself. As the skull
receives the initial impact, it transfers the energy from the impact
to the brain causing a contusion to form where the brain collides
against the rough surface of the skull. A contusion can result in
coma and death. Fig.1 shows an area of subarachnoid hemorrhage with
bleeding and an area of brain contusion where the white ischemic
brain has died.
Figure
1
Each area of the brain is responsible for a specific function of the human body. For example, parts of the frontal lobe (located in the front of the brain) are responsible for
the ability to think and the ability to plan ahead. Other parts within the frontal lobe are devoted to motor capabilities; like the ability to move our eyes or head, orient our
bodies and minds to what is going on around us, and move the opposite arm and leg. Brain damage (a contusion) results from the destruction of neurons. Neurons act as a communications
network for the human nervous system. The extent of the damage, as well as the effects of that damage, are dependent on the area of the brain which is injured. If the injury impacts
the frontal lobe you are likely to have impaired thought processes or paralysis of the opposite side of the body. The Occipital lobe, on the other hand, is located in the back of the
head and is responsible for all aspects of our visual capabilities. So, if a contusion were to form in the Occipital lobe, it would be probable that the victim could loose a half of
their vision field in each eye.
A contusion is a permanent injury. The effects of the injury are dependent upon where the contusion forms. If a contusion forms in a critical area needed to perform a specific
function of the brain, such as a direct hit to the brain’s motor area, the injury wipes out any hope of recovering that function, in this case leaving the victim with permanent paralysis.
There is also a chance that the contusion will not cause any alteration in the person’s ability to function normally, if it forms in an area of the brain that is not critical, or what is
called a silent area.
The third possibility is if the contusion forms in an overlapping area of the brain. An overlapping area of the brain is one that is used to perform parts of more than one function.
Because only part, of the area needed to perform that function is gone, it is possible to re-learn the ability that was lost in the injury by re-routing the signals to areas of the brain not
affected by the contusion. This means that although brain function is impaired, the patient may recover.
What are the symptoms of a contusion?
Symptoms depend on the extent of the brain contusion. A small contusion may not produce any visible symptoms if the damaged areas are not critical. The involvement of functional areas of the brain will produce varying degrees of impairment in:
- Thinking
- Reading and Writing
- Speech
- Memory
- Vision
- Coordination
If you experience a head injury it is always a good idea to have it looked at by a physician. It is also important to pay close attention to any changes or irregularities in your physical or mental
capabilities after the incident and if they persist for any length of time to consult a physician. For example, if your vision is impaired, or you are having trouble manipulating a part of your body,
like a leg or arm. Or if your speech is slowed, or thought process is cloudy.
Treatment
Treatment focuses on:
- Steroids which stabilize enzyme systems.
- Mechanical respirators and osmotic drugs
that attempt to control swelling of the brain.
- Anti-convulsants to prevent seizure.
- Control of blood pressure to avoid
worsening brain swelling.
- General fluid and nutritional support.
- Surgical procedure to control brain swelling by draining spinal fluid and removing hemorrhagic areas of the brain that aggravate brain swelling.
With time and luck the brain contusion can heal. At that time rehabilitation is started. The specific program depends on the area damaged.
For example, speech therapy for impaired speech, cognitive-retraining of the brain for higher mental function losses, and physical therapy for
motor paralysis.
The permanent residual of a brain contusion depends on the areas damaged, the severity of the damage and the size of the injured area.
The Recovery Process is often a slow, frustrating process of re-learning a previously simple activity performed by the victim on a daily basis.
Support from family and friends can be crucial to the success of treatment.
