Traumatic Brain Injury, Pt. 2

Causes of TBI

The majority of TBI cases result from falls (35%), followed by motor vehicle accidents (17%), pedestrian and bike accidents (17%), assaults (10%) and “other” factors, including warzone explosions and IED blasts (21%). Falls constitute the major cause of TBI for older adults. One in five patients diagnosed with TBI are victims of violence, including firearms, as well as domestic and child abuse. Despite the increase publicity regarding the prevalence of concussions among football players, only 3% of all TBI are sports-related (http://www.brainline.org/content/2008/07/facts-about-traumatic-brain-injury.html).

Cause of TBI also is strongly correlated with prognosis or patient outcome. Approximately 91% of all TBI resulting from firearms (including suicidal intent) result in death, while only 11% of TBI resulting from falls end in a fatality.

Diagnosis

TBI requires prompt medical evaluation for diagnosis and treatment. A health care professional will want to obtain a full medical history, including how and when the injury occurred, whether the patient has suffered any prior head injuries, and what other health conditions might be contributing to symptoms. The healthcare practitioner will perform a physical exam and look for obvious signs of trauma, such as changes in thinking, speaking, behavior, balance and coordination and/or difference in pupil size. A GCS is likely to be administered and other specialized tests may be performed to evaluate brain function. Some of the more common specialized tests include:

• Electroencephalogram (EEG) or brain wave tests: An EEG helps determine if a patient’s level of alertness or consciousness is normal, if abnormalities exist in a specific part of the brain or if the patient is showing any signs of seizures or convulsions.
• Head Computed Topography (CT): A Head CT consists of a series of X-rays taken from many different directions used to quickly detect the presence of brain injuries.
• Magnetic Resonance Imaging (MRI, MRA and fMRI) of the Brain: There are a number of magnetic resonance imaging technologies that can be used to detect brain injury. Some of the more common ones include MRI, MRA (Magnetic Resonance Angiogram) and fMRI (functional MRI).
• An MRI of the brain uses magnetic field and radio pulses to take pictures or images of the brain. The MRI is capable of showing tissue damage that cannot be seen on an X-ray, Ultrasound or Computed Topography (CT) scan. Sometimes a dye will be injected into a patient’s vein, allowing for clearer visualization of brain structures.
• An MRA takes pictures of the blood vessels in the brain. MRA can find problems with the blood vessels that may be causing obstructed or reduced blood flow. With an MRA, both blood flow and the condition of blood vessel walls can be visualized.
• An fMRIis a relatively new procedure that uses MR imaging to measure the tiny metabolic changes that take place in an active part of the brain.
• Neuropsychological or Neurocognitive Testing: These are special tests designed to assess different areas of brain functioning, such as intelligence, memory, conceptual reasoning, and linguistic (language) skills, etc. The tests are designed to correspond to different areas or neural pathways in the brain. An abnormally low score on any one of these tests can indicate the possibility of brain impairment.