Mild Traumatic Brain Injury/
Concussion
What is a mTBI/ concussion?
A concussion is a type of traumatic brain injury—or TBI—caused by a bump, blow, or jolt to the head or by a hit to the body that causes the head and brain to move rapidly back and forth. This sudden movement can cause the brain to bounce around or twist in the skull, creating chemical changes in the brain and sometimes stretching and damaging brain cells (CDC, 2019)

Current Understanding
According to the CDC, mTBI represents 75% of all TBIs that occur in the United States, which translates to 1.1 million persons incurring mild traumatic brain injuries each year. The true incidence, however, is believed to be higher, given that 16% to 25% of those injured not seek needed medical care (BIAA, 2019).

Causes
While there are many potential causes leading to a mTBI, a few primary causes include acceleration-deceleration movements, (such as motor vehicle accidents), striking the head against a hard surface, the head being struck by an object, and blasts or explosions (BIAA, 2019).
mTBI can lead to undesirable chemical changes in the brain, also known as metabolic alterations, or direct damage to structural components.
Whether chemical or structural, alterations to the brain, alter neurological function, dependent upon the damaged location.
Even mild concussions should not be taken lightly. Neurosurgeons and other brain injury experts emphasize that although some concussions are less serious than others, there is no such thing as a minor concussion. In most cases, a single concussion should not cause permanent damage. A second concussion soon after the first one does not have to be very strong for its effects to be permanently disabling (AANS, 2021).
Symptoms may include:
Physical/ Somatic
Confusion
Fatigue
Seizure
Headache
Vision disturbances (double or blurry vision)
Dizziness or imbalance
Nausea or vomiting
Numbness
Memory loss
Ringing ears
Difficulty concentrating
Sensitivity to light
Loss of smell or taste
Poor sleep
Light/ noise sensitivity
Cognitive
Inattentiveness
Diminished concentration
Poor memory
Impaired judgement
Slowed processing speed
Executive dysfunction
Behavioral/ Emotional
Depression
Anxiety
Agitation
Irritability
Impulsivity
Testing and Diagnosis
Brain imaging studies with MRI and CT scans should not be performed routinely in the diagnosis of concussions. They typically do not show any significant changes and, with CT scans, expose individuals to unnecessary radiation. While such tests are more useful for identifying structural defects, an injury from concussion is metabolic and microscopic in nature that often presents normally on neuroimaging (AANS, 2019).