What is a concussion? Acquired Brain Injury? Traumatic brain injury?

A traumatic brain injury (or TBI) is one of the types of acquired brain injuries. This means that you acquired the trauma during your lifetime. If you have a TBI, you may have been told you have suffered either a mild TBI, moderate TBI or severe TBI. These classifications have little to do with how you are feeling after your head injury, but more to do with factors such as loss of consciousness upon injury. Many people who have quite debilitating symptoms are upset to learn that they have been diagnosed with a mild TBI. Do not confuse the seriousness of your symptoms with the clinical definition of TBI. For example, people with severe TBI usually suffer less headaches (among other symptoms) than people with mild TBI. (I will share these references in future posts).

The term ‘concussion’ is commonly used to describe non-severe head injuries (by TBI definitions). If you are looking for information about your, ‘concussion’, look for articles that relate to mild or moderate traumatic brain injury depending on what your diagnosis is. ‘Concussion’ is considered a catch-all phrase for the most common head injuries which are mild or moderate. Public awareness strategies have led to some confusion in terminologies.

A traumatic brain injury is defined as a physiological disruption or pathophysiological process affecting the brain as a result of trauma from biomechanical forces (McCrory, Meeusisse, Cantu, et al., 2013; Menon, Schwab, Wright, & Maas, 2010; Parker, 2001). Two kinds of insults can take place. One kind is biomechanical, “resulting from the translation of kinetic-energy and force vectors in linear acceleration-deceleration mechanism, rotational mechanism (or both)” (Dashnaw et al., 2012), leading to shear, tensile, and compressive stress (Signoretti et al., 2010). The second kind is physiological, resulting from immediate or delayed pathophysiological injury (Dashnaw et al., 2012). Potential injury mechanisms include, “traction, dilation, distention, or displacement of intracranial arteries, extracranial arteries, and intracranial veins of the dura; compression, traction or inflammation of sensory cranial and spinal nerves; voluntary or involuntary spasm or inflammation of cranial and cervical muscles; meningeal irritation; raised intracranial pressure and hemorrhage” (Parker, 2001). Another important thing to note is that unless injuries are especially severe in nature, such disturbances are not revealed in standard structural neuroimaging examinations (McCrory, Meeusisse, Cantu, et al., 2013). This pretty much means that unless your skull is fractured or your brain is bleeding, you probably will not get picture of the extent of your injuries or your recovery.

References:

Dashnaw, M. L., Petraglia, A. L., & Bailes, J. E. (2012). An overview of the Basic Science of Concussion and Subconcussion: Where Are We and Where are We Going. Neurosurg Focus, 33(6), E5. 

McCrory, P., Meeusisse, W. A., M, Cantu, B., Dvorak, J., Echemendia, R., Engebretsen, L., . . . Turner, M. (2013). Consensus Statement on Concussion in Sport: the 4th International Conference on Concussion in Sport Held in Zurich, November, 2012. Br J Sports Med, 47, 250-258. 

Menon, D. K., Schwab, K., Wright, D. W., & Maas, A. (2010). Position Statement: Definition of Traumatic Brain Injury. Arch Phys Med Rehabil, 91(11), 1637-1640.