Degrees of Brain Injury
Brain Injury: "Mild," "Moderate," and "Severe" Defined
Medical and rehabilitation professionals label the severity of traumatic brain injuries as mild, moderate, or severe based on one of several methods. The duration of coma and/or post-traumatic amnesia (PTA) can be used to make a judgment of injury severity. Following are some time lines on which such decisions are based:
Medical and rehabilitation professionals label the severity of traumatic brain injuries as mild, moderate, or severe based on one of several methods. The duration of coma and/or post-traumatic amnesia (PTA) can be used to make a judgment of injury severity. Following are some time lines on which such decisions are based:
- Coma or PTA less than one hour: Mild
- Coma or PTA between one and 24 hours: Moderate
- Coma or PTA greater than 24 hours: Severe
Additionally, the Glasgow Coma Scale (GCS) is often used to label the severity of a TBI. The GCS is an objective measure that rates the injured person based on eye opening, and verbal and motor abilities. A score is assigned for each of these areas, and then added for the total GCS Score. Below is a chart describing each domain and the score derived for performance in those areas:
See the following chart:
Activity |
Score |
|
| Eyeopening |
Spontaneous To Speech To Pain None |
4 3 2 1 |
| Verbal |
Oriented
Confused Inappropriate Word Nonspecific Sound
None |
5 4 3 2 1 |
| Motor |
Follows Commands Localizes Pain Withdraws to Pain Decorticate posture (bending) Decerebrate posture (straightening) None |
6 5 4 3 2 1 |
GCS scores range from 3 (no eye opening, verbal response, or motor reactions) to 15 (spontaneous eye opening, fully oriented, and able to follow commands). Following are GCS scores and corresponding injury severity:
- GCS Score of 3 to 8: Severe
- GCS Score of 9 to 12: Moderate
- GCS Score of 13 to 15: Mild
These measurements are some of the most reliable indicators of what long-term outcome will be. However, there is not a direct relationship between severity of injury and extent of disability. In other words, not every kid with a severe brain injury will have serious disabilities. Conversely, some children with seemingly mild concussions may have long-term, life altering complications, although such outcomes are more likely for their peers with moderate-to-severe injuries. Studies indicate that 10% of people with mild brain injuries will have life-long difficulties; approximately 33-50% of those with moderate injuries will have disabilities; and around 80% of people with severe TBIs will have enduring difficulties.
References
Christensen, J.R. (2001). What is Traumatic Brain Injury? In Schoenbrodt, L., ed. Children with Traumatic Brain Injury: A Parents’ Guide. Woodbine House: Bethesda, MD.
Teasdale, G., Jennet, B. (1974). Assessment of coma and impaired consciousness: A practical scale. Lancet, 2, 81-84.
Turnbull, R., Turnbull, A., Shank, M., Smith, S., & Leal, D. (2002). Exceptional Lives: Special
Education in Today’s Schools, 3rd Edition. Prentice Hall: Upper Saddle River, NJ.
