PTA and GCS
Whether a person has sustained a concussion through a car accident or a severe brain injury due to an accident at work, a neuropsychological assessment is extremely useful in providing details to aid in understanding the persons cognitive, behavioural and emotional functioning as well as their prognosis
When considering the classification of the severity of an acquired brain injury, it is important to note that severity is not always predictive of the outcome. More specifically, people with severe brain injuries can have positive outcomes and there are circumstances where people who sustain a concussion have a poorer outcome.
There are many factors that influence the severity of an acquired brain Injury. This can include factors such as the site and size of the damage to the brain, the developmental stage of the individual and other factors related to the person and the environment. The severity and outcome following a brain injury may indeed be an expression of the total interaction of the factors.
The measurement and classification of severity, however, is different. The severity of an acquired brain injury is gained from obtaining information about a person’s mental state and level of consciousness following an injury where there is a suspicion that the brain has sustained some form of damage. Tests and procedures have been developed in an attempt to standardise the data obtained about a person’s state and, overtime, classifications have been associated with performances on these measures and procedures. The two main classification tools / processes used today include the Glasgow Coma Scale and measurement of Post Traumatic Amnesia.
The Glasgow Coma Scale involved measuring responses by a person soon after a suspected injury has been sustained. Areas measured include, eye response, verbal response and motor response. The scoring on each of these areas is detailed below:
Best eye response
- No eye opening (1)
- Eye opening in response pain (2)
- Eye opening to speech (3)
- Eyes opening spontaneously (4)
Best verbal response
- No verbal response (1)
- Incomprehensible sounds (2)
- Inappropriate works (3)
- Confused (4)
- Oriented (5)
Best motor response
- No motor response (1)
- Extension to pain (2)
- Abnormal flexion to pain (3)
- Flexion / Withdrawal to pain (4)
- Localizes to pain (5)
- Obeys commands (6)
During the assessment, the examiner records and adds together the score obtained on each of these areas. Classification of severity is then based upon the final score achieved, as detailed below:
GCS score of greater than or equal to 13 equates to a Mild Traumatic Brain Injury Classification.
GCS score of 9 – 12 equates to a Moderate Traumatic Brain Injury Classification.
GCS score of less than or equal to 8 equates to a Severe Traumatic Brain Injury Classification.
It is important to note that GCS scores can fluctuate overtime as reflective of a person’s mental state and changes in their condition.
Post Traumatic Amnesia (PTA) is also a commonly relied upon state that is used to estimate the severity of an acquired brain injury. Post-traumatic amnesia is considered to be the best single indicator of the severity of closed head injury.PTA is considered to be a state of confusion that is reflective of damage and disruption to the normal operation of the brain. It is characterised by an alteration to attention, orientation and memory (rapid forgetting). A number of measures have been developed to attempt to determine where a person is in a post-traumatic amnesic state. The Westmead PTA scale is scale designed to measure PTA. The Westmead PTA scale uses a series of orientaiotn and memory questions to produce a score out of 12. When a person consistently achieves a score of 12 over a period of time, they are considered to have emerged from PTA. The question used in this scale are provided below:
How old are you?
What is your date of birth?
What month are we in?
What time of day is it? (Morning, Afternoon or Night)
What day of the week is it?
What year are we in?
What is the name of this place?
Who do you have to remember? (Show set of 3 photos)
What is their name?
What were the 3 pictures that you had to remember?
The duration that a person is considered to remain is PTA is considered as indicative of the severity of PTA. Accordingly, there have been a number of attempts to apportion a period of time to a severity classification. The most traditional measure classification based on PTA duration is detailed in the table below.
| PTA Duration | Traditional Classification |
| < 5 minutes | Very Mild |
| 5-60 minutes | Mild |
| 1-24 hours | Moderate |
| 1-7 days | Severe |
| 1-4 weeks | Very Severe |
| > 4 weeks | Extremely Severe |
While this continues as the traditional classification system, it is at odds with contemporary approaches to understanding concussion. Accordingly, Neurodynamics has developed a Contemporary Classification of Severity.
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