Brain-surgery.us ~ Brain surgery, Brain surgeon, Neurosurgery, Neuro...
1 of 1
file:///C:/Users/USER/AppData/Roaming/Mozilla/Firefox/Profiles/c2y...
Assessing the severity of TBI
The severity of TBI is best measured by the Glasgow Coma Score (GCS) and the duration of Post-Traumatic Amnesia
(PTA) period. The GCS is an objective method of following the patient’s neurological status, and a score for “normal” is 15.
Eye movements are scored from 1 to 4, voice responses from 1 to 5, and limb motor responses from 1 to 6. The acute
application of the GCS does have some limitations. For example, hypoxia, hypotension and intoxication can all falsely lower the
GCS. On the other hand, PTA is defined as that period of time after the injury in which the brain is unable to lay down new and
continuous day-to-day memories. Approximately 70% of patients with TBI will experience PTA. In Australia, the Westmead PTA
Scale is commonly used. It consists of orientation and memory items and used to assess the patient daily. Patients are deemed
to be “out of PTA” once a score of 12/12 is achieved on three consecutive days. As a rule of thumb, the lower the GCS and the
longer the PTA period, the worse the severity of the TBI. The length of the period of PTA is a strong predictor of functional
outcome.
By definition, the severity of a TBI can be classified as follows: “Mild” = PTA period of < 1 hour; “moderate” = PTA Period of
1-24 hours; “severe” = PTA period of 1-7 days; “very severe” = PTA period of > 7 days; and “chronic amnestic state” = PTA
period of > 6 months.
7/03/2012 3:29 PM