The clinical assessment of head injury severity is commonly based on what is known as the Glasgow Coma Scale (GCS) according to doctors. A score of 3-8 means severe injury, 9-12 is a moderate brain injury, while 13-15 is mild head injury, based upon examination six hours after injury. The score is obtained by observing the patient’s impairment in speech, motor function, and eye movement. It does not, however, show what might have caused the impairment. Patients with the same GCS score may well have completely different causes for it, which means completely different treatment is necessary. Fatalities may even occur in patients who are not treated properly, even those with GCS scores above 9.
The damage to the brain is often vascular, studies have learned. The contusion index rates these injuries, giving them numerical values according to surface extend and depth. Another means to assess vascular injury is the hemorrhagic lesion score. This measures, in Westchester and Brooklyn, the total vascular damage in a traumatized brain by mapping macroscopic and microscopic evidence of bleeding on a diagram of sections of the brain, which are further divided into sectors.
Cell damage is a bit harder to quantify. The distribution and extent of such damage is not uniform or symmetrical, so systematic microscopic study of the brain is required to properly assess it. It has often been divided into three grades of severity, depending upon a number of criteria determined by examining both macroscopic and microscopic lesions.