Author: Michael Hunt, MD Educational Pearls:   Studies have shown that patients with decreasing GCS scores have worse outcomes, however GCS of 4 has worse outcome than GCS 3. Alternative scoring system is the GCS-P score which is GCS score - number of non-reactive pupils. GCS3 50% mortality 70% poor outcome at 6 months; GCS-P of 1 had mortality 74% and poor outcome at about 90% at 6 months. GCS-P score is a better prognostic indicator than GCS score.   References: Han J, et al (2014). External validation of the CRASH and IMPACT prognostic models in severe traumatic brain injury. Journal of Neurotrauma. 31(13):1146-52. Maas AI, et al. (2007). Prognosis and clinical trial design in traumatic brain injury: the IMPACT study. Journal of Neurotrauma.  24(2):232-8. The CRASH trial management group, & the CRASH trial collaborators. (2001). The CRASH trial protocol (Corticosteroid randomisation after significant head injury) [ISRCTN74459797]. BMC Emergency Medicine, 1, 1. http://doi.org/10.1186/1471-227X-1-1.