A PCA Interpretation of the Glasgow Coma Scale in the Trauma Brain Injury PECARN Dataset

CT scan is strongly recommended for a patient affected by head trauma, but he/she must absorb a certain amount of radiations. For this reason, the physician tries to avoid such a practice for pediatric patients. The symptoms analysis, visual/tactile inspection, and reactions to appropriate stimuli from the physician could induce him/her to put the patient in a period of observation instead of performing an immediate CT scan. As a consequence, the correct evaluation of those symptoms is a crucial task. For this reason, the Pediatric Glasgow Coma Scale (PGCS) plays a fundamental role, because it is a numeric scale regarding the patient's mental status. It is computed as the sum of the score for the eye, motor and verbal response evaluated by the physician. In this paper, the Principal Component Analysis (PCA) is performed on the PGCS of the Trauma Brain Injury (TBI) dataset collected by the PECARN (Pediatric Emergency Care Applied Research Network). The PCA is performed in all cases when the sum of the three partial scores results in a value less than 14, because a patient with PGCS = 15 is not considered at risk. Under this constraint, the PCA reveals that each partial GCS give the same contribution to the first principal component, but a scale variation is introduced.