Novel Clinical Scale for Evaluating Pre-Operative Risk of Cerebral Herniation from Traumatic Epidural Hematoma

Secondary massive cerebral infarction (MCI) is the predominant prognostic factor for cerebral herniation from epidural hematoma (EDH) and determines the need for decompressive craniectomy. In this study, we tested the clinical feasibility and reliability of a novel pre-operative risk scoring system, the EDH-MCI scale, to guide surgical decision making. It is comprised of six risk factors, including hematoma location and volume, duration and extent of cerebral herniation, Glasgow Coma Scale score, and presence of preoperative shock, with a total score ranging from 0 to 18 points. Application of the EDH-MCI scale to guide surgical modalities for initial hematoma evacuation surgery for 65 patients (prospective cohort, 2012.02-2014.01) showed a significant improvement in the accuracy of the selected modality (95.38% vs. 77.95%; p = 0.002) relative to the results for an independent set of 126 patients (retrospective cohort, 2007.01-2012.01) for whom surgical modalities were decided empirically. Results suggested that simple hematoma evacuation craniotomy was sufficient for patients with low risk scores (≤9 points), whereas decompressive craniectomy in combination with duraplasty were necessary only for those with high risk scores (≥13 points). In patients with borderline risk scores (10-12 points), those having unstable vital signs, coexistence of severe secondary brainstem injury, and unresponsive dilated pupils after emergent burr hole hematoma drainage had a significantly increased incidence of post-traumatic MCI and necessity of radical surgical treatments. In conclusion, the novel pre-operative risk EDH-MCI evaluation scale has a satisfactory predictive and discriminative performance for patients who are at risk for the development of secondary MCI and therefore require decompressive craniectomy.