High-risk mild head injury

The generally accepted definition of mild head injury is a Glasgow Coma Scale (GCS) score of 13-15. However, many studies have already shown that there is a heterogeneity in pathophysiology among patients with GCS scores ranging from 13-15. Patients with GCS score 13 or 14 tended to have more serious injury. There is a statistically significant trend across GCS scores in terms of percentage of patients with positive acute radiographic findings, percentage of patients with neurosurgical interventions, and percentage of patients with poorer outcome. Patients with the so-called "mild" head injury may have serious long-term sequelae. The current definition of mild head injury is misleading because the sequelae of the injury may not be mild. A more precise classification of head injury is necessary. An ideal classification of head injury is one that can accurately predict the outcome of the injury. Based on the results of our earlier study [Hsiang et al. High-risk mild head injury. J Neurosurg 1997; 87:234-238], the head injury patients with GCS 13-15 should be further subdivided into "mild head injury" or "high-risk mild head injury." Mild head injury is defined as GCS 15 without any acute positive radiographic findings, whereas high-risk mild head injury is defined as GCS 13 or 14, or GCS 15 with acute positive radiographic findings. Using this more precise classification, the truly mild head injury patients can be safely discharged from the emergency department, and the high-risk mild head injury patients can either be admitted or be warned about the expected sequelae. The addition of the subgroup "high-risk mild head injury" may help to avoid the confusion caused by the current classification of mild head injury.