Traumatic acute subdural hematoma (ASDH) is a major clinical entity in traumatic brain injury (TBI). It acts as a space occupying lesion to increase intracranial pressure, and is often complicated by co-existing lesions, and is modified by cerebral blood flow (CBF) changes, coagulopathy, and delayed hematomas. Because of its complicated pathophysiology, the mortality of ASDH is still remaining high. In this review article, its epidemiology, pathophyiology, surgical treatment, and salvage ability are described. With regard to epidemiology, as the population ages, growing number of elderly patients with ASDH, especially patients with prehospital anticoagulant and antiplatelets, increase. Concerning pathophysiology, in addition to well-known initial intracranial hypertension and subsequent ischemia, delayed hyperemia/hyperperfusion, or delayed hematoma is being recognized frequently in recent years. However, optimal treatments for these delayed phenomenons have not been established yet. With regard to surgical procedures, all of craniotomy, decompressive craniectomy, and initial trephination strategies seem to be effective, but superiority of each procedure have not been established yet. Since Glasgow Coma Scale (GCS) scores, age, papillary reaction, and computed tomographic findings are strongly correlated to outcome, each factor has been investigated as an indicator of salvage ability. None of them, however, has been defined as such one. In future studies, epidemiological changes as population ages, management of delayed pathophysiology, superiority of each surgical procedures, and salvage ability should be addressed.
2014 by The Japan Neurosurgical Society