Possible delayed neuronal death after seemingly successful evacuation of traumatic acute subdural hematoma: Image report.

Background: The term delayed neuronal death (DND) was originally used to describe the histopathological sequence of neuronal injury following severe global brain ischemia. Owing to the lack of histopathological verification, it is technically impossible to confirm DND in clinical settings. Case Description: A 22-year-old military serviceman presenting with clinical signs of impending uncal herniation was found to have a traumatic acute subdural hematoma (ASDH) over the left cerebral hemisphere. Following emergency hematoma evacuation, signs of brainstem dysfunction rapidly resolved, and brain computed tomography (CT) obtained the following day appeared unremarkable. However, a low-density area (LDA) emerged on CT obtained 4 days postoperatively in the left temporal lobe, which did not exhibit interval change in the extent and degree. Although the LDA eventually resolved, atrophy of the left temporal lobe was observed 1 month after injury. Conclusion: Among various possible reasons for the delayed emergence of the LDA, we hypothesized that DND might have played a role based on its unique chronological change in the imaging studies. Awareness of the possibility of DND may help neurosurgeons facilitate outcome prediction in patients with severe traumatic brain injury who exhibit initially unremarkable postoperative imaging.