Late onset of subdural hematoma after bifrontal contusion.

Cerebral cortical contusions are one of the most common computed tomography findings in head-injured patients and common sequel of traumatic brain injury. These contusions tend to show a progressive increase in mass effect on repeated imaging, most small contusions do not require surgical evacuation. However, progression to subdural hematoma (SDH) in a late aspect is unique. Here we present a 71-year-old man with bifrontal contusion, who deteriorated 43 days after initial trauma with sudden onset of acute SDH. This unusual case suggests that neurosurgeons should be alert for the possibility of very late onset of acute SDH after bifrontal contusions.