A 17-year-old female was struck by a motor vehicle and thrown 15 feet. She lost consciousness immediately, and GCS remained 3 at the scene. She was hemodynamically stable but experienced a drop in oxygen saturation, which was remedied with intubation and supplemental oxygen. GCS improved to 7 in the emergency department. By hospital day 3, she began displaying purposeful movements on the right side and localizing sounds. She could track approximately 1 week later and consistently followed commands 12 days after injury. She began participating in rehabilitative therapies, but participation was limited by frequent episodes of agitation. Depakote and Seroquel were added to her medications and improved the behavioral changes. After transferring to an acute rehabilitation facility, she later returned home with 24-hour supervision.

Brain MRI showed multifocal microhemorrhages throughout the cerebrum and brainstem ( Fig. 65.1 ).

Severe diffuse axonal injury. Brain MRI, axial SWI, shows petechial hemorrhages throughout the left greater than right subcortical white matter and midbrain ( arrows ).

Global cerebral injury can be seen with trauma, hypoxic-ischemic injury, seizures, recreational drugs, and medication effects. Posttraumatic ischemia and hemorrhage can result from vascular injury, vasospasm, and increased ICP.

Diffuse microhemorrhages can be seen in DAI, small vessel vasculopathies, and following radiation therapy.

Localized macro- and microhemorrhages may be seen in association with underlying vascular malformations or tumors.

Severe (grade 3) diffuse axonal injury.