The patient was an unrestrained driver in a high-speed motor vehicle collision. 24 hours later CT shows punctate hemorrhages. The diagnosis is?

• A. Diffuse axonal injury
• B. Subgaleal hemorrhage
• C. Cushing's Syndrome
• D. Cerebral capillary hemorrhage

Answer: (A)

The main concept here is how diffuse axonal injury presents after high-velocity head trauma. When the head experiences rapid deceleration and rotational forces, the long nerve fibers in the white matter get sheared, causing widespread axonal damage. This produces tiny, punctate hemorrhages that CT can reveal a day after injury, often at the gray–white matter junctions and in the brain’s deep structures like the corpus callosum or brainstem. Those microhemorrhages reflect the widespread axonal and vascular injury typical of DAI, which is why this pattern fits best in an unrestrained driver after a high-speed crash.

Subgaleal hemorrhage is a scalp bleed typically seen with birth-related or minor scalp trauma, not a brain parenchymal injury seen on head CT. Cushing’s syndrome is a systemic endocrine condition with clinical features and imaging findings not produced by acute traumatic microhemorrhages. Cerebral capillary hemorrhage isn’t the standard diagnosis for this scenario; the described punctate intracerebral bleeds after a high-speed crash are characteristic of diffuse axonal injury.