What is diffuse axonal injury and its typical clinical course?

• A. Widespread axonal damage from acceleration-deceleration forces; coma lasting days to weeks with poor prognosis.
• B. Localized contusion with rapid recovery.
• C. Ischemic stroke due to vascular occlusion; rapid recovery.
• D. Peripheral nerve injury with quick resolution.

Answer: (A)

Diffuse axonal injury results from rapid acceleration-deceleration forces that shear axons throughout the brain, especially in white matter tracts, rather than producing a single focal lesion. This widespread axonal disruption disrupts neural communication and often presents with a markedly impaired level of consciousness. The typical clinical course is immediate loss of consciousness after trauma, followed by a prolonged coma lasting days to weeks, and many patients have a poor long-term prognosis with substantial cognitive and motor deficits. Survivors may experience persistent vegetative or severely disabled states, even when initial imaging doesn’t show a major focal injury. This pattern distinguishes it from a localized contusion (which tends to yield focal deficits and quicker recovery), an ischemic stroke (caused by vascular occlusion with a different onset and imaging pattern), or a peripheral nerve injury (involving the peripheral nervous system rather than widespread brain axons).