Why does axonal injury often occur during concussions from diffuse shear strain, even when visible brain bleeds are absent on initial CT scans?

💡 Explanation

Axonal injury from concussion involves a cascade: The diffuse shear strain causes microscopic axonal disruption, which leads to impaired axonal transport and subsequent metabolic crisis. This precedes visible bleeds; therefore, metabolic compromise is the initial failure mode, rather than immediate structural damage seen on CT scans alone.

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