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III. Brain Traumatic Lesions

C. Lacerations (rupture or tearing of brain tissue).

This physical disruption of tissue, often accompanied by contusions, is caused by a penetrating injury, e.g. by bony fragments or weapons. Meninges and cortex are both involved. The sequence of pathologic changes differs from that of contusion only with respect to the increased amount of hemorrhage, more disruptive effect and the more obvious fibroblastic proliferation and scarring of meninges in lacerations.

D. Diffuse Axonal Injury

Diffuse axonal injury is a major cause of prolonged traumatic coma. This type of lesion is present in 35% of head trauma deaths and is the most common cause of poor neurological outcome. Lesions are located in deep white matter regions. Pathological changes include axonal swellings within hours and later degeneration of fiber tracts.


This is a close-up of a gross coronal section of frontal lobe, showing contusions in the orbital frontal lobe.  Hemorrhagic areas are clearly seen; microscopic analysis would reveal neuronal necrosis. 
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