B. Mechanisms of damage in closed-head injury (cont)
2. Rotation of brain within cranial cavity
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shearing of bridging veins producing subdural hemorrhage
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shearing of small vessels producing petechial intracranial hemorrhages or subarachnoid hemorrhage
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shearing stresses in brain causing rupture or stretching of axons
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contusions: the orbital surfaces may be damaged by contact with the floor of the anterior fossa; the temporal lobe tips may be damaged by edges of the sphenoid ridge; the corpus callosum may be damaged by the falx cerebri; the superior surface of the cerebellum or brainstem may be injured by contact with the tentorium cerebelli.
3. Secondary damage may be produced by the space-occupying effects of edema and/or hematoma
C. Additional mechanisms of damage involved in open-head injuries.
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Direct inoculation of bacteria
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Laceration by bony fragments
