What type of skull fracture usually occurs when the person is conscious?
They fall back
What type of skull fracture usually occurs when the person is unconscious?
They fall forward
What type of skull fractures are common after side impact and occipital trauma?
What is the result?
- CSF or blook leakage from the nose/ears
- Hematomas on the face
- Cranial nerve deficits
What is the result of sudden change in momentum of the head?
What are the symptoms of a concussion and what will accumulate that can histologically identify it?
- Instantaneous transient neurologic dysfunction
- Loss of consciousness
- Loss of reflexes
- Amnesia of event
Results in full nerologic recovery
Beta-amyloid precursor protein accumulates
What is a contusion?
•Bruising resulting from transmission of force through other tissues (looks like wedge)
•Vessel injury, tissue damage, edema
•Crests of gyri
•Inferior surfaces of frontal lobe, temporal poles
•Anywhere adjacent to fractures (fracture contusion)
What is a laceration?
Direct tearing of tissues by penetrating objects
What is Coup vs. Contrcoup?
Coup lesion - At the site of the trauma, while the head is still
Contrecoup lesion - At the opposite site of the trauma, while the head is in motion
What causes Diffuse Axonal Injury (DAI)?
- Angular acceleration
- Direct impact or contusion not necessary
- Results in axonal swellings and multifocal petechial hemorrhage and accumulation of Beta-APP
What is an epidural hematoma and what is the cause?
Hematoma above the dura (looks lens shaped)
Middle meningeal arter tear by fracture
- Clinical presentation several hours after injury (lucid interval)
What is a subdural hematoma and what is the cauase?
- Hematoma beneath the dura (looks crescent shaped)
Bridging vein tear by sudden movement of brain
Slowly progessive neurologic deterioration
What is the zone of injury surrounding an area of complete infarction called?
What are the characteristics of penumbra?
- Partial ischemia and reperfusion
- Delayed cell death vs. viability with or without altered cellular structure or function
- Secondary damage due to inflammation
- Potentially pharmacologically salvageable.
What causes subarachnoid hemorrhages?