Pathophysiology Of TBI Flashcards
Which type of brain edema leads to extracellular edema and which leads to intracellular edema?
Vasogenic edema leads to extracellular edema
Cytogenic edema leads to intracellular edema
What 2 neurotransmitters are involved in TBI that leads to excitotoxicity
Glutamate and potassium
Vasogenic edema is due to…
Protein rich fluid leaving damaged blood vessels in the brain and causing fluid to accumulate extracellularly
What do you see on MRI that indicates DAI
White matter petechial hemorrhages
How is brain swelling seen on CT?
Collapse of ventricles and loss of CSF cisterns
What causes the white matter changes characteristic of DAI?
Injury to axons with increased permeability of axons leading to calcium influx and cytoskeletal abnormalities
When does secondary injury occur after TBI?
<24 hours to days
Grade 1, 2 and 3 of DAI
Grade 1 = widespread damage with no focal findings.
Grade 2 = widespread damage with focal findings, most commonly the corpus callosum
Grade 3 = damage to brainstem
When does primary injury occur after TBI
Minutes to hours after impact
Plasticity occurs via 2 mechanisms
Collateral sprouting and functional reorganization/unmasking neural reorganization)
(PUN: Plasticity = Unmasking + Neuronal sprouting
Epidural hematoma results from injury to what vessels
Middle meningeal artery or veins
2 types of brain edema
Vasogenic and cytogenic
What kind of shearing forces cause DAI
Acceleration-deceleration forces and rotational forces
_____________ is the process by which neuronal damage occurs as a result of a massive surge in _______________
Excitotoxicity; Neurotransmitters
Subarachnoid hemorrhage results from injury to what vessels
Ruptured aneurysms and AVMs
Focal ischemia after TBI occurs secondary to…
Vasospasms
3 most common locations for DAI in the brain
- Corpus callosum
- Central white matter
- Midbrain
Subdural hematoma results from injury to what vessels?
Bridging veins
2 most common locations for brain contusions from a TBI
- Inferior frontal lobe
2. Anterior temporal lobe
Damage to one region of brain can produce altered function in other areas of the brain that were not severed
Diaschisis
What chemical process directly causes cell death after TBI
Increase in calcium influx
Brain swelling vs edema
Swelling = increase in blood volume; occurs within 24h Edema = increase in brain water; occurs after swelling
Is diffuse axonal injury considered primary or secondary injury?
Primary
Most common cause of unconsciousness during and following the first 24 hours TBI
Diffuse axonal injury
Subdural shape seen on CT
Concave/crescentic mass
Capability of damaged brain to repair itself by means of morphological and physiologic responses
Plasticity
Shape of Epidural hematoma seen on CT
BiConvex mass
