Trauma Flashcards
Dura mater
appreciate that shit
subdural vs epidural spaces
Appreciate that shit
Subarachnoid vs Subdural space
Appreciate everything!!!
What is responsible for draining CSF in the meningeal layers of brain?
arachnoid granulations
Be able to recognize the Falx and Tentorium cerebri and sinuses
know these
Be able to identify Uncus
And uncal herniation
Appreciate anatomy around tonsil of cerebellum
see image
“Blood-brain neurovascular unit”
- Site of BBB: ___________
- Tight intercellular junctions (non-permissive compared to systemic endothelial cells)
- Endothelium has low _______ & basement membrane
- Dynamic interaction of endothelium with _______
brain capillary endothelium
pinocytotic rate
astrocytes & pericytes
What diffuses freely and what requires active transport to get across teh BBB?
- Small substances & small lipophilic molecules freely diffuse through membrane
- Large substances & hydrophilic molecules require active
Defined as an accumulation of excess fluid in intracellular or extracellular spaces of the brain
Cerebral edema
*see increased intracranial pressure d/t variety of processes & associated with significant
morbidity/mortality
What are the two types of cerebral edema?
What does it look like grossly?
vasogenic and cytotoxic edema
flattened, widened gyri with narrowed sulci
See disruption and increased permeability of BBB: see a shift of fluid form the INTRAvascular –> Extravascular compartment
Vasogenic edema = Extracellular edema
What part of brain is effected by vasogenic edema? What are causes?
White matter affected
primary or secondary brain tumors, abscesses, contusions, intracerebral hematomas
What are the three mechanism for Vasogenic (extracellular) edema
- Newly formed vessels (in tumors) deficient in tight junctions
- Production of vascular endothelial growth factor (VEGF) by tumor cells
- Production of inflammatory mediators, chemokines, cytokines, and other growth factors
What features are typical of vasogenic edema?
What therapy does vasogenic edema usually respond to?
Flattened gyri/narrow sulci with compressed ventricles and soft brain
will respond to coticosteroids and anti-VEGF!!!
(picture is glioblastoma with vasogenic edema)
Explain how a brain tumor like glioblastoma results in vasogenic edema
Have extensive angiogenesis w/ microvascular proliferation, poorly formed BBB
end up with extensive vasogenic edema and mass effect
How can we get a clear idea of the extent of cerebral edema in a pt through imaging?
T1 will give us good idea of location of lesion
T2 really highlights extent of edema
What are some consequences of vasogenic edema as it’s responding to insult?
can see right to left or left to right shifts
get mass effect
get herniations
- Occurs secondary to cellular energy failure
- Results in shift of water from EXTRA–>INTRACELLULAR compartment
Cytotoxic edema “intracellular”
Where in brain do we see Cytotoxic edema and what causes the intracellular swelling?
GRAY matter
ntracellular swelling - large amounts of sodium enter cells, water follows
Most common causes of cytotoxic edema and mechanism
Most common causes: ischemia/infarct, meningitis, trauma, seizures, hepatic encephalopathy
• Mechanisms: dysfunction of neuronal and astrocytic membrane pumps (caused by excess glutamate, extracellular potassium, inflammatory cytokines, etc.),
Increased intracranial pressure
The brain is in a closed rigid box
Brain volume =
Increased volume =
Brain volume = Brain + blood + CSF (+ lesion)
Increased volume = increased pressure
Increased pressure leads to :
_______ dictate what type of herniation
decreased perfusion and/or herniation syndromes
Rigid dural folds (falx, tentorium)
The cingulate gyrus herniates under the falx d/t an ASYMMETRIC expansion of hemisphere lesions
Subfalcine Hernation
What vascular stuctures are compromised in a subfalcine hernation?
May compress the anterior cerebral artery–> leading to infarct
Medial temporal lobe displaced through the tentorial opening because of asymmetric expanding lesion
Transtentorial Uncal Herniation
What four complications can we see d/t Transtentorial Uncal Hernation?
- Ipsilateral IIIrd nerve compression + pupillary dialation
- Compression of brainstem (midbrain peduncle containing corticospinal tracts) on tentorial edge opposite direction of hernation
- PCA compression
- Duret hemorrhage
Why do we see Ipsilateral cranial nerve III compression in transtentorial hernation?
Tentorium firmly attached to skull, midbrain pushes down from above and compresses 3rd nerve (oculomotor)
**see pupillary dilation bc pupillary constrictor fibers are on the surface of 3rd nerve.
You pt comes in with a Babinski sign on the left side. Your preceptor suspects hernation based on imaging she saw. Where would the herniation be located?
what other symptos would you see?
Why was there a babinski sign
Called Kernohans notch; seen in Transtentorial uncal hernation
babinski shows up IPSI to the lesion and is result of compression of midbrain from hernation aove the opposite cerebral peduncle being pushed against opposite free edge