Brain injury Flashcards
3 components of intracranial volume
brain tissue (80%)
blood (10%)
CSF (10%)
what is normal ICP
5-15 mmHg
how is cerebral perfusion pressure calculated? what is the average pressure
MAP - ICP
60-80 mmHg
when does cerebral ischemia occur
when CPP < 50
what is the monro-kellie hypothesis
small fluctuations in tissue/fluid volume are compensated for by each other in order to maintain stable ICP
what are the 3 compliances of increasing intracranial pressure
1st compliance: displace, reabsorb, decrease secretion of CSF
2nd compliance: decrease perfusion
final consequence: compression and brain displacement
what is the 2nd ICP compliance limited by
can only decrease to 50 mmHg because after this there will be cerebral ischemia
what are the modifiable components of intracranial pressure
blood and CSF
how is homeostasis maintained within the cranium
the monro-kellie hypothesis
components of cushing’s reflex (triad)
- widening pulse pressure
- irregular breathing
- bradycardia
what is pulse pressure
the difference between systolic and diastolic pressure
what is cushing’s reflex a manifestation of
increased ICP
what is the trigger for cushing’s reflex
cerebral ischemia
what will occur right before death in the event of cerebral ischemia
cushing’s triad
a hematoma will cause loss of function where
- the neural tissue affected (local)
- the part of the body controlled by that area (target site)
what usually causes an epidural hematoma
arterial loss
severed middle meningeal artery
what usually causes a subdural hematoma
venous loss
what are the 3 classifications of hematoma and their locations
intracerebral - within brain tissue
epidural - between cranium and dura mater
subdural - between dura mater and arachnoid mater
which type of hematoma is due to a severed artery
epidural
which type of hematoma is due to a severed vein
subdural
which type of hematoma will result in encapsulation
subdural
encapsulation of a hematoma will lead to what
cell lysis increased concentration of cells cellular efflux dehydration of surrounding brain tissue increased ICP
3 risk factors for hemorrhage/hematoma
HTN
diabetes
aging
non modifiable risk factors for stroke
- aging
- gender
- race
- family history
modifiable risk factors for stroke
- alcohol
- cocaine
- diabetes
- HTN
- hyperlipidemia
- coagulation disorders
- smoking
- heart disease (afib, wall motion defects)
- carotid disease
- obesity
what is a stroke
name and define
cerebrovascular accident
an acute neurologic deficit d/t ischemia
5 sources of cardiogenic emboli
- aortic arch plaque
- atrial fibrillation
- valve disease
- left ventricular thrombi
- cardiogenic emboli
2 complications of hemorrhagic stroke
coma
death
2 concerns of hemorrhagic stroke
increased intracranial pressure
ischemia
ischemic stroke is caused by
an occluded vessel
ischemic stroke will have what identifier
a necrotic core surrounded by a penumbra
a necrotic core will have what types of loss
structural and functional loss
a penumbra will have what types of loss
functional loss, but structurally intact
is a penumbra permanent
no
prolonged ischemia will enlarge the
necrotic core
a severed vessel will cause hemorrhage which will lead to what 3 things
brain compression
increased intracranial pressure
ischemia
a transient ischemic attack is to a cerebrovascular accident as ______ is to myocardial infarction
angina
a transient ischemic attack has what 2 characteristics
- temporary
- reversible
