3.28 Stroke Flashcards
2 types of strokes
- ischemic
- hemorrhagic
Which type of stroke accounts for 80% of all strokes?
ischemic
ischemic strokes occur because of
blockages
types of blockages
- embolytic
- thrombotic
embolytic blockage
- caused by an embolus
- travels to the spot of occlusion in the brain
types of emboli
- fat
- blood clot
- plaque
- air
fat embolus can happen when?
- post-surgery
- massive injury with bony damage
Where does the blood clot embolus from a DVT go?
DVT from the leg (usually goes through to the lungs)
Who gets blood clot emboli that could cause an ischemic stroke?
pts with ectopic heartbeat or a-fib
Why are a-fib pts susceptible to ischemic stroke?
- blood hangs out in the heart
- get asynchronous pumping
What can help determine where a stroke is?
ECG (echocardiogram)
How can plaque cause a stroke?
- from arteries
- can be caused during an angioplasty
Where does plaque buildup that causes a stroke start?
carotid arteries
What is the procedure where plaque is removed from the carotid arteries?
carotid endartectomy
How does an air embolus cause a stroke?
air in IV or syringe that gets pushed through the artery
What is a thrombotic ischemic stroke?
- caused by a thrombus
- grows in spot of occlusion - brain
What does TPA stand for?
tissue plasminogen activator
What type of stroke is the best type to get and why?
- embolytic stroke from a blood clot
- can be given TPA to break it up
What is TPA?
super duper blood thinner that can dissolve a clot
downfall to taking TPA?
high bleed risk
When does TPA need to be started?
- within 3-4 hours of the first symptom
- after 3 hours, the damage has been done
What must be confirmed before giving TPA?
must be sure it’s an ischemic stroke from a clot
signs of stroke
FAST = face, arms, speech, time
Where does stroke usually occur?
MCA
Why is TPA such an important drug for stroke?
can make a huge impact “miracle drug”
What type of stroke accounts for 20% of all strokes?
hemorrhagic
What causes a hemorrhagic stroke?
bleed in the brain (not inside an artery anymore)
- artery is damaged
- accident can create a tear that bleeds
Hemorrhagic strokes are usually caused by
aneurysms
Where do most aneurysms happen?
in the Circle of Willis
Why is the Circle of Willis susceptible to aneurysms?
vessels come together at almost 90˚
- blood flow deflected, can get blockage
- high risk for extra pressure
- artery wall weakens, blood pushes in and pouches
What kinds of “shapes” an aneurysms make?
- ball/bubble
- dissection
Ball/bubble aneurysms usually occur here
in the brain
Dissection aneurysms usually occur here
large vessels (i.e. abdominal aorta)
Major risk factors for aneurysms
- long term HBP
- valsalva in HBP pt may jump BP and cause aneurysm to rupture
Berry aneurysm
- runs along the Circle of Willis
- looks like a raspberry
Why do we not know we have an aneurysm until it ruptures (typically)?
- bleeds until pressure builds up - nowhere else for it to go
- enough pressure stops the blood flow
What will be done if an aneurysm is bad enough?
craniotomy
- aneurysm is clipped
result in brain tissue of clipping an aneurysm
brain tissue distal to the aneurysm dies: body reabsorbs the tissue
AVM
arteriovenous malformation
What is an AVM?
congenital defect that can result in stroke
- poor blood flow
- weakened walls
- increased pressure occurs » ruptures
Percentage of AVMs that rupture
50%
preventative craniotomy
clip (fix) aneurysms before they rupture
Why would a coiling procedure be done?
aneurysm creating strokelike symptoms because it’s pushing on other tissues
What is coiling?
- catheter through femoral artery to the aneurysm in the brain
- make a bird’s nest of wire inside the aneurysm
- fills space so that blood isn’t going into it anymore
What is the result of a coiling procedure?
- body eventually heals up over it and encapsulates the wire
- restores blood flow
