ICL 10.6: Stroke Flashcards
what is a stroke?
a sudden onset of neurological deficit caused by alteration in blood flow to a portion of the brain
what is a TIA?
transient (<24 hours) focal symptoms and neurological deficits secondary to ischemia
most resolve in within 60 minutes – if it doesn’t, it usually transitions into a stroke
what are the 2 subtypes of strokes?
- primary ischemic (80%)
- primary hemorrhagic (20%)
less common but has a higher mortality rate
what are the 2 types of hemorrhagic stroke?
- subarachnoid hemorrhage
2. intracerebral hemorrhage (in the parynchamal tissue)
what usually causes a subarachnoid hemorrhage?
- Berry aneurysm rupture
- fusiform aneurysms can also cause SAH but those are usually from hypertension
- mycotic aneurisms are usually from an infectious source
25% mortality, usually effects women more than men, over 50 years old
usually solitary so it’s just one aneurism
what is the location of most aneurysms?
- anterior communicating artery
- posterior communicating artery
- middle cerebral artery
how can you treat an aneurism?
- surgically by opening up the skull and clipping off the aneurism
- interventional by going in with a catheter and filling the aneurism with coils
what are the causes of intracerebral hemorrhage?
- hypertension**
- cerebral amyloidosis
- arteriovenous malformation (AVM)
- medications
- illicit drugs
hypertension related intracerebral hemorrhages are usually located in what parts of the brain?
- putamen-claustrum
- cerebral white matter
- thalamus
- pons
- cerebellum
what is the big problem with intracerebral hemorrhages in the posterior fossa?
they’re not very forgiving, the fossa doesn’t have that much space and it’s really contained so whenever you have a bleed or stroke causing ICP, you have high risk of herniation
what are the types of ischemic stroke?
- embolic/thrombotic
- large vessels disease
- small vessel disease
- other
- unknown
what is an embolic stroke?
blockage of a blood vessel by material that originated elsewhere
can be cause by atrial fibrillation, air, amniotic fluid, fat paradoxical, or aortic atheroma = plaque in the aorta
which artery is most frequently effected by embolic stroke?
middle cerebral artery
what is a paradoxical emboli?
patent foramen oval is an opening between the left and right atrium
if someone has a DVT in the leg or arm, it can break loose and travel to the right atrium then pass over through the PFO to the left atrium and then go up and cause a stroke in the brain via the aorta, carotid artery, vertebral artery etc.
most people with DVTs end up with a PE but it’s a possibility that the DVT could cause a stroke
what is a large vessel occlusion strokes?
a type of ischemic stroke that is caused by occlusion of large vessels
the symptoms are often fluctuating because even though the large vessel is occluded, you have collateral flow that is trying to compensate for this
75% are in the anterior circulation because of the carotid while only 25% are in the posterior like the vertebral artery