Neuro- stroke/TIA Flashcards
TIA vs stroke (CVA): what are they both? what is the difference between their timing and reversibility
vascular problem in the brain:
TIA (“mini stroke”): symptoms temporary (<24 hours) w/out permanent brain damage (aka reversible) … but if between 24 hours and 7 days, may only be partially reversible (but >24 hours without resolving = “completed stroke”
CVA: can be evolving or complete. >24 hours- may be irreversible
two main causes/types of stroke, two subcategories of each
ischemic (thrombotic- static/local clot or embolis- moving/distant clot)
hemorrhagic: rupture of artery w/ bleeding into the brain (intracerebral and subarachnoid)
what can cause atrial fibrillation?
stroke
how does an ischmemic (aka artherothrombotic) stroke come about?
stroke caused by an embolis (more often) or thromis
- a “vulnerable plaque” (plaque exposed to bloodstream) ruptures and forms the clot which enters the cerebral vasculature
age, cardiac disease, HTN, hyperlipidemia, polycythemia, and severe anemia are all risk factors for what?
CVA
*anything that causes CVD can cause CVA
what is polycythemia?
increase RBC level
what are the 2 main causes of an intracerebral hemorrhagic stroke?
bleed in the brain: pressure (BP increase) and vascular disease that is bad enough to cause an aneurysm
what is an aneurysm?
An aneurysm occurs when an artery’s wall weakens and causes an abnormally large bulge. This bulge can rupture and cause internal bleeding. Although an aneurysm can occur in any part of your body, they’re most common in the: brain
what causes a subarachnoid hemorrhagic stroke?
bleed between arachnoid and pia or brain:
from pressure on the brain
what are lacunar infarcts?
intracerebral hemorrhage leaves a small area of damage which develops into a “little lake” - lacunae
- these show scattered throughout the brain in white matter
what are two main blood supplies to the brain?
carotid arteries- internal and external
vertebral arteries
-joined in the circle of willis (anastomosis)
what is the difference in supply from the internal vs external carotid?
external: face, thyroid, tongue, pharynx, dura
internal: anterior cerebral, middle cerebral, opthalmic
what is the path of the vertebral arteries? … where do they originate, fuse and divide?
originate- subclavian
fuse- basilar
divide- posterior cerebral
what is the difference in the effects from vascular occlusions (stroke) in the anterior cerebral, middle cerebral and vertebral area?
anterior cerebral: contralateral paralysis (lower>upper)
middle cerebral: contralateral paralysis (lower>upper) and aphasia (dominant hemisphere)
vertebral: visual and labyrinthine (coordination)
what is amaurosis fugax?
opthalmic nerve occlusion that can last minutes to hours
- can come from TIA
what is the clinical presentation of TIA?
amasurosis fugax weakness/paresthesias/hemiplegias dysphasia visual problems/diplopia amnesia episodes ataxia/imbalance/stagger/"drop attacks"
what is considered a “herald of ischemic stroke” and what is the significance of this
TIA, there is an opportunity to intervene (b/c not complete)
A-fib with TIA/CVA? what must you do?
treat and anticoagulate
what drugs would you give for TIA/CVA for plaque stabilization and lipid control?
statins
fresh blood (hemorrhage) shows up well in what kind of imaging?
non-contrast CT
how does an ischemic stroke normally present? what time of day? what kind of pt? symptoms?
often preceded by TIAs, sudden onset and usually progressive
- often at night and pt awakes w/ symptoms
- Loss of consciousness, drowsy, stupor, confused
- pts with high HTN
- focal neurologic deficits (depending on occlusion site)
ischemic stroke in MCA (middle cerebral artery) will effect what parts of the body?
face, upper extremity
dysphasia (if in dominant hemisphere)
nondominant parietal symptoms
ischemic stroke in ACA (anterior cerebral artery) will effect what parts of the body?
lower extremities
ischemic stroke in the PCA (posterior cerebral artery/vertbrobasilar) will effect what parts of the body?
homolateral cerebellar ataxia (lateral medullary syndrome, dyscoordination)
- vertigo, hiccups,sympathetic system
- horner’s syndrome on ipsilateal side
- brainstem syndromes
what is horner’s syndrome?
disruption of a nerve pathway from the brain to the face and eye on one side of the body.
- decreased pupil size
- miosis
- decreased sweating (anyhydrosis)
what are the two way to evaluate a stroke, the two stroke scales?
cincinnati prehospital stroke scale (FAST) or NIH stroke scale
what is the cincinnati prehospital stroke scale?
FAST facial droop arm drift abnormal speech time of the essence
what is the NIH stroke scale?
score 0-34 <6 = minor stroke >20 = major/severe stroke -you can do the most good between 6 and 20 *more universally used scale
what is an atherothrombotic ischemic stroke?
blood clot forms on an atherosclerotic plaque within a blood vessel in the brain and blocks blood flow to that part of the brain
what is the treatment for an atherothrombotic stroke?
- hospital/ER
- tPA if less than 3 hrs into stroke
- unconscious: ABCs, IV, intermittent cath
- slowly reduce BP (it provides perfusion)
- EKG, CT (most important), CBC, BMP
what is tPA? who can you use it on?
tissue plasmanergic activator- clotbuster!
- must be >17 years old
- firm Dx of disabling ischemic stroke
- time of onset < 3hrs
- previously independent function status
- “door to tPA time” = 60 min
contraindications for tPA?
- bleeding risk (like hemorrhagic stroke)
- glucose <60
- recent surgery
- if they are already improving
- not for mild stroke
- can do more harm than good
what is the scary part about using tPA?
increases ICH (intracransial hemorrhage) risk by tenfold
- benefits dissapear beyond 3 hour window, due to this increased risk
- ischemic tissue is fragile
what is an alternative option to treat ischemic stroke beyond 3hour window?
intra-arterial thrombolysis - tPA DIRECTLY into the area where the clot is
*new treatment
ischemic stroke treatment - 4 parts
- hospital
- acute anticoagulation
- platelet inhibition
- physical therapy ASAP once stable
ischemic stroke- long term management
- penumbra areas (shadow adjacent) can recover
- very sudden and severe depression post-CVA
what are penumbra areas in the brain?
Brain cells within the penumbra, a rim of mild to moderately ischemic tissue lying between tissue that is normally perfused and the area in which infarction is evolving, may remain viable for several hours
what is almost always a factor with hemmorrhagic stroke?
HTN
3 types of hemorrhagic stroke
lacunar, parenchymal, subarachnoid
lacunar hemorrhagic stroke: what is it? what areas does it effect? what is vascular dementia?
infarcts small, lesser neuro effects, often transient
- subcortical structures effected
- “vascular dementia” : >40yo w/ uncontrolled HTN, numerous lacunar infarcts over time, mental status fluctuates
parenchymal hemorrhagic stroke: what is it? how does it present? what labs to check?
sudden, severe, fatal
- bleeding, edema
- presents: daytime, severe HA, N/V, LOC, seizures, hemiparesis/neuro signs
- increase ICP (no LP!)
- coag status?
treating hemorrhagic stroke?
stop the bleed
-post stroke treatment- same for any stroke, same as ischemic
subarachnoid hemorrhagic stroke? what is it? how does it present? what do you want to do to determine?
- usually rupture of anuerysm in circle of willis or AVM (arteriovenous malformation)
- thunderclap HA, LOC, seizure
- meningeal sings, fundoscopic bleed, monocular blindness
- inc sympathetic tone (BP and glucose)
- inc CSF (b/c blood adding to it)
- CT to find bleed
why does you have aneurysms in the circle of willis more often than other areas?
branch points of arteries - weak points
-sites around the circle: anterior communicating, posterior communication, basilar, internal carotid, posterior inferior cerebellar
acute care for subarachnoid hemorrhage
- lower BP to lessen bleed but maintain perfusion
- surgical clip or endovascular coil insertion of aneurysm that have bled
- Ca+ channel blocker to prevent vasospasm (longterm prevention)
what is endovascular coiling?
Coil embolization is a minimally invasive procedure to treat an aneurysm by filling it with material that closes off the sac and reduces the risk of bleeding. It is performed from “within” the artery (endovascular) through a steerable catheter inserted into the blood stream at the groin and guided to the brain
what is a “sentinel bleed”? what lifestyle change must you make after one?
subarachnoid hemorrhage- small bleed that gets better but is a sign that there is at very high risk for rebleeding
-control HTN aggressively!
anatomical location of a stroke- where can you do the most good?
middle
