Vascular Neurology Flashcards
4 classes of ischemic stroke
transient ischemic attack (TIA)
reversible ischemic neurologic deficit
evolving stroke
completed stroke
TIA vs. stroke
main difference is in DURATION of symptoms
TIAs usually last a few minutes to less than 24 hours
blockage of blood flow does not last long enough to cause permanent infarction
Why are TIA symptoms transient
reperfusion occurs (either due to collateral circulation or break up of embolus)
Etiologies of TIA
embolic (most common)
but transient hypotension 2/2 carotid artery stenosis (>75% occlusion) can also cause
TIA increases risk for…
STROKE in coming months
10% per year and 30% 5- year risk of stroke
risk factors for ischemic stroke
2 MOST IMPORTANT = age and HTN
others - smoking, DM, hyperlipidemia, afib, CAD, fmaily hx of stroke, PREVIOUS STROKE/TIA, carotid bruits
risk factors for stroke in younger patients
OCP use hypercoagulable states (protein C/S def, APA syndrome, cocaine/amphetamines, polycythema vera, sickle cell
transient, curtain like loss of sight in ipsilateral eye due to microemboli to the retina
amaurosis fugax (example of TIA)
common sources of emboli that cause stroke
heart (mural thrombus from afib)
internal carotid artery
aorta
paradoxical stroke (ASD, patent foramen ovael, pulmonary AV fistula)
thrombotic strokes occur due to atherosclerotic plaques in which arteries typically
large arteries of neck (carotid artery usu. at bifurcation of common carotid)
medium sized arteries of brain; i.e. middle cerebral artery MCA)
where do you typically see lacunar strokes
in small vessels of brain
usually affects subcortical structures (basal ganglia, thalamus, itnernal capsule, brainstem)…NOT CORTEX
how to evaluate for source of embolic stroke
echocardiogram
carotid doppler
ECG, holter monitoring
predisposing factors for lacunar stroke
hx of HTN!
DM also important risk factor
symptoms of vertebrobasilar arterial insufficiency
dizziniess, double vision, vertigo, numbness of ipsilateral face and contralateral limbs, dysarthria, hoarsness, dysphagia
caused by decreased perfusion in posterior fossa
subclavian steal syndrome
stenosis of subclavian artery proximal to origin of vertebral artery - exercise of left arm causes reversal of blood flow down the ipsilateral artery to fill the subclavian artery distal to stenosis because it cannot supply adequate blood to left arm; leads to decreased cerebral blood flow “stolen” from basilar system
BP in left arm is less than right arm; decreased pulses in left arm
subclavian steal
treatment for subclavian steal syndrome
surgical bypass
stroke with contralateral lower extremity and face
ACA
stroke with aphasia, contralateral hemiparesis
middle cerebral artery
dizziness, double vision, numbness of ipsilateral phase, contralaterla limbs, dysarthria, hoarseness, dysphagia, projectile vomiting, headahces, drop attacks
vertebrobasilar system
pure sensory deficit
thalamus
pure motor hemiparesis
internal capsule
alexia without agraphia
left PCA
patient presents to ED with stroke like symptoms…what to do and in what order
1) non contrast CT head
2) ECG, chest radiograph
3) CBC, plts
4) PT/INR
5) electrolytes
6) glucose
7) bilateral carotid ultra sound
8) echocardiogram
how do ischemic strokes look on non contrast CT?
dark area
If you suspect stroke, but CT negative…what other test can you order?
MRI
more sensititive but no ideal in emergencies
What labs to order in YOUNG patient with stroke
high suspicion for vasculitis, hypercoagulable, or thrombophilia
get: protein c, protein s, antiphospholipid antibodies, factor V leiden mutation, ANA/rheumatoid factor, ESR, VDRL/RPR, Lyme serology, TEE
DON’T FORGET COCAINE NIGGA
definitive test for identifying stenosis of vessels of head and neck, and check for aneurysms
magnetic resonance angiogram (MRA)
evaluates carotids, vetebrobasilar circulation, circle of Willis, ACA, MCA, PCA
complications of stroke (3)
cerebral edema within 1-2 days -> mass effect
seizure
hemorrhage into infarction
When not to give TPA
- more than 3 hours have passed
- uncontrolled HTN
- bleeding disorder
- patient is taking anticoagulants
- hx or recent trauma or surgery
these all increase risk for hemorrhagic transformation
If patient presents after 3 hours of stroke, what to give?
if patient can’t take that, what else to give?
aspirin only!
if not, clopidogrel
if not, clopidogrel….ticlopidine
if patient is given TPA, what else can be given to reduce bleeding risk?
antihypertensives!
do NOT give aspirin (this will make bleeding worse)
When to give warfarin/heparin for stroke
these haven’t been proven effective in acute setting
antihypertensives are typically not given in stroke unless….
1) super high BP (>220/120)
2) patient is receiving tPA
3) acute MI< aortic dissection, severe heart failure, hypertensive encephalopathy
indications for carotid endarterectomy in preventing stroke in the setting of carotid artery atherosclerosis
1) symptomatic
2) >70% occlusion
how to prevent carotid atherosclerotic strokes in NON-symptomatic patients
aspirin, BP control, control DM, smoking cessation, reduce obesity and hypercholesterolemia
how to prevent embolic strokes
aspirin, warfarin/NOACs if afib, reduction of atherosclerotic risk factors
how to prevent lacunar stroke
HTN control
causes of hemorrhagic stroke
1) HTN, particularly sudden increase
2) ischemic stroke converting to hemorrhagic stroke
3) amyloid angiopathy, iatrogenic (anticoag/antithromb use), brain tumors, AVMs)
locations of hemorrhagic stroke
basal ganglia (MOST COMMON)
pons
cerebellum
how to hemorrhagic strokes present
sudden focal neurologic deficit
altered levels of consciousness, stupor/coma
headache/dizziness/vomiting from increased ICP
in addition to noncon CT head, what panel to get in evaluating for hemorrhagic stroke
coag panel
complications hemorrhagic stroke
increased ICP rebleeding seizure hydrocephalus SIADH vasospasm
In ICH, what pupillary findings can be seen if pons, thalamus, and or putamen involved?
pons - pinpoint pupils
thalamus - poorly reactive pupils
putamen - dilated pupils
how to acutely manage hemorrhagic strokes
ICU admission
ABCs NIGGA DAYUM
BP control
reduce ICP with mannitol/diuretics and hyperventilation
Dangers with aggressive BP control in hemorrhagic stroke
correcting too quickly can reduce CPP which will worsen neurologic deficit
Is surgery helpful for ICH?
not usually, treatment usually supportive for intraparenchymal bleeds
DO IT FOR CEREBELLAR BLEEDS THOUGH, they can be life saving
subarachnoid hemorrhage (SAH) often occurs at junction of anterior communicating artery and…
ACA
SAH often occurs at bifurcation of….
MCA
SAH often occurs at junction of posterior communcating and….
internal carotid
SAH’s HAPPEN AT JUNCTIONS…see the pattern?
Where can you typically find berry/saccular aneurysms?
bifurcations
If you see a patient with polycystic kidney disease, you should check for…
BERRY ANEURYSMS
MCC SAH
berry aneurysm rupture
can also be caused by trauma/AVMs
besides “worst headache of my life” how can SAH present?
sudden LOC vomiting meningismus (photophobia/nuchal rigidity/meningeal irritation) retinal hemorrhage death
First test for SAH….and if this is unrevealing, what to get?
non con CT
LP to look for blood in CSF/xanthochromia
once SAH is diagnosed, what test to get?
cerebral angiogram to detect bleeding source (and for surgical clipping)
If suspect SAH, CT negative, and there is papilledema, what test to get?
NOT LP!!! YOU CAN CAUSE HERNIATION
repeat CT first
contraindications for LP
herniation infection overlying puncture site bleeding disorder/coagulopathy brain abscess increased ICP (do imaging first) mass lesion (do imaging first)
treatment SAH
CONSULT NEURO
non surgical rx SAH
reduce rebleeding risk and cerebral vasospasm
- bed rest
- stool softeners to reduce straining
- analgesia for headache
- IV fliuds
- gradual lowering of BP
what pharmacotherapy to prevent cerebral vasospasm
nifedipine
5 “deadly D’s” of posterior circulation strokes?
Diplopia dizziness dysphagia dysarthria drop attacks + vertigo
can also cause homonymous hemianopsia
MCA strokes can cause CHANGes.
What CHANGes?
Contralateral paresis and sensory loss in face/arm Hemiparesis Aphasia (dominant) Neglect (non dominant) Gaze preference toward side of lesion
