Ch. 10 - Stroke Flashcards
Stroke definition
sudden neuro deficit 2/2 vascular etiology lasting > 24 hrs
TIA definition
transient neuro deficit lasting < 24 hrs
Stroke types
ISCHEMIC (infarct) vs HEMORRHAGIC vs both
Primary stroke prevention
lifestyle modification and treatment of risk factors in pt without cerebrovascular sx
Stroke risk factors
smoking, HTN, diabetes, heart dz (a fib), hypercholesterolemia, age, males, smoking
most common cause of cardiogenic cerebral infarct
non-valvular atrial fibrillation
treatment of atrial fibrillation
warfarin with INR 2-3 for pts 60+, ASA adds moderate benefit
Secondary stroke prevention
tailored to underlying stroke pathology including antiplatelet therapy, warfarin, CEA, and stenting
ASA mechanism
irreversible inhibition of platelet cyclooxygenase (no thromboxane for plt aggregation)
clopidogrel mechanism
inhibits platelet ADP (receptor that activates plt aggregation)
- small ARR compared to ASA but more expensive = second line
- can combo with ASA
dipyridamole mechanism
inhibits PDE, maintaines high levels of cAMP/cGMP to prevent platelet activation
- can combo with ASA
CEA indications
beneficial for pts with > 70% stenosis
TIA work up
CT, carotid doppler, ECG, +/- echo within 24 hrs
amaurosis fugax sx
transient monocular blindness “shade pulled over one eye”
MCA occlusion
contralateral hemiplegia (arm > leg), hemianesthesia, homonymous hemianopia, aphasia, inattention, cortical sensory loss
ACA occlusion
hemiparesis (mostly leg)
PCA occlusion
homonymous hemianopia, disconnecting syndromes, hemianesthesia, amnesia, midbrain/thalamic syndromes
vertebrobasilar thrombosis
quadriparesis, bulbar paralysis, impaired gaze, cortical blindness, coma
ventral pontine infarct
quadriparesis, bulbar paralysis, absent horizontal gaze, normal consciousness, “locked in” syndrome
lateral medullary syndrome
ipsilateral ataxia, horners syndrome, nystagmus, facial numbness, CN9/10 palsy, contralateral spinothalamic loss
lacunar infarcts most likely secondary to
HTN causing ‘lipohyalinosis’
most common cause of cardiogenic embolism
non-valvular arterial fibrillation > valvular heart dz, MI, post cards surgery, prosthetic valves, endocartis, atrial myxoma
Types of cerebral hemorrhage
intracerebral vs subarachnoid hemorrhage
risk factor for intracerebral hemorrhage
HTN –> charcot-bouchard microaneurysms
lobar hemorrhage
superficial vascular rupture w/i cerebral lobes
risk factor for lobar hemorrhage
amyloid angiopathy
Principles of stroke management
early recognition, rapid transport to tx facility “time is brain”, early triage/imaging, assess for thrombolysis, monitoring in stroke unit
ddx stroke
cerebral tumor, subdural hematoma, abscess, migraine, metabolic disturbances, epilepsy
all patients with suspected stroke need a…
CT or MRI. MRI better at identifying acute ischemia and just as good at ID’ing hemorrhage
Do you ever LP a suspected stroke patient?
yes if negative imaging and you suspect meningitis or SAH
Major difference in treatment: ischemic vs hemorrhagic stroke
ischemic stroke = indication for thrombolysis. hemorrhagic stroke = absolute contraindication
clinical factors important for tPA administration
ischemic stroke, given w/i 3 hours of stroke onset
most common site of cerebral infarct
middle cerebral artery. classified as cortical or deep
difference between cortical or subcortical infarcts
subcortical = deep perforating vessels supplying internal capsule, thalamus, basal ganglia and brainstem
lacunar infarct
occlusion of single perforating vessel <1.5 cm, assoc. w/ htn
classic lacunar infarct presentations
pure motor hemiparesis, pure sensory stroke, sensorimotor stroke, ataxic hemiparesis and dysarthria/clumsy hand
classic cortical infarct presentations
dysphasia, apraxia, anosognosia, sensory/motor/visual agnosia, acalculia, right/left confusion, dysgraphia, cortical sensory loss (2 pt discrimination, astereognosis, dysgraphasthesia)
apraxia
difficulty with motor planning to produce speach
dysphasia
inability to comprehend/form speech
anosognosia
denial of stroke
agnosia
inattention
acalculia
inability to perform simple arithmetic
dysgraphia
inability to write
dysgraphesthesia
inability to perceive what is written
astereognosia
inability to id object by touch
presentation of hemorrhagic stroke
rapid onset of stroke w/ early depression fof conscious state
work up of stroke patient
- blood glucose
- ECG - a fib, acute MI (causes of thromboemboli)
- CT brain = MRI, also consider MRA/CTA
- duplex doppler (less urgent)
dedicated stroke units have reduced mortality by __%
25%
initial management of a stroke
- monitoring vitals/neuro/cardiac status
- ASA (if no tPA)
- ID prior fxnal status and current deficits
- early mobililization/ROM
- aspiration precautions - drop NG if dysphagic
- basic precautions: prevention of DVT, pneumonia, bed sores, UTI
what hemodynamic instability is tolerated during acute stroke?
hypertension is common and settles over 2-3 days. avoid hypotension = decreased cerebral perfusion
preferred fluid for acute stroke
NS. avoid glc containing fluids (hyperglycemia)
most common cause of mortality in stroke patients by week
week 1: transtentorial herniation
week 2: secondary systemic factors
week 3: pneumonia, PE, cardiac
progressive deteriorating neuro deficit seen in what percent of stroke population? 2/2 to what?
33% caused by cerebral edema. NOT helped by corticosteroids, no evidence for mannitol, hemicrani may help some
when is heparin indicated following a stroke?
pt at high risk for recurrent embolism, otherwise risk of hemorrhagic transformation too risky
when is neurosurgical intervention indicated?
cerebellar hemorrhage, young patients with lobar hemorrhage = possible evacuation
subacute follow up of stroke
- Tx underlying cause: warfarin @ 1w for a fib, CEA for carotid stenosis
- REHAB
Rarer causes of strokes, usually younger adults
migraine, OCPs, mitral valve prolapse, vasculitis, extracranial arterial dissection, fibromuscular dysplasia, moya-moya dz, hypercoagulability
work up of rarer causes of stroke
angiogram, TEE, LP, hematologic investigation
migraine-induced stroke presentation
pt with persistent neuro deficit following classic migraine. dx of exclusion
OCP-induced stroke presentation
estrogen containing OCPs (hypercoag). dx of exclusion
rare cardiac associated with stroke in young pt
mitral valve prolapse/PFO, req TEE to tx
causes of cerebral vasculitis
polyarteritis nodosa, granulomatous angiitis, giant cell arteritis, heroin/amphetamines/cocaine, TB/syphilis, opthalmic herpes zoster
lab/imaging findings of vasculitis
beading of arteries on angiography, lymphocytosis in CSF, elevated ESR
FMD
females, assoc. with renal FMD, increased risk of berry aneurysms/dissection. Tx w/ aspirin
moya moya
obliterative arterial condition = fine telangiectatic web of anastamotic intracranial vessels = “puff of smoke” appearance on angio. Tx with revascularization
hypercoagulable states assoc. with stroke
lupus, activated protein C resistance, deficiencies in protein C/S
cerebral venous thromboembolism presentation
insidious HA, papilledema –> hemiplegia, drowsiness, fever, seizures, meningismus in hypercoagulable state (post partum, OCPs, lupus) or in pts with infxn
carotid artery dissection presentation
neck pain, eye pain and horner’s syndrome
Indications for carotid endarterectomy
Symptomatic carotid stenosis of 70-99% and life expectancy of at least 5 years PLUS
- surgically accessible lesion
- absence of clinically significant comorbid conditions
- no prior ipsilateral endarterectomy
