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54 Cards in this Set
- Front
- Back
What non-modifiable risk factors have been associated with stroke?
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Advancing age (independent factor)
Hypertension (#1 based on prevalance) Hx of TIA Atrial fibrillation associated with valvular dz increase risk the most, non-valvular afib less so |
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What is the most common cause of ischemic stroke?
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Cardiogenic embolism
small penetrating arterial dz (lacunar infarct), large artery dz and cryptogenic stroke |
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What is the yearly mortality associated with all strokes?
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25%
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Discuss the 30-day mortality rate of thrombotic and embolic stroke.
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Embolic rate is higher then thrombotic due to the propensity to have further emboli in the brain.
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What is the major underlying pathology associated with extracrainal/larger arteries in the brain?
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deposition of lipid in the subendothelium (arterio/atherosclerosis) leading to ectasia and stenosis of arteries
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What is ectasia?
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vascular enlargement
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What is a lacune?
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small subcortical infarction associated with lipohyalinosis (lipid dep), disruption of arterial wall and fibrinoid necrosis of penetrating arteries. Most frequently occuring and most benign brain infarction.
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What is the appearance of ischemic infarcts on CT?
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Low density (hyodense)
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What are early signs of infarction frequently noted on CT?
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effacement of cortical sulci, or loss of cortical ribbon (area between frontal/temporal lobes) definition
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How do infarcts appear on MRI?
T1? T2? |
MRI infarcts appear as low signal or dark (hypointense)
on T1 weighted images. On T2 weighted images appear bright (high signal). On DWI very bright |
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What is ischemic penumbra?
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Salvageable hypoperfused areas of the brain circrumscribing the necrotic area....detected with perfusion weighted imaging
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What clincal syndromes are associated with occlusion of the middle cerebral artery?
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1. hemiparesis
2. hemisensory loss 3. language deficit (w/left hemisphere involvement) 4. spatial/visual neglect (w. right hemishpere involvement) |
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What clincal syndromes are associated with occlusion of the anterior cerebral artery?
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weakness involving contralateral leg (least frequent)
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What clincal syndromes are associated with occlusion of the posterior cerebral artery?
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contralateral hemianopsia (visual field loss)
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What clincal syndromes are associated with occlusion of the verterbral-basilar arteries?
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vertigo, dysarthria, diplopia, ataxia, hemiparesis, hemisensory changes
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Discuss syndromes associated with lacunar infarct?
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1. pure motor hemiparesis
2. pure sensory loss 3. ataxic-hemiparesis 4. dysarthria-clumsy hand syndome lacunar infarcts are due to occlusion of small subcortical penetrating arteries. |
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What symptoms are associated with multifocal and bilateral lacunes?
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1.multi-infarct dementia
2. gait disorders 3 dysarthria * This triad is called the lacunar state |
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What is the treatment/ work-up for ischemic stroke?
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1. MRI, MRA, DWI, carotid dopplers
2. Echocardiogram (to rule out cardiac source) *look for PFO in young- a common cause of stroke from paradoxical embolus 3. Treatment of risk factors 4. *IV heparing anitcoagulation. |
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Define crescendo TIAs.
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multiple Transient ischemic attackes occuring in a short period of time.
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What is the benefit of IA rtPA versus IV tPA?
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Intraarterial extends the window in which tPA can be administered to 6 hours for anterior circulation and 12 hourst for posterior circ.(brainstem)
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What is the MERCI device?
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A clot retrieval device that can be used withing 8 hours of the onset of ischemic stroke.
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What patients should be considered for CEA (Carotid Endarterectomy)?
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Patients with non-disabling infarcts that have symptomatic (stroke or TIA) internal carotid artery stenosis of > 70%, non-symptomatic the cutoff is 60% occlusion
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Define "malignant" MCA Infarction? What is the treatment?
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Hemispheric MCA infarct with significant edema. Tx: Hemicraniectomy with duroplasty or dehydrating osmotic agents (mannitol)
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T/F CEA immediately following acute stroke is contraindicated?
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T. Surgical cannulation of a thrombosed ICA following a cerebral infarction could lead to hemorrhagic conversion of bland infarct with resultant mass effect.
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T/F carotid bruit is not neccessarily essential for Dx of carotid stenosis.
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Presence of carotid bruit may indicated stenosis, but absence can indicate patency or highly stenosed vessel permitting very little flow.
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How does one effictively prophylax against thrombotic stroke?
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Antiplatelet agents
1. aspirin 2. Clopidogril (Plavix) 3. Aggrenox (combo of dipyrimadole and aspirin) |
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From where do brain emboli arise?
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Cardiac sources (a-fib, mural thrombi, infective endocarditis)
Non-cardiac sources (artery-artery embolus from any atherosclerotic source) Annuerysms...cardiac dissection |
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Where are most brain emboli localized?
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Middle cerebral artery (MCA) affecting primarily cortical areas
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Discuss the pathophysiology of hemmorrhagic conversion of ischemic stroke.
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Emboli may break up after a brain infarction permitting reperfusion and hemmorrahgic infarction (hemorrhage will be high density white on CT scan)
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What is the treatment for embolic infarction? What about embolic infarction secondary to carotid dissection.
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Anticoagulation with IV heparin followed by warfarin for Embolic Stroke. Carotid dissection pts are anticoagulated for 6mos and converted to an aspirin/day.
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What are the two causal pathologies associated with primary intracerebral hemorrhage?
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Hypertension and cerebral amyloid angiopathy (CAA).
*CAA is frequently associated with lobar hemorrhage. |
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What are the four most common sites affected by hypertensive Intracerebral hemorrhage?
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Thalamus
Basal ganglia (putamen) pons cerebellum |
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What three factors determine the outcome of intracerbral hemmorhage?
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1. Size of hemmorhage (>60cc has a 70-80% mortality)
2. Location (deeper lesions are worse) 3. Initial clinical presentation |
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How is ICH treated?
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maintainenance of blood systolic pressure between (150-160mHg)
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For what types of hemorrhages is surgical evacuation indicated?
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Lobar or superficial, Surgical evacuation will reduce the mass effect
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True/False. Surgical evacuation is indicated for deep hemorrhages in the left hemisphere?
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False. Surgical evacuation in the dominant hemisphere may lead to speech difficulties. It is seldomly efficacous in deep hemorrhages.
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Discuss the pathophysiology of subarachnoid hemorrhage (SAH)?
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Saccular annuerysm ("berry")...occuring most often in women ages 40-60.
Less commonly (AVM) arteriovenous malformations as they bleed intraparenchymally young patients (not into the Sub arachnoid space). Typically present as the "worst headache of my life" |
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What are the three most common sites for saccular annuerysms?
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1. Junction of ICA and 1.Posterio communicating arteries
2.ACoM a 3.MCA 4.PICA (posterior internal carotid) |
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What is xanthochromia?
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yellow-tinged appearanec of CSF due to breakdown of blood products...usually seen in SAH
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T/F. A normal CT scan rules out Subarachnoid hemmorrhage.
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False. LP should be performed as xanthochromia is typically present 6 hours after SAH.
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What are secondary complications of SAH?
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1. Rebleeding (clipping or coil embolization reduces risk)
2. Vasospasm or (DCI) delayed cerebral ischemia- due to irritation of vasculature by metabolic products of blood |
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What is the treatment for SAH?
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Nimodipine (oral Ca channel blocker)...prophylaxis for vasospasm.
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For what pathology is treatmemnt "triple-H" indicated?
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Vasopasm. 3H (hypertension, hemodilution and hypervolemia) instituted to restore or aid perfusion
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What vasculopathies are frequently associated with brain infarctions and TIA's?
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dysimmune vasculopathies such as SLE, thrombotic thrombocytopenic purpura and antiphospholipid antibody syndrome.
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What symptoms are frequently associated with TIA's?
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Aneterior
Transient aphasia, dysarthria, numbness/weakness on one side of the body, loss of vision in one or both eyes Posterior diploplia, vertigo |
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Define aphasia.
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language difficulty
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Define dysarthria.
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slurred speech
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Define amaurosis fugax & hemianopsia.
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loss of vision in one or both eyes respectively.
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True/False. Loss of consciousness are frequently associated with TIA's.
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False. Loss of consciousness is rare with TIA's
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True/False. Cardiac Emboli are rarely causal for TIA's.
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True.
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Why is TIA considered a medical emergency?
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5% of patients have a stroke within 2days of TIA onset. 10% have strokes within 90days after onset.
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How is TIA treated?
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Dependent upon etiology...if carotid artery stenosis (70%) CEA is recomended. Otherwise anticoagulation with warfarin or antiplatelet therapy (aspirin, clopidogrel or aggrenox) reduce recurrence of TIA or stroke.
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True/False. Low dose of alcohol is neuroprotective against stroke.
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True.
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True/False. If you have a stroke your risk of dying will be from a subsequent stroke.
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True.
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