Handler: Stroke Flashcards by Setha Treadwell

the sudden or rapid onset of a neurologic deficit in distribution of a vascular territory lasting > 24 hours

Stroke

“Brain attack”

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the sudden or rapid onset of a neurologic deficit in the distributionof a vascular territory lasting < 24 houts.

Most last <30 mins

TIA

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Reversible ischemicinsult to brain cells that recover but increases risk of subsequent stroke

TIA

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Worsening signs or symtpoms over time

Stroke-in-evolution

(progressive stroke)

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Ischemia/infart __%

hemorrhage __%

85%

15%

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3rd leading cause of death in the US

>200,000 deaths/year

Perception of elderly

Men 1.3x > Women

Blacks 1.3x > whites

Stroke

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Most common cause of death in patients with cerebrovascular disease is _________?

Myocardial infarction

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What is the most powerful risk factor for a stroke?

HTN

goal <140/90

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Smoking (2-4x)

Atherosclerosis eslewhere (CHD, PAD)

Diabetes Mellitus (3x)

A fib (cardaic emboli)

Male gender, OCP, ETOH in excess, hyperlipidemia

Risk factors for?

Stroke

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Large vessels (atheroscleorsis) often involved in ___% of all ischemic strokes (infarcts)

50%

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Atherosclerosis: ______ vessels often involved

Large

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___% of strokes are in anterior circulation of brain

80%

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Why has incidence of stroke declined?

Development and treatment of HTN

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Pathological outcomes depend on:

Adequacy of collateral circulation

Development of Circle of Willis

Duration of insult/restoration of blood flow

Stroke

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Carotid bifurcation, origin of internal carotid

Base of aorta, external carotid, vertebral/basilar arteries

Effected in _____ strokes?

Ischemic

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Small vessel disease

deep penetrating arterioles occlude/thrombose

Lacunar infarcts

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20% of ischemic strokes are ____?

Lacunar infarcts

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Major risk factor for lacunar infarcts is ____

lipids, DM contribute

HTN

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Fibrous cap can erode and lead to an ______ placque?

ulcerative

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Very small strokes or TIA’s defect < ____ cm (most are 5mm) on CT or MRI

1.5

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May be without sx

detected by CT scan as incidental finding (small, punched out lesion)

lacunar infarcts

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Embolism from heart or artery to brain

Important role in pathology of strokes and TIA’s

Cerebral Emboli

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Blood clot breaks off, occludes more distant/distal vessel

Cerebral emboli

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Often lodge in medium sized vessels (MCA,ACA)

If identified one, likely there are others

Cardiac emboli

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20% of ischemic strokes are \_\_\_\_?

Cardioembolism

What is a very common cause of cardioelmbolism?

A fib

**Abrupt onset** of non-convulsive **focal defect in a vascular territory**

Stroke

\_\_\_% of patients have no warning sx of stroke \_\_\_% have warning (TIA)

80-90% 10-20%

Contralateral hemiparesis or hemisensory loss Hemianopsia (visual field defect) If dominant hemisphere (left side of brain)-aphasia If non-dominant- Speech and comprehension preserved; may develop anosognosia (denial/neglect of deficit) or a confusional state.

MCA

less common Sx more pronounced in leg, associated language, gait disturbance.

ACA

least common Vertebral artery (Branch of subclavian artery) Crossed contralateral dysfunction (motor/sensory) plus ipsilateral bulbar/cerebellar signs: vertigo, dizziness, gait disturbance, diplopia, facial palsy, dysarthria, etc.

Posterior circulation

Clinical syndrome depending on where infarct is, may also present as TIA Ex: contralateral motor/sensory deficit Prognosis usually good

Lacunar strokes/infarcts

Carotid dx present Transient monocular blindness Embolism to opthalmic artery (off carotid)

Amaurosis fugax

What do you need to do to r/o hemorrhage associted with stroke?

MRI best in 1st 48 hours after intracranial hemorrhage

Detection of infarcts on CT is limited to what?

size and timing

\_\_% of infarcts visible on CT in 1st 12 hours \>\_\_% visible at one week

5% 90%

Changes of infarct may be seen as early as 1 hour usually not available or needed emergently Provides better detail than CT for small lesions and for imaging posterior fossa

MRI/MRA

**Non-invasive** with excellent resolution of large vessels replaces need for arteriogramin some patients May be difficult to differentiate complete vs. near complete occlusion

MRA

**Screening tool** for evaluating common carotid and origin of internal carotid artery May be difficult to differeniate complete vs. near complete occlusions Non-invasive but limited capacity

Carotid Doppler Ultrasound (Duplex)

MOST accurate **Invasive- "gold standard"** for extra and intracranial disease

Arteriography

Complications: contrast reaction, kidney failiure, placque rupture, stroke Use of non-ionic constrast has reduced complications What type of imaging?

Arteriography

Risk factor modification: agressive control of BP, lipids, diabetes, smoking cessation, exercise, diet Atrial fibrillation and emolization: full anticoagulation (Warfarin therapy long term) Prevention for what?

CHD and stroke

Abrupt onset of sx with **transient** focal neuro deficit dependent on involved anatomy Sx may vary during episodes Exam between episodes normal Warning for subsequent stroke

TIA's

**Embolic from carotid stenosis/placque** or **Embolic from cardiac source** Severe carotid stenosis with transient HoTN Small vessel occlusion: lacunar infarcts may minic Etiology for \_\_\_?

TIA's

Important to listen for ___ with stethoscope with TIA's?

bruit

Carotid Endarterectomy and carotid angioplasty/stenting are surgical rx for?

Carotid TIA/Incomplete Stroke

Surgical rx to remove placque Best results if symptomatic blockage and **\>70%** stenosis Significantly recuces risk of subsequent ipsilateral stroke **For selected patients with sx and 50-70% stenosis** Risks: stroke and complications of surgery

Carotid endarterectomy

Promising alternative to carotid endarterectomy but long term data is lacking option in POOR surgical candidates

Carotid angioplasty/stenting

For patients with poor operative risk \<70% stenosis or asymptomatic carotid disease Risk factor modification: HTN, smoking, lipids, DM

Medical rx for carotid TIA's

Indicated for ALL patients with \<70% stenosis and TIA sx, diffuse cerebrovascular dx, poor operative candidates, and asx carotid dx Prevent platelet aggregation and release of vasoactive substances like thromboxane A2

Anti-platelet agents

Inhibits cyclooxygenase Inhibits synthesis of thromboxane A2, decreasing both platelet aggregation and vasoconstriction Decreases frequency of TIA's and risk of subsequent stroke and decreased recurrence of stroke 325mg daily: GI side effects and bleeding

Aspirin

Inhibits platelet aggregation and prevents activation of glycoprotein ||b/|||a (a fibrinogen binder) Decreases atherosclerotic events Alternative to ASA for patients with **recurrent TIA's or ASA intolerance/allergy** 75 mg/day: Diarrhea, rash

Clopidogrel (Plavix)

Supportive measures plus ASA or Clopidogrel Aggressive long term tx of BP and lipids Usually good prognosis for recovery over 4-6 weeks

Lacunar infarct tx

Hospitalize all patients (most TIA-1st episode) Supportive (IV fluids) Consider thrombolytic therapy Tx for what?

Stroke

What do you want to avoid when treating a stroke?

Rapid BP reduction decreases perfusion and brain will autoregular perfusion Only tx if \<200/100 --\> wait 2 weeks for oral meds if possible

Dependent on timing **1st obtain head CT to r/o hemorrhage** if onset of sx \<4.5 hours --\> thrombolytic therapy with **t-PA (**bolus/infusion up to 90 mgs) over 1 hour Tx for?

Cerebral infarct

Requires team approach- best done in large tx centers neurologic outcome improved at 3 mon and 1 year with decrease in expected deficit and **reduction of intial deficit** increases chances of favorable outcome by ~50% What type of stroke therapy?

Thrombolytic therapy

Risks: Cerebral hemorrhage (6-7% incidence adn half will die) Contraindications: recent bleeding, prior stroke, BP \>185/110, recent major surgery For what type of stroke therapy?

thrombolytic therapy (t-PA)

loose mesh stent placed in thrombus obstructing cerebral vessels removes thrombus and restores blood flow Not yet FDA approved for all stroke patients

Solitare FR Revascularization Device

Indications: **Embolus from heart** (stroke or TIA) **A fib** \> 72 hours Risk is cerebral hemorrhage What type if tx?

FULL anticoagulation

What must you do before starting full anticoagulation?

CT to r/o hemmorrhage

Used for immediate and short term anticoagulation Inhibit action of clotting factors

Heparin

Long term oral anticoagulation Inhibits production of clotting factors in liver Stroke or TIA from cardiac embolism (decrease subsequent stroke risk) Chronic A fib (decrease stroke risk) Monitored by INR and frequent follow up for dosing

Warfarin

Physical therapy, occupation therapy, speech therapy Avoid prolonged best rest (UTI's, skin infection/ulcers, PE)

Post stroke management

What are the two types of Hemorrhagic stroke?

Intracerebral (HTN, AVM, Trauma) Subarachnoid space (Aneurysm, AVM)

\_\_\_\_\_\_\_\_ is diagnositic for hemorrhagic stroke

What should you do if CT is negative for to rule out SAH?

Spinal tap

Rupture of small arteries or microaneurysms of perforating vessels Risks: HTN, hematologic and bleeding disorders (leukemia, thrombocytopenia, hemophilia), trauma, anticoagulant therapy, liver dx

Intracerebral hemorrhage

Rapid evolution of neuro deficit often progressing to hemiparesis, hemiplegia, or hemisensory loss 50% mortality Loss of or impaired consciousness develops in 50% Vomiting and HA are common

Intracerebral hemorrhage

Cautious BP reduction where applicable Conservative and supportive tx - some benefit from surgical evacuation of hematoma Surgery: decompression (limited usefulness)--\> best in cerebellar bleeds and bleeding in AVM Tx for?

Hemorrhagic stroke

Most due to bleeding from **saccular aneurysms** In 3-4% of population, usually w/o sx 2-3% risk of bleed per year Highest risk if \>6mm

Subarachnoid bleeds

Sudden onset of severe HA followed by N and V, impaired or loss of consciousness +/- neuro deficits Meningeal signs often present

Subarachnoid bleeds

What are the two meningeal signs?

Kernigs and Brudzinski signs

What imaging is used to identify blood in subarachnoid space?

If subarachnoid hemorrhage is suspected and CT is negative do _______ to look for blood or xanthochromia

CSF tap

If patient conscious: bed rest, sx and supportive care with cautious reduction of BP Once patient stable: angiography **Surgery** or coil placement to precent re-bleed when applicable Tx for?

Subarachnoid hemorrhage

most common vascular malformation of CNS often involving MCA and branches