Stroke

Question 1

Stroke Background

Answer 1

• Abrupt onset of focal neurologic damage that is presumed to be vascular in origin
• Stroke is leading cause of disability and fifth in mortality
• CVA: defined as decreased blood flow to brain as a result of obstructed ruptured blood vessels
• Overall, on a downward trend

Question 2

Ischemic Stroke

Answer 2

• 83% of stroke incidences
• Caused by occlusion with a cerebral artery or emboli from a proximal source resulting in cerebral artery occlusion
• Emboli may be cardiac or non-cardiac sources
• Vascular changes can lead to occlusion
• Blood vessels ability to dilate/constrict can be impaired in chronic HTN, acute injury, or atherosclerosis
• Tissue surrounding core area of infarct is ischemic but maintain tissue integrity, aka ischemic penumbra

Question 3

Hemorrhagic Strokes

Answer 3

• 13% of stroke incidences
• Occurs when blood enters either subarachnoid space or within intracerebrum forming a hematoma in brain
• Significantly higher mortality compared to ischemic stroke
• Types: SAH or ICH

Question 4

SAH

Answer 4

• Subarachnoid Hemorrhage
• Occurs when blood enters subarachnoid space
• Can occur following trauma, rupture of intracerebral aneurysm, or rupture of an arteriovenous malformation (AVM)

Question 5

ICH

Answer 5

• Intracerebral hemorrhage
• Uncontrolled HTN is common etiology
• Antithrombotic therapy is associated with ICH

Question 6

TIA

Answer 6

• Transient Ischemic Attack
• Transient episode of neuological dysfxn caused by focal brain, spinal cord, or retinal ischemia without acute infarction
• TIA thought to be benign but should be considered similar in spectrum to stroke
• Require urgent intervention to reduce risk of stroke
• TIA patients have a 10-15% chance of a subsequent stroke especially the first few days following TIA

Question 7

Comorbidities

Answer 7

• Atherosclerosis of large arteries can increase ischemic stroke risk
• Afib, valvular heart disease, or other prothrombogenic heart problems can increase risk of emboli

Question 8

Pathophysiologies

Answer 8

• Ischemic: manifested occlusion of cerebral artery reduces cerebral blood flow causing neurologic deficits
• Hemorrhagic stroke: neuronal damage by mechanical compression of the brain parenchyma itself

Question 9

Clinical Presentation

Answer 9

• Specific areas of neurologic deficit are determined by the area of brain that is not involved
• Posterior circulation: vertigo and double vision
• Anterior circulation: asphasia
• Ischemic strokes are not painful but may include headache
• Hemorrhagic strokes are more severely painful and have headaches

Question 10

BEFAST

Answer 10

• B: balance, loss of balance, HA, or dizziness
• E: Eyes, blurred vision
• F: Face, drooping on one side of face
• A: Arms, arm or leg weakness
• S: Speech: speech difficulty
• T: Time to call for ambulance immediately

Question 11

Diagnosis

Answer 11

• Lab: blood glucose, platelet count, coagulation parameters
• Imaging: CT scan (immediately on arrival to rule out hemorrhagic), if used IV contrast may be able to reveal ischemic stroke
• MRI: longer duration, visualizes small, deep infarcts, can help distinguish between acute and chronic ischemic

Question 12

CPSS

Answer 12

• Tests for 3 signs of abnormal findings: facial droop, arm drift, or changes in speech
• If one of the findings is new there is a high chance its ischemic stroke
• If all three are abnormal, there is a higher chance of acute stroke

Question 13

NIHSS

Answer 13

• Evaluation to qualify severity of stroke
• Scoring tool ranges from 0-42
• 0: no stroke, 0-4: minor, 5-15: moderate, 16-20: moderate to severe, 21-42: severe

Question 14

Fibrinolytic Therapy

Answer 14

• Beneficial for patients presenting <4.5 hours with an acute ischemic stroke sxs
• Alteplase of tenecteplase are utilized, others aren’t recommended
• Binds to fibrin and initiates fibrinolysis by converting plasminogen to plasmin
• Don’t delay initiation; only blood glucose levels are needed before starting alteplase
• Baseline ECG and troponins are recommended but not necessary before initiation
• Alteplase is standard therapy, make sure they have NO CI to tPA
• Tenecteplase considered as an alternative for patients who can undergo mechanical thromboectomy

Question 15

Absolute tPA CI

Answer 15

• Head trauma or stroke in last 3 months
• History of ICH, AVM, or aneurysm
• Signs/sxs suggesting SAH
• Recent intracranial or intraspinal surgery in past 3 months
• Elevated BP (>185/110)
• Known bleeding disorder or low platelets
• Blood glucose <50
• Aortic arch dissection or infective endocarditis
• Anticoagulant use

Question 16

Anticoagulant Use

Answer 16

• Warfarin: INR > 1.7
• Therapeutic heparin: aPTT>40
• Therapeutic enoxaparin: last dose =< 24 hor or anti-Xa >= 0.3
• DOAC: last dose =< 48 hours or abnormal renal fxn (CrCl < 30)

Question 17

Blood Pressure Management

Answer 17

• Not a candidate for fibrinolytic therapy: don’t treat in acute period of stroke
• Lower blood pressure if >220/120 or evidence of aortic dissection, acute MI, pulmonary edema, or hypertensive encephalopathy
• Candidates for alteplase: correct blood pressure if >185/110 with CCB or BB before initiating
• During/following tPA: strict BP control should be continued with <180/105 as the foal for at least 24 hours after infusion

Question 18

Managing Hemorrhagic Strokes

Answer 18

• No standard management
• Obtain history to determine if patient is on antiplatelet for anticoag therapy
• If so, determine when last dose was taken
• Usually reversed in an attempt to prevent further bleed expansion

Question 19

Hemorrhagic BP Control

Answer 19

• Greatly elevated BP can expand bleeding or can re-bleed, but too low can cause cerebral ischemia
• Optimal BP isn’t determined, but aggressive reduction if SBP >= 220 and modest if SBP >= 180
• General goal: 140-160

Question 20

Vasospasms

Answer 20

• Thought to cause delayed ischemia and can occur 4-21 days after hemorrhagic stroke
• Nimodipine should be administered to patients with aneurysmal SAH
• Start with 96 hours of onset
• Greater effect on cerebral arteries, believed to be due to lipophilicity

Question 21

Seizures

Answer 21

• Patients with change in mental status found to have electrographic seizures on ECG should be given anti-seizure drugs
• Guidelines: recommend against prophylactic use of anti-seizure

Question 22

Large Vessel Occlusion

Answer 22

• Non-pharm
• LVO: catheter guided to femoral artery, aorta, and carotid to remove clot
• Eligible up to 24 hours of last known normal
• Depending on location, timing, and severity, could use along or with tPA

Question 23

CEA

Answer 23

• Non-pharm
• Carotid Endarterectomy: carotid cut open to remove plaque to improve vessel blood flow
• Usually done in patients with 70-99% stenosis
• Use ASA and clopidogrel after procedure for at least 3-6 months after, maybe life lof

Question 24

Other Non-pharm

Answer 24

• Surgical clipping or endovascular coiling

- Mechanical treatment for prevention of rebleeding or aneurysmal SAHs

Question 25

Primary Stroke Prevention

Answer 25

- Identify modifiable and non-modifiable risk factors - Physical activity - Statin therapy if high 10-year risk for CV events - Maintaining regular blood pressure or treating HTN - Smoking cessation/abstinence - Afib patients at increased risk, give anticoagulation therapy - Aspirin 81-100 mg a day can be useful for CV prophylaxis and in women (diabetes) - Cilostazol may be reasonable to prevent first stoke in peripheral arterial disease patients

Question 26

Secondary Ischemic Stroke/TIA Prevention

Answer 26

- Antiplatelet therapy: ASA 160-325 mg daily - Delay ASA if treated with IV alteplase for 24 hours after infusion - Clopidogrel and Ticagrelor can also be recommended (latter not over aspirin for ischemic stroke patients) - Minor ischemic strokes can be treated with DAPT (ASA/clopidogrel) indefinitely - Anticoag therapy may be indicated for cardioembolic stroke patients - High intensity statin for those with atherosclerosis - Venous thromboembolism prophylaxis: compresion device, chemical prophylaxis after 24 hours of tPA infusion, no clear recommendation on restarting after hemorrhagic stroke