LVO stroke accounts for an estimated 11–20% of all ischemic strokes but is responsible for a disproportionate share of stroke-related death and disability, with up to 2 million neurons lost per minute during an untreated LVO. [1-2] The cornerstone of management is rapid reperfusion via IV thrombolysis (within 4.5 hours) and mechanical thrombectomy (up to 24 hours in selected patients), with a number needed to treat of 2.6 to reduce meaningful disability. [3-4]
The following figure from Powers (NEJM 2020) provides a stepwise algorithm for initial management:
1. History
- Time last known well (LKW) — the single most critical data point; determines treatment eligibility [5]
- Acute onset of focal neurologic deficit: hemiparesis, facial droop, speech difficulty, visual field cut, neglect, gaze deviation
- Symptom progression vs. improvement; fluctuating deficits suggest unstable thrombus
- Wake-up stroke: treat LKW as bedtime; advanced imaging can extend treatment window [1][6]
- Mechanism clues: palpitations (AF), recent cardiac procedure, known carotid disease, hypercoagulable state, IV drug use
- Important negatives: seizure at onset (mimic?), head trauma, recent surgery, anticoagulant use
2. Alarm Features
- NIHSS ≥6 with cortical signs (gaze deviation, neglect, aphasia) — high suspicion for LVO [7-8]
- Rapid deterioration or declining level of consciousness — suggests large territory infarction or herniation
- Dense hemiplegia with forced gaze deviation — classic for proximal MCA or ICA occlusion
- Signs of posterior fossa involvement (bilateral motor deficits, coma, locked-in syndrome) — basilar artery occlusion
- Malignant MCA syndrome: progressive obtundation, pupil asymmetry, Cushing response — impending herniation requiring emergent neurosurgical evaluation [4]
3. Medications
Acute Reperfusion Therapies
- IV alteplase 0.9 mg/kg (max 90 mg): 10% bolus, remainder over 60 min; within 4.5 hours of LKW [9-10]
- IV tenecteplase 0.25 mg/kg (max 25 mg): single bolus; FDA-approved for AIS as of 2025; increasingly used for ease of administration and prehospital use [9][11]
- IV thrombolysis should not delay thrombectomy but should be given if eligible [9]
Key Contraindications to IV Thrombolysis: [10][12-13]
- Active internal bleeding, current intracranial hemorrhage, SAH
- Intracranial/spinal surgery or severe head trauma within 3 months
- Bleeding diathesis: platelets <100,000, INR >1.7, therapeutic LMWH within 24 hours
- DOAC use within 48 hours (unless reversal achieved)
- BP >185/110 despite treatment
- Extensive clear hypoattenuation on CT
- Infective endocarditis, intra-axial neoplasm, aortic arch dissection
Post-Reperfusion Antithrombotics
- Aspirin 325 mg started 24 hours after thrombolysis [4-5]
- If no thrombolysis given: aspirin within 24–48 hours [5]
- High-intensity statin therapy should be initiated [4]
- For cardioembolic etiology (AF): anticoagulation (typically DOAC) once hemorrhagic transformation excluded [3]
Medications to Avoid Acutely
- Antiplatelet agents within 24 hours of thrombolysis [5]
- Glycoprotein IIb/IIIa inhibitors concurrently with alteplase [12]
- Aggressive BP lowering to SBP <120 mmHg post-thrombectomy [9]
4. Diet
- NPO until swallow evaluation completed — dysphagia screening is mandatory before oral intake [4]
- Aspiration risk is high, especially with dominant hemisphere or brainstem strokes
- Long-term: Mediterranean-style diet, sodium restriction (<2 g/day), and moderation of alcohol for secondary prevention
5. Review of Systems
- Cardiac: palpitations, chest pain, dyspnea (AF, concurrent MI, heart failure)
- Neurologic: headache (hemorrhagic conversion, dissection), seizure, visual changes
- Vascular: claudication, prior TIA, amaurosis fugax
- Systemic: fever (endocarditis, infection), recent illness, weight loss (malignancy/hypercoagulability)
- GI/GU: recent bleeding (thrombolysis contraindication)
6. Collateral History and Family History
- Collateral from bystanders/family is essential: exact time of symptom onset or LKW, baseline functional status (pre-stroke mRS), medication list (especially anticoagulants)
- Baseline cognitive function and independence — critical for thrombectomy decision-making (pre-stroke mRS 0–1 is standard inclusion criterion) [7][14]
- Family history: AF, stroke, hypercoagulable disorders, premature atherosclerosis
- Social context: living situation, support system, advance directives
7. Risk Factors
- Atrial fibrillation — most common cause of cardioembolic LVO [15-16]
- Hypertension, diabetes mellitus, hyperlipidemia, smoking
- Carotid/intracranial atherosclerosis
- Heart failure, valvular disease, recent MI, PFO with atrial septal aneurysm
- Hypercoagulable states: malignancy, antiphospholipid syndrome, oral contraceptives
- Prior stroke or TIA
- Obesity, sedentary lifestyle, obstructive sleep apnea
8. Differential Diagnosis
Cannot-miss diagnoses
- Intracerebral hemorrhage — excluded by NCCT before any reperfusion therapy [5]
- Basilar artery occlusion — coma, quadriplegia, locked-in syndrome
- Cervical artery dissection — younger patients, neck pain, Horner syndrome
Important mimics
- Hypoglycemia (check glucose immediately) [5]
- Seizure with Todd's paralysis
- Complex migraine with aura
- Conversion/functional neurological disorder
- Intracranial mass lesion or abscess
- Hypertensive encephalopathy / PRES
- The risk of symptomatic ICH from thrombolysis in stroke mimics is very low; treatment should not be delayed for additional diagnostic studies if clinical suspicion is high [17]
9. Past Medical History
- Prior stroke/TIA — recurrence risk, prior imaging for comparison
- Known AF or cardiac disease
- Recent surgery or trauma (thrombolysis contraindication within 3 months for intracranial; 14 days for major surgery) [12]
- History of intracranial hemorrhage, aneurysm, AVM
- Chronic kidney disease (contrast considerations for CTA, though risk of AKI is low) [7]
- Malignancy (hypercoagulability, potential contraindication)
- Baseline functional status and cognitive function
10. Physical Exam
Vitals
- BP: must be <185/110 for thrombolysis eligibility; post-thrombectomy target <180/105 [4][12]
- Heart rate/rhythm: irregular rhythm suggests AF
- Oxygen saturation, temperature, glucose
Focused Neurologic Exam (NIHSS)
- Level of consciousness, orientation, commands
- Gaze deviation (forced gaze toward lesion = cortical/LVO sign)
- Visual fields (homonymous hemianopia)
- Facial palsy (central pattern — lower face)
- Motor: arm and leg drift/plegia
- Limb ataxia
- Sensory
- Language (aphasia — dominant hemisphere)
- Neglect/extinction (nondominant hemisphere)
- Dysarthria
Cardiac Exam: irregular rhythm, murmurs, signs of heart failure
Vascular: carotid bruits, peripheral pulses
11. Lab Studies
Stat (do not delay treatment)
- Point-of-care glucose — only lab required before thrombolysis [5]
- CBC with platelets, BMP, coagulation studies (PT/INR, aPTT) — can be drawn but results should not delay treatment unless clinical suspicion of coagulopathy [12]
- Troponin (concurrent MI, neurogenic cardiac injury)
Routine
- Type and screen
- Hemoglobin A1c, fasting lipid panel
- LFTs, renal function
- Toxicology screen if indicated
- Hypercoagulability workup in young patients or cryptogenic stroke (antiphospholipid antibodies, protein C/S, factor V Leiden — defer to outpatient)
12. Imaging
Immediate (do not delay)
- NCCT head — exclude hemorrhage; assess ASPECTS score; target door-to-imaging <25 minutes [5][18]
- CTA head and neck — identify LVO location (ICA, M1, M2, basilar); sensitivity 92–100% for proximal LVO [3][13]
Extended Window (6–24 hours) or Wake-Up Stroke
- CT perfusion (CTP) or MRI DWI/perfusion — assess ischemic core vs. salvageable penumbra; required for thrombectomy eligibility in the late window (DAWN/DEFUSE-3 criteria) [4][6]
- Automated software (e.g., RAPID) for volumetric mismatch analysis [3]
Post-Acute
- MRI brain with DWI — most sensitive for infarct characterization
- Carotid duplex ultrasound or CTA for extracranial disease
- Echocardiography (TTE ± TEE) for cardioembolic source [13][19]
When imaging is unnecessary: Do not delay thrombolysis for MRI if NCCT is sufficient within the standard window [5]
13. Special Tests
Scoring Systems
- NIHSS — quantifies stroke severity; NIHSS ≥6 is standard thrombectomy criterion; NIHSS ≥10 balances sensitivity/specificity for LVO prediction (73%/74%) [8][13]
- ASPECTS — 10-point CT score of early ischemic changes in MCA territory; ≥6 is standard thrombectomy criterion; recent trials support EVT even with ASPECTS 3–5 [20-21]
- mRS (modified Rankin Scale) — pre-stroke functional status; mRS 0–1 is standard inclusion for thrombectomy trials [7]
Prehospital LVO Screens
- RACE (AUC 0.83), G-FAST, CG-FAST — best-performing prehospital scales; RACE ≥5 has sensitivity 67%, specificity 87% for anterior LVO [22]
- No single scale has both high sensitivity and specificity; CTA remains the gold standard [8]
Point-of-Care
- Bedside glucose
- Emerging: prehospital GFAP blood biomarker combined with LVO scales may improve diagnostic accuracy [23]
14. ECG
- 12-lead ECG on arrival — detect AF, atrial flutter, acute MI, or other arrhythmias [19]
- AF is detected on initial ECG in up to 7% of ischemic stroke patients [19]
- Continuous telemetry for ≥24–72 hours recommended to detect paroxysmal AF [15][24]
- Prolonged monitoring (30-day external or implantable loop recorder) detects AF in 12–16% of patients with cryptogenic stroke [25-26]
- ECG patterns to recognize: AF/flutter, ST changes (concurrent MI or neurogenic), prolonged QTc (risk of torsades), Wellens-like T-wave inversions (neurogenic)
15. Assessment
LVO stroke is a neurological emergency with the highest morbidity among ischemic stroke subtypes. Only 10–15% of ICA occlusions and 25–50% of proximal MCA occlusions recanalize with IV thrombolysis alone, underscoring the critical role of mechanical thrombectomy. [3]
Severity Stratification
- Mild (NIHSS <6): may still harbor LVO with risk of deterioration; obtain CTA [7][27]
- Moderate-severe (NIHSS 6–25): classic thrombectomy candidate
- Very severe (NIHSS >25): higher hemorrhagic risk but still benefits from reperfusion [12]
- Large core (ASPECTS 3–5): recent trials (SELECT2, ANGEL-ASPECT, TENSION) demonstrate benefit of EVT, though with higher sICH risk (RR 1.7) [21][28]
Complications to anticipate
- Hemorrhagic transformation (symptomatic ICH ~2–6%)
- Malignant cerebral edema (peak 48–72 hours) — may require hemicraniectomy [4]
- Recurrent vessel occlusion
- Aspiration pneumonia, DVT/PE, seizures
16. Treatment Plan
Hyperacute Phase (Minutes Matter)
- ABCs, IV access ×2, cardiac monitor, supplemental O2 if SpO2 <94%
- NCCT + CTA — door-to-imaging <25 min [18]
- IV thrombolysis if within 4.5 hours and no contraindications:
- Alteplase 0.9 mg/kg (max 90 mg) OR tenecteplase 0.25 mg/kg (max 25 mg) [9][11]
- BP must be <185/110 before and <180/105 for 24 hours after [12]
- Mechanical thrombectomy — activate neurointerventional team immediately:
- 0–6 hours: NIHSS ≥6, ASPECTS ≥6, ICA or M1 occlusion, pre-stroke mRS 0–1 (Class IA) [7][17]
- 6–24 hours: must meet DAWN or DEFUSE-3 imaging criteria (clinical-core mismatch or perfusion mismatch) [4][6]
- Target: door-to-groin puncture <90 min (direct arrivals) or <60 min (transfers) [7]
- Large core (ASPECTS 3–5): EVT supported within 6–12 hours based on recent trial data [14][21]
Post-Reperfusion Care
- ICU/stroke unit admission with serial neuro checks (q15 min × 2 hours, then q1h)
- BP management: SBP <180/105 post-thrombectomy; avoid SBP <120 [4][9]
- Aspirin 325 mg at 24 hours post-thrombolysis (after repeat NCCT to exclude hemorrhage) [4]
- High-intensity statin [4]
- DVT prophylaxis (SCDs immediately; pharmacologic when safe)
- Swallow evaluation before oral intake
- Glycemic control (avoid hypoglycemia and hyperglycemia)
- Normothermia
- Etiologic workup: telemetry, echocardiography, carotid imaging, hypercoagulability panel as indicated [13]
17. Disposition
Admission Criteria (all LVO patients)
- ICU or dedicated stroke unit — mandatory for post-thrombolysis and post-thrombectomy monitoring [4]
- Serial neurologic assessments to detect hemorrhagic conversion or re-occlusion
- If at a non-thrombectomy-capable center: emergent transfer to a comprehensive stroke center; do not delay for thrombolysis — give and ship ("drip and ship") [1][9]
Neurosurgery Consultation Triggers
- Large MCA territory infarction with risk of malignant edema (especially age <60)
- Cerebellar infarction with brainstem compression or hydrocephalus
- Hemorrhagic conversion with mass effect
Specialist Consultations
- Neurointerventional/endovascular (thrombectomy)
- Vascular neurology
- Cardiology (AF management, PFO evaluation)
- Rehabilitation medicine (PT/OT/SLP) — initiate early
18. Follow Up / Return Precautions
Inpatient
- Repeat NCCT at 24 hours post-thrombolysis before starting antithrombotics
- Depression screening [4]
- Rehabilitation evaluation and early mobilization
- Smoking cessation counseling
Discharge Planning
- Stroke neurology follow-up within 1–2 weeks
- Cardiology follow-up if AF detected or cardiac workup pending
- If AF: initiate DOAC (typically after 3–14 days depending on infarct size and hemorrhagic risk)
- If non-cardioembolic: antiplatelet therapy (aspirin or clopidogrel) [3][29]
- Statin optimization (LDL goal <70 mg/dL for atherosclerotic etiology)
- BP target <130/80 after the acute phase
- Prolonged cardiac monitoring (30-day event monitor or implantable loop recorder) if stroke source unclear [15][25]
Return Precautions — Counsel Patient/Family
- Return immediately for: new or worsening weakness, speech difficulty, vision changes, severe headache, altered consciousness, seizure
- Expected recovery: variable; most improvement occurs in first 3–6 months with rehabilitation
- Driving restrictions per local regulations (typically minimum 3–6 months)
References
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