Management Algorithm of Thrombotic (Ischemic) Stroke

STEP 1 - Prehospital & Initial Recognition

• Time of symptom onset (or "last known well") is the single most important piece of information
• Use validated screening tools: FAST (Face, Arm, Speech, Time), Cincinnati Prehospital Stroke Scale, or LAMS
• EMS pre-notification to receiving hospital activates stroke team
• Patients presenting within 72 hours of symptom onset should be admitted to hospital regardless of severity

STEP 2 - Emergency Department: Stabilize ABCs

Blood Pressure Management (non-thrombolysis candidates): Do not lower BP aggressively. AHA guidelines recommend treatment only if BP > 220/130 mmHg, with a careful 15% reduction in the first 24 hours. If thrombolysis is planned, target BP < 185/110 mmHg before administering tPA.

• Preferred IV agents: Labetalol 10 mg IV over 1-2 min (max 300 mg), or Nicardipine 5 mg/h IV titrated to max 15 mg/h. Avoid immediate-release nifedipine.

• Bradley and Daroff's Neurology in Clinical Practice, p. 1405-1406

STEP 3 - Emergent Workup (Target Door-to-Imaging < 25 minutes)

• CBC, PT/INR, aPTT, general chemistry screen, glucose
• Cardiac troponin

• Non-contrast CT head (first line) - excludes hemorrhage, detects early ischemic changes (ASPECTS score), identifies large hypodense territory (>1/3 MCA territory)
• CT angiography (CTA) ± CT perfusion - identifies large vessel occlusion (LVO), site of occlusion, penumbra vs. core
• MRI/DWI - more sensitive for early infarct, used when CT is non-diagnostic or in wake-up/unknown onset stroke

• NIHSS score (guide to severity and treatment eligibility)
• NIHSS ≥ 15 or forced gaze deviation + hemiplegia = likely large infarct
• mRS score (baseline functional status)

STEP 4 - Reperfusion Decision Tree

Acute Ischemic Stroke confirmed on imaging
              │
     ┌────────┴──────────┐
  Within 4.5 h?       Beyond 4.5 h?
     │                    │
  IV tPA eligible?     LVO present?
     │                    │
  YES → IV Alteplase   YES → Mechanical Thrombectomy
  NO  → Consider        (0-24 h with imaging selection)
        Thrombectomy
        if LVO present

4A - Intravenous Thrombolysis (IV Alteplase)

• Intracranial hemorrhage on imaging
• Recent major surgery or trauma within 14 days
• Platelets < 100,000; INR > 1.7; on direct oral anticoagulants within 48 hours
• BP > 185/110 mmHg not controllable
• Blood glucose < 50 mg/dL (correct first)
• Prior stroke + DM combination (in 3-4.5 h window)

Cerebral microbleeds (CMBs): if > 10 CMBs on prior MRI, risk of symptomatic ICH is 30-47% vs. 1-4% without CMBs - benefit of thrombolytics is uncertain.

• Rosen's Emergency Medicine, p. 1435-1439; Fuster and Hurst's The Heart, p. 819

4B - Mechanical Thrombectomy (Endovascular Treatment)

• No significant prestroke disability (mRS ≤ 1)
• Causative occlusion of ICA or M1-MCA
• NIHSS ≥ 6
• ASPECTS ≥ 6 on CT

• Selected patients with LVO in anterior circulation
• Evidence of perfusion-core mismatch on CT perfusion or DWI-MRI

• Advanced imaging mismatch required; functional independence criteria

Every 1-hour delay to reperfusion is associated with worse outcomes. Time to arterial puncture is critical - benefit becomes non-significant after 7 hours in pooled trial data.

Note: IV alteplase should still be given first (if eligible) and thrombectomy performed without waiting to assess alteplase response.

• Rosen's Emergency Medicine, p. 1439-1440

STEP 5 - Acute Medical Management (ICU/Stroke Unit)

• Bradley and Daroff's Neurology in Clinical Practice, p. 1406-1408

STEP 6 - Antithrombotic Therapy (Early Post-Stroke)

• Start aspirin 325 mg within 24-48 hours (if no tPA given within 24 hours, or no hemorrhagic transformation)
• For high-risk minor stroke (NIHSS ≤ 5) or TIA: dual antiplatelet therapy - aspirin + clopidogrel for up to 90 days (POINT, CHANCE trials), then aspirin monotherapy long-term
• For intracranial atherosclerotic stenosis (>50%): aspirin + clopidogrel 90 days + high-intensity statin (SAMMPRIS data - stenting inferior to aggressive medical management)

• Start anticoagulation (DOAC preferred over warfarin); timing depends on infarct size (generally 2-14 day "1-2-3-6 rule")

• Fuster and Hurst's The Heart, p. 820-821

STEP 7 - Secondary Prevention (Long-term)

STEP 8 - Rehabilitation

• Begin as soon as life-threatening complications are stabilized
• Early mobilization reduces complications (DVT, pneumonia, pressure sores)
• Multidisciplinary stroke unit care reduces mortality, length of stay, and discharge to nursing home
• Address: physiotherapy, occupational therapy, speech therapy, cognitive rehabilitation
• Screen for depression (post-stroke depression occurs in ~30-40%)

Summary Algorithm Flowchart

Symptom Onset / Last Known Well
         │
         ▼
 Prehospital Activation → ED Arrival
         │
         ▼
    ABCs + Labs + ECG
         │
         ▼
  Neuroimaging (CT head ± CTA ± CT perfusion)
         │
    ┌────┴────┐
Hemorrhage?   No Hemorrhage
    │              │
   NO tPA      ┌───┴───────────────┐
  Neurosurgery  < 4.5 h?        > 4.5 h?
  consult        │                  │
              IV tPA eligible?   LVO on imaging?
              YES → tPA          YES → Thrombectomy
              NO → Supportive    (0-24 h with mismatch)
                   + Thrombectomy
                   if LVO present
         │
         ▼
  Stroke Unit / ICU Monitoring
  BP, glucose, temperature, DVT prophylaxis
         │
         ▼
  24-48 h: Start antithrombotic (aspirin ± clopidogrel)
         │
         ▼
  Secondary Prevention:
  Statin + Antihypertensive + Antiplatelet/Anticoagulant
         │
         ▼
  Early Rehabilitation

Key Time Targets

• Bradley and Daroff's Neurology in Clinical Practice, pp. 1405-1408
• Rosen's Emergency Medicine: Concepts and Clinical Practice, pp. 1435-1440
• Fuster and Hurst's The Heart, 15th Edition, pp. 819-822
• AHA/ASA 2019 Acute Stroke Management Guidelines

Recent evidence note (2023-2026): A 2023 Chinese Stroke Association guideline update (PMID: 38158224) aligns with AHA recommendations on IV thrombolysis and thrombectomy windows. A 2026 ILEP consensus (PMID: 41249078) advocates for LDL targets < 55 mg/dL in very high-risk secondary stroke prevention. Tenecteplase is an emerging alternative to alteplase with "weak" recommendation by Canadian guidelines for minor stroke with LVO pending further trial data.