A 72-year-old woman from Mumbai with a history of atrial fibrillation (not on anticoagulation) and hypertension presents with acute onset right hemiparesis and expressive aphasia that began 6 hours ago. Her daughter found her unresponsive on the floor. On examination: BP 182/104 mmHg, HR 102/min irregular, temperature 37.8°C. NIHSS score is 18. Non-contrast CT head shows no hemorrhage. What is the most appropriate next step in management?

Explanation

## Clinical Scenario Analysis This patient presents with acute ischemic stroke **beyond the IV thrombolytic window** but potentially within the **mechanical thrombectomy window**. ### Key Clinical Features - **Time from onset:** 6 hours (beyond 4.5-hour IV thrombolysis window) - **NIHSS score:** 18 (severe stroke) - **Atrial fibrillation:** High-risk cardioembolic source - **Presentation:** Expressive aphasia + right hemiparesis → left MCA territory (large-vessel distribution) - **CT:** No hemorrhage ### Pathophysiology & Management Strategy ```mermaid flowchart TD A[Acute ischemic stroke]:::outcome --> B{Time from onset?}:::decision B -->|0-4.5 hours| C[IV alteplase eligible]:::action B -->|4.5-24 hours| D[Consider mechanical thrombectomy]:::action D --> E[Perform CTA/MRA]:::action E --> F{Large-vessel occlusion?}:::decision F -->|Yes + NIHSS ≥6| G[Urgent mechanical thrombectomy]:::action F -->|No| H[Medical management + anticoagulation]:::action C --> I[IV thrombolysis]:::action G --> J[Reperfusion + improved outcomes]:::outcome H --> K[Aspirin + anticoagulation]:::action ``` ### Why Mechanical Thrombectomy is Correct **Key Point:** Mechanical thrombectomy is indicated for acute ischemic stroke with **large-vessel occlusion (LVO)** in the **extended window (4.5–24 hours)**, provided imaging and clinical criteria are met [cite:Stroke Council 2019; Harrison 21e Ch 455]. **High-Yield:** This patient has: - **NIHSS 18** (severe deficit, high likelihood of LVO) - **Expressive aphasia + hemiparesis** (left MCA/ICA territory) - **Time 6 hours** (within extended thrombectomy window) - **No hemorrhage on CT** **Clinical Pearl:** CTA (CT angiography) or MRA (MR angiography) is essential to confirm LVO before thrombectomy. The presence of LVO in the extended window with moderate-to-good collateral circulation on imaging predicts favorable response to thrombectomy. ### Evidence Base | Criterion | Status | Implication | |-----------|--------|-------------| | Time from onset | 6 hours | ✗ Beyond IV thrombolysis window | | NIHSS score | 18 | ✓ Severe; suggests LVO | | Atrial fibrillation | Present | ✓ Cardioembolic source likely | | CT findings | No hemorrhage | ✓ Safe for intervention | | Likely territory | Left MCA | ✓ Large-vessel distribution | | Thrombectomy window | 4.5–24 hrs | ✓ Within extended window | **Mnemonic: THROMBECTOMY CRITERIA** — **T**ime 4.5–24 hrs, **H**emorrhage excluded, **R**NIHSS ≥6, **O**cclusion confirmed on imaging, **M**oderate-good collaterals, **B**aseline mRS 0–1, **E**ligible age, **C**ore infarct < 70 mL, **T**ransfer to capable center, **O**utcome: 90-day mRS 0–2, **M**ultiple trials support, **Y**es to intervention.