What is the appropriate management for a 46-year-old man with acute ischemic stroke, National Institutes of Health Stroke Scale (NIHSS) score of 20, and normal urgent unenhanced computed tomography (CT) head scan?

Management of Acute Ischemic Stroke with NIHSS 20

This patient requires immediate intravenous alteplase (0.9 mg/kg, maximum 90 mg) followed by urgent CT angiography to assess for large vessel occlusion and potential endovascular thrombectomy. 1, 2

Immediate Thrombolysis Decision

This 46-year-old man meets all criteria for IV alteplase administration within the 3-hour window (last known well at 22:30, presented at 05:30 = approximately 7 hours, but symptoms discovered at 04:30 = within 6 hours from discovery). However, the critical determination is last known well time of 22:30, which places him outside the standard 3-hour window but potentially within the 3-4.5 hour extended window depending on exact timing. 1

Key eligibility factors present:

• Normal CT head scan excluding hemorrhage 1, 2
• Measurable severe neurological deficit (NIHSS 20) 1, 3
• Normal coagulation parameters (INR 1.0, aPTT 36s) 1
• Blood pressure 160/92 mmHg (below 185/110 mmHg threshold) 1, 3
• Glucose 5.2 mmol/L (normal range) 3
• No recent surgery or contraindications identified 1

Critical timing consideration: If the patient can be definitively established as within 4.5 hours from last known well (not just symptom discovery), he qualifies for IV alteplase. The 3-4.5 hour window is supported by ECASS-III trial data, and importantly, stroke severity (NIHSS 20) is NOT an exclusion criterion - the ECASS-III exclusion of NIHSS >25 was not justified by subsequent data analysis. 1

Alteplase Administration Protocol

Dosing: 0.9 mg/kg (maximum 90 mg total), with 10% given as IV bolus over 1 minute and remaining 90% infused over 60 minutes. 1, 3, 4

Blood pressure management:

• Current BP 160/92 mmHg is acceptable (must be <185/110 mmHg before starting) 1, 3
• Maintain BP ≤180/105 mmHg during and for 24 hours after infusion 1, 3
• Monitor BP every 15 minutes during infusion and for 2 hours after, then every 30 minutes for 6 hours, then hourly until 24 hours 3, 4

Urgent Vascular Imaging for Endovascular Therapy

Immediately obtain CT angiography (arch-to-vertex) to identify large vessel occlusion. 1, 2 With NIHSS 20, this patient almost certainly has a proximal large vessel occlusion (likely left middle cerebral artery M1 or internal carotid artery given the right hemiplegia, aphasia, and hemianopia). 1

Endovascular thrombectomy indications:

• NIHSS 20 indicates severe stroke with likely proximal large vessel occlusion 1
• EVT is indicated for internal carotid artery, M1, or proximal M2 occlusions 2, 3
• Can be performed in conjunction with IV alteplase (bridging therapy) 2, 3
• Standard window is within 6 hours, but can extend to 24 hours with favorable imaging (CT perfusion or multiphase CTA showing good collaterals) 1, 2

The presence of good collaterals on multiphase CTA would support EVT even in extended time windows, and with NIHSS 20, treatment should be pursued aggressively regardless of exact timing if collaterals are favorable. 1

Critical Monitoring Post-Thrombolysis

Neurological assessments every 15 minutes during and for 2 hours after alteplase infusion: 3, 4

• Any sudden worsening, severe headache, acute hypertension, nausea/vomiting requires immediate cessation of alteplase and emergent repeat CT head 3
• Symptomatic intracranial hemorrhage occurs in approximately 2-6% of patients 1, 5

Aspiration precautions are mandatory - this patient failed bedside swallow assessment (choked on water). 2, 3

• Keep NPO until formal swallow evaluation 2, 3
• Consider NG tube for medications if needed 3

Antiplatelet Therapy Timing

Do NOT give aspirin until 24 hours after alteplase administration and after repeat CT head excludes hemorrhage. 2, 3, 4 Then initiate aspirin 160-325 mg daily. 2, 4

Stroke Unit Admission

Admit immediately to a geographically defined stroke unit with specialized staff - this reduces mortality and dependency. 2, 3 Intensive monitoring in a stroke unit is particularly critical given the high NIHSS score and risk of malignant cerebral edema with large territory infarction. 3

Common Pitfalls to Avoid

Time is brain: Every 30-minute delay in recanalization decreases good functional outcome by 8-14%. 3, 4 Do not delay thrombolysis for additional testing beyond essential CT head and basic labs. 2, 3

Do not withhold treatment based on stroke severity alone - while NIHSS 20 indicates severe stroke, this is NOT a contraindication to either IV alteplase or EVT. 1 The original ECASS-III exclusion of NIHSS >25 was not supported by subsequent evidence. 1

Wake-up stroke consideration: If exact timing cannot be established but patient was normal at 22:30, advanced imaging (MRI with DWI-FLAIR mismatch or CT perfusion) could potentially extend treatment eligibility, though this should not delay immediate CTA for EVT assessment. 1

Monitor for malignant cerebral edema: With NIHSS 20 and likely large territory infarction, this patient is at significant risk for life-threatening cerebral edema within 24-48 hours, potentially requiring decompressive hemicraniectomy. 3