What is the management of a patient with an acute non-malignant Middle Cerebral Artery (MCA) infarct?

Management of Acute Non-Malignant MCA Infarct

Administer IV alteplase 0.9 mg/kg (maximum 90 mg) within 3-4.5 hours of symptom onset if no contraindications exist, and proceed immediately with endovascular thrombectomy using stent retrievers if large vessel occlusion is confirmed and criteria are met—these therapies should be pursued in parallel, not sequentially. 1

Immediate Hyperacute Assessment (Door-to-Needle <60 Minutes)

Rapid Clinical Evaluation

• Assess stroke severity using the National Institutes of Health Stroke Scale (NIHSS); scores ≥6 indicate potential candidates for endovascular therapy 1
• Obtain focused history specifically for: exact time of symptom onset (or last known well time), recent surgery within 2-4 weeks, history of intracranial hemorrhage, current anticoagulation status (INR >2-3), and recent trauma including head injury 2
• Measure blood pressure immediately; BP must be <185/110 mmHg before thrombolysis 1

Emergent Neuroimaging

• Perform non-contrast CT immediately to exclude hemorrhage and assess early ischemic changes using ASPECTS (Alberta Stroke Program Early CT Score ≥6 required for thrombectomy) 1
• Early CT signs predict malignant course: hypodensity >50% of MCA territory, attenuation of lentiform nucleus, loss of insular ribbon, and hemispheric sulcus effacement indicate large infarct and poor prognosis 3
• Obtain CT angiography or MR angiography simultaneously (not sequentially) to identify large vessel occlusion of ICA or proximal MCA (M1 segment) 2
• Diffusion-weighted MRI volumes ≥80 mL within 6 hours predict rapid fulminant course requiring close monitoring 4

Reperfusion Therapy

Intravenous Thrombolysis (Class I Recommendation)

• Administer IV alteplase 0.9 mg/kg (maximum 90 mg): give 10% as bolus over 1 minute, infuse remaining 90% over 60 minutes 1, 5
• Eligible patients: symptom onset within 3-4.5 hours, no contraindications, age ≥18 years 2, 1
• Do NOT delay IV alteplase while waiting for endovascular team—start immediately and pursue mechanical thrombectomy in parallel 1, 5
• Target door-to-needle time <60 minutes 5

Blood Pressure Management During Thrombolysis

• Reduce BP to <185/110 mmHg BEFORE starting alteplase 1
• Maintain BP ≤180/105 mmHg during infusion and for 24 hours post-treatment 1, 5
• Use short-acting IV agents (labetalol, nicardipine) for rapid titration; avoid sodium nitroprusside infusions as BP may be too unstable for safe thrombolysis 2

Endovascular Thrombectomy (Class I Recommendation)

Proceed with mechanical thrombectomy using stent retrievers if ALL criteria met: 1

• Prestroke modified Rankin Scale (mRS) score 0-1
• Causative occlusion of ICA or proximal MCA (M1) confirmed on CTA/MRA
• Age ≥18 years
• NIHSS score ≥6
• ASPECTS ≥6 on non-contrast CT
• Groin puncture can be initiated within 6 hours of symptom onset

Stent retrievers (Solitaire FR, Trevo) are strongly preferred over coil retrievers (Merci) based on superior recanalization rates (TICI 2b/3 in 59-91%) and functional outcomes from MR CLEAN, ESCAPE, SWIFT PRIME, EXTEND-IA, and REVASCAT trials 2, 5

Post-Thrombolysis Monitoring Protocol

• Monitor neurological status and vital signs every 15 minutes during and for 2 hours after alteplase, then every 30 minutes for 6 hours, then hourly until 24 hours 5
• Maintain BP ≤180/105 mmHg throughout 24-hour monitoring period 5
• Obtain CT scan at 24 hours post-thrombolysis to exclude intracranial hemorrhage before starting antiplatelet therapy 5

Acute Stroke Unit Care

Admission and Early Mobilization

• Admit to geographically defined stroke unit with specialized nursing staff 5
• Begin frequent brief mobilization within 24 hours if no contraindications 5
• Monitor closely for neurological deterioration over 24-72 hours, particularly for signs of malignant cerebral edema 1

Antiplatelet Therapy Timing

• Delay aspirin initiation until after 24-hour post-thrombolysis CT excludes hemorrhage 5
• If thrombolysis not given: start aspirin 160-325 mg within 24-48 hours of stroke onset 1
• After thrombolysis: start aspirin 325 mg daily once hemorrhage excluded 5

Monitoring for Malignant Transformation

Clinical Warning Signs

• Progressive decline in consciousness, severe headache, vomiting, and papilledema indicate developing malignant edema 6
• Obtain urgent neurosurgical consultation if any signs of clinical deterioration with mass effect 4

Radiological Predictors Requiring Urgent Intervention

• Midline shift ≥10 mm indicates malignant edema with mortality 50-70% without surgery 4
• Hypodensity >50% of MCA territory on CT predicts malignant course 6, 3
• Early midline shift within first 6 hours, even if minimal, predicts rapid edema development 4
• Serial CT scans every 12-24 hours for first 48 hours in patients with large infarcts 4

Decompressive Hemicraniectomy (For Malignant Course)

Note: This section applies if the infarct becomes malignant, though the question specifies non-malignant MCA infarct

• Perform decompressive hemicraniectomy within 48 hours of symptom onset in patients <60 years with clinical deterioration and mass effect on imaging to reduce mortality by approximately 50% 1, 4
• Surgical criteria: declining neurological status with reduced consciousness, mass effect on CT/MRI, exclusion of other causes of impaired consciousness 4
• Contraindications: bilateral nonreactive pupils (not drug-induced), severe irreversible brainstem ischemia, severe comorbidities 4

Secondary Prevention Workup

Cardiac Evaluation

• Obtain transthoracic echocardiography to assess for cardioembolic sources 5
• Consider transesophageal echocardiography if cardioembolic source suspected but not identified on transthoracic study 5
• Continuous cardiac monitoring for at least 24 hours to detect paroxysmal atrial fibrillation 5

Critical Pitfalls to Avoid

• Every 30-minute delay in reperfusion reduces probability of favorable outcome by 10.6%—time is brain 5
• Never wait to assess clinical response to IV tPA before pursuing endovascular therapy; these treatments must proceed in parallel when both are indicated 1, 5
• Do not use full-dose anticoagulation (IV or subcutaneous heparin) for acute stroke treatment—it does not improve outcomes and increases hemorrhage risk (Class III recommendation) 5
• Avoid routine prophylactic anticonvulsants; initiate only if seizures occur 1
• Do not perform lumbar puncture or place central lines after thrombolysis due to bleeding risk 2
• In Japan, a lower alteplase dose (0.6 mg/kg) is used, but the standard international dose remains 0.9 mg/kg 7