What is the recommended management for patients presenting with left Middle Cerebral Artery (MCA) and left Posterior Inferior Cerebellar Artery (PICA) strokes?

Management of Left MCA and Left PICA Strokes

Immediate Acute Management

For both left MCA and left PICA strokes, administer intravenous alteplase 0.9 mg/kg (maximum 90 mg) over 60 minutes with 10% as a bolus over 1 minute if the patient presents within 4.5 hours of symptom onset and meets eligibility criteria. 1

Reperfusion Therapy Decision Algorithm

For Left MCA Stroke:

• Proceed immediately with mechanical thrombectomy for proximal MCA occlusions (M1 or proximal M2) with ASPECTS ≥6, initiating groin puncture within 6 hours of symptom onset 1, 2
• Use stent retrievers as the preferred mechanical thrombectomy device (Class I evidence) 2
• Target TICI grade 2b/3 angiographic result for optimal functional outcomes 2
• Do not wait to assess clinical response to IV alteplase before pursuing endovascular therapy—this delays treatment and worsens outcomes 2

For Left PICA Stroke:

• Intra-arterial thrombolysis may be considered for basilar/vertebral artery occlusions, though evidence is more limited than for anterior circulation 1
• The decision to treat with endovascular therapy should be made by a physician with stroke expertise in consultation with the neuro-interventionalist 1

Blood Pressure Management

• Maintain blood pressure ≤180/105 mmHg during and for 24 hours after mechanical thrombectomy 1, 3, 2
• For patients receiving IV alteplase, blood pressure must be reduced below 185/110 mmHg to avoid hemorrhagic complications 1
• Monitor blood pressure every 15 minutes during and after IV alteplase infusion for 2 hours, then every 30 minutes for 6 hours, then hourly until 24 hours 1
• Avoid aggressive blood pressure reduction that causes cerebral vasodilation, as this may decrease perfusion pressure and worsen ischemia 1, 3

Antiplatelet Therapy

• Administer aspirin 325 mg daily within 24-48 hours after stroke onset, but delay for 24 hours in patients who received thrombolytic therapy 1, 3, 2, 4
• If true aspirin allergy exists, substitute clopidogrel 75 mg orally daily 3
• Avoid ibuprofen as it blocks aspirin's antiplatelet effects 3

Critical Monitoring for Malignant MCA Infarction

Left MCA strokes carry significant risk of malignant cerebral edema, particularly with complete MCA territory infarction:

Clinical Warning Signs

• Severe neurological deficit with hemiplegia, hemisensory loss in face/arm/leg, hemianopia, and global aphasia 5
• Reduced consciousness or coma developing on day of admission predicts brain death from edema 5
• Nausea, vomiting, and progressive neurological deterioration 3

Edema Management Protocol

• Position head of bed elevated at 20-30 degrees to facilitate venous drainage 3, 6
• Restrict free water to avoid hypo-osmolar fluid that worsens edema 3, 6
• Correct hypoxemia, hypercarbia, and hyperthermia 3, 6
• Administer mannitol 0.25-0.5 g/kg IV over 20 minutes every 6 hours (maximum 2 g/kg) for significant edema and increased intracranial pressure 3, 6
• Hypertonic saline is an effective alternative to mannitol 6

Surgical Decompression Criteria

Decompressive hemicraniectomy significantly reduces mortality in malignant MCA infarction and should be performed within 48 hours of stroke onset, before severe neurological deterioration occurs. 3, 6

Optimal candidates:

• Patients under 60 years of age (strongest evidence) 3
• Complete or near-complete MCA territory infarction 5
• Progressive neurological deterioration despite medical management 6

Technical requirements:

• Large bone flap (at least 12 cm diameter) 3
• Extension down to temporal skull base 3
• Wide dural opening 3

For patients over 60 years: Surgery may be reasonable, but likelihood of resulting severe disability (50% of survivors) should be discussed with patient/family, as medical management alone has not proven efficacious 3, 6, 5

PICA-Specific Considerations

For left PICA strokes with cerebellar infarction:

• Monitor closely for brainstem compression from edematous cerebellar tissue 6
• Suboccipital craniectomy is life-saving for patients with brainstem compression 6
• Consider cerebrospinal fluid drainage by ventriculostomy for acute hydrocephalus following stroke 6

Post-Acute Care

Intensive Monitoring

• Admit to intensive care or stroke unit 1
• Perform neurological assessments every 15 minutes during alteplase infusion for 2 hours, then every 30 minutes for 6 hours, then hourly until 24 hours 1
• If severe headache, acute hypertension, nausea, vomiting, or worsening neurological examination develops, discontinue alteplase infusion and obtain emergency head CT 1

Follow-up Imaging

• Obtain follow-up CT or MRI at 24 hours after IV alteplase before starting anticoagulants or antiplatelet agents 1
• Obtain repeat imaging if headache is severe, sudden, or associated with neurological worsening to rule out hemorrhagic transformation 4

Catheter Management

• Delay placement of nasogastric tubes, indwelling bladder catheters, or intra-arterial pressure catheters if patient can be safely managed without them 1
• Indwelling urethral catheter is not routinely needed prior to IV thrombolysis unless patient is acutely retaining urine 1
• If inserted, assess daily and remove as soon as possible 1

Common Pitfalls

• Brain edema peaks at 3-5 days but can persist—maintain vigilance beyond the acute period 4, 6
• Younger patients (mean age 57 years) are more likely to die from brain edema than older patients, and die sooner (mean 5 days vs 37 days) 5
• Medical management alone (including osmotic diuretics) without surgical decompression has not proven efficacious for malignant MCA infarction 3
• Every 30-minute delay in recanalization decreases chance of good outcome by 8-14%—establish rapid transfer protocols to endovascular-capable centers 2
• Mortality for large MCA infarction is 17% with severe disability in 50% of survivors 5