What is the management of an ischemic core infarct in the left Middle Cerebral Artery (MCA)?

Management of Ischemic Core Infarct in the Left Middle Cerebral Artery

For patients with an ischemic core infarct in the left MCA territory, early identification of malignant progression followed by prompt intervention is critical, with decompressive craniectomy being the most effective life-saving measure for those with significant brain swelling.

Initial Assessment and Diagnosis

• Clinical predictors of malignant course include high stroke severity scores, nausea/vomiting, and progressive neurological deterioration 1

• Radiological assessment should include:

  • Non-contrast CT to rule out hemorrhage and estimate ischemic core using ASPECTS score 2
  • CT angiography to confirm MCA occlusion and assess collateral circulation 2
  • Diffusion-weighted MRI (when available) to precisely determine infarct volume, as it is the gold standard for ischemic core assessment 2

• Large infarct cores (ASPECTS ≤6) on initial imaging indicate higher risk of malignant progression and hemorrhagic transformation 2

• Multiphase CT angiography can provide valuable information about collateral circulation, which is an independent predictor of outcome 2

Acute Management

• For patients presenting within the treatment window:

  • Intravenous thrombolysis with alteplase should be administered within 4.5 hours if no contraindications exist 2
  • Mechanical thrombectomy is strongly recommended for patients with proximal MCA occlusion, particularly those with small-to-moderate ischemic cores (ASPECTS ≥6) 2
  • For patients with large ischemic cores (ASPECTS <6), mechanical thrombectomy may still be beneficial but carries higher risk of hemorrhagic transformation 2

• Blood pressure management:

  • For patients who undergo mechanical thrombectomy, maintain BP ≤180/105 mmHg during and for 24 hours after the procedure 2
  • After successful reperfusion, more aggressive BP control (<180/105 mmHg) might be reasonable 2

• Antiplatelet therapy:

  • Administration of aspirin (160-300 mg) is recommended within 24-48 hours after stroke onset 2
  • For those treated with IV alteplase, aspirin administration should generally be delayed until 24 hours later 2

Management of Cerebral Edema and Increased Intracranial Pressure

• Early transfer to a center with neurosurgical expertise and neuromonitoring capabilities is recommended for patients with signs of large MCA infarction 1

• Initial medical management includes:

  • Elevating the head of bed to 30 degrees 1
  • Restricting free water and avoiding hypotonic fluids 1
  • Avoiding antihypertensive agents that cause cerebral vasodilation 1

• For patients with clinical deterioration from cerebral swelling:

  • Osmotic therapy with mannitol or hypertonic saline is reasonable, targeting serum osmolarity of 315-320 mOsm/L 1
  • Brief moderate hyperventilation can be used as a bridge to more definitive therapy 1

Surgical Intervention

• Decompressive craniectomy with dural expansion is the most effective intervention for malignant MCA infarction, reducing mortality by approximately 50% in patients ≤60 years 1, 3

• Key considerations for decompressive craniectomy:

  • Optimal timing is within 48 hours of stroke onset, before severe neurological deterioration occurs 1
  • The procedure should include a large bone flap (at least 12 cm diameter), extension down to the temporal skull base, and wide dural opening 1
  • Decrease in level of consciousness attributed to brain swelling is a reasonable trigger for intervention 1

• Decompressive craniectomy may also be considered in patients >60 years, although functional outcomes are worse than in younger patients 1

Monitoring and Complications

• Hemorrhagic transformation is a common complication of severe stroke and is associated with blood-brain barrier disruption 2

• The risk of hemorrhagic transformation increases with:

  • Large infarct size 2
  • Use of thrombolytic agents 2
  • Reperfusion of severely damaged tissue 2

• Transcranial Doppler sonography can be used as a non-invasive method to monitor elevated intracranial pressure, with increased pulsatility indexes correlating with midline shift 2

Follow-up Care

• After decompressive surgery, patients require intensive care unit monitoring and should use a custom-fitted protective helmet until cranioplasty 1
• Cranioplasty can be scheduled when there are no signs of persisting brain swelling, typically 12-16 weeks after discharge 1

Prognosis

• Despite aggressive management, mortality remains high with medical management alone for malignant MCA infarction 1, 4
• Predictors of poor outcome include:
  • Reduced consciousness at presentation 4
  • Hemianopia 4
  • Complete MCA territory infarction 4
  • Younger patients (mean age 57) are more likely to develop fatal brain edema compared to older patients 4