What is the diagnosis and treatment for Malignant Middle Cerebral Artery (MCA) infarction?

From the Guidelines

Decompressive hemicraniectomy is the most effective treatment for malignant Middle Cerebral Artery (MCA) infarction, particularly in patients under 60 years with large infarct volumes, and should be performed within 48 hours of stroke onset to reduce mortality and improve functional outcomes. The diagnosis of malignant MCA infarction is typically made through CT or MRI imaging, which confirms a large MCA territory infarction. Initial management includes close neurological monitoring for signs of deterioration and consideration of intravenous thrombolysis with alteplase (0.9 mg/kg, maximum 90 mg) if within 4.5 hours of symptom onset, or mechanical thrombectomy if within 24 hours and there is a large vessel occlusion 1.

Key Considerations

• Decompressive hemicraniectomy has been shown to reduce mortality by close to 50% in patients under 60 years with malignant MCA infarction, with 55% of surgical survivors achieving moderate disability or better (mRS score 2 or 3) at 12 months 1.
• Medical management includes osmotic therapy with mannitol (0.25-1 g/kg IV every 4-6 hours) or hypertonic saline (3% solution at 30-50 mL/hour), head elevation to 30 degrees, maintaining normothermia, normoglycemia, and euvolemia.
• Intubation and mechanical ventilation may be necessary for airway protection, and prophylactic anticonvulsants are not routinely recommended unless seizures occur.
• The benefit of decompressive hemicraniectomy in older patients is less certain, with some studies suggesting a reduction in mortality but with worse functional outcomes compared to younger patients 1.

Treatment Approach

• Rapid diagnosis and intervention are critical in managing malignant MCA infarction.
• Decompressive hemicraniectomy should be considered in patients under 60 years with large infarct volumes and signs of malignant cerebral edema.
• Medical management should focus on preventing further deterioration and managing complications such as increased intracranial pressure and seizures.
• A multidisciplinary approach, including neurology, neurosurgery, and critical care, is essential in managing these complex patients 1.

From the Research

Diagnosis of Malignant Middle Cerebral Artery (MCA) Infarction

• The diagnosis of malignant MCA infarction is based on clinical characteristics and imaging findings, including hypodensity in more than 50% of the MCA territory on computed tomography (CT) and stroke volume greater than 145 ml on diffusion-weighted imaging (DWI) 2, 3.
• Early severe neurological symptoms, such as hemiparesis, gaze deviation, and higher cortical signs, followed by headache, vomiting, papilloedema, and reduced consciousness, may predict a malignant course 3.
• Imaging findings, including the size of the probably infarcted tissue and midline shift on CT, as well as the size of the lesion on DWI, are predictive of a malignant course 3.

Treatment of Malignant Middle Cerebral Artery (MCA) Infarction

• Decompressive surgery, including hemicraniectomy, has been shown to be effective in reducing mortality and improving functional outcome in patients with malignant MCA infarction 2, 4, 3, 5, 6.
• The timing of surgery is crucial, with early decompression (within 48 hours after symptom onset) being more effective in reducing mortality and improving functional outcome 2, 6.
• Patient selection is also important, with younger patients (less than 60 years old) being more likely to benefit from decompressive surgery 2, 6.
• Other treatment strategies, such as intravenous and intra-arterial thrombolysis and mechanical thrombectomy, may also be considered, but their effectiveness is still being studied 2.
• General measures to limit the extent of space-occupying edema, such as osmotic agents, have not been shown to be efficacious 4.