Malignant Middle Cerebral Artery Infarct

Large space-occupying middle cerebral artery or hemispheric ischaemic brain infarcts are associated with the development of massive brain oedema, which may lead to herniation and early death. This condition, which has been described as malignant middle cerebral artery infarction, is associated with 80% mortality due to herniation during the first week [40, 41].

About 5% of strokes result in this complication, and almost all are caused by embolic occlusion of the proximal middle cerebral artery. The patient’s condition usually deteriorates on the third to fifth day, despite maximal conservative ICU treatment [42].

Young patients are particularly at risk because they have little cerebral atrophy and, therefore, little spare space for any brain swelling to occur without significant symptoms.

Hemicraniectomy relieves mechanical compression of the brain, and may improve cerebral perfusion and prevent further ischaemia. Evidence suggests if indicated, it should be performed within 48 hours of stroke onset [41].

A section of skull is removed to allow the brain to swell. The bone is stored, and can be replaced at a later date.

UK National Guidelines [1]

Patients with middle cerebral artery (MCA) infarction who meet all the criteria below should be considered for decompressive hemicraniectomy:

• Pre-stroke modified Rankin Scale score of less than 2;
• Clinical deficits indicating infarction in the territory of the MCA;
• NIHSS score of more than 15;
• A decrease in the level of consciousness to a score of 1 or more on item 1a of the NIHSS (i.e no longer alert);
• Signs on CT of an infarct of at least 50% of the MCA territory with or without additional infarction in the territory of the anterior or posterior cerebral artery on the same side, or infarct volume greater than 145 cubic centimetres on diffusion-weighted MRI.

Patients should be referred to neurosurgery within 24 hours of stroke onset and treated within 48 hours of stroke onset.

A previous upper age limit of 60 years was withdrawn on the basis of the DESTINY-II trial [40]. It is recommended that decisions to undertake major life-saving surgery need to be carefully considered on an individual basis, but patients should not be excluded from this treatment by age alone.

ED physicians should be aware of this likely fatal complication, and of the treatment options.

Neurosurgical centres may not have much experience of the procedure, and senior decision makers may need to be involved to get the patient appropriate treatment.

Learning Bite

Decompressive hemicraniectomy can be lifesaving in malignant MCA stroke