A 67-year-old man is brought to the emergency department due to right-sided weakness, numbness, and slurred speech. The patient was in his usual state of health last night but awoke this morning with these symptoms. He has a history of hypertension, hyperlipidemia, type 2 diabetes mellitus, and peripheral arterial disease. The patient does not drink alcohol regularly but has a 45-pack-year history. Physical examination shows an awake and alert patient with right-sided weakness, hemisensory loss, homonymous hemianopsia, and aphasia. CT scan of the head reveals a large left hemispheric infarction due to an occluded middle cerebral artery. The patient is hospitalized but is not treated with fibrinolytic therapy or mechanical thrombectomy due to ineligibility. Forty-eight hours later, he becomes obtunded. Temperature is 38.3 C (100.9 F), blood pressure is 154/86 mm Hg, and pulse is 64/min. Physical examination now shows complete right hemiplegia and deviation of the eyes to the left. Which of the following is the best next step in management of this patient?
This patient's rapid neurologic deterioration (eg, obtundation, eye deviation) 48 hours after a large ischemic stroke is concerning for malignant hemispheric infarction (MHI), a life-threatening condition that may occur when an ischemic stroke causes massive cerebral edema and/or hemorrhagic transformation:
Cerebral edema results from endothelial dysfunction and breakdown of the blood-brain barrier. The resulting mass effect and increase in intracranial pressure (ICP) can cause brain herniation (eg, herniation of the temporal lobe onto the brainstem).
Hemorrhagic transformation occurs when blood extravasates from injured cerebral vessels into the brain parenchyma. The larger the infarct, the greater the risk of hemorrhagic transformation.
Strokes that cause MHI typically are due to occlusion of a large vessel (eg, internal carotid, proximal middle cerebral artery) and initially present with severe deficits (eg, right-sided weakness, hemisensory loss, aphasia) due to the large affected area of the brain. Deterioration usually occurs in the first 48 hours but can be more gradual (up to a week).
Patients with suspected MHI (such as this one) should have a noncontrast CT scan of the head performed emergently to determine the extent of edema and/or hemorrhage and guide further management. Decompressive hemicraniectomy is often necessary.
(Choice A) Although this patient has a fever, the most likely cause is a defect in central thermoregulation (due to extensive stroke or intracerebral hemorrhage) rather than infection (for which blood cultures and antibiotics would be indicated). Prior to any other testing, a noncontrast CT scan of the head should be performed to assess for life-threatening cerebral edema or hemorrhagic transformation.
(Choices B and C) Osmotic diuretics (eg, intravenous mannitol, hypertonic saline) can decrease cerebral edema (eg, due to stroke) by creating an osmolar gradient that draws water out of edematous brain tissue. Given the high suspicion for elevated ICP in this patient, administering either agent is reasonable; however, subsequent observation is insufficient. This patient may require emergency craniectomy, and a CT scan should be obtained emergently to diagnose the extent of cerebral edema and/or hemorrhage and guide management.
(Choice D) Although MRI has greater sensitivity for the diagnosis of ischemic stroke, noncontrast CT scan of the head is the preferred modality for detection of cerebral hemorrhage due to its better availability and testing rapidity.
Educational objective:
Massive cerebral edema and/or hemorrhagic transformation, with rapid neurologic deterioration, can occur following a large, hemispheric ischemic stroke. Noncontrast CT scan of the head should be performed emergently to determine the extent of edema and/or hemorrhage and guide management.