The patient exhibits findings of a stroke of the superior division of the middle cerebral artery. Thrombolytic therapy is indicated in ischemic stroke if symptoms have been present for less than 3-4.5 hours.
Thrombolytics include tissue plasminogen activator (tPA), anistreplase, urokinase, and streptokinase. Two randomized clinical trials - NINDS Trial 1 and NINDS Trial 2 - found that in 624 subjects randomized to either placebo or tPA within 3 hours of stroke onset, patients treated with tPA within 3 hours of onset had a substantially better chance of functional independence with minimal or no disability 3 months after treatment. Given the risk of bleeding, therapy is contraindicated in patients with active bleeding, a history of intracranial bleeding, recent surgery, bleeding diatheses, or severe hypertension.
Bivard et al. discuss the use of thrombolytics in acute ischemic stroke. Current clinical guidelines recommend the use of tPA following a brain non-contrast CT to exclude hemorrhage within 4.5 hours of onset. Studies using advanced imaging (incorporating perfusion CT or diffusion/perfusion MRI) may allow the use of thrombolytics, or possibly endovascular therapy, in an extended time window. Recent clinical trials have suggested that Tenecteplase, used in conjunction with advanced imaging selection, resulted in more effective reperfusion than tPA, which translated into increased clinical benefit.
Bernheisel et al. discuss subacute management of ischemic stroke. The subacute period after a stroke refers to the time when the decisions not to administer thrombolytics is made up until two weeks after the stroke occurred. Imaging studies, including magnetic resonance angiography, carotid artery ultrasonography, and/or echocardiography, may be indicated to determine the cause of the stroke. For secondary prevention of future strokes, antiplatelet therapy with aspirin should be initiated within 24 hours of ischemic stroke in all patients without contraindications, and one of several antiplatelet regimens should be continued long-term. Statin therapy should also be given in most situations.
Figure A shows a normal head CT.
Illustration A depicts a CT showing evidence of a hemorrhagic stroke. On CT without contrast, blood appears hyperdense. Illustration B depicts a CT without evidence of hemorrhage and a hypodense area representing the point of ischemic infarct, classically appearing at 24-hours post infarct.
Answer 1: The CT confirms that the stroke is ischemic and not hemorrhagic.
Answer 3: Use of tPA is contraindicated for systolic blood pressures greater than 185 or diastolic blood pressures greater than 110, neither of which are present in this patient.
Answer 4: Aggressive lowering of blood pressure may reduce cerebral perfusion and worsen stroke, and is not generally recommended.
Answer 5: Waiting for an MRI could waste valuable time, resulting in a missed opportunity for effective thrombolytic therapy.
Bivard A1, Lin L, Parsonsb MW. Review of Stroke Thrombolytics. J Stroke. 2013 May;15(2):90-98. Epub 2013 May 31.
PMID:24324944 (Link to Abstract)
Bernheisel CR1, Schlaudecker JD, Leopold K. Subacute management of ischemic stroke. Am Fam Physician. 2011 Dec 15;84(12):1383-8.
PMID:22230273 (Link to Abstract)