Title: Neuroimaging & Endovascular Therapy in Acute Ischemic Stroke<br/>Author: Kim Boswell<br/><a href='http://umem.org/profiles/faculty/311/'>[Click to email author]</a><hr/><p>
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The initial evaluation for stroke has always included obtaining an emergent CT Head to evaluate for the possibility of hemorrhage and to identify clear areas of subacute ischemia, if present. As our imaging techniques improve and our interventions become more advanced, we are changing out approach to the urgent evaluation of the possible AIS patient.</p>
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As part of your initial evaluation of the possible AIS patient you should perform a Rapid Arterial Occlusion Evaluation Scale (see below). A score of greater than or equal to 5 warrants concern for large vessel occlusion (LVO). In this instance, a CT Angio of the head & neck as well as a CT perfusion (CT-P) scan should be obtained. The CTA will identify the presence of a thrombus resulting in a LVO. So, what does the CT perfusion tell you? CT-P identifies the penumbra – or the area of brain that is at risk, but not yet irreparably damaged. The penumbra is the area of brain that could most benefit from reperfusion strategies such as thrombolysis and mechanical thrombectomy and the information provided by the CT-P can assist with immediate treatment decisions.</p>
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Why is this important? Well, the majority of patients presenting with AIS have contraindications to thrombolysis (nearly 69%). Thrombolysis can only be given within 4.5 hours of symptom onset based on current recommendations. Endovascular interventions, such as mechanical thrombectomy, can be performed <strong><em>up to 24 hours after symptom onset</em></strong> for select patients, which means that more patients may have treatment options after the thrombolysis window closes. Revascularization can potentially improve outcomes in patients, who previously, wouldn’t have had treatment options.</p>
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Rapid Arterial Occlusion Evaluation Scale:</p>
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- Facial palsy: None (0), mild (1), moderate (2)</p>
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- Arm motor function impairment: Normal to mild (0), moderate (1), and severe (2)</p>
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- Leg motor function impairment: Normal to mild (0), moderate (1), and severe (2)</p>
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- Head/gaze deviation: Absent (0), present (1)</p>
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- Aphasia: Performs tasks correctly (0), performs one task correctly (1), performs neither task (2)</p>
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- Agnosia: Recognizes his/her arm and deficit (0), does recognize his/her arm but not or deficit (1), does not recognize his/her arm or deficit (2)</p>
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<fieldset><legend>References</legend>
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Herpich, Franziska MD<sup xmlns:mrws="http://webservices.ovid.com/mrws/1.0">1,2</sup>; Rincon, Fred MD, MSc, MB.Ethics, FACP, FCCP, FCCM<sup xmlns:mrws="http://webservices.ovid.com/mrws/1.0">1,2</sup> Management of Acute Ischemic Stroke, Critical Care Medicine: November 2020 - Volume 48 - Issue 11 - p 1654-1663 doi: 10.1097/CCM.0000000000004597</p>
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<a href="https://pmid.us/31662037" target="_blank">Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association.</a> Stroke. 2019 Dec;50(12):e344-e418. doi: 10.1161/STR.0000000000000211. Epub 2019 Oct 30.</p>
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