41-year old female. COVID-19 positive. Left side weakness. • Xray of the Week
Figure 1. CT scan and CT perfusion scan in 41 year old COVID-19 positive female with left side weakness.
Figure 2. CT scan and CT perfusion scan of brain with color mapping.
A. Non-contrast CT. Hyperdense M1 segment of right MCA (red arrow) indicating acute thrombus in the artery.
B. Post contrast perfusion CT brain. Large area of decreased blood flow in the right MCA distribution (orange arrows). Normal perfusion of the left MCA distribution (green arrows).
C,D. Cerebral blood volume (CBV) and cerebral blood flow (CBF) maps. Large area of decreased blood flow and decreased cerebral blood volume in the right MCA distribution (orange arrows) with no significant penumbra suggesting large area of core infarction without evidence of reversible ischemia. Normal perfusion of the left MCA distribution (green arrows).
CT angiogram shows occlusion of the M1 segment of the right MCA near its origin without reconstitution of flow distally indicating acute thrombus (white arrow). There is some reconstitution of flow in distal cortical branches via leptomeningeal collaterals. Right ACA, ophthalmic artery and intracranial ICA are patent without significant narrowing. This confirms the findings on the non-contrast CT scan and the CT perfusion scan (Fig.2).
Strokes are the second leading cause of death worldwide, particularly within the middle cerebral artery (MCA) which supplies deep structures of the brain in addition to the frontal, temporal and parietal lobes (1,2). SARS-CoV-2 is a viral disease typically presenting with pulmonary complications. Recently, case studies have found COVID-19 to be linked to neurologic manifestations and an increased risk of cryptogenic large vessel ischemic stroke (4). Such arterial thrombotic complications may be due to inflammation-induced hypercoagulability, cytokine storm, and direct viral-induced endotheliitis (5,7,8). Additional studies also demonstrate abnormalities in fibrinogen, D-dimer, interleukin-6, and troponin levels (5,7).
Presentations of an MCA stroke secondary to COVID-19 have included contralateral hemiparesis, contralateral hemisensory loss, aphasia, dysarthria, and reduced level of consciousness (3, 10). This is in addition to typically seen pulmonary and systemic manifestations of COVID-19 such as fever, cough, and hypoxia (11). Typical risk factors for ischemic stroke include hypertension, diabetes mellitus, cardiovascular disease, hypercholesterolemia, smoking, age, family history, and inflammatory conditions (9). Thus, patients with high risk factors may be at higher risk for mortality. However, patients with minimal or no risk factors with COVID-19 have also presented with ischemic stroke, particularly those under 50 years of age (10,11).
Imaging findings of ischemic stroke in the acute setting on non-contrast CT scan may include hyperdense MCA sign as seen in this case (Fig. 2A) (6). CT may also show decreased attenuation and loss of grey/white matter differentiation due to cytotoxic cerebral edema (6). Perfusion scans are able to differentiate penumbra (potentially reversible with reperfusion therapy) from the core (non-reversible) infarct (6). Core infarct demonstrates increased mean transit time (MTT), markedly decreased CBF and markedly decreased CBV; whereas penumbra demonstrates increased MTT, moderately reduced CBF and near-normal or increased CBV (Fig. 2B-D). The increased CBV is due to autoregulatory vasodilatation. Large vessel occlusion may be identified on CT angiogram (Fig. 3) (6). On chest x-ray, associated COVID-19 findings are predominantly peripheral with patchy or diffuse ground glass and reticulonodular opacities (12). The true association between COVID-19 and increased risk of stroke is still under study, with new evidence-based guidelines underway (5,8).
Typical treatment and management of an ischemic stroke include restoration of vascular supply via IV tPA, thrombectomy, or stent placement (2). With the added uncertainty and hypercoagulable state associated with COVID-19, anticoagulation and further management should be individualized on a case by case basis (5).
Khaku AS, Tadi P. Cerebrovascular Disease (Stroke) [Updated 2020 Aug 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430927/
Nogles TE, Galuska MA. Middle Cerebral Artery Stroke. [Updated 2020 Aug 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK556132
R. Kollmar, S. Schwab, Ischaemic stroke: acute management, intensive care, and future perspectives, BJA: British Journal of Anaesthesia, Volume 99, Issue 1, July 2007, Pages 95–101, https://doi.org/10.1093/bja/aem138
Merkler AE, Parikh NS, Mir S, et al. Risk of Ischemic Stroke in Patients With Coronavirus Disease 2019 (COVID-19) vs Patients With Influenza. JAMA Neurol. Published online July 02, 2020. doi:10.1001/jamaneurol.2020.2730
Tsivgoulis G, Katsanos AH, Ornello R, Sacco S. Ischemic Stroke Epidemiology During the COVID-19 Pandemic: Navigating Uncharted Waters With Changing Tides. Stroke. 2020;51(7):1924-1926. doi:10.1161/STROKEAHA.120.030791
Lin MP, Liebeskind DS. Imaging of Ischemic Stroke. Continuum (Minneap Minn). 2016;22(5, Neuroimaging):1399-1423. PubMed full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5898964/ doi:10.1212/CON.0000000000000376
Fifi JT, Mocco J. COVID-19 related stroke in young individuals. Lancet Neurol. 2020;19(9):713-715. doi:10.1016/S1474-4422(20)30272-6
Ntaios G, Michel P, Georgiopoulos G, et al. Characteristics and Outcomes in Patients With COVID-19 and Acute Ischemic Stroke: The Global COVID-19 Stroke Registry. Stroke. 2020;51(9):e254-e258. doi:10.1161/STROKEAHA.120.031208
“Stroke.” National Heart Lung and Blood Institute, U.S. Department of Health and Human Services, www.nhlbi.nih.gov/health-topics/stroke
Oxley TJ, Mocco J, Majidi S, et al. Large-Vessel Stroke as a Presenting Feature of Covid-19 in the Young. N Engl J Med. 2020;382(20):e60. doi:10.1056/NEJMc2009787
Yaghi S, Ishida K, Torres J, et al. SARS-CoV-2 and Stroke in a New York Healthcare System [published correction appears in Stroke. 2020 Aug;51(8):e179]. Stroke. 2020;51(7):2002-2011. doi:10.1161/STROKEAHA.120.030335
Cozzi D, Albanesi M, Cavigli E, et al. Chest X-ray in new Coronavirus Disease 2019 (COVID-19) infection: findings and correlation with clinical outcome. Radiol Med. 2020;125(8):730-737. doi:10.1007/s11547-020-01232-9
Rabab Zaidi is an aspiring radiologist and fourth year medical student at the Loyola University Chicago Stritch School of Medicine (SSOM). She currently serves as the Community Support Co-Lead for the Loyola University COVID-19 Response Team and Co-President of the Radiology Interest Group at SSOM. At the Stritch School of Medicine, she has also worked with the Department of Radiation Oncology to study prostate cancer imaging and adaptive radiotherapy techniques, where she learned about the intersection of patient care and radiology. Rabab graduated magna cum laude with a degree in Economics from Loyola University Chicago in 2016. She is further passionate about mentorship, advocacy, and photography.
Follow Rabab Zaidi on Twitter @ZaidiRabab
All posts by Rabab Zaidi
Kevin M. Rice, MD is the president of Global Radiology CME
Dr. Rice is a radiologist with Renaissance Imaging Medical Associates and is currently the Vice Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.
Follow Dr. Rice on Twitter @KevinRiceMD
All posts by Kevin M. Rice, MD