Case Report

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American Journal of Emergency Medicine

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Identification of painless aortic dissection before Thrombolytic treatment for acute ischemic stroke?

Abstract

Early detection of acute ischemic stroke secondary to painless aortic dissection is a challenge for emergency physicians, especially when under the stress of the 3-hour golden time window for thrombolytic therapy. We reported a 57-year-old man with acute right hemisphere watershed ischemic stroke caused by painless Type A aortic dissection was diagnosed in time with computed tomo- graphic (CT) angiography. The possible detrimental impact which may have been incurred by thrombolytic therapy was avoided. We suggest that cerebral CT angiography, covering from the aortic arch to intracranial arteries, should be performed in acute ischemic stroke patients, particularly in those with watershed CT perfusion deficits, to exclude the possibility of aortic dissection before thrombolytic treatment.

Thrombolytic treatment for acute ischemic stroke requires careful selection of patients. Painless aortic dissection with only focal neurologic deficits can be a challenge for emergency physicians, and inadvertently treating this situation with thrombolytic agents may threaten the patient’s life. Herein, we present a patient with acute ischemic stroke caused by type A aortic dissection, which was diagnosed in time with Computed tomography angiography before thrombolytic treatment.

A 57-year-old man with hypertension presented to our emer- gency department (ED) because of sudden onset of left limb weakness and slurred speech for 30 minutes. His Glasgow coma scale score was E3M6V5, and his vital signs were stable (blood pressure 118/72 mm Hg, pulse 55 beats per minute, respiration 20 times per minute). He denied chest pain or transient loss of consciousness. A neurologic examination disclosed left central type facial palsy and left hemiplegia (Medical Research Council, MRC 1/5) with left extensor plantar response. The National Institute of Health stroke score was 17. Biochemistry tests were unremarkable. Computed tomography (CT) of the brain showed no hemorrhage. The patient was eligible for intravenous recombinant tissue activator plasminogen (rt-PA) treatment at the spot. Cerebral CT perfusion and CTA were performed in quick succession. The transverse perfusion map showed decreased cerebral blood flow and cerebral volume in the right anterior-middle cerebral arterial junction and right middle-posterior cerebral arterial junction,

? The study was supported in part by the Taiwan Department of Health Clinical Trial and Research Center of Excellence(DOH101-TD-B-111-004), “Aim for the Top University Plan” of the National Chiao Tung University and Ministry of Education” and China Medical university hospital (DMR-101-112), Taiwan.

respectively (Fig. 1A and B). The CTA covering from the aortic arch to the intracranial arteries revealed a type A aortic dissection extending from the Ascending aorta to the right Common carotid artery (Fig. 2A and B). Thrombolytic treatment was withheld because of the painless acute aortic dissection. His family refused to allow an operation due to the high risk of mortality. About 3.5 hours after onset, his left-sided hemiplegia had completely resolved (MRC 1/5 to 5/5). He was discharged 5 days later without any neurologic deficits.

Strict inclusion and exclusion criteria should be adhered to acute ischemic stroke patients before rt-PA treatment. Administering thrombolytic agents to undiagnosed patients with aortic dissection may contribute to the extension of the dissection, worsening the hemothorax, or hemopericardium [1,2]. However, early detection of acute ischemic stroke secondary to aortic dissection may be hindered by the multifaceted clinical presentations, particularly in patients with only neurologic deficits without pain [1] and the narrow time window in which the physicians have to make the diagnosis.

Several methods have been recommended to make an early diagnosis. Careful attention should be paid to subtle symptoms and signs such as chest discomfort, carotid bruits, or asymmetric radial pulsation. Nevertheless, these clinical clues are not always present. Chest radiography may be helpful but cannot provide perfect diagnostic accuracy for aortic dissection. Carotid duplex ultrasound offers a rapid and Noninvasive tool to diagnose aortic dissection before rt-PA infusion [3]. However, although positive findings can be detected by ultrasonography, aortic CT is still required to differentiate between an aortic dissection extending into the cervical arteries and a primary cervical arterial dissection, in which rt-PA treatment should not be withheld [4].

Our patient presented with acute stroke within the 3-hour time window and was initially considered to be a suitable candidate for thrombolytic treatment. Cerebral CT perfusion demonstrated a unilateral cortical watershed infarction. This unique pattern leads to the consideration of Internal carotid artery disease caused by either occlusion or dissection [5,6]. The tentative diagnosis was further elucidated by CTA, which revealed a type A dissection extending from the ascending aorta to right common carotid artery. Thrombolytic treatment was withheld in time under this diagnosis. The duration from the arrival at the ED to acquisition of all CT examinations was 22 minutes, which was within the time window of first hour surveys for acute stroke patients.

The current report illustrates that cerebral CT perfusion followed by CTA is possible to assess the aortic arch, cervical, and intracranial arteries without significantly lengthening the duration of stroke CT surveys before rt-PA treatment. It should be performed in acute

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Fig. 1. Cerebral CT perfusion illustrated decreased cerebral blood flow (A) and cerebral volume (B) in the anterior-middle cerebral arteries junction and middle-Posterior cerebral arteries junction, respectively.

Fig. 2. computed tomographic angiography covering from the aortic arch to intracranial arteries illustrated a type A aortic dissection extending from the ascending aorta (A) to right common carotid artery (B, arrow).

ischemic stroke patients, particularly in those with watershed CT Perfusion defects, to exclude the possibility of aortic dissection before thrombolytic treatment.

Chen-Hsiung Huang MD¹

Department of Emergency Medicine, China Medical University Hospital

Taichung, Taiwan School of Medicine, College of Medicine, China Medical University

Taichung, Taiwan

Hui-Chun Huang MD¹ Kang-Hsu Lin MD

Department of Neurology, China Medical University Hospital

Taichung, Taiwan School of Medicine, College of Medicine, China Medical University

Taichung, Taiwan

Wei-Kung Chen MD

Department of Emergency Medicine, China Medical University Hospital

Taichung, Taiwan School of Medicine, College of Medicine, China Medical University

Taichung, Taiwan E-mail address: [email protected]

Chon-Haw Tsai MD, PhD

Department of Neurology, China Medical University Hospital

Taichung, Taiwan School of Medicine, College of Medicine, China Medical University

Taichung, Taiwan Graduate Institute of Neural and Cognitive Sciences China Medical University, Taichung, Taiwan

E-mail address: [email protected]

¹Authors contributed equally.

http://dx.doi.org/10.1016/j.ajem.2012.12.027

References

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