Identification of Painless Aortic Dissection before Thrombolytic Treatment for
Acute Ischemic Stroke
Chen-Hsiung Huanga,c*,M.D., Hui-Chun Huangb,c*,M.D., Kang-Hsu Linb,c,M.D.,
Wei-Kung Chena,c,M.D., Chon-Haw Tsaib,c,d,M.D.,Ph.D.
a
Department of Emergency Medicine; bDepartment of Neurology, China Medical
University Hospital; cSchool of Medicine, College of Medicine; dGraduate Institute of
Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan
*Authors contributed equally.
Correspondence: Dr. Chon-Haw Tsai or Wei-Kung Chen, Department of Neurology
or Emergency Medicine, China Medical University Hospital, 2, Yuh-Der Road, 404
Taichung, Taiwan
Tel: +886-4-22052121 Ext.5035
Fax: +886-4-22344055
E-mail: windymovement@yahoo.com.tw(CH Tsai); ercwk@mail.cmuh.org.tw(WK
Chen)
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.
Key Words: dissection, stroke, thrombolysis
Word count: 674
_______________________________
Identify painless aortic dissection in 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 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 neurological 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 (CTA) before thrombolytic treatment.
A 57-year-old man with hypertension presented to our emergency department
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 mmHg, pulse 55 beats/minute, respiration 20 times/minute). He
denied chest pain or transient loss of consciousness. A neurological 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. 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, respectively (Fig. 1A
and 1B). 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 2B). 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
neurological 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 neurological
deficits without pain [1], and the narrow time window in which the physicians have to
make the diagnosis.
Several methods have been recommended in order 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 non-invasive tool to diagnose aortic dissection before rt-PA infusion [3].
However, even though 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 emergency department 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 prior to rt-PA treatment.
It should be performed in acute ischemic stroke patients, particularly in those with
watershed CT perfusion defects, to exclude the possibility of aortic dissection before
thrombolytic treatment.
References
[1] Gaul C, Dietrich W, Friedrich I, et al. Neurological symptoms in type a aortic
dissections. Stroke 2007;38:292-297.
[2] Tsai TY, Seow VK, Shen TC, et al. Painless aortic dissection masquerading as
brainstem stroke with catastrophic anticoagulant use. Am J Emerg Med
2008;26:253 e251-252.
[3] Iguchi Y, Kimura K, Sakai K, et al. Hyper-acute stroke patients associated with
aortic dissection. Intern Med 2010;49:543-547.
[4] Zinkstok SM, Vergouwen MD, Engelter ST, et al. Safety and functional outcome
of thrombolysis in dissection-related ischemic stroke: A meta-analysis of
individual patient data. Stroke 2011;42:2515-2520.
[5] Koch S, Rabinstein AA, Romano JG, et al. Diffusion-weighted magnetic
resonance imaging in internal carotid artery dissection. Arch Neurol
2004;61:510-512.
[6] Bladin CF, Chambers BR. Clinical features, pathogenesis, and computed
tomographic characteristics of internal watershed infarction. Stroke
1993;24:1925-1932.
Figure Legend
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. CT 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).