Introduction

1. A Potential Pitfall of Aortic Dissection Presenting as Acute Stroke Chung-Shun Wong 王忠信, Tzong-Luen Wang 王宗倫, Kuo-Chih Chen 陳國智 Department of Emergency Medicine, Shin Kong Wu Ho-Su Memorial Hospital Introduction Acute aortic dissection (AD) is a cardiovascular emergency frequently encountered in the emergency departments. It has varied clinical presentations which made prompt diagnosis difficult. Delayed or missed diagnosis can have fetal consequences with a mortality of 1% per hour if left untreated. (1). Patient with type A AD may present as acute cerebral infarction up to 5-10% due to carotid dissection or global hypoperfusion. It is challenge to emergency physicians and neurologists when AD presenting as acute stroke initially. Case Report A 44 years old man admitted to the emergency department 20 minutes after the onset of slurred speech and left side weakness. He had complained cold sweating but not experienced any chest, abdominal or back pain. He had hypertension history without medical control for years . On examination, he was afebrile. The blood pressure was 130/90mmHg and the pulse rate was 57 beats per minute. There were no cardiac murmurs and no pathologic findings on auscultation of the lungs. The Glasgow Coma Scale was E4V5M6. The neurological examination revealed left side hemiplegia and right central facial palsy (National Instituted of Health Stroke Scale:18). Laboratory examination, including complete blood counts, electrolytes, glucose, prothrombin time and partial thromboplastin time, were normal. Chest radiography was normal. The computer tomography (CT) at 45 minutes from the onset of stroke did not show any intraparenchymal focal lesions or hemorrhage.(fig.1) The neurologist consultant agreed with thrombolytic therapy according to the patient’s neurologic deficits. However, after initial bolus of recombinant tissue plasminogen activator (rt-PA) (6.5mg), the patient complained severe right flank pain at the same time. AD was highly suspected because of the unusual features and thrombolytic therapy was stopped. Emergent aortic CT revealed type A AD with right subclavian artery, common carotid artery, superior mesentery artery and celiac axis involved (fig. 2). Emergent operation with graft replacement of ascending aorta was preformed. The next day after operation, transcranial and extracranial duplex revealed aneurysmal dilation of the right common carotid artery with clear intimal flap and repeat brain CT showed right middle cerebral artery infarction. (fig.3). The patient discharged two months later with neurological sequelae of left side hemiplegia. (fig.1) (fig. 2) (fig.3) Discussion Although sudden onset of chest, back or abdominal pains are present in more than 80% of patients with AD, 10-55% may not experience any significant pain. (2) AD has neurological symptoms in about 18-30% patients, which include syncope, ischemic stroke, ishcemic peripheral neuropathy and spinal cord infraction. (3) It has been reported that type A AD may cause cerebral infarction in up to 5 –10%.(4) Prompt and accurate exclusion of AD with stroke mimics remains a challenge to emergency physicians. Several clinical predictors has been suggested to the challenging scenario, such as chest pain with immediate onset and tearing character, pulse or blood pressure differentials, and mediastinal widening on chest radiography. The probability of AD was low with absence of all predictors (7%), intermediate with isolated finding of aortic pain or mediastinal widening (31% and 39% respectively) and high with isolated pulse or blood pressure differentials or any combination of the 3 variables (>85%).(5) Several institutes have suggest emergent chest X-ray or routine peripheral pulses check to avoid thrombolyis in AD with stroke mimics.(6,7) Our patient was challenging because absence of all three clinical predictors. But initial unusual sweating and subsequent unexplained flank pain during thrombolytic bolus did help us to diagnose correctly at the crucial moment. Beside routine check all above three predictors, thrombolytic therapy should be withheld in acute stroke patients presenting as unusual features, such as sweating or unexplained pain, until AD has been excluded by adequate images. In our institute, we have adopted above recommendations in our routine checklist for thrombolysis screening in acute ischemic stroke scenarios. • References • R.Anand, Ggumberbatch, R.Swallow, J.Loehry. Difficulties in the diagnosis of acute aortic dissection. Hospital Medicine 2003;64:241-243 • Gerber O, Heyer EJ, Vieux U. Painless dissections of the aorta presenting as acute neurologic syndrome. Stroke 1986;17:644-647 • Ijaz A Khan, Chandra K Nair. Clinical , diagnostic, and management perspectives of aortic dissection. Chest 2002;122:311-328 • Cambria RP, Brewster DC, Gertler J, et al. Vascular complications associated with spontaneous aortic dissection. J Vasc Surg 1988;7:199-207 • Von Kodolitsch Y, Schwartz AG, Nienaber CA. Clinical prediction of acute aortic dissection. Arch Intern Med 2000;160:2977-2982 • Wright V, Horvath R, Baird AE. Aortic dissection presenting as acute ischemic stroke. Neurology 2003:61:581-582 • Flemming KD, Brown RD Jr. Acute cerebral infarction caused by aortic dissection: caution in the thrombolytic era. Stroke 1999;30:477-478.