TOPIC: Signs and Symptoms of Chest Diseases TYPE: Medical Student/Resident Case Reports INTRODUCTION: An acute aortic dissection (AAD) is defined as a tear in the intimal layer of the aorta and is considered a rare cardiovascular event [1]. AAD can contribute to the weakening of the adjacent aortic intimal layer, thereby resulting in the expansion of the dissection to other arteries, reduction of blood flow through the aortic lumen, and reduction of vital organ perfusion [2]. We present a case of a painless AAD, which was identified after a syncopal episode and manifested as right lower extremity weakness along with a "lump in the throat." CASE PRESENTATION: A 70 year old female with a history of hypertension presented to the emergency department (ED) after having a syncopal episode just prior to arrival. The patient denied any pain but reported non-specific tightness in her neck and new-onset right lower extremity weakness. Neurological examination revealed reduced muscle strength and decreased sensitivity to light touch in the right lower extremity. Computed tomography (CT) Angiography of the head and neck revealed a dissection involving a significant portion of the aortic arch and the brachiocephalic, left common carotid, and subclavian arteries. The dissection of the left subclavian artery extended to the left vertebral artery. CT of the chest, abdomen, and pelvis with contrast revealed a type I aortic dissection that extended from the aortic root to the aortic bifurcation. The patient was subsequently transferred to our tertiary care center and underwent emergent vascular surgery. DISCUSSION: An AAD classically presents with severe, acute chest, abdominal, or back pain [3]. Atypical symptoms include migratory pain [4], nonspecific gastrointestinal symptoms such as vomiting or diarrhea [5], and neurological symptoms such as seizures, syncope, paraparesis, and ischemic neuropathy [6]. Painless AAD has been associated with persistent altered mental status, syncope, and focal neurological deficits [7]. Early diagnosis is critical due to its high mortality rate [1]. Barriers to early diagnosis include identification of individuals with little to mild pain [8] as well as understanding the differing presentations between genders. Although less frequently affected by AAD, women tend to present at an older age, with atypical symptoms, and demonstrate higher mortality rates when compared to their male counterparts [9]. CONCLUSIONS: Acute aortic dissection can have a wide array of presentations that may often imitate common cardiovascular conditions. This case underscores the importance of maintaining a high index of suspicion for AAD in the presence of well established risk factors and non-specific symptom presentations. REFERENCE #1: Sen I, Erben YM, Franco-Mesa C, DeMartino RR. Epidemiology of aortic dissection. Semin Vasc Surg. 2021;34(1):10-17 REFERENCE #2: Juang D, Braverman AC, Eagle K. Aortic dissection. Circulation. 2008 Sep 30;118(14):e507-10. doi: 10.1161/CIRCULATIONAHA.108.799908. PMID: 18824647. REFERENCE #3: Siegal EM. Acute aortic dissection. J Hosp Med. 2006;1(2):94-105. doi:10.1002/jhm.69 DISCLOSURES: No relevant relationships by Taylor Charter, source=Web Response No relevant relationships by Winnie Chu, source=Web Response No relevant relationships by Elise Hsu, source=Web Response No relevant relationships by Minyoung Park, source=Web Response No relevant relationships by Samantha Shetty, source=Web Response