Paradoxical Embolism Secondary to Asymptomatic Venous Thoracic Outlet Syndrome
Shumaila Anwer1, Alex O'connor1, Philip Tatman2, Merry Joseph3, Eric Christiansen4, Stephanie Lyden1, Vivek Reddy1, Veronica Moreno Gomez1
1Department of Neurology, 2Department of Neurosurgery, 3School of Medicine, 4Department of Radiology and Imaging Sciences, University of Utah
Background:
Introduction:
Approximately 30-40% of strokes are considered cryptogenic. Identifying etiology is essential to determining appropriate secondary prevention. We describe the case of paradoxical embolic stroke in a young male with PFO, upper extremity deep vein thrombosis (UEDVT), and venous thoracic outlet syndrome (vTOS). vTOS can be asymptomatic and, therefore, missed. Risk factors for vTOS are thought to be a combination of anatomic variants and repeat overhead arm activity, prompting damage to the subclavian vein endothelium.
Results:
Presentation:
26-year-old previously healthy male presented after an episode of vision changes and left-sided weakness and was found to have right thalamic acute infarct. Patient had no personal or family history of autoimmune disease, inflammatory disease, thrombophilia, or malignancy. Basic and stroke in young workup was negative, except for a PFO. Bilateral lower extremity (LE) duplex ultrasound was negative. A right UE duplex ultrasound was ordered (after incidental finding of right-sided vTOS on chest imaging), revealing acute DVT in the proximal subclavian vein. As a result, PFO was closed, and the patient was started on anticoagulation.
Conclusions:
Conclusion:
UEDVTs are considered to have lower risk of embolism compared to LE DVTs. Therefore, we routinely do not screen for UEDVTs unless the patient has risk factors for or symptoms of UEDVT. Our patient did not present with any arm swelling, pain, or cyanosis. In this case, incidental imaging finding of vTOC led to the discovery of a UEDVT as etiology of paradoxical embolic stroke in this patient with a PFO and an otherwise unremarkable workup. On cursory search of PubMed, we found only one other case report of paradoxical stroke with primary etiology of vTOC in contrast to multiple case reports of retrograde propagation of thrombus in the setting of arterial thoracic outlet syndrome highlighting this rare case with a "second hit phenomenon"
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