Paradoxical cerebral embolism secondary to superior vena cava occlusion and development of a right-to-left shunt

Paradoxical cerebral embolism, although rare, can be secondary to acquired causes such as superior vena cava (SVC) occlusion and development of a mediastinal right-to-left shunt. Such shunts allow undisturbed passage of thromboemboli to bypass the pulmonary circulation and enter the systemic circulation. This report presents a case of paradoxical cerebral embolism due to a right-to-left shunt originating from occlusion of the SVC. The etiology of the SVC occlusion stems from a prior central venous access line used for treatment of lymphoma. The patient underwent endovascular treatment with successful coil embolization of the mediastinal shunt.