Acute neurological deficit with submassive pulmonary emboli

Pulmonary embolism (PE) is frequently encountered in the emergency department. Syncope, often as a consequence of impending haemodynamic collapse, is associated with increased mortality. While loss of consciousness owing to cerebral hypoperfusion and reduced left ventricular preload is a common cause of collapse with large volume PE, other syndromes can also cause neurological deficit in thromboembolic disease. Here, we describe a case of a woman in her 60s, presenting to the emergency department with features of high-risk PE. During clinical examination, the patient collapsed and became unresponsive with a Glasgow Coma Scale of 4/15 despite normal haemodynamics. Neurological signs were noted and CT revealed evidence of a large territory cerebral infarction. Further cardiovascular investigations identified a grade 4 patent foramen ovale. We describe a challenging case of established venous thromboembolism complicated by paradoxical embolism, highlighting the importance of thorough clinical examination and investigation and discuss the current evidence base of treatments.