paradoxical cerebral fat embolism in an adolescent plha: a convergence of trauma, art induced hypercoagulability, and septal heart defect

Fat embolism syndrome (fes) is a life-threatening complication following long bone fractures, primarily affecting the pulmonary circulation. however, cerebral fat embolism (cfe) is a rare yet severe variant that can occur when fat emboli bypass the lungs through a right-to-left cardiac shunt, such as an atrial septal defect (asd). in individuals with hiv on antiretroviral therapy (art), persistent endothelial dysfunction andart-induced hypercoagulability predispose them to an exaggerated thrombo-inflammatory state, amplifying the risk of paradoxical embolism. we describe a 14-year-old male with perinatally acquired hiv on art who presented after a high-impact road traffic accident. the patient sustained comminuted fractures of the rightfemoral shaft, tibia, and femoral condyle. initially neurologically intact (glasgow coma scale [gcs] 15), he experienced rapid neurological deterioration (gcs dropped to 8), alongside respiratory distress and acute respiratory distress syndrome (ards)-like symptoms. urgent evaluation with a 2d echocardiogram revealed an asd with a right-to-left shunt, strongly supporting the diagnosis of paradoxical cerebral fat embolism.this case illustrates how trauma, combined with hiv-related endothelial dysfunction, artinduced hypercoagulability, and a congenital cardiac anomaly, can converge to precipitate severe neurological decline through paradoxical embolism.