Paradoxical Cerebral Embolism after Gastrointestinal Endoscopy in a Patient with Crohn's Disease.

Development of paradoxical cerebral embolism requires both unstable venous thrombosis and right-to-left shunt (RLS). Gastrointestinal endoscopy (GE) has the potential to affect intrathoracic and abdominal venous thrombi and to enhance RLS because the procedure alters intrathoracic and abdominal pressure. We describe a patient with Crohn's disease who developed paradoxical cerebral embolism after GE. Both an unstable venous thrombus in the superior vena cava and RLS through patent foramen ovale were thought to be responsible for the stroke. Considering that patients with digestive system diseases undergo GE as a routine examination or therapy, screenings for hypercoagulable state and intrathoracic and abdominal thrombi are important to prevent thromboembolism related to GE.