[A case of cryptogenic stroke with platypnea-orthodeoxia syndrome and paroxysmal atrial fibrillation].

The patient was a 72-year-old man who presented to our hospital with gait disturbance. He had sustained a spinal fracture one year earlier. Neurological examination revealed left-sided hemiparesis, dysarthria, and a National Institutes of Health Stroke Scale (NIHSS) score of 3. Brain MRI demonstrated cortical infarctions in both cerebral hemispheres. Transesophageal echocardiography revealed a grade 3 patent foramen ovale (PFO) accompanied by an atrial septal aneurysm. He exhibited hypoxemia in the upright position, which improved when supine, leading to a diagnosis of platypnea-orthodeoxia syndrome (POS). He underwent percutaneous PFO closure and was subsequently discharged home. Fifteen weeks after surgery, left-sided paralysis was observed, and paroxysmal atrial fibrillation was detected, leading to a diagnosis of cardioembolic stroke. A PFO, which had been asymptomatic, contributed to the development of POS due to its impact on thoracic compression fractures and atherosclerosis. In the care of elderly patients, the coexistence of multiple conditions is not uncommon, necessitating careful interpretation of test results.