Embolic Stroke Associated With a Pulmonary Arteriovenous Fistula: An Unignorable Rare Causes of Stroke.

INTRODUCTION: Here, we described a patient with ischemic stroke due to embolism, through an isolated pulmonary arteriovenous fistula (PAVF). Our case could be a paradigm of embolic stroke of undetermined source (ESUS) with an uncommon cause, providing an etiologic investigation process in addition to diagnostic pitfalls and pearls, eventually raising neurologists' ability to treat ESUS.

CASE REPORT: A 37-year-old right-handed woman presented to our emergency department with sudden onset left upper limb and lower limb weakness. She denied a past medical history of hypertension, diabetes, heart diseases, and other cerebrovascular disease risk factors, and she is without a family history of stroke, previous trauma, toxic exposure, or drug use. On admission, her physical and neurological examinations were negative, except for left-sided hemiparesis. Her routine evaluations, serum autoantibody testing, and digital subtraction angiography were negative. Subsequent diffusion-weighted brain magnetic resonance imaging demonstrated acute infarction in the right frontoparietal lobe. To find the etiology of this case, more detailed examinations were performed. Finally, she was diagnosed with ESUS, which was caused by the PAVF.

CONCLUSIONS: This case raises the awareness of a potential important emboligenic mechanism, the existence of an isolated PAVF as a right-to-left shunt in patients with a stroke of unknown origin should not be overlooked, even if a PAVF is not suggested by the initial physical findings or chest x-ray.