Recurrent Stroke Due to Pulmonary Arteriovenous Malformation: Diagnostic Challenges and Management.

Pulmonary arteriovenous malformations (PAVMs) are rare vascular anomalies that establish a direct right-to-left shunt (RLS). Although uncommon, they may cause paradoxical embolism leading to stroke, cryptogenic stroke, or hemorrhage. Despite their potential severity, PAVMs remain an unrecognized entity. We report a case of a 57-year-old woman with cardiovascular risk factors and a previous recurrent stroke of undetermined origin, admitted with acute right-sided weakness, dysarthria, and facial droop. Computed tomography (CT) confirmed acute infarcts in the left frontal and temporal cortices. During the diagnostic workup, transcranial Doppler with bubble contrast revealed RLS, and transesophageal echocardiography excluded an intracardiac defect. Pulmonary CT angiography identified a right lower lobe PAVM that was embolized with an Amplatzer Vascular Plug 4 (St. Paul, MN: Abbott). Further investigations excluded other etiologies. A comprehensive investigation of RLS is crucial when no other etiology for a stroke is found. Transcranial Doppler and CT angiography are key tools for diagnosis, and embolization is an effective treatment.