An overlooked cause in a patient with recurrent ischemic stroke: A case report

The majority of ischemic strokes are due to cardioembolism, large vessel atherothromboembolism, small vessel occlusive disease, or other unusual mechanisms. In most clinical settings, many strokes without a well-defined etiology requires a thorough diagnostic evaluation, otherwise the underlying cause might be easily overlooked. Here we report on the rare cause of a patient with recurrent stroke.

A 50-year-old female patient had a 4-year history of recurrent acute onset of neurological deficits.

Contrast transcranial Doppler ultrasound detected a typical "curtain" appearance of microbubbles, indicative of a right-to-left shunt. Computed tomography pulmonary angiogram was then initiated and a pulmonary arteriovenous malformation (PAVM) in the left lower lobe was found.

The patient underwent percutaneous closure of PAVM. Afterward, warfarin was commenced because of the high risk of further thromboembolic complications in the following weeks to months. Post-treatment computed tomography pulmonary angiogram (CTPA) demonstrated successful closure of PAVM. No microbubble signals were detected on post-treatment contrast transcranial Doppler ultrasound (TCD) study.

The patient suffered no further embolic events during 3-year follow-up. No recanalization or new PAVMs were detected on CT scan.

Neurological PAVM-associated risks are common but remain poorly recognized. A strategic protocol is imperative in searching for the etiologies of cryptogenic stroke.