[Transient ischemic attack as the presenting symptom of a pulmonary arteriovenous fistula]

Transient ischemic attacks (TIA) occur as the clinical manifestation of a pulmonary arteriovenous malformation in up to 20% of cases.

We report the case of a 41-year-old female with an episode of TIA lasting half an hour, with right-side hemiparesis caused by a paradoxical embolisation due to the presence of a single pulmonary arteriovenous fistula (PAVF). Complementary analytical and imaging tests (CAT scan of the head without contrast, brain RMI and intra and extracranial MR-angiography) were normal. A transthoracic echocardiogram showed the presence of a patent foramen ovale which obstructed the passage of hemoce, although it was observed in the left auricle after presumably arriving through the pulmonary arteries. Since a pulmonary vascular malformation was suspected, a computerised tomographic angiography scan of the thorax was performed and this confirmed the presence of a single PAVF in the right lung. A pulmonary arteriography was then carried out to confirm the presence of the malformation, which was later embolised. Two months later, the patient was asymptomatic and the fistula did not appear in the computerised tomographic angiography scan of the thorax.

PAVFs can give rise to neurological conditions due to paradoxical embolisms that can produce abscesses and infarcts and/or concomitant lesions in the central nervous system. This is a certain indication of treatment of the malformation and the preferred technique is endovascular embolisation with coils, while surgery is reserved for cases in which endovascular treatment is not possible.