Recurrent Transient Ischemic Attack in A Young Lady with Embolic Stroke of Undetermined Source and Patent Foramen Ovale: Quo Vadis- Direct Cause, Risk Factor, or Incidental Finding?

Approximately 40% of ischemic strokes have no clearly definable etiology and are termed cryptogenic strokes. Patent foramen ovale (PFO), a small communication between the left and right atria, is a common benign finding in healthy subjects. Its prevalence is higher in patients with cryptogenic stroke. There is conflicting data and it remains uncertain whether PFO is the direct cause, a risk factor or an incidental finding. Potential stroke mechanisms include paradoxical embolism from a venous clot which traverses the PFO, in situ clot formation within the PFO, and atrial arrhythmias due to electrical signaling disruption. Main risk factors linked with PFO-attributable strokes are young age, PFO size, right-to-left shunt degree, PFO morphology, presence of atrial septal aneurysm, intrinsic coagulation-anticoagulation systems imbalance, and co-existence of other atrial abnormalities, such as right atrial septal pouch, Eustachian valve and Chiari’s network. These may act independently or synergistically, multiplying the risk of embolic events. Recent trials have shown that closure of PFO, especially if associated with an atrial septal aneurysm and/or a large interatrial shunt, may reduce the risk of recurrent stroke as compared to medical treatment. PFO presence in young patients with cryptogenic stroke should be considered as etiologically suspect. In this study, we report the case of a 32-year-old woman with diagnosis of recurrent transient ischemic attack (TIA) due to PFO. The aim of this report is to discuss the relevant aspects of the PFO and the cryptogenic stroke, its clinical presentation, diagnosis, management and recurrence.

Keywords:Cryptogenic stroke; Paradoxical embolism; Transient ischemic attack; Atrial arrythmia