A right-to-left shunt and prothrombotic disorders in pediatric patients presenting with transient ischemic attack.

Arterial ischemic stroke is an important cause of morbidity and mortality in pediatric population. A right-to-left shunt (RLS) across the patent foramen ovale was recently demonstrated as a possible risk factor for pediatric stroke. Prothrombotic disorders are frequently identified in pediatric patients with stroke. Data regarding RLS and prothrombotic disorders in pediatric patients presenting with transient ischemic attack (TIA) are lacking. The aims of the present study were (1) to compare the prevalence and grade of RLS in pediatric patients presenting with TIA vs. controls using contrast transcranial Doppler with Valsalva maneuver and (2) to identify prothrombotic disorders in pediatric patients presenting with TIA. Twenty-three consecutive pediatric patients presenting with TIA were included in the study. Logistic regression analysis showed that RLS was significantly associated with TIA (OR 4.75, 95 % CI 1.39-16.2, p = 0.013). The prevalence of RLS was significantly higher in patients in comparison to controls (p = 0.019). Significantly more microembolic signals (MES) were detected in patients than in controls (p = 0.003). Prothrombotic disorders were identified in 14 of the 23 patients. Both the prevalence of RLS and number of detected MES were significantly higher in pediatric patients presenting with TIA in comparison to controls. Prothrombotic disorders were identified in a high proportion of patients. These findings suggest that paradoxical embolism may be important in pediatric patients presenting with TIA.