Abstract
Background: The aims of this study were to evaluate the difference in the incidence of paradoxical cerebral embolism of sudden and subacute onset in patients with stroke of uncertain etiology, and the rate of stroke recurrence over the last two years. Methods and Results: Thirty-seven patients with ischemic stroke of uncertain etiology (M; 23, F; 14, 53.7 ± 12.8 years) were investigated. They were divided into two groups; 19 patients with sudden onset and 18 with subacute onset. The detection of “chirp” sounds by transcranial Doppler sonography after intravenous injection of contrast medium was defined as positive for paradoxical contrast embolization (PE) . Positive PE was detected more frequently in the patients with sudden onset (12/19, 63%) than those with subacute onset (1/18, 6%) (p<0.05) . Furthermore, we examined whether 10 positive PE patients with sudden-onset stroke of uncertain etiology had stroke recurrence during the last 2 years. Stroke recurrence was detected in 2 of 3 patients taking only antiaggregant therapy and in 1 (PT-INR (prothrombin time-international normalized ratio) =1.6) of 2 taking only low-dose anticoagulant. Five patients taking both antiaggregant and low-dose anticoagulant therapy (PT-INR =1.2-2.0) had no stroke recurrence.
Conclusions: Positive PE findings were frequently detected in the patients with sudden-onset stroke of uncertain etiology, and we should therefore consider that paradoxical cerebral embolism often exists in these patients as a rather common cause of stroke. Combination therapy with antiaggregant and low-dose anticoagulant (PT-INR =1.2-2.0) might be useful for the prevention of stroke recurrence in patients with positive PE findings.
