Characteristics of childhood arterial ischemic stroke with normal MR angiography.

BACKGROUND AND PURPOSE The purposes of this study were to describe clinical and radiological characteristics of children with arterial ischemic stroke and normal MRA to compare them with children with arterial ischemic stroke and abnormal MRA. METHODS We conducted a retrospective review of clinical records and imaging. RESULTS Forty children with arterial ischemic stroke and normal MRA were identified (24 male; median age, 55 months). MRA had been acquired <24 hours of symptom onset in 4, at 24 to 48 hours in 10, 48 to 96 hours in 10, 4 to 7 days in 10, and >1 week in 6 children (median, 4 days). Ten of 40 had prior diagnoses (5 cardiac, 5 malignancies). Other risk factors were identified in 30 (1 in 17 and >1 in 13; prothrombotic abnormalities in 14, prior Varicella in 7, anemia in 7, minor trauma in 4). Infarction was confined to the lenticulostriate branches of the middle cerebral artery in 21 of 40. Two patients had further clinical events, both with new infarcts; 28 patients were reimaged and MRA remained normal in all. Although similar in terms of age and gender to those with abnormal MRA, children with normal MRA were significantly more likely to have at least 1 RF (P=0.012). Those with abnormal MRA were significantly more likely to have multiple territory infarcts (P<0.001), but lesion topography was otherwise not predictive of abnormal MRA (P=0.45). Abnormal MRA was significantly associated with clinical recurrence (P<0.001). CONCLUSIONS Children with arterial ischemic stroke and normal MRA are not a distinct demographic group but are more likely to have single-territory lesions and have nonvascular risk factors. The stroke mechanism in children with normal MRA remains unclear.