Prothrombotic disorders in children with Moyamoya syndrome

Background and Purpose-Moyamoya syndrome is an uncommon chronic occlusive c erebrovascular disease in children. The origin of moyamoya syndrome remains undetermined. The role of the prothrombotic disorders contributing to its pathogenesis has not been completely elucidated. The purpose of this study was to determine the frequency of prothrombotic disorders in a pediatric po pulation with moyamoya syndrome. Methods-From May 1992 to April 2000, a prospective study of 10 consecutive children with moyamoya syndrome was carried out at a single center. Evaluat ion included the following assays: protein C, protein S, antithrombin, plas minogen, activated protein C resistance, factor V Leiden, and prothrombin g ene mutations. Lupus anticoagulant, anticardiolipin antibodies, and anti-be ta (2)-glycoprotein I antibodies assays were also performed. The clinical c haracteristics, underlying diseases, family history of thrombosis, radiolog ical findings, treatment, and outcome were also recorded. Results-In our series, prothrombotic disorders were detected in 4 patients (40%). Inherited protein S deficiency was found in I patient; lupus anticoa gulant and anticardiolipin antibodies were detected in the remaining 3 pati ents. One presented persistent lupus anticoagulant for 2.7 years until his death. In the case of the other 2 patients, I has maintained lupus anticoag ulant for 9 months, whereas the other has kept anticardiolipin/anti-beta (2 )-glycoprotein I antibodies for 10 months. Conclusions-We report the hemostatic data of the largest prospective pediat ric study carried out at a single center in the western hemisphere. In 4 pa tients (40%), a prothrombotic disorder was detected. It is tempting to spec ulate that these hemostatic abnormalities may contribute to the pathogenesi s of moyamoya syndrome in some of our patients.