Data from the International Pediatric Stroke Study were analyzed by researchers at Royal Children’s Hospital, Melbourne, Australia, and other centers. Risk factors (RFs) for arterial ischemic stroke (AIS) and their characteristics were identified in a total of 676 patients. RFs included arteriopathies (53%), cardiac disorders (31%), infection (24%), acute head and neck disorders (23%), acute systemic disorders (22%), chronic systemic conditions (19%), prothrombotic states (13%), chronic head and neck disorders (10%), atherosclerosis-related RFs (2%), other (22%), and none was identified in 9%. RFs were multiple in 52% patients. Prevalence of RFs varied with geography and with age: arteriopathy was relatively less prevalent in Asia and prothrombotic states more prevalent in Europe; cardiac disease was most prevalent in preschoolers, arteriopathies in children 5 to 9 years old, and chronic head and neck disorders were highest in children aged 10 to 14 years. Arteriopathies were associated with focal signs and multiple infarcts, and cardiac disease with hemorrhagic conversion. 
COMMENT. RFs, especially arteriopathy and cardiac disorders, are common in childhood AIS. Emphasis of investigation and preventive therapies may be determined by geographical and age-related prevalences of risk factors.