Stroke is a sudden loss of brain function due to disturbance in the cerebral blood supply with symptoms lasting

at least 24 hours or leading to death with vascular background as its only cause. Stroke can be caused either by

rupture of a blood vessel or aneurysm (hemorrhagic stroke, HS), or by thrombosis or embolisms (ischemic stroke,

IS). In children stroke is defined as any neurological event related to an acute brain ischemia shown by the brain

imaging technique. The incidence of arterial ischemic stroke (AIS) in children (about 2–13 / 100,000 children per

year) is much lower than the incidence in the adult population. Still, adverse outcomes of acute brain ischemia in

childhood include death, neurological sequel, epileptic seizures, and recurrence. The knowledge of childhood

stroke etiology is still insufficient and the diagnostic and therapeutic procedures remain underdeveloped. Ischemic stroke is a heterogeneous condition with many different risk factors, both genetic and biochemical. The authors have reviewed the recent literature on risk factors of childhood ischemic stroke with the focus on biochemical factors like dyslipidemias, protein C deficiency and homocysteine, lipoprotein(a) and fibrinogen excess, and genetic factors like polymorphisms of 5,10-methylenetetrahydrofolate reductase, factor V, and fibrinogen genes.