Stroke can affect any person at any age; it can even happen during pregnancy. It is the risk factors for stroke in children that make this condition different from adult stroke. Ischaemic strokes, in particular, occur for different reasons in children compared with adults.
Adult stroke is usually caused by atherosclerosis, the furring up of arteries. Other contributing factors are medical conditions such as high blood pressure, high cholesterol and diabetes, and the impact of lifestyle choices, like smoking or drinking alcohol excessively and lack of exercise.
Strokes in babies during pregnancy to within 28 days of birth (known as pre- and perinatal ischaemic stroke) are usually caused by clots breaking off from the placenta and lodging in the childs brain or because of a blood clotting disorder that the mother or baby may have.
Strokes in children from 28 days to 18 years are associated with existing conditions, most commonly congenital heart disease and sickle cell disease (SCD). Other risk factors are infectious diseases, trauma to the head or neck, vascular problems and blood disorders.
In many cases of childhood stroke, there is more than one risk factor.
Stroke can also affect previously healthy children and in some cases, there may be no apparent cause. In around 10 per cent of childhood stroke cases, the cause is unknown.