Causes of Cerebral Palsy

Causes of Cerebral Palsy

In most cases, the specific cause of CP is unknown.

For a long time, it was believed that CP was due to complications at birth, including asphyxia (lack of oxygen). Researchers now understand that this accounts for only a very small percentage of cases of cerebral palsy.

It is now generally accepted that CP arises from a series of ‘causal pathways’, i.e. a combination of events that can lead to a disturbance in a baby’s developing brain.

In most cases of CP in Australia, the brain disturbance that leads to CP occurs either before the child is born or in very early childhood. When CP is acquired after birth, it is most commonly due to infection, vascular episodes (such as strokes), or head injury.

Are there risk factors?

An Australian study[1] has identified the following risk factors for cerebral palsy:

  • gestational age less than 32 weeks,
  • small for gestational age,
  • multiple birth,
  • breech position,
  • multiple miscarriage,
  • illicit drug use,
  • bleeding at any time in pregnancy,
  • male sex,
  • a relative with cerebral palsy,
  • recorded maternal infection during pregnancy, and
  • smoking.

If a child has one or more of these risk factors, then the chance of CP is higher than if none of these risk factors is present. However, the vast majority of children born with any one of these risk factors still do not have CP.

Does CP run in families?

Familial CP is uncommon. A genetic disposition to certain characteristics (for example, prematurity, small size for gestational age) may be one in a chain of events (a causal pathway) that increases the chance of CP. One or more events along a pathway can result in a child having CP.

 

[1] O’Callaghan, M.E. et al. Epidemiological associations with cerebral palsy. Obstetrics and Gynecology 2011: 118(3): 576.