What causes cerebral palsy?
Cerebral Palsy is the result of brain damage or faulty brain development in certain parts of the brain controlling movement.
At one time it was thought that the main cause of cerebral palsy was problems during labour and delivery, but we now know this is only true of a small number of cases. For example, if there has been severe prolonged lack of oxygen during birth.
Most children have congenital cerebral palsy, which means they are born with it. A small number acquire cerebral palsy through damage to the infant brain in the first months of life. A variety of factors can cause cerebral palsy, although it may be difficult to pinpoint with any certainty the exact cause of the damage.
Here are some of the factors known to increase the chances of developing cerebral palsy:
- The brain of the foetus in the womb doesn’t develop properly.
- Being born preterm, especially before 28 weeks when the brain is more vulnerable to lower levels of oxygen and can bleed more easily.
- Twin, triplet or multiple births.
- Children born with a low birthweight (less than 1500grams) have a much higher chance (70 times more likely) of having CP than those born with weights of 2500grams or more.*
- Infections during pregnancy, such as rubella, chicken pox, herpes, cytomegalovirus or toxoplasmosis.
- Smoking, drinking large amounts of alcohol or taking drugs (e.g. cocaine, heroin) during pregnancy.
- Foetal trauma during pregnancy.
- In a few cases it may be due to genetic or hereditary factors.
- A severe lack of oxygen during labour, which is prolonged. (Only a cause in about in about one in ten cases.**)
- Severe jaundice in a newborn.
- Infections affecting the baby in the period just after birth, such as meningitis or encephalitis.
- Trauma after birth in a young baby, e.g. head injury, stroke, near cot death or almost drowning.
How common is cerebral palsy?
In a study* of populations of children in Europe including the UK, the prevalence rate of CP was found to be 2.08 per 1000 live births. Of those, 85.5% had spastic cerebral palsy. 6.5% athetosis, 4% ataxia and the remaining were unknown.
*Source: SCPE (2002). ‘Prevalence and characteristics of children with cerebral palsy in Europe.’ Developmental Medicine and Child Neurology 44. 633-640.