The term used to describe a group of conditions characterised by a combination of abnormal muscle tone, posture and movement caused by damage to brain cells and which is acquired during fetal life, infancy or early childhood. The brain disorder is static but its effects change as the child develops. In some 80 per cent of cases it takes the form of spastic paralysis (muscle stiffness) while others have reduced tone (ataxia) or primarily a disorder of the control of movement (dystonia). It occurs in around 2 or 2.5 per 1,000 infants. In the majority of cases the abnormality dates from well before birth: among the factors are some genetic malformations of the brain, a congenital defect of the brain, or some adverse effect on the fetal brain as by infection during pregnancy. Among the factors during birth that may be responsible is prolonged lack of oxygen, such as can occur during a difficult labour; this may be the cause in up to 15 per cent of cases. In some 10–15 per cent of cases the condition is acquired after birth, when it may be due to KERNICTERUS, infection of the brain, cerebral thrombosis or embolism, or trauma. Acute illness in infancy, such as meningitis, may result in cerebral palsy.
The type of paralysis varies tremendously. It may involve the limbs on one side of the body (hemiplegia), both lower limbs (paraplegia), or all four limbs (DIPLEGIA and QUADRIPLEGIA). Learning disability (with an IQ under 70) is present in around 75 per cent of all children, but children with diplegia or athetoid symptoms may have normal or even high intelligence. Associated problems may include hearing or visual disability, behavioural problems and epilepsy.
Although there is no cure, much can be done to help these disabled children, particularly if the condition is detected at an early stage. Assistance is available from NHS developmental and assessment clinics, supervised by community paediatricians and involving a team approach from medical specialists such as paediatric neurologists, gastroenterologists and orthopaedic surgeons and experts in education, physiotherapy, occupational therapy and speech & language therapy.