Cerebral palsy

Neurological impairments acquired before or around birth make an important contribution to the total burden of neurological disease in the community. The multiple aetiologies of these disorders are imperfectly understood, and tend to be grouped under the broad heading of cerebral palsy.

Cerebral palsy is usually defined as a non-progressive neurological syndrome caused by injury to the immature brain, although recent data have questioned whether the pathological progress is genuinely non-progressive.1 The predominant feature is motor impairment, although about half of the affected population will have significant cognitive or intellectual impairment, and these children comprise about 50% of the total number of those with severe mental retardation in the community.2 Associated features such as visual impairment, hearing loss, or feeding problems are common.

The birth prevalence of cerebral palsy shows geographical variations, but is generally in the range of 1.5-3 per 1000 live births.3 Trends in prevalence over time have been somewhat contradictory; a fall from 2.24 to 1.9 per 1000 occurred in Sweden between 1954-8 and 1967-70,4 whereas in Western Australia a significant rise from 2.2 to 2.5 per 1000 occurred over a similar period.5 However, in the past two decades most investigators have found a significant increase in the birth prevalence of cerebral palsy, due largely to an increase in the rates recorded for extremely small or preterm infants.6 There is some evidence that this increase is now being reversed.7

Epidemiological analysis has defined a large number of risk factors for cerebral palsy, including low birth weight, preterm birth, multiple pregnancy, neurological disorder in mother or sibling, thyroid disease or therapy during pregnancy, thyroid hormone deficiency in preterm infants, low placental weight, chorioamnionitis, birth asphyxia, and neonatal hyperbilirubinaemia. During the past decade it has become clear that, contrary to previous views, …