Cerebral palsy is a term used to describe a range of developmental motor disorders arising from a non-progressive lesion or disorder of the brain.1 The associated brain damage is characterized by paralysis, spasticity, or abnormal control of movement or posture. While the brain injury itself is considered static, the pattern of motor impairment may change over time.
The term cerebral palsy is often reserved for brain injuries that occur in the prenatal or perinatal periods. However, research indicates that for the estimation of life expectancy, both traumatic brain injury and stroke in infancy are essentially equivalent to cerebral palsy. Given this, it is reasonable to apply the literature on life expectancy in cerebral palsy to such cases.
The main factors for life expectancy in cerebral palsy are gross motor function and feeding. Children who are fully ambulatory and who self-feed have life expectancies that are not dramatically less than normal. Less significant factors include fine motor function (hand use), cognitive function, epilepsy.
Type of cerebral palsy. The most common type of cerebral palsy is the spastic form, which is characterized by rigid muscle tone (i.e., spasticity). Less common are the athetoid type, characterized by continual slow movements and the dyskinetic type (impairment of voluntary movements resulting in jerky motions). Other types of cerebral palsy, such as ataxia (an inability to coordinate voluntary muscular movements), or mixed types are also possible. It is sometimes speculated that the different types are associated with differences in life expectancy. However, in unpublished research our group did not find any support for this notion, once severity of disabilities, as measured by level of function, is taken into account. For the estimation of life expectancy, by far the most useful classification is the pattern of disability.
The main sources of data for research on life expectancy in cerebral palsy are (1) databases maintained by Professor Jane Hutton and her colleagues in the UK,2-6 and (2) the California developmental disabilities database.7-12 In addition there are a few other studies from other countries/regions, such as Canadian study of Crichton13 and the Western Australian study of Blair.15 The research suggests that when children with comparable disabilities are compared, the resulting prognoses for life expectancy are similar.7,15 This point has sometimes been misunderstood, because the California database is able to identify children with exceptionally severe patterns of disabilities (e.g., tube fed and unable to lift head when lying in prone) who have lower life expectancies than groups of children in other studies with less severe disabilities.
Some earlier studies had major methodological errors, and the results are therefore not to be relied on.16-18 The errors in Plioplys et al.16 are noted in Strauss et al.21 and explained here. The errors in the Eyman et al. studies17,18 are noted in Strauss et al.20,21 and explained here.
The first large study to give life expectancy (as opposed to survival curves) appears to be our 1998 study of life expectancy of adults with cerebral palsy.12 This has been updated and superseded by our more recent work.7 For convenience, the Table of life expectancies given there is reproduced below. Full details and technical discussion is given in the source article.7
Older persons with cerebral palsy. The 2004 study by Strauss et al.9 appears to be the only published article that addresses life expectancy for older persons (age 60+) with cerebral palsy. As is usually the case, persons who are still fully ambulatory have life expectancies that are not dramatically shorter than normal, while those with more severe motor dysfunction have shorter ones.
Secular trend. There has been much discussion of whether longevity in cerebral palsy has improved over recent decades.
Until recently, the studies that looked into this had reported finding no such trend. However, the 2007 Strauss et al.8
study found evidence for such a trend, though confined to persons with the most severe disabilities. This trend is taken
into account in our most recent research.7
New cerebral palsy growth charts are available here.
[The studies referenced above are available on the articles page.]