‘Outgrowing’ a cerebral palsy diagnosis

Some children thought in early life to have cerebral palsy (CP) may later not be considered to warrant that diagnosis. Chen et al. identify early signs, such as an uneventful perinatal course, term birth, non-spastic CP, and normal magnetic resonance imaging, that may predict the loss of a CP diagnosis. Other studies have found early signs associated with retention of an early CP diagnosis that include preterm birth, small head size, and delay in meeting psychomotor milestones. One study found that on evaluation at age 7 years, more children who had ‘outgrown’ CP had other neurological problems, such as IQ below 70, seizures, and sensory disorders, compared to children who never had a CP diagnosis. So, motor signs in very young children may resolve with healing or maturation, but in some of those children non-motor neurological abnormalities may persist. A change in a CP diagnosis may occur because of alterations in physical findings or because there is a change in interpretation of the findings. Abnormal head size and failure to meet early milestones might have influenced examiners to give greater weight to marginally abnormal early motor findings. Another source of potential change in application of a CP diagnosis involves whether a specific known or suspected etiology should be the basis for exclusion from a CP diagnosis. As Chen et al. observe, however, ‘what is included or excluded under this umbrella [CP] has not always been evident’. This question is likely to arise increasingly as more CP and other developmental disabilities are ‘explained’ by expanding knowledge of the pathobiology of brain development. Certainly, genetic/genomic investigations will be an important part of that explanatory process. Information on the etiology of neurological depression in newborn infants, a pathway to CP, may increase with the application of existing technologies for multiplexed microanalyses of minute amounts of blood or spinal fluid, to aid recognition of inflammatory mediators and metabolic or genetic alterations. Information about the placenta, its gross and histological findings, functional characteristics, and the role of placental genes, are likely to contribute to a better understanding of the etiology of CP. The CP diagnosis is descriptive and, except for the exclusion of progressive diseases, does not depend upon etiology. As MacLennan et al. argue: ‘if one removes genetic causes or other causes of cerebral palsy. . .then in countries with cerebral palsy registers. . .there will be an artificial reduction in the incidence of this disorder. . .[I]n some countries the diagnosis of cerebral palsy allows access to financial benefits and social services. . .Removing genomic causes may disenfranchise these patients and families from the support they need. So, it is very helpful to keep the umbrella clinical diagnosis of cerebral palsy but have subclassifications by possible or likely cause’.