Definition and classification of cerebral palsy.

The International Workshop on the Definition and Classification of Cerebral Palsy have proposed a fresh definition and classification of cerebral palsy (CP; p 571). In their accompanying paper they explain their reasoning behind this. Why is there the need for revision of the widely accepted and comfortably familiar definitions of Bax1 and Mutch2? These definitions are beautifully succinct and clear but perhaps not inclusive enough, making no mention of pathogenesis or of the functional and ‘non-motor’ features of CP which are most significant when it comes to everyday life. There has been debate in the past as to whether a more aetiological definition should be adopted but we are not yet ready for this. CP remains unexplained in around 15% of children, even after good neuroimaging and metabolic investigation3 and we recognize that a wide range of CNS disorders can result in a similar clinical picture. Thus, a predominantly phenotypic definition and classification remains the most appropriate. The workshop clearly deliberated long and hard over every word of the revised definition producing a much more detailed description of CP that now encompasses the effect on function (activity limitation) and the comorbid features. As a result, the definition is longer and it does not ‘trip off the tongue’ in the way the old ones did. I think a fresh classification of CP is most welcome. With the standard classification there is considerable confusion in describing the neurological abnormalities of tone and the anatomical distribution of the disorder. When does hemiplegia become an asymmetric diplegia or diplegia become quadriplegia and when does a spastic disorder become mixed spastic/dystonic? Causation is not always described and functional consequences are not systematically recorded. This makes it difficult to document significant changes for an individual (particularly important when it comes to any therapeutic interventions) and is unsatisfactory for scientific research. The Workshop has set out a useful and detailed template listing the important components of a classification system. There is much greater emphasis on timing and causation of injury and I welcome and fully endorse their advice that, whenever possible, the diagnosis should be confirmed with neuroimaging. It is also entirely appropriate that functional assessments should be routinely employed for which suggestions are given in the accompanying document. For clinicians and therapists the most provocative suggestion is that CP should now be classified as unilateral or bilateral with the old terms of diplegia, quadriplegia, etc being abandoned, and that there should be specific description of all body areas affected (including trunk and oromotor involvement). The predominant abnormalities of tone should also be recorded and the presence of a hyperkinetic movement disorder documented. om m etary Definition and classification of cerebral palsy