[Definition and classification of cerebral palsy: a problem that has already been solved?].

Aim: To carry out a review of the definition and classification of cerebral palsy (CP) from a historical point of view and in the light of current knowledge.

Development: Defining and classifying CP in the medical literature have been difficult to achieve. The different definitions and classifications have represented a limitation when it comes to interpreting the results of epidemiological studies. The definitions do not specify any age limits as regards the moment the brain injury occurred or with respect to the onset of motor disorders or how severe such disorders must be in order to be considered as CP. Within the classifications there are significant inter-observer differences in the interpretation of certain terms, particularly in the topographical and pathophysiological classifications. It has only been in recent years that the first steps have been taken towards achieving greater consistency in the definition and classification of CP. The most recent definition proposed by the Executive Committee for the Definition and Classification of CP, in April 2005, partly satisfies the clinical demands but not those of epidemiological research; nevertheless, the classification of CP proposed here would be useful for both clinical and epidemiological purposes if a number of small modifications mainly concerning the search for causations were introduced.

Conclusions: The definition and classification of CP are a problem that has still not been solved. We recommend drawing up a complementary definition of CP, for epidemiological research purposes, obtained by international agreement.