From syndrome toward disease

Syndromes are collections of symptoms, signs, and sometimes historical information, put together to group individuals and, hopefully, identify a disease entity. A disease is not defined only in terms of symptoms and signs but in knowledge, first of the pathophysiology of a condition and then of the cause (eg. genetic, infections, etc.) of the disease. Identification of disease, hopefully, leads to effective treatment or prevention of disease but in many fields of medicine we are struggling still to identlfy what has actually caused the condition. Severe learning disability* is clearly a description of a syndrome but now many children, and indeed adults, with severe learning disability have had the cause recognized as a consequence of the great developments in the field of genetics in the past 2 decades. When thinking about cerebral palsy (CP), it should be recognized that some children who used to be diagnosed as having CP syndromically now prove to have a diagnosed genetic condition. An example is Rett’s syndrome. In recent decades, the development of neuroimaging, first CT and now with magnetic resonance imaging (MRI), has allowed more information to be obtained about the pathophysiology of conditions than was possible in the past when the only resource was pathological examination after the individualwith the condition had died. While this provided indications of the anatomical nature of the deficits, it rarely helped towards any conclusion about the cause, partly because of the very restricted numbers of cases that could be examined. In the recent European collaborative study of CP involving eight centres, it was possible to examine over 350 MRI scans from a clinical population of some 430 cases. Bax’s classic definition of CP2 was used and the sub-classifications of CP used classically hemiplegia, spastic diplegia, athetoid CI: and ataxic CI? For a discussion of this classification see Bax and Keith Brown.3 In this somewhat exploratory paper, the significance of some of the findings is reviewed.