The value of subclassifying children with unilateral cerebral palsy

Abstract

Among children with cerebral palsy (CP), those with a unilateral subtype represent around one-third of all CP subtypes, and nearly all of them show a spastic neurological subtype. Of course in these predominant spastic subtypes some children may also have mixed signs of dystonia or choreo-athetosis.An interesting question is whether a unilateral pure dyskinetic ⁄ dystonic subtype exists: it is probably a very rare feature, i.e. 6% of unilateral subtypes in the (Australian) Victorian CP register, 1 and thus represents less than a few percent of all CP cases. Many uncertainties exist surrounding this subtype, and thus there is a need to describe further such children, using data from collaborative studies ⁄ registers.As shown in the Dobson paper, 1 despite very often being considered the mildest CP subtype, nearly one out of six children with unilateral CP will require some orthopaedic or surgical treatment. This relatively high proportion explains why it is important to study in detail, among the unilateral CP subtypes, those children who will require such treatment. Another main reason for studying unilateral CP is that the prevalence rates of this CP subtype have not shown a trend toward decreasing during the last decades; moreover, recent published studies showed either a stable rate 2,3 or even an increase in some places. 4 Thanks to the efforts in research for understanding walking mechanisms, gait analyses are currently more often performed and more often available in different countries. Yet, these analyses are still time-consuming and costly, and thus are not performed in all ambulatory children with CP. 5 Laudable efforts have been made by the Victorian CP register's team to study the association between gait analysis patterns and intermediate assessment tools measuring function and ⁄ or activity level. However, with their results showing a rather moderate association, it is not completely clear up to which point these intermediate assessments can be used to limit systematic gait analysis to those children who are likely to benefit from it. The value of gait analysis is quite evident for evaluating benefits of surgery (before and after treatment), but hopefully the vast majority of children with CP may not have indication for surgery. Dobson et al. showed that among children with unilateral CP subtype who were assessed at Gross Motor Function Classification System (GMFCS) level I (44 ⁄ 58), nearly all of them were classified within the mildest group of gait pattern anomaly. In this group there is no need to perform gait analysis because orthopaedic ⁄ surgical procedures are unlikely to be indicated, or only a single level orthopaedic procedure if such a procedure was required. Gait analysis seemed to be useful only for those children assessed in GMFCS level III (14 ⁄ 58) to evaluate the need of surgical procedures, single level procedure, or more complex ones.Despite the small number of children, the Dobson et al. study is interesting in that it is population-based, with all children having gait analysis...