PP12.1 – 2938: Comparison of Burke-Fahn-Marsden dystonia severity, Gross Motor, Manual Abilities and Communication Function classification scales in childhood hyperkinetic movement disorders including cerebral palsy: a Rosetta Stone study

Abstract

Objective The Burke-Fahn-Marsden Dystonia Rating Scale-Movement (BFM-M) evaluates dystonia impairment, but may not reflect functional ability in paediatric movement disorders (PMD). The Gross Motor Classification System (GMFCS), Manual Ability Classification System (MACS) and Communication Function Classification System (CFCS) are widely used in the cerebral palsy (CP) literature to classify functional ability. This study explores the concordance of the three functional scales in a large sample of PMD and the impact of dystonia severity on these functional scales. Methods Children with PMD (n=161, median age 10y3mo SD 4y) were assessed using the BFM-M, and classified using the 3 scales. Data analysis was performed using the R language and environment for statistical computing, version 3.01 RDev. Overall relationships between BFM-M and categorical variables were evaluated with the Kruskal-Wallis Rank Sum Test and the proportion variation explained (R b ). Relationships between two categorical variables were assessed using Pearson's chi-squared test and Pearson residuals. Spearman correlations (rs) were also provided as an estimate of the strength of the association between variables. The information provided by these scales is compared. Results Of the 161 children included, secondary dystonias (n=125, 78%) included those of both static (n=99, 61%), including dystonic/dyskinetic CP (n=75, 47%), and progressive (n=26, 16%) dystonia. All four scales were strongly associated (all rS>0.72, p Conclusion The BFM-M is strongly linked with the GMFCS, MACS and CFCS, irrespective of aetiology. PMD other than CP could be effectively evaluated using these scales. The ability of the BFM-M scale to discriminate between GMFCS levels in this sample offers the possibility to compare samples across different studies. However, the similarity between MACS I-III in terms of BFM-M scores indicates that non-motor components such as process skills and planning are required for functional activities and cannot be explained by dystonia alone.