BACKGROUND: The Burke-Fahn-Marsden Dystonia Rating Scale is a universally 
applied instrument for the quantitative assessment of dystonia in both children 
and adults. However, immature movements by healthy young children may also show 
"dystonic characteristics" as a consequence of physiologically incomplete brain 
maturation. This could implicate that Burke-Fahn-Marsden scale scores are 
confounded by pediatric age.
OBJECTIVE: In healthy young children, we aimed to determine whether 
physiologically immature movements and postures can induce an age-related effect 
on Burke-Fahn-Marsden movement and disability scale scores.
METHODS: Nine assessors specializied in movement disorders (3 adult 
neurologists, 3 pediatric neurologists, and 3 MD/PhD students) independently 
scored the Burke-Fahn-Marsden movement scale in 52 healthy children (4-16 years 
of age; 2 boys and 2 girls per year of age). Independent of that, parents scored 
their children's functional motor development according to the 
Burke-Fahn-Marsden disability scale in another 52 healthy children (4-16 years 
of age; 2 boys and 2 girls per year of age). By regression analysis, we 
determined the association between Burke-Fahn-Marsden movement and disability 
scales outcomes and pediatric age.
RESULTS: In healthy children, assessment of physiologically immature motor 
performances by the Burke-Fahn-Marsden movement and disability scales showed an 
association between the outcomes of both scales and age (until 16 years and 12 
years of age, β = -0.72 and β = -0.60, for Burke-Fahn-Marsden movement and 
disability scale, respectively [both P < 0.001]).
CONCLUSIONS: The Burke-Fahn-Marsden movement and disability scales are 
influenced by the age of the child. For accurate interpretation of longitudinal 
Burke-Fahn-Marsden Dystonia Rating Scale scores in young dystonic children, 
consideration of pediatric age-relatedness appears advisory.