Motor impairment in children with Neurofibromatosis type 1: Effect of the comorbidity with language disorders.

BACKGROUND: There is a body of evidence demonstrating comorbidity of motor and cognitive deficit in «idiopathic¼ developmental disorders. These associations are also found in developmental disorders secondary to monogenic disorders as in Neurofibromatosis type 1 for which the principal complication during childhood is learning disabilities. The comparison of motor impairment between developmental disorders either idiopathic or secondary as in NF1 could help us to better understand the cause of the combined language/motor deficit in these populations. AIM: The aim of this current study was to investigate motor impairment in children with NF1 for which oral language had been specified and then to compare the motors skills of the NF1 group to motor performance of children with Specific Language Disorder (SLD). METHOD: Two groups of 49 children between 5 and 12years old were included and compared, the NF1 group and the SLD (Specific Language Disorder) group. Each child completed evaluation involving cognitive, language and motor assessment. RESULTS: In NF1 group, motor impairment was more frequent and more severe and concerned specifically balance rather than manual dexterity or ball skills, compared to a group of children with SLD. This motor impairment was independent of language status in the NF1 group. CONCLUSIONS: These results as well as other studies on the same topic could suggest that in NF1 children, fine motor skills impairment would be dependent on the existence of comorbidity with language disorders. Also, that gross motor skills impairment, and more precisely the balance deficit would be characteristic of NF1. This issue encourages studies of procedural learning that can involve the fronto-striatal or the fronto-cerebellar loops according to the type of motor tasks and the stage of learning.