British and American researchers studied an international cohort of 196 children with Duchenne muscular dystrophy (DMD) in order to compare their motor performance with any associated neurodevelopmental impairment:
- the children were aged between 4 and 8 years and had never received long-term corticosteroid therapy,
- neurodevelopmental impairment (learning difficulties or language delay) was confirmed on the basis of observations made by the parents, but without any specific neuro-cognitive tests,
- the NSAA (North Star Ambulatory Assessment) motor score was significantly lower in children with learning difficulties,
- children with mutations in the distal portion of the DMD gene also performed less well on certain timed motor scores.
These results argue in favour of taking better account of cognitive impairment in the design of clinical trials.
