One Year Outcome of Boys With Duchenne Muscular Dystrophy Using the Bayley-III Scales of Infant and Toddler Development

Abstract Background The pathogenesis of Duchenne muscular dystrophy starts before birth. Despite this, clinical trials exclude young boys because traditional outcome measures rely on cooperation. We recently used the Bayley-III Scales of Infant and Toddler Development to study 24 infants and boys with Duchenne muscular dystrophy. Clinical evaluators at six centers were trained and certified to perform the Bayley-III. Here, we report 6- and 12-month follow-up of two subsets of these boys. Patients Nineteen boys (1.9 ± 0.8 years) were assessed at baseline and 6 months. Twelve boys (1.5 ± 0.8 years) were assessed at baseline, 6, and 12 months. Results Gross motor scores were lower at baseline compared with published controls (6.2 ± 1.7; normal 10 ± 3; P P  = 0.20) at 6 months. Repeated measures analysis of the 12 boys monitored for 12 months revealed that gross motor scores, again low at baseline (6.6 ± 1.7; P P  = 0.11). Cognitive and language scores were lower at baseline compared with normal children (range, P  = 0.002- P  = 0.89-0.09). Fine motor skills, also low at baseline, improved >1 year ( P  = 0.05). Conclusion Development can reliably be measured in infants and young boys with Duchenne muscular dystrophy across time using the Bayley-III. Power calculations using these data reveal that motor development may be used as an outcome measure.