One year outcome of boys with Duchenne muscular dystrophy using the Bayley-III scales of infant and toddler development.
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.


METHODS
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 < 0.0001) and revealed a further declining trend to 5.7 ± 1.7 (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 < 0.0001), declined at 6 months (5.9 ± 1.8) and further at 12 months (5.3 ± 2.0) (P = 0.11). Cognitive and language scores were lower at baseline compared with normal children (range, P = 0.002-<0.0001) and did not change significantly at 6 or 12 months (range, P = 0.89-0.09). Fine motor skills, also low at baseline, improved >1 year (P = 0.05).


CONCLUSIONS
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.
Department of Neurology, Saint Louis Children's Hospital, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri; Department of Pediatrics, Saint Louis Children's Hospital, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri. Electronic address: connollya@wustl.edu.
Anne M
AM
Connolly
Department of Neurology, Saint Louis Children's Hospital, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri.
Julaine M
JM
Florence
Department of Pediatrics, Saint Louis Children's Hospital, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri.
Mary M
MM
Cradock
Department of Neurology, Newcastle University, Newcastle upon Tyne, England; Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, England.
Michelle
M
Eagle
Departments of Pediatrics and Neurology, The Ohio State University, Columbus, Ohio; Gene Therapy Center, Nationwide Children's Hospital, Columbus, Ohio.
Kevin M
KM
Flanigan
Department Physical Medicine and Rehabilitation, University of California Davis Medical Center, University of California, Sacramento, California.
Craig M
CM
McDonald
Department of Neurology, University of Minnesota, Minneapolis, Minnesota.
Peter I
PI
Karachunski
Department of Neurology, Boston Children's Hospital, Harvard University, Boston, Massachusetts.
Basil T
BT
Darras
Department of Neurology, Newcastle University, Newcastle upon Tyne, England; Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, England.
Kate
K
Bushby
Department of Neurology, Saint Louis Children's Hospital, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri.
Elizabeth C
EC
Malkus
Department of Neurology, Saint Louis Children's Hospital, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri; Department of Pediatrics, Saint Louis Children's Hospital, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri.
Paul T
PT
Golumbek
Department of Neurology, Saint Louis Children's Hospital, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri; Department of Pediatrics, Saint Louis Children's Hospital, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri.
Craig M
CM
Zaidman
Division of Biostatistics, Washington University School of Medicine in Saint Louis, Saint Louis, Missouri.
J Philip
JP
Miller
Departments of Pediatrics and Neurology, The Ohio State University, Columbus, Ohio; Gene Therapy Center, Nationwide Children's Hospital, Columbus, Ohio.
Jerry R
JR
Mendell
D002657:Child Development; D002675:Child, Preschool; D003071:Cognition; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007802:Language; D007807:Language Tests; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D009048:Motor Skills; D020388:Muscular Dystrophy, Duchenne / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology / Q000523:psychology
Bayley-III; Duchenne muscular dystrophy; clinical trial outcomes; infant development