Quadriceps muscle strength in Duchenne muscular dystrophy and effect of corticosteroid treatment.
Acta Myol
; 39(4): 200-206, 2020 Dec.
Article
em En
| MEDLINE
| ID: mdl-33458575
ABSTRACT
OBJECTIVES:
In Duchenne muscular dystrophy, quadriceps weakness is recognized as a key factor in gait deterioration. The objective of this work was three-fold first, to document the strength of the quadriceps in corticosteroid-naïve DMD boys; second, to measure the effect of corticosteroids on quadriceps strength; and third, to evaluate the correlation between baseline quadriceps strength and the age when starting corticosteroids with the loss of ambulation.METHODS:
Quadriceps muscle strength using hand-held dynamometry was measured in 12 ambulant DMD boys who had never taken corticosteroids and during corticosteroid treatment until the loss of ambulation.RESULTS:
Baseline quadriceps muscle strength at 6 years of age was 28% that of normal children of the same age; it decreased to 15% at 8 years and to 6% at 10 years. The increase in quadriceps muscle strength obtained after 1 year of corticosteroid treatment had a strong direct correlation with the baseline strength (R = 0.96). With corticosteroid treatment, the age of ambulation loss showed a very strong direct relationship (R = 0.92) with baseline quadriceps muscle strength but only a very weak inverse relationship (R = -0.73) with the age of starting treatment. Age of loss of ambulation was 10.3 ± 0.5 vs 19.1 ± 4.7 (P < 0.05) in children with baseline quadriceps muscle strength less than or greater than 40 N, respectively.CONCLUSIONS:
Corticosteroid-naïve DMD boys have a quantifiable severe progressive quadriceps weakness. This long-term study, for the first time, shows that both of the positive effects obtained with CS treatment, i.e. increasing quadriceps strength and delaying the loss of ambulation, have a strong and direct correlation with baseline quadriceps muscle strength. As such, hand-held dynamometry may be a useful tool in the routine physical examination and during clinical trial assessment.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pregnenodionas
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Prednisona
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Distrofia Muscular de Duchenne
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Músculo Quadríceps
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Força Muscular
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Glucocorticoides
Limite:
Adolescent
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Adult
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Child
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Child, preschool
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Humans
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Male
Idioma:
En
Revista:
Acta Myol
Assunto da revista:
CARDIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Itália