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Updated: Aug 21, 2026
Measurements of Motor Function and Other Clinical Outcome Parameters in Ambulant Children with Duchenne Muscular Dystrophy
Published on: January 12, 2019
Compositional analysis of muscle in boys with Duchenne muscular dystrophy using MR imaging
Franklin A Marden1, Anne M Connolly, Marilyn J Siegel
1Mallinckrodt Institute of Radiology at Washington University Medical Center, 510 South Kingshighway Blvd., St. Louis, MO 63110, USA.
Insights
Magnetic resonance imaging reveals characteristic fatty infiltration patterns and edema in Duchenne muscular dystrophy (DMD) muscles. These changes correlate with age and muscle size, offering insights for treatment strategies.
Area of Science:
- Neurology
- Biomedical Imaging
- Musculoskeletal Disorders
Background:
- Duchenne muscular dystrophy (DMD) is a progressive genetic disorder causing muscle degeneration.
- Boys with DMD experience weakness and loss of ambulation by adolescence.
- Understanding age-related muscle changes in DMD is crucial for effective management.
Purpose of the Study:
- To investigate age-related changes in muscle composition and distribution using magnetic resonance (MR) imaging in boys with DMD.
- To identify patterns of fatty infiltration, edema, and muscle size variations.
Main Methods:
- MR imaging (T1-weighted spin echo and STIR sequences) of thigh muscles at three levels in eleven boys with DMD (mean age 7.1 years).
- Quantitative muscle strength and functional testing.
- Assessment of intramuscular fatty infiltration, intermuscle fat deposition, edema, and muscle size.
Main Results:
- Older boys showed more significant fatty infiltration in muscles.
- Characteristic fatty infiltration patterns were observed, with gluteus and adductor magnus muscles most affected and gracilis spared.
- Increased free water content indicated intramuscular edema or inflammation, and muscle atrophy occurred in fatty infiltrated areas, while spared muscles showed hypertrophy.
Conclusions:
- Fibrofatty changes in DMD are further defined by differential muscle involvement and widespread edema/inflammation.
- Advanced imaging techniques can quantify these changes, aiding in the evaluation of treatment efficacy and regimen selection.
Objective:
Boys with Duchenne muscular dystrophy (DMD) present by age 5 years with weakness and, untreated, stop walking unaided by age 10 or 11 years. We used magnetic resonance (MR) imaging to study age-related changes in the composition and distribution of diseased muscles.
Design And Patients:
Eleven boys (mean 7.1+/-1.6 years) with DMD underwent clinical and MR examinations. Quantitative muscle strength and timed functional testing was performed. Thigh muscles were scanned at three levels (hip, mid-thigh, and knee) using T1-weighted spin echo and short-tau inversion recovery (STIR) sequences. Outcome measures included intramuscular fatty infiltration, intermuscle fat deposition, edema, and muscle size.
Results:
Ten boys completed the study. Older boys demonstrated more prominent fatty infiltration of muscles. Fatty infiltration occurred in a characteristic pattern with the gluteus and adductor magnus muscles most commonly involved and the gracilis most commonly spared. Similarly, patchy increases in free water content suggested a pattern of intramuscular edema or inflammation. Atrophy occurred in muscles heavily infiltrated with fat, and true hypertrophy selectively occurred in those that were spared.
Conclusions:
While fibrofatty changes have been described in DMD, this study further defines differential involvement and additionally suggests widespread edema or inflammation. Improved imaging techniques to quantify the degree and distribution of these changes may provide a basis for exploring mechanisms of action of medications and perhaps another means for selecting treatment regimens and monitoring their effects.
