title: Magnetic Resonance Assessment of Hypertrophic and Pseudo-Hypertrophic Changes in Lower Leg Muscles of Boys with Duchenne Muscular Dystrophy and Their Relationship to Functional Measurements.
abstract: BACKGROUND
  The primary objectives of this study were to evaluate contractile and non-contractile content of lower leg muscles of boys with Duchenne muscular dystrophy (DMD) and determine the relationships between non-contractile content and functional abilities.
  
  
  METHODS
  Lower leg muscles of thirty-two boys with DMD and sixteen age matched unaffected controls were imaged. Non-contractile content, contractile cross sectional area and non-contractile cross sectional area of lower leg muscles (tibialis anterior, extensor digitorum longus, peroneal, medial gastrocnemius and soleus) were assessed by magnetic resonance imaging (MRI). Muscle strength, timed functional tests and the Brooke lower extremity score were also assessed.
  
  
  RESULTS
  Non-contractile content of lower leg muscles (peroneal, medial gastrocnemius, and soleus) was significantly greater than control group (p<0.05). Non-contractile content of lower leg muscles correlated with Brooke score (rs = 0.64-0.84) and 30 feet walk (rs = 0.66-0.80). Dorsiflexor (DF) and plantarflexor (PF) specific torque was significantly different between the groups.
  
  
  CONCLUSIONS
  Overall, non-contractile content of the lower leg muscles was greater in DMD than controls. Furthermore, there was an age dependent increase in contractile content in the medial gastrocnemius of boys with DMD. The findings of this study suggest that T1 weighted MR images can be used to monitor disease progression and provide a quantitative estimate of contractile and non-contractile content of tissue in children with DMD.
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Ravneet S
authors.initials: RS
authors.lastname: Vohra
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Donovan
authors.initials: D
authors.lastname: Lott
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Sunita
authors.initials: S
authors.lastname: Mathur
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Claudia
authors.initials: C
authors.lastname: Senesac
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Jasjit
authors.initials: J
authors.lastname: Deol
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Sean
authors.initials: S
authors.lastname: Germain
authors.affiliation: Department of Occupational Therapy, University of Florida, Gainsville, FL, United States of America.
authors.forename: Roxanna
authors.initials: R
authors.lastname: Bendixen
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Sean C
authors.initials: SC
authors.lastname: Forbes
authors.affiliation: Department of Physiology, School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America.
authors.forename: H Lee
authors.initials: HL
authors.lastname: Sweeney
authors.affiliation: Department of Physiology and Functional Genomics, University of Florida, Gainsville, FL, United States of America.
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Walter
authors.affiliation: Department of Physical Therapy, University of Florida, Gainesville, FL, United States of America.
authors.forename: Krista
authors.initials: K
authors.lastname: Vandenborne
mesh_terms: D002648:Child; D002675:Child, Preschool; D006801:Humans; D006984:Hypertrophy / Q000503:physiopathology*; D007866:Leg / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000503:physiopathology*; D020388:Muscular Dystrophy, Duchenne / Q000503:physiopathology*