title: Contractile properties are disrupted in Becker muscular dystrophy, but not in limb girdle type 2I.
abstract: We investigated whether a linear relationship between muscle strength and cross-sectional area (CSA) is preserved in calf muscles of patients with Becker muscular dystrophy (BMD, n = 14) and limb-girdle type 2I muscular dystrophy (LGMD2I, n = 11), before and after correcting for muscle fat infiltration. The Dixon magnetic resonance imaging technique was used to quantify fat and calculate a fat-free contractile CSA. Strength was assessed by dynamometry. Muscle strength/CSA relationships were significantly lower in patients versus controls. The strength/contractile-CSA relationship was still severely lowered in BMD, but was almost normalized in LGMD2I. Our findings suggest close to intact contractile properties in LGMD2I, which are severely disrupted in BMD. Ann Neurol 2016;80:466-471.
authors.affiliation: Copenhagen Neuromuscular Center, Copenhagen, Denmark.
authors.forename: Nicoline
authors.initials: N
authors.lastname: Løkken
authors.affiliation: Copenhagen Neuromuscular Center, Copenhagen, Denmark.
authors.forename: Gitte
authors.initials: G
authors.lastname: Hedermann
authors.affiliation: Department of Diagnostic Radiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Carsten
authors.initials: C
authors.lastname: Thomsen
authors.affiliation: Copenhagen Neuromuscular Center, Copenhagen, Denmark. John.Vissing@regionh.dk.
authors.forename: John
authors.initials: J
authors.lastname: Vissing
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007866:Leg / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D049288:Muscular Dystrophies, Limb-Girdle / Q000503:physiopathology*; D020388:Muscular Dystrophy, Duchenne / Q000503:physiopathology*; D055815:Young Adult