Muscle magnetic resonance imaging changes and relationship with clinical symptoms in patients with dysferlinopathy

Objective To investigate the characteristics of muscle edema and fatty infiltration in thighs and relationship with clinical symptoms in Chinese patients with different phenotypes of dysferlinopathy. Methods A total of 32 patients were enrolled, including 13 limb-girdle muscular dystrophy 2B (LGMD2B), 13 Miyoshi myopathy (MM), 4 proximodistal myopathy and 2 hyper-creatine-kinase-emia.Clinical symptoms were evaluated using modified Gardner-Medwin and Walton (GM-W) score.Muscle MRI was performed in thighs to observe fatty infiltration and edema.We then compared the age of onset, disease duration, GM-W score, muscle edema and muscle fatty infiltration between LGMD2B and MM groups，and the relationship of muscle edema score and fatty infiltration score with disease duration and GM-W score in all patients. Results The median GM-W score was 4.00（2.00,5.00）in all patients, 4.00（3.00,4.50）in LGMD2B and 4.00（2.00,5.00）in MM, respectively.Muscle fatty infiltration appeared in 30 cases (93.75%), with the same pattern in LGMD2B and MM.The mean fatty infiltration score was 28.20±12.86 in all patients, 28.50±13.03 in LGMD2B and 29.00±12.63 in MM, respectively.Muscle edema appeared in 26 cases (81.25%) with same pattern in LGMB2B and MM.The mean edema score was 18.36±13.60 in all patients, 22.88±11.59 in LGMD2B and 16.77±13.80 in MM.The age of onset, disease duration, GM-W score, muscle fatty infiltration and edema score were not significantly different between LGMD2B and MM patients.Muscle fatty infiltration score significantly correlated with GM-W score (rs=0.737，P=0.000) and disease duration (rs=0.637，P=0.000). Conclusions Fatty infiltration and edema in thigh muscles are very common in patients with dysferlinopathy, with similar radiological changes in main subtypes.The muscle fatty infiltration can be used as a predictor of disease progression. Key words: Muscular dystrophies, limb-girdle; Leg; Muscle, skeletal; Edema; Magnetic resonance imaging