Relationship between muscle inflammation and fat replacement assessed by MRI in facioscapulohumeral muscular dystrophy

• Published in: Journal of neurology 2019-05, Vol.266 (5), p.1127-1135
• Main Authors: Dahlqvist, Julia R., Andersen, Grete, Khawajazada, Tahmina, Vissing, Christoffer, Thomsen, Carsten, Vissing, John
• Format: Article
• Language: English
• Subjects: Desserts; Edema; Growth industries; Inflammation; Inflammatory diseases; Magnetic resonance imaging; Medicine; Medicine & Public Health; Muscular dystrophy; Musculoskeletal diseases; Neurology; Neuroradiology; Neurosciences; Original Communication
• ISSN: 0340-5354; 1432-1459
• DOI: 10.1007/s00415-019-09242-y

Objective Unlike most muscular dystrophies that progress symmetrically at a constant rate, facioscapulohumeral muscular dystrophy (FSHD) is characterized by stepwise, asymmetric progression of muscle wasting, and weakness. Muscle tissue is progressively replaced by fat; however, its relation to preceding inflammation is unclear. In this longitudinal study of FSHD, we assessed muscle inflammation and fat replacement and their relation quantitatively. We also investigated whether fat replacement in muscle varies along its length. Methods Forty-five patients with FSHD were evaluated twice, 14 months apart. Using MRI sequences with short TI inversion recovery (STIR), we quantified the degree of STIR hyperintensity in muscles (≥ 2 SD above control intensity). STIR hyperintensities (STIR+) suggest edema or inflammation. We used Dixon MRI to quantify fat content. Results Of 370 thigh muscles, 83 were STIR+ at baseline and 103 at follow-up. The highest frequency of STIR+ was seen in muscles with inter-mediate fat content (40–60% fat). The progression of fat replacement was higher in STIR+ muscles (5.0 ± 4.0%) vs. STIR− muscles [2.3 ± 3.3% ( P