Whole‐Body Muscle Magnetic Resonance Imaging in 81 Patients with Spinal and Bulbar Muscular Atrophy: A Prospective Study

• Published in: Annals of neurology 2024-03, Vol.95 (3), p.596-606
• Main Authors: Kim, Hyunjin, Seo, Incheol, Kang, Minsung, Park, Jin‐Mo, Seok, Hung Youl, Kim, Sohyeon, Park, Jin‐Sung
• Format: Article
• Language: English
• Subjects: Atrophy; Clinical trials; Cluster analysis; Correlation; Creatinine; Infiltration; Magnetic resonance imaging; Medical imaging; Muscles; Pelvis; Regression analysis; Spinal and bulbar muscular atrophy; Thigh
• ISSN: 0364-5134; 1531-8249
• DOI: 10.1002/ana.26846

Objective Spinal and bulbar muscular atrophy (SBMA) is characterized by slow, progressive bulbar and limb muscle weakness; however, the pattern of progression of muscle fat infiltration remains unclear. We assessed the progression of muscle involvement in 81 patients with SBMA using whole‐body muscle magnetic resonance imaging (MRI), alongside clinical and laboratory findings. Methods This prospective study included patients with genetically confirmed SBMA who underwent whole‐body muscle MRI. We analyzed muscle fat infiltration and the pattern of involved muscles using cluster analysis, visualizing the sequential progression of fat infiltration. Muscle clusters demonstrated correlation with clinical scales and laboratory findings. Additionally, linear regression analysis was performed to identify the MRI section most strongly associated with 6‐minute walk test (6MWT). Results We included 81 patients with SBMA (age = 54.3 years). After categorizing the patients into 6 clusters based on the pattern of muscle fat infiltration, we observed that muscle involvement began in the posterior calf and progressed to the posterior thigh, pelvis, trunk, anterior thigh, medial thigh, anterior calf, and upper extremity muscles. These muscle clusters correlated significantly with disease duration (τ = 0.47, p