Selective Fatty Replacement of Paraspinal Muscles in Facioscapulohumeral Muscular Dystrophy

A 65-year-old man with a history of facioscapulohumeral muscular dystrophy presented to his physician with a complaint of new-onset low back pain, bilateral foot numbness, and left lower extremity radicular symptoms with foot drop. He subsequently underwent magnetic resonance imaging of the lumbar spine, which revealed complete fatty replacement of the erector spinae musculature throughout the lumbar spine. Preservation of the lumbar multifidus muscles above the L4 level was observed, which has not previously been reported in patients with this condition. The patient's lower extremity symptoms were consistent with left L5-S1 radiculopathy, and the magnetic resonance images indicated mild to moderate central canal stenosis at L2-L3 with severe bilateral L5-S1 foraminal narrowing. J Orthop Sports Phys Ther 2019;49(6):483. doi:10.2519/jospt.2019.8815.