Rinsho Shinkeigaku (Clinical Neurology)

Brief Clinical Note

Thoracoabdominal muscle involvement in anti-PL-7 myopathy revealed by whole-body magnetic resonance imaging

Nozomu Matsuda, M.D., Ph.D.1), Shuzo Sato, M.D., Ph.D.2), Ayaka Nemoto, M.S.3), Hitoshi Kubo, Ph.D.3)4), Shunsuke Kobayashi, M.D., Ph.D.1) and Yoshikazu Ugawa, M.D., Ph.D.1)5)6)

1)Department of Neurology, Fukushima Medical University
2)Department of Rheumatology, Fukushima Medical University
3)Advanced Clinical Research Center, Fukushima Medical University
4)Preparing Section for New Faculty of Medical Sciences, Fukushima Medical University
5)Department of Neuro-Regeneration, Fukushima Medical University
6)Department of Neurology, Aidu Chuo Hospital

A 33-year-old woman developed progressive weakness in the proximal limbs with myalgia and morning stiffness. Physical examination revealed low-grade fever, heliotrope eyelids and mechanic's hand. On neurological examination, she showed Medical Research Council grade 4 weakness in the shoulder girdle, proximal limb muscles, and grade 4 weakness in the abdominis muscle according to Daniels's scale. Laboratory tests revealed elevated serum creatine kinase (6,824 IU/l) and positive anti-PL-7 antibody. A needle electromyography study detected short motor unit potentials of myogenic pattern with abundant fibrillations and positive sharp waves. Whole-body MRI detected high intensity signals in the muscles of the shoulder girdle, proximal limbs, and thoracoabdominal trunk on short-tau inversion recovery sequence images. We diagnosed her as anti-PL-7 myopathy. After treatments with steroid, immunosuppressant, and immunoglobulin, her symptoms improved and abnormal MRI signals were normalized. Although MRI is known to be useful for detection of asymptomatic muscular inflammation in myositis, thoracoabdominal muscles are generally not covered in routine evaluation. To our knowledge, ours is the first case to detect acute inflammation of the thoracoabdominal muscles in antisynthetase syndrome. The present study suggests that whole-body MRI is useful for comprehensive evaluation of muscular involvement and longitudinal assessment for treatment outcomes.
Full Text of this Article in Japanese PDF (437K)

(CLINICA NEUROL, 58: 692－695, 2018)
key words: anti-PL-7 myopathy, antisynthetase syndrome, myositis-specific autoantibody, whole-body MRI, truncal muscle

(Received: 5-Jul-18)