A case of rigid spine syndrome with rimmed vacuolar myopathy

ABSTRACT

Rigid spine syndrome (RSS) is a childhood onset muscle disorder characterized by marked limitation of motility of cervical and lumbar spine with severe lordosis, contracture of limb joints, mild and nonprogressive proximal muscle weakness, moderately elevated muscle enzymes, myopathic electromyographic patterns, and histological features of nonspecific myopathies. Here we present a 14-year-old girl with distinctive clinical features of rigid spine syndrome. She developed slowly progressive difficulty on walking because of joint contracture and rigid spine with severe lordosis since 4 years of age. There was mild but generalized muscle weakness. The serum creatine kinase was increased up to 743 IU/ml and the EMG studies showed combined features of myopathy and neuropathy. The muscle biopsy of vastus lateralis revealed the typical findings of rimmed vacuolar myopathy with perivascular inflammatory cell infiltration, which were consistent with the inclusion body myositis.