Rigid spine syndrome. Two case-reports.

UNLABELLED: Rigid spine syndrome is characterized by massive spinal rigidity, usually most marked in the cervical region. Stiffness of the peripheral joints is sometimes present. We report two cases. Patient 1 was a 12-year-old boy diagnosed at three years of age with Duchenne's muscular dystrophy because of delayed onset of walking. Contracture of the Achilles tendons, flexion contracture of the elbows, and loss of motion of the cervical spine were the main findings during the current evaluation. Radiographs of the affected joints were normal. An electrocardiogram showed an incomplete left bundle branch block. Muscle enzyme activities were moderately elevated. A myopathic pattern was seen on the electromyogram. A muscle biopsy showed muscle fiber atrophy with peri- and endomysial fibrosis. Patient 2 was a 39-year-old man with a five-year history of isolated rigidity of the cervical spine thought to be due to a spondylarthropathy. Extension was the only movement possible at the cervical spine. The peripheral joints showed no motion range limitation. Findings were normal from radiographs of the spine and sacroiliac joints, an erythrocyte sedimentation rate determination, an electromyogram, and muscle enzyme activity assays. A muscle biopsy showed muscle fiber atrophy with peri- and endomysial fibrosis.

DISCUSSION: Rigid spine syndrome is rare in rheumatological practice and can simulate a number of other muscle and joint diseases. Peri- and endomysial fibrosis may be strongly suggestive, although nonpathognomonic. Involvement of the heart governs the prognosis.