The rigid spine syndrome in two sisters.

Abstract

SUMMARY Two half-sisters aged 14 and 18 years are described with a rigid spine syndrome as the cardinal clinical feature of an autosomal dominant neuromuscular disorder. Ten years previously, a diagnosis of multicore disease had been made from the clinical signs and muscle biopsy findings. Long term follow-up revealed a non-specific muscular dystrophy with axial predominance and a rigid spine in the younger girl; the older sister presented at the age of 18 with a rigid spine as the only myopathic sign. Computed tomography of the muscles showed severe involvement of the paraspinal musculature, in contrast with either less or no involvement of the other muscles. We describe two half-sisters who were thought initially to have a non-progressive autosomal dominant multicore myopathy. After a 9 year follow up, both girls eventually displayed the clinical features of the rigid spine syndrome, and the younger sister also showed evidence of aspecific muscular dystrophy. The diagnostic contribution of CT scanning of the muscles is stressed, as this appears not to have been mentioned in previous reports of this syndrome. Case 1 was born at term in 1972; there were no feeding problems and motor development was normal without apparent floppiness. First examination was in 1977 for excessive muscle fatigue. The girl was very small, with general slight muscle hypotrophy and weakness, MRC grade 4+, except for the foot extensors which displayed a more pronounced paresis, MRC grade 3. Winged scapula and ankle contracture were present bilaterally. All myotatic reflexes were either hypoactive or absent. There was no sensory disturbance. The serum creatine kinase activity (CK) was slightly increased at three times the normal value and the previously described biopsy findings of the quadriceps muscle25 were consistent with multicore disease.Further clinical progression unexpectedly occurred in the summer of 1982: she then presented with diffuse and substantial muscle atrophy; the musculature of the trunk and the extremities was diffusely paretic (MRC grade 4), and even more severe weakness (MRC grade 3) was noted in the neck flexors and the foot extensors. There was increased dorsal kyphosis and lumbar lordosis; flexion of the thoracolumbar spine was markedly limited and an obvious contracture of the neck extensors was now present; there was no increase of the ankle contracture. A repeated biopsy of the right quadriceps muscle showed randomly distributed and irregular cores with absence of mitochondria and Z-band smearing or disruption. However, additional abnormalities consisted of muscle dystrophic signs including fibre splitting, some necrotic and a few basophilic fibres, many internal nuclei and increased endomysial fibrosis. There was a fibre 1 predominance of 60% (fig la).Six months later, CT of the muscles revealed areas of very low attenuation in the erectores spinae, consistent with replacement of muscle by lipofibrotic tissue. It was striking that the paravertebral musculature was much more involved than the muscles of the e...

Rigid spine syndrome: case report

“…The differential diagnosis includes the muscular dystrophies 10 (Duchenne, Becker and Emery-Dreifuss); congenital myopathies 4,9 (central core disease, centro-nuclear myopathy, mitochondrial and multicore myopathy), nemaline myopathy 13 and ankylosing spondylitis 7 .…”

“…The reason for the involvement, mainly of paraspinal muscles, is not well known 9 . It is suggested that the increase of connective tissue in extensor muscles would result in their shortening which would inhibit the spine flexor muscles.…”

“…During the evolution of the disease, five years after its onset, was noted a progressive limitation of trunk and neck flexure and was redefined as "rigid spine syndrome". Even though other cases have been described, the diagnostic criteria have not yet been established [2][3][4][5][6][7][8][9][10][11][12] .…”