In 2 cases of severe, longstanding rheumatoid arthritis involving the cervical spine, a progressive spinal cord syndrome developed in which spastic paraparesis was combined with a lower motoneuron paresis affecting the upper limbs. In both cases necropsy showed the cause to be subluxation between the C4 and C5 vertebral bodies and backward encroachment into the spinal canal of the upper and posterior part of the C5 vertebral body. A feature of the spinal cord abnormality was central infarction, apparently caused by an effect on a patent anterior spinal artery and manifested not only at the site of spinal cord compression but for several spinal cord segments caudal to this level. [7, 8,[13][14][15][16][17]. Subaxial dislocations are less common, and in neither has the pathological abnormality of the spinal cord been studied in detail. For these reasons the present report records the findings in 2 cases of subaxial dislocation in which the mechanism of spinal cord damage was studied at necropsy.
Patient 1For the seven years preceding her death in 1974 at the age of 57 years, this woman had suffered from severe, mutilating, seropositive rheumatoid arthritis; during this time she had been vigorously treated with steroids and azathioprine. In the three years before her death she had suffered neck pains, and roentgenograms showed marked abnormalities of the cervical spine (Fig 1). She had then experienced the gradual onset and progression of a spastic paraparesis, affecting her right side more than her left, accompanied by a complicated pattern of sensory loss. One year before her death she developed lower motoneuron weakness in both arms, right more than left. Wasting and weakness were detectable in most of the upper limb muscles, right more than left.However, the severe deformity and immobility caused by the arthritis made it very difficult to determine on clinical grounds how much of this wasting and weakness was due to denervation. By electromyography, evidence of denervation (denervation potentials, including fibrillation or positive potentials or both) was found on the left side in the deltoid, biceps brachii, and extensor digitorum muscles and on the right side in the deltoid, extensor digitorum, and first dorsal interosseus muscles. She died from bronchopneumonia after a week of respiratory weakness.
Genevul Necropsy FindingsExtensive bilateral bronchopneumonia was present. The other internal organs were unremarkable. The brain was normal.FIXED SPINE. The cervical and upper thoracic spine had been fixed with the spinal cord in situ. The vertebral arteries had been injected with radiopaque material and were demonstrated to be patent. Externally the specimen was abnormal in having a pronounced curve, convexity backward, in the upper cervical region, while anteriorly there was prominent midline swelling some 1.5 cm in diameter due, as was confirmed by postmortem roentgenograms, to forward protrusion of the lower part of the C4 vertebral body.From the Department of Neuropathology, Radcliffe Infirmary, Address repr...