This study was designed to reveal any correlation between radiological signs and clinical findings of cervical spine involvement in rheumatoid arthritis (RA).
Fifty patients with definite rheumatoid arthritis were evaluated for cervical spine involvement by a clinical neurological examination, a somatosensory evoked potential (SEP) study and different radiological techniques including tomograms, computerized tomography (CT) and magnetic resonance imaging (MRI).
Anterior atlantoaxial subluxation was a common finding, frequently associated with superior migration of the dens and subaxial subluxation. Two patients presented a posterior atlantoaxial subluxation due to complete erosion of the dens. Both had cervical cord compression and one of them had hypoglossal nerve paresis. The delineation of peridental pannus formation was clearly demonstrated by MRI. In the majority of cases cervical cord compression was caused by pannus formation or by vertical atlantoaxial subluxation.
The correlation between the severity of the radiological findings and the clinical-neurological signs was poor. A 4-limb SEP study appeared to be a useful screening method for the detection of cervical medullary compression.