Atlanto-occipital subluxation in rheumatoid arthritis demonstrated by magnetic resonance imaging.

Atlanto-occipital subluxation is a rare but recognized form of subluxation that occurs in rheumatoid arthritis (RA) at the cranio-cervical junction. Magnetic resonance imaging (MRI) clearly demonstrates the bony and soft tissue changes of RA in the cervical spine. We report a single case of atlanto-occipital subluxation in RA demonstrated by MRI.