Massive intracranial pannus and a pseudomeningocoele in the atlanto-dental interval in rheumatoid arthritis

The joints in the region of the cranio-vertebral junction have been estimated to be involved radiologically in 19–36% of patients with chronic, deforming rheumatoid arthritis (Sharp & Purser, 1961; Stevens et al, 1971; Matthews, 1974). Eulderink and Meders (1975) reported that pathological evidence of involvement of the cervical spine was found in 59% of 44 cases at autopsy, and in over 70% of these the joints of the cranio-vertebral junction were affected. Existing literature emphasises the clinical significance of subluxation rather than of associated granulation tissue. Nevertheless, it has been shown on computed myelo-cisternography that pannus is frequently the dominant factor responsible for the actual configuration of compressive deformity of the spinal cord near the foramen magnum (Stevens et al, 1986), though the clinical importance of this observation has been denied by others (Laasonen et al, 1985). This is a report of a case which showed two distinctly unusual features: a huge intracranial mass of rheumatoid granulation tissue, most probably of synovial origin, causing brain-stem compression, and a pseudomeningocoele prolapsing into the atlanto-dental interval when the neck was flexed. Mrs D. B., aged 65 years, suffered from progressively deforming rheumatoid arthritis for over 30 years. The disease had been complicated by neutropenia in the past 3 years and the patient was known to have mild hepato-splenomegaly. Three months previously she had noticed progressive weakness in the arms and legs; then, suddenly, 8 days before admission she felt her neck “give way”, and experienced severe neck pain radiating between her shoulders.