Segmental demyelination in rheumatoid arthritis.
Sural nerve histopathological examination in nine rheumatoid patients revealed varying nerve and arterial changes, which were absent in the two osteoarthritic and seven road-accident necropsy controls.

Segmental demyelination without arterial change was found in four of the uncomplicated milder cases. Segmental demyelination with arterial intimal proliferation were the major findings in the two cases of the intermediate group. Wallerian degeneration with varying arterial findings were present in the three patients of the most severe group, two of whom had clinical neuropathy and arteriopathy.

Segmental demyelination seems the fundamental nerve abnormality in rheumatoid arthritis. Only in the more severe cases with superimposed arterial occlusion did Wallerian degeneration appear.