Peripheral white matter lesions of the spinal cord with changes in small arachnoid arteries in systemic lupus erythematosus.

The spinal cords of two autopsy cases of systemic lupus erythematosus (SLE) (case 1, 34-year-old woman; case 2, 40-year-old woman) showed lesions restricted to the periphery and frequent changes in small arteries in the spinal subarachnoid space. There had been clinical cord involvement in both cases, for two months (case 1) and six years (case 2) before death, respectively. The spinal cord of case 1 had circumferentially located, multiple, round, spongy, sometimes necrotic, lesions, containing many swollen axons. Even the apparently spared peripheral regions showed moderate axon loss. Observation of serial sections of the cord revealed the direct connection of some occluded subarachnoid small arteries with vessels within the spongy lesions, indicating the responsibility of the vascular changes for the cord lesions. In case 2, the whole length of the spinal cord showed marked axonal loss in the entire circumferential white matter. Groups of old axonal retraction balls and localized spongy changes were occasionally observed at the periphery. The affected peripheral zone coincided with the region supplied by marginal arteries. These observations suggest that primary vascular lesions, followed by secondary degeneration of axons, played fundamental roles in the development of this unique lesion in case 2, and that localized changes such as those observed in case 1 gradually develop into the continuous lesion seen in case 2.