A case-control and nerve biopsy study of CREST multiple mononeuropathy.

From 536 patients with the CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasis), seven were identified as having peripheral neuropathy not attributable to another cause. Peripheral neuropathy developed 0 to 25 years after their first symptoms of scleroderma. Unexplained neuropathy in CREST patients (seven patients) was more frequent than in control subjects (two patients) matched for age, sex, time of evaluation, and geographic referral region. Multiple mononeuropathy occurred significantly more frequently in the CREST group (six patients) than in the control group (0 patients). Four sural nerve biopsy specimens from the CREST patients demonstrated multifocal fiber loss and perivascular inflammation; one was diagnostic for necrotizing vasculitis and two others were highly suggestive for necrotizing vasculitis. The density of myelinated fibers in three nerves from CREST patients was significantly decreased, whereas the index of dispersion (a measure of multifocal fiber loss) was increased, and the frequency of axonal degeneration was significantly increased. Based on these clinical and pathologic findings, we conclude that in the CREST syndrome multiple mononeuropathy, although occurring infrequently, occurs more frequently than by chance and necrotizing vasculitis is the cause of this multiple mononeuropathy.