Sural nerve biopsy in systemic necrotizing vasculitis.

This study of 17 patients with vasculitic neuropathy (polyarteritis nodosa in 11, rheumatoid arthritis in five, and systemic lupus erythematosus in one) revealed the following: (1) Polyneuropathy is the most common manifestation of peripheral neuropathy in polyarteritis nodosa. (2) Peripheral neuropathy is more common in systemic necrotizing vasculitis than physical evaluation alone suggests. Adequate electrophysiologic tests can detect asymptomatic peripheral neuropathy in a substantial number of patients. (3) Abnormal sural nerve condition is a prerequisite to the demonstration of vasculitis on biopsy of this nerve. Thus, in using abnormal sural nerve conduction as a guide in nerve biopsy, the diagnostic yield of sural nerve biopsy will be greatly enhanced.