Electrophysiologic Characteristics in Systemic Necrotizing Vasculitis Patients with Peripheral Neuropathy

ABSTRACT

OBJECTIVE: To evaluate the clinical findings and the results of an electrophysiological study in seven patients with a systemic necrotizing vasculitis and neuropathy. METHOD: Clinical and electrophysiological studies were performed in seven patients of whom three had a polyarteritis nodosa, other three a Churg-Strauss syndrome, and one an overlapping syndrome. RESULTS: In the electrophysiological study, five patients presented an overlapping multiple mononeuropathy, one a multiple mononeuropathy and the other one a distal symmetric polyneuropathy. The neuropathies were mainly axonopathies with a decreased amplitude of compound motor action potential and sensory nerve action potential; however one patient showed the conduction blocks in the tested nerves. In electromyography, the most prominent feature was a neurogenic pattern with fibrillation potentials and reduced recruitments. No patient had a myopathic pattern. CONCLUSION: The most prominent features of the systemic necrotizing vasculitis patients with neuropathy were the axonopathic findings in the nerve conduction studies and neurogenic pattern in the electromyographic studies. Electrodiagnostic study was helpful for the diagnosis of vasculitic neuropathy, however further studies would be necessary to clarify the characteristics of the neuropathy of polyarteritis nodosa and the Churg-Strauss syndrome.