Vasculitic neuropathy--electrodiagnostic findings and association with malignancies.

BACKGROUND: Vasculitic neuropathies occur in the context of systemic disorders or in isolation. Histopathologic evaluation remains the gold standard for diagnosis, but certain electrodiagnostic findings may heighten suspicion of vasculitic neuropathy and improve the yield of nerve and muscle biopsy.

AIM OF THE STUDY: Description of electrodiagnostic patterns associated with vasculitic neuropathies, and a report of a possible association with malignancies.

METHODS: Retrospective review of medical records of patients with histopathologically proven vasculitic and non-vasculitic axonal neuropathies evaluated at the University of Pittsburgh Medical Center from November 1995 to November 2003.

RESULTS: The most distinctive electrodiagnostic patterns associated with vasculitic neuropathy were mononeuritis multiplex (27.5% vs 4% in controls; P = 0.003) and axonal sensorimotor polyneuropathy with side-to-side amplitude asymmetry (50% vs 32%, P > 0.05). Additionally, six patients (15% vs 2%; P = 0.034) developed various malignancies within 2 years of onset of vasculitic neuropathy.

CONCLUSIONS: While generalized polyneuropathy was the most common presentation of nerve vasculitis, our study affirms side-to-side amplitude asymmetry and mononeuritis multiplex as the most distinctive electrodiagnostic features. The frequent occurrence of malignancies suggests a possible association with the vasculitic neuropathy and warrants additional investigation.