Rinsho Shinkeigaku (Clinical Neurology)

Case Report

Neuropathy presenting conduction block in ANCA-negative eosinophilic granulomatosis with polyangiitis

Masaya Honda, M.D.1), Yukio Takeshita, M.D., Ph.D.1), Michiaki Koga, M.D., Ph.D.1), Ryota Sato, M.D.1), Masatoshi Omoto, M.D., Ph.D.1) and Takashi Kanda, M.D., Ph.D.1)

1) Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine

A 74-year-old woman with a history of asthma and allergic rhinitis rapidly developed multiple mononeuropathy. Although anti-neutrophil cytoplasmic antibodies were negative, the presence of eosinophilia and eosinophilic infiltrations in the sural nerve led to a diagnosis of eosinophilic granulomatosis with polyangiitis. A motor nerve conduction study on admission revealed conduction block, which promptly disappeared after initiating immunotherapy without findings suggestive for remyelination or axonal degeneration. This electrophysiological change distinct from that of Wallerian degeneration. A biopsy of the sural nerve showed many eosinophil infiltrations and degranulation of eosinophilic cationic protein within nerve fascicles, whereas findings of necrotizing vasculitis were absent. These findings suggest that a direct effect of eosinophilic cationic protein, rather than ischemic damage due to vasculitis, was the main mechanism of transient nerve conduction failure in this patient.
Full Text of this Article in Japanese PDF (2748K)

(CLINICA NEUROL, 61: 613−617, 2021)
key words: eosinophilic granulomatosis with polyangiitis, anti-neutrophil cytoplasmic antibody negative, eosinophilic cationic protein, conduction block

(Received: 2-Nov-20)