Acute motor axonal neuropathy in a case of granulomatosis with polyangiitis

A 65 years-old woman started developing arthralgias, mild cough and dyspnea. When symptoms progressed to productive cough and moderate exertional dyspnea, she was admitted to the hospital. Thoracic CT revealed diffuse interstitial pneumopathy, pulmonary function tests indicated moderate obstruction (FEV1 = 60%) and bronchoalveolar lavage was suggestive of severe alveolar-hemorrhagic syndrome. Laboratory workup confirmed the presence of antibodies against myeloperoxidase (i.e. p-ANCA) and absence of mycobacterium tuberculosis, hence a diagnosis of granulomatosis with polyangiitis was established. During hospitalization, she developed rapidly progressive paraparesis with retained deep tendon reflexes. Electroneurography highlighted the presence of subacute onset motor axonal polyneuropathy affecting both upper and lower limbs. Under treatment with methylprednisolone, oral cyclophosphamide, alpha-lipoic acid and intravenous immunoglobulins, improvement of neurological status was noted.