P.187 - Dermatomyositis associated with hearing loss, peripheral nerve vasculitis and multi-system dysfunction

Abstract

Classic myopathological features of dermatomyositis include perifascicular muscle fiber atrophy and perimysial perivascular inflammation, typically associated with focal microvascular depletion and membrane attack complex deposits on capillaries. The etiology behind microvascular injury however remains poorly understood. Co-existing systemic vasculitis is uncommon and peripheral nerve involvement has been rarely reported. A 39-year-old female, on Rituximab for “seronegative rheumatoid arthritis”, developed myalgias, night sweats, 30-pound weight loss and amenorrhea, followed by rapidly progressive proximal weakness. Months later she developed refractory atrial fibrillation with rapid ventricular rate and reported intermittent tingling in her feet. Ten months from onset, the patient developed left followed by right hearing loss. Neurological examination showed mild neck weakness, severe proximal and distal limb weakness, mildly decreased proprioception at the toes and complete hearing loss. Electrodiagnostic testing showed diffusely myopathic motor units, fibrillation potentials and absent sural nerve responses. CSF analysis showed 146 nucleated cells (89% lymphocytes) and markedly elevated protein level (458 mg/dl). Deltoid muscle biopsy showed perifascicular atrophy and prominent perimysial perivascular inflammation; diagnostic of dermatomyositis. The high suspicion for systemic vasculitis prompted sural nerve biopsy, which showed multiple collections of inflammatory cells involving epineurial vessels with vessel wall destruction and neovascularization; diagnostic of vasculitis. Liver and enteric biopsy showed diffuse lymphocytic infiltration. Cancer screen was unremarkable. The patient was treated with high dose prednisone and oral cyclophosphamide. This is a unique case of dermatomyositis associated with complete hearing loss, peripheral nerve vasculitis, refractory atrial fibrillation as well as lymphocytic hepatitis and enteritis.