Motor neuron disease in a patient with overlap syndrome (rheumatoid arthritis; systemic lupus erythematosus, Sjogren's syndrome).

Autoimmune rheumatic diseases have their own specific clinical presentation, and can affect multiple systems. Neurological involvement of autoimmune rheumatic diseases may involve both the central and peripheral nervous systems. Inflammation of neural tissue, autoantibody-mediated reactions, and small vessel vasculitis may be effective in the pathogenesis of neuropathy in autoimmune rheumatological diseases. Autoimmune rheumatic disease with pure motor neuron involvement is very rare in the literature. The case is here presented of a 58-year-old female patient who presented with the complaints of increasing pain and weakness in the extremities and was diagnosed with lower motor neuron disease and overlap syndrome. The patient was treated with cyclophosphamide, pulse steroid, hydroxychloroquine and intravenous immunoglobulin. After 3 months of treatment, a significant improvement was observed in the patient's clinical complaints and laboratory parameters. In conclusion, some patients with undiagnosed autoimmune rheumatic diseases may have neurological complaints. Clinicians should investigate patients with such neurological complaints for autoimmune rheumatic diseases.