[A case of combined paraneoplastic neurological syndrome, with Lambert-Eaton myasthenic syndrome manifesting as severe respiratory failure, and anti-Hu syndrome].

A 63-year-old man complained of rapidly progressive respiratory failure, requiring a control respiration. He subsequently, presented with muscle weakness involving the neck and all the extremities, superimposed by painful paresthesia. He was proven to carry small-cell lung cancer (SCLC). Neurophysiological examinations revealed the waxing phenomenon at 30 Hz repetitive motor nerve stimulation. Positive serum autoantibodies were detected to voltage-gated calcium channel and Hu proteins. He received diagnosis of combined Lambert-Eaton myasthenic syndrome (LEMS) and anti-Hu syndrome. The initial chemotherapy for SCC alleviated his respiratory and neurological symptoms. But he developed multiple cranial palsies and fatal respiratory distress two months later. There is only a few reports about LEMS complicated by respiratory failure as an initial presentation. Various clinical manifestations including respiratory failure at the onset could be best explained by the combination of LEMS and anti-Hu syndrome in this case.