反復する運動失調と呼吸不全を呈し，血漿交換療法が奏効した傍腫瘍性神経症候群と考えられた 例

An 80-year-old male with prostatic adenocarcinoma who was treated with orchiectomy presented dysarthria and difficulty in walking. His symptoms subacutely progressed. Seven days later, he was non-ambulatory and was admitted to our hospital. He had poor vision and cerebellar ataxia of the lower extremities; however, his muscle strength, tendon reflexes, and sensory functions were preserved. Paraneoplastic retinopathy was diagnosed based on electroretinographic and visual field defect. Further, brain and spinal MRI, cerebral spinal fluid, and nerve conduction assessments were normal. These symptoms were followed by consciousness disturbance and respiratory failure; consequently, he required non-invasive positive pressure ventilation (NPPV) and tube feeding. Steroid pulse therapy and plasma exchange (PE) were performed. In response to the therapy, all these symptoms were relieved, and NPPV and tube feeding were withdrawn. However, the same symptoms occurred additional three times throughout the course of approximately 1 year. Each time, PE was the most effective treatment. Although paraneoplastic neurological syndrome associated with prostatic cancer is rare, immunotherapy could be a therapeutic choice to relive symptoms.