Critical illness polyneuropathy (CIP) and critical illness myopathy (CIM) occur commonly in the patients who havebeen on mechanical ventilation for more than 1 week. Even in some patients diagnosed with CIP, an underlyingmyopathy may be the primary cause of the muscle weakness. The cormorbid status of CIP and CIM is called as criticalillness polyneuropathy and critical illness myopathy (CIPNM). We describe a 56-year-old man with acute quadriparesisand areflexia after systemic inflammatory response syndrome. The diagnosis of CIPNM is important to avoid unnecessaryinvestigations and unreasonably pessimistic prognosis. Electrophysiologic studies are essential for the diagnosis and forplanning further clinical management.

Autoimmune myasthenia gravis (MG) is the neuromuscular junction disorder mostly caused by antibody against the acetylcholine receptor (AChR antibody) at the muscle endplate. The goal of treatment is to induce and maintain remission, i.e., absence of symptoms, with the least cost-to-benefit ratio. Although corticosteroids are effective in inducing remission in most patients, they have numerous potentially serious adverse effects with their long-term use. In addition, some patients do not respond or are intolerant to the conventional treatment. In this article, we discuss the difficulties encountered in long-term immunosuppressive treatment of MG, and review useful tips for the use of corticosteroids. Long-term immunosuppressive agents that can be used in steroid-refractory or -dependent patients will be reviewed with their safety profiles and efficacy in MG.