467 - Myositis, Myasthenia, and Myocarditis: A Case Report Reviewing Successful Rehabilitation After Immune Checkpoint Inhibitor Related Adverse Events

Case Diagnosis: Myositis, Myasthenia, and Myocarditis

Case Description: 76M with melanoma metastatic to brain. Family history of myasthenia gravis in brother. Patient started immunotherapy and within two weeks developed a rash with progressive dyspnea, therefore his treating oncologist directly admitted him to the hospital. Neurology diagnosed myositis, myasthenia, and myocarditis. He received plasmapheresis, steroids, and pyridostigmine with benefit. He admitted to inpatient rehabilitation with a cancer rehabilitation service. Physiatrists collaborated with physical, occupational, and speech therapists to develop a therapy plan which considered his cardiopulmonary system, fatigue, and dysphagia. He discharged home with a rolling walker and outpatient therapies. Completion of neuromuscular labs and outpatient electrodiagnostics supported myasthenia gravis after immunotherapy.

Discussions: The incidence of immune-related adverse events is relatively low but can become much higher with certain drug combinations such as those this patient received. The types of adverse events vary greatly from gastrointestinal, endocrine, neuromuscular, and cardiopulmonary concerns. Adverse events typically occur in the first 6-12 weeks of therapy and can result in treatment cessation or even death. There is no strong evidence that family history contributes to adverse event frequency or severity, however this case might provide anecdotal evidence to the contrary. With immune checkpoint inhibitor therapies becoming more commonly prescribed by oncologists, physiatrists must be cognizant of how to manage cardiopulmonary rehabilitation at the inpatient and outpatient levels.

Conclusions: Immune checkpoint inhibitor therapy has increased in popularity among prescribing oncologists. Similarly, immune-related adverse events with their associated functional impairments has increased in prevalence. These diagnoses remind us that cardiopulmonary rehabilitation is a valuable topic for physicians to understand as the acuity of medical care is typically high. Physiatrists must offer guidance to their inpatient therapy and nursing teams for safety monitoring and therapy modification in order to make appropriate functional improvements and ultimately discharge patients to home.