Nivolumab-Induced Neuromyopathy: A Case Report.

Nivolumab is an immune checkpoint inhibitor (ICI) that treats various malignancies. Although ICIs have proven efficacious, they can also have detrimental side effects. We present a case of nivolumab-induced quadriparesis mimicking Guillain-Barré syndrome in a patient with stage III squamous cell carcinoma (SCC) of the pharynx with a chronic tracheostomy, who presented after being found unconscious at home. He later developed acute kidney failure, requiring dialysis, and bilateral weakness of his upper and lower extremities. The patient was treated with corticosteroids and intravenous immunoglobulin (IVIG) with minimal improvement. Nivolumab-induced quadriparesis is very threatening and can be fatal if inappropriately managed. Therefore, we strongly advocate for a multidisciplinary team and early corticosteroid prescription to monitor patients on nivolumab therapy to prevent adverse clinical outcomes.