Opsoclonus-myoclonus-ataxia syndrome as a complication of pembrolizumab treatment in an adult patient (a case report and literature review)

Background. Opsoclonus-myoclonus-ataxia syndrome (OMAS) in adults is an extremely rare condition, often leading to rapidly deteriorated neurological performance. The majority of published cases are considered as being post-infectious, paraneoplastic or idiopathic origin. However, there have been reported few OMAS developed after administration check-point inhibitors used various oncological conditions. In the last decade, widespread use immunotherapy oncology has led rise immune-related adverse events, including diverse toxicities. Objective: evaluate opportunity OMAS-triggering PD-1 treatment. Material and methods. We present case report a subacute onset elderly man continuous pembrolizumab first line treatment bronchial squamous cell carcinoma. study was conducted accordance with Helsinki Declaration. also review main clinical features, pathogenesis immunological mechanisms along potential diagnostic management strategies. Results. development severe picture during required withdrawal targeted treatment, which combination glucocorticoids prominent regression deficit. After thorough investigation, infectious organic factors were excluded, allowing for proposal immunotherapy-triggered etiology patient. Conclusion. Discontinuation may be justified means features adult patients verified condition undergoing (considering all other etiologies ruled out).