Immune checkpoint inhibitors (ICIs) have acquired a central role in the treatment of cancer within the last decade. Over 50 different tumor types have approval for the use of T-cell targeted immunomodulators blocking immune checkpoints like cytotoxic T-lymphocyte associated antigen-4 (CTLA-4), programmed death-1 (PD-1), or programmed death ligand 1 (PD-L1).
1 However, because of their unique mechanism of action, ICIs present their own set of adverse events (AEs), called immune-related adverse events. Neurologic immune-related AEs are an emerging area of interest because of the complexity of the nervous system and the potential for long-term morbidity.
2,3 Although the overall incidence of neurologic AE (NAE) is reported to be approximately 1%,
4 NAEs constitute 11% of all the fatal events secondary to ICIs.
3 In a systematic review of literature, Cuzzubbo et al
5 reported that the overall incidence of NAEs of any grade was 3.8% with anti–CTLA-4, 6.1% for anti–PD-1/PD-L1, and 12% with the use of dual checkpoint inhibitors (a combination of anti–PD-1 and anti–CTLA-4 therapy).