Central nervous system complications of immune checkpoint inhibitors: A comprehensive review

Abstract

The ever-increasing use of immune checkpoint inhibitors (ICIs) has significantly improved cancer management, but at the cost of frequent immunologic side effects. Among them, neurologic immune-related adverse events (nirAEs) are less common but pose a challenge to clinicians due to their severity, heterogeneous nature and nonspecific clinical presentation, making diagnosis complex. The prognosis of these nirAEs, especially those related to the central nervous system (CNS), correlates with their rapid recognition and therapeutic management. Indeed, the therapeutic options are sometimes unfamiliar and may be further complicated by the lack of recommendations in the event of failure of a well-managed first-line treatment. Finally, the attribution of ICIs to certain CNS disorders is controversial and may lead to an incorrect decision to discontinue or contraindicate treatment, resulting in an irremediable loss of opportunity for the patient. Therefore, the aim of this review is to present known/suspected CNS nirAEs induced by ICI, their diagnostic approach and management through therapeutic advices for optimal treatment and rechallenge opportunities.

Keywords: Encephalitis; Hypophysitis; Immune checkpoint inhibitors; Meningitis; Myelitis; Neurologic adverse event; Vasculitis.