Neurological Adverse Events Associated with Immune Checkpoint Inhibitors: Diagnosis and Management

Abstract

Purpose of review: Immune checkpoint inhibitors represent a major step forward in the field of oncologic immunotherapy these last years and have significantly increased survival of cancer patients in an ever-growing number of indications. These agents block specific immune checkpoint molecules (programmed cell death protein 1 and its ligand as well as cytotoxic T-lymphocyte-associated antigen 4) that normally downregulate the immune response. These new agents show a specific range of adverse effects induced by abnormal immunologic activation.

Recent findings: Many different neurologic adverse events have been described, including encephalitis, myelopathy, aseptic meningitis, meningoradiculitis, Guillain-Barré-like syndrome, peripheral neuropathy (including mononeuropathy, mononeuritis multiplex, and polyneuropathy) as well as myasthenic syndrome. Immune checkpoint inhibitors have shown promising results in cancer but can possibly induce autoimmune disorders. Although rare, neurological adverse events require prompt recognition and treatment to avoid substantial morbidity.

Keywords: Anti-CTLA-4; Anti-PD-1; Encephalitis; Immune checkpoint inhibitors; Meningitis; Myositis; Neurological adverse events; Polyneuropathy.