Neurologic Complications of Cancer Immunotherapy

The use of oncologic-directed immunotherapies, including immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T cell (CAR-T) therapy, has risen exponentially in recent years. Although these therapies have been shown to improve long-term survival and quality of life in responsive patients, their nonspecific immune system activation can lead to unanticipated neurotoxicity, among other complications. Immune-related adverse events (irAEs) may involve any location in the entire neuroaxis, posing a diagnostic challenge, and may cause severe, life-threatening complications. ICI-related neurotoxicities may include peripheral neuropathies, myositis, myasthenia gravis, encephalitis, aseptic meningitis, myelitis, and demyelinating disorders. CAR-T therapies carry a comparatively higher risk of neurologic irAEs, most notably immune effector cell-associated neurotoxicity syndrome. In this review, neurotoxicity syndromes associated with ICI and CAR-T therapies are outlined, along with diagnostic approaches and management strategies.