Identification of Neurotoxicity after Chimeric Antigen Receptor (CAR) T Cell Infusion without Deterioration in the Immune Effector Cell-Associated Encephalopathy (ICE) Score

A consensus grading schema for cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) resulting from chimeric antigen receptor (CAR) T cell therapy was published in 2019. Although this consensus grading schema has been imperative in identifying and monitoring CRS and ICANS in our CAR T cell population, we observed patients exhibiting subtle neurotoxicity symptoms prior to a decrease in their immune effector cell-associated encephalopathy (ICE) score, which is one component of ICANS. Because we treat grade 1 ICANS at our institution, identification of early neurotoxicity symptoms is important. Additionally, we found changes in personality, occupational confusion, or inability to answer dichotomous questions were early signs of neurotoxicity. Therefore, we developed a 3-step command tool to supplement the ICE evaluation. We present 2 examples of patients who exhibited early neurotoxicity symptoms and led us to develop this tool and 1 in whom it was effective. We propose that CAR T cell patients are consistently followed by a clinical care provider who is familiar with the patient to recognize early changes in personality, behavior, and cognition. Additionally, we propose that the multistep command tool be used in conjunction with the ICE score to detect early symptoms of ICANS. Early intervention has the potential to prevent irreversible neurotoxicity.