Clinical diagnosis and treatment recommendations for immune checkpoint inhibitor‐related adverse reactions in the nervous system

Immune checkpoint inhibitors (ICIs) can cause adverse reactions in the nervous system. The incidence rate is 0.1%–12% and 80% of nervous system adverse reactions occur within the first four months of application. ICIs can cause diseases of various parts of the nervous system including central nervous system diseases such as aseptic meningitis, meningeal encephalitis, necrotizing encephalitis, brainstem encephalitis, transverse myelitis, etc., and peripheral neuropathy such as cranial nerve peripheral neuropathy, multifocal nerve root neuropathy, Guillain‐Barré syndrome, spinal nerve root neuropathy, myasthenia gravis, myopathy, etc. For these complications of the nervous system, diagnosis could be difficult. Physicians require a specific collection of nervous system symptoms and signs, combined with supplementary examinations including imaging, cerebrospinal fluid cytology, EEG or electromyography in order to exclude infection or malignant tumor before reaching a final diagnosis. With regard to treatment, ICIs should be discontinued in severe cases, and large doses of glucocorticoid or gamma globulin administered, and supportive treatment may be necessary. If severe adverse reactions of the nervous system occur, the prognosis could be poor.