Objective:

Characterize the clinical features of neurological complications associated with immune checkpoint inhibitors (ICIs) through a case serial study to achieve early recognition and management of these complications.   

Background:

ICI has been a breakthrough in cancer treatment, but immune-related adverse events (irAEs) have been reported. Neurologic irAEs (nAEs) are rare but could cause significant morbidity and mortality.   

Design/Methods:

16 cases of nAEs after ICIs from January 2020 to September 2024 at University of California, Davis were retrospectively collected to analyze the symptoms, lab tests, treatment courses and patient outcomes.   

Results:

Among these cases, prevalence in men (73%) is higher than women (27%) with a mean age of 65 years. The most used ICI was Nivolumab and most often in cases of renal cell carcinoma. There were 8 cases of myasthenia gravis (MG), 4 cases of Guillain-Barre syndrome (GBS), 2 cases of transverse myelitis, 1 case of encephalitis and 1 case of chronic axonal sensorimotor polyneuropathy. Additionally, 8 MG cases had concurrent myositis, two MG cases overlapped with myocarditis and myositis, one MG case had concurrent myocarditis and hepatitis. In our study, 7 of the 16 patients (44%) had mild to moderate improvement to IVIG+/- steroids, two had good remission in cancer and mild residual deficit of nAE. Mortality rate from nAEs were 7 of 16 patients (44%). Our study showed a higher prevalence (50%) and mortality (75%) of MG, compared with neuropathies.  

Conclusions:

Our study underscores the importance of early recognition and management of nAEs. Clinicians should maintain a high index of suspicion for nAEs in patients with a recent history of ICI therapy. Prompt discontinuation of ICIs and initiation of IVIG +/- corticosteroids are critical for favorable outcomes. Our study adds to the growing knowledge of ICI-related nAEs and highlights the need for vigilance in dynamic monitoring to decrease morbidity and mortality.