Neurological autoimmunity in melanoma patients: a comparison between those exposed and non-exposed to immune checkpoint inhibitors

Background The clinical spectrum of melanoma-associated neurological autoimmunity, whether melanoma-associated paraneoplastic neurological syndromes (PNS) or induced by immune checkpoint inhibitors (ICI), is not well characterized. We aim to describe the clinical spectrum of melanoma-associated neurological autoimmunity. Methods A systematic review of the literature combined with patients from French databases of paraneoplastic neurological syndromes was conducted. All melanoma patients with a possible immune-mediated neurologic syndrome were included and classified according to whether they had previously been exposed to ICI (ICI-neurotoxicity) or not (ICI-naïve) at first neurological symptoms. Results Seventy ICI-naïve (literature: n = 61) and 241 ICI-neurotoxicity patients (literature: n = 180) were identified. Neuromuscular manifestations predominated in both groups, but peripheral neuropathies were more frequent in ICI-neurotoxicity patients (39.4% vs 21.4%, p = 0.005) whereas myositis was more frequent in ICI-naïve patients (42.9% vs 18.7%, p