Clinical and Electrophysiological Characteristics of Peripheral Neuropathy in Immune-Related Adverse Event of Immune Checkpoint Inhibitors: A Retrospective Study and Literature Review

PURPOSE: To summarize clinical and laboratory characteristics of peripheral neurological immune-related adverse event (irAEs-PN) patients, to improve understanding and provide reference for early diagnosis of irAEs-PN caused by immune checkpoint inhibitors. METHODS: We screened 61 patients with irAEs in our center from September 2020 to June 2025. In addition, studies with detailed clinical data related to irAEs-PN were collected in PubMed database from January 2015 to June 2025. A total of 50 patients with irAEs-PN were included, including 8 cases from our center and 42 cases reported in literature. The patients' demographic information, clinical characteristics, electrophysiological examination, therapy and outcomes were retrospectively analyzed and summarized. RESULTS: Among the eight patients in our center, the first symptom was paresthesia, occurring in two cases, and limb weakness, occurring in six cases. Electrophysiology identified two axonal neuropathies, three demyelinating, and three mixed axonal and demyelinating neuropathies. Among the 42 patients reported in literature, the first symptom was paresthesia, occurring in 39 cases, and limb weakness, occurring in 41 cases. Electromyography identified 13 axonal neuropathies, 25 demyelinating neuropathies, and 4 mixed axonal and demyelinating neuropathies. CONCLUSIONS: In most patients, irAEs-PN is characterized by demyelinating sensorimotor involvement of both the upper and lower limbs. In individuals receiving immune checkpoint inhibitors, prompt electromyography after the onset of neuropathic symptoms can aid in detecting neurological involvement and facilitate earlier treatment.