The authors report a 73-year-old woman with LEMS that occurred during nivolumab treatment for pulmonary squamous cell carcinoma. After the 20th week of nivolumab, she experienced various neurological symptoms such as ptosis, lower limb weakness, and photophobia. Findings from a nerve conduction study and a positive anti-P/Q-type voltage-gated calcium channel antibody made a diagnosis of LEMS. Pyridostigmine and 3,4-diaminopyridine temporarily improved her symptoms. This was the first case of LEMS as a neurological irAE. LEMS should be considered as a possible neurological irAE.
Case reports in Neurology