Abstract Paraneoplastic movement disorders (PMDs) constitute a distinct subset of paraneoplastic neurological syndromes (PNS) that are characterized by immune-mediated movement abnormalities in association with an underlying malignancy. The malignancy may not be concurrent; occasionally, the malignancies may appear later than the neurological syndromes. In this scoping review, we synthesized the available literature on PMDs to delineate the antibody profiles, oncologic associations, therapeutic strategies, and treatment responses across these disorders. Among all PMDs, cerebellar ataxia is the main phenotype. PMDs are clinically important, particularly in the era of immune checkpoint inhibitor (ICI) usage for cancer therapy. Paraneoplastic cerebellar degeneration is the predominant phenotype, followed by stiff person spectrum disorders, opsoclonus–myoclonus syndrome, peripheral nerve hyperexcitability (PNH), and rarer manifestations such as chorea, dystonia, tremor, and parkinsonism. Notably, our review identified the emergence of these disorders triggered or exacerbated by immune checkpoint inhibitors (ICIs), such as pembrolizumab and dostarlimab. This result highlights a converging pathway between tumor immunomodulation and autoimmunity. The neurological adverse events related to cancer immunotherapy may not be a direct paraneoplastic entity; however, these events may be a crucial indicator of the neurological syndromes associated with malignancies. Although classical onconeural antibodies (anti-Yo, Hu, Ri, CV2/CRMP5) remain definitive for PMD diagnosis, the increasing detection of surface-directed antibodies, such as CASPR2, LGI1, and GAD65, expands the pathogenic landscape of PMDs. The tumor spectrum extends beyond the traditional associations to include endometrial, prostate, and pancreatic malignancies. This tumor spectrum emphasizes the evolving relevance of paraneoplastic mechanisms across cancer types. Importantly, early detection and antibody testing are crucial, as PMDs are potentially treatable movement disorders.
Mittal et al. (2026) studied this question.