Elena Ardila Jurado

Background: JAK2 variants are a hallmark of myeloproliferative neoplasms (MPNs), including polycythemia vera and essential thrombocythemia. These disorders are often associated with thrombotic and inflammatory complications. From a movement disorder perspective, chorea is a rare but well‐recognized neurological occurrence in this context, whereas parkinsonism has received limited attention. Objectives: To describe parkinsonian phenotypes in patients with JAK2 ‐mutated MPNs and explore possible pathophysiological links. Methods: We identified five patients with a JAK2 ‐mutated MPNs and parkinsonism and reviewed their demographic and clinical features, neuroimaging, and levodopa response. Results: Parkinsonian phenotypes were heterogeneous, including Parkinson's disease ( n = 2), atypical parkinsonism ( n = 1), motor neuron disease with parkinsonism ( n = 1), and chorea followed by parkinsonism ( n = 1). The latter patient developed parkinsonism approximately 22 months after onset of generalized chorea. When available ( n = 2), DaTscan was abnormal. Levodopa responsiveness was variable. Conclusion: Although JAK2 ‐mutated MPNs and parkinsonism may coexist coincidentally, recent evidence suggests plausible pathophysiological links, including vascular, inflammatory, immune‐mediated, and treatment‐related mechanisms.