Chorea and Cognitive Impairment in JAK2V617F-Positive Myeloproliferative Disorders: A Case Report and Literature Review.

Chorea is a hyperkinetic movement disorder, accompanied by dystonia, myoclonus, tics, stereotypies, and tremors. It is characterized by excessive, purposeless movements that are distressing, irregularly timed, and randomly distributed. Chorea can be present in many diseases, such as hereditary, metabolic disturbance, drug-induced, and functional disorders, and, rarely, genetic, autoimmune, and infectious diseases. Primary myelofibrosis (PMF) is a myeloproliferative neoplasm that leads to ineffective clonal hematopoiesis, fibrous tissue deposits in the bone marrow, extramedullary hematopoiesis, and splenomegaly. In rare cases, following uncertain pathological mechanisms, it can present with chorea, particularly affecting the limbs, head, and orofaciolingual muscles. We present a case of a male patient with evolving PMF over several years who was admitted for progressive cognitive impairment and generalized involuntary movement disorder. We also present a review of all cases of myeloproliferative disorders presenting with chorea published in the last 40 years.