Chorea in the elderly with mutation positive polycythemia vera: a case report.

Chorea is a hyperkinetic movement disorder characterized by excessive spontaneous movements that are irregularly timed, randomly distributed and abrupt. Chorea in an elderly patient poses a diagnostic challenge. The differential diagnosis is broad and includes medication effects, vascular disorders, metabolic abnormalities, autoimmune syndromes and neurodegenerative disorders.1,2 Important causes of late onset chorea have been listed in the Table. A significant number of cases of late-onset chorea without a clear etiology are lumped together as “senile chorea”. This diagnostic term may obscure a subset of cases where a specific diagnosis can be clinched with further investigations. We present a case of new onset chorea in an elderly patient uncovering Polycythemia Vera (PV) with hematological examination positive for the characteristic Janus Kinase-2 (JAK2) mutation. Chorea was the only presenting feature in this patient, and treatment of polycythemia led to reduction of the abnormal movements significantly. We also review the association of PV and chorea and possible mechanism of causation of chorea in patients with polycythemia.