Neuropsychiatric Derangement by Polycythemia Vera: A Case Report of an Unexpected Disease Presentation and Review of the Literature.

Cerebral infarction as well as other thromboses, headaches, and visual complaints are well-known symptoms of polycythemia vera. However, chorea and neuropsychiatric disturbances are less recognized consequences of this chronic disease. Whereas chorea is a rare but acknowledged symptom of polycythemia vera, neuropsychiatric symptoms have only sporadically been reported. We depict 2 patients with an unusual presentation of polycythemia vera. Our first patient presented with right-sided hemiballism and psychosis, and the second patient had a long diagnostic trajectory of unexplained chorea. In both cases diagnosis of JAK2 positive polycythemia vera was established, and in both cases remarkable recovery occurred after the initiation of phlebotomies. The underlying pathophysiology of these symptoms has not been clearly elucidated. Because of the unfamiliarity of the link between especially neuropsychiatric symptoms and polycythemia, current reported numbers are probably an underestimation. Benefit of treatment appears to be large. We seek to create more awareness among physicians about this phenomenon.