Essential thrombocythemia: Rare cause of chorea
A 55-year-old female patient presented to us with an acute onset of involuntary movements involving limbs, face and tongue. These movements were random and fleeting from one part of the body to another causing dysarthria and social embarrassment. There was no history of headache, visual disturbances or transient ischemic attack (TIA). There was no history of recent exposure to anti psychotic's medication. There was no family history of chorea or dementia and no history of rheumatic fever. On examination, patient had generalized chorieform movements involving limbs face and tongue. There was no extra pyramidal or pyramidal sign. Higher mental functions were normal with mini mental score of 28. There was no facial plethora or splenomegaly.\nOn investigation, she had total white blood cell count 14.2 × 103/uL, total red blood cell count 5.07 × 106/uL, platelet count 1092 × 103/uL, hemoglobin 15.1 g/dL, hematocrit 46.3%, mean corpuscular volume 91.3 fL, mean corpuscular hemoglobin 29.8 PG, mean corpuscular hemoglobin concentration 32.7 gm/dL and erythrocyte sedimentation rate 01 mm. The peripheral blood smear revealed no abnormal cell or acanthocytes. Neutrophil alkaline phosphatase was 240, ceruloplasmin was normal and bcr-abl gene expression was negative. Janus kinase 2(JAK2) V617F mutation was positive. Bone marrow showed hyper cellular marrow with a marked increase in megakaryocytes without any atypical blast cells. Magnetic resonance imaging (MRI) brain was normal and the ultrasound sonography abdomen did not reveal organomegaly. Renal, hepatic and other metabolic profiles were normal. Anti-nuclear antibody and anti-double-stranded deoxyribonucleic acid were negative. The chest X-ray and echocardiogram were normal. Hence, a diagnosis of ET was made and she was started on haloperidol initially to control chorea symptomatically. She showed only some improvement, but her platelet count was rising further and was started on hydroxyurea. On 3rd month of follow-up her chorea completely subsided, haloperidol was slowly withdrawn and her platelet count was 562 × 103/uL.