Chorea disclosing a polycythemia vera
A 70 year-old woman attended the outpatient clinic of neurology department (Huadong Hospital) with a complaint of involuntary movements in her left limbs during the past 4 days, beginning with involuntary twitching of the muscles in the limbs. A diagnosis of chorea was made and she was treated with haloperidol 2 mg twice a day. One week later, her choreic symptoms had resolved. One month later, she experienced an episode of dizziness, and the next morning involuntary movements reappeared with new symptoms of dysarthria and dysphagia. Five days later, the twitching had escalated to jerking of the muscles which became generalized, extending to the shoulders and face but it ceased during sleep. Her speech and swallowing were moderately affected.\nThere was no family history of movement disorders, dementia or psychiatric illness, and no medical history of stroke, peripheral vascular disease, metabolic or endocrine disorders, or autoimmune disease. She had otherwise been well except for gingival bleeding as a result of taking aspirin. She was not being treated with chorea-inducing drugs such as antiparkinsonian drugs, amphetamines, tricyclic antidepressants, anticonvulsants, or antipsychotics.\nPhysical examination showed facial plethora and erythema of the hands with mild clubbing of the fingers but no splenomegaly. Blood pressure was 130/80 mmHg and temperature was 36.5°C. Neurological examination disclosed choreiform movements of the limbs and orofaciolingual muscles with writhing movements of the tongue, grimacing, grunting, and moderately severe dysarthria and dysphagia. All four limbs were hypotonic with decreased tendon reflexes and flexor plantar responses. Peripheral arterial pulses were palpable in all distal extremities. She was in a state of mild euphoria with a mini-mental state examination (Chinese version) score of 29/30.\nThe results of investigations were as follows and the figures in parenthesis are the normal ranges: hemoglobin 201.0 g/L (113–151 g/L), hematocrit 0.658 L/L, (0.335–0.450 L/L), mean corpuscular volume 89.4 fL (82.6–99.1 fL), oxygen saturation 93.7%, uric acid 390 umol/L (155–357 umol/L), total bilirubin 52.1 umol/L(3.4–25.0 umol/L), direct bilirubin 10.6 umol/L (0–8.0 umol/L), indirect bilirubin 41.5 umol/L(0–17.0 umol/L). The bone marrow aspirate and trephine biopsy specimens were hypercellular for the patient’s age, with biopsy cellularity approximately 80%; erythroid hyperplasia was present. The granulocyte/erythroid (G/E) ratio was 1:2, megakaryocytic 8–10/higher power field (HPF). Reticulin was graded 1 according to a modified Bauermeister scale. Serum erythropoietin was 5.74 mIU/mL (4.3–29 mIU/mL). Results of the following investigations were normal: vitamin B12, calcium concentrations, thyroid function, tests for syphilis and HIV. Retrospective review of laboratory test results revealed an elevated hemoglobin and hematocrit levels 7 months prior to the development of chorea. Apart from mild ischemic white matter lesions, no abnormalities were seen on magnetic resonance imaging. Chest computed tomography demonstrated slight pulmonary arterial dilation. Genetic analysis showed JAK2V617F in her peripheral blood granulocytes. A diagnosis of polycythemia vera was established according to the World Health Organization (WHO) criteria for polycythemia vera (PV).\nShe was treated with hydroxyurea 1,500 mg and clopidogrel 50 mg daily which led to resolution of her chorea within 4 days.