Chorea Induced by Low-Dose Trazodone

cause movement disorders. CT brain and chest radiograph were normal. It was decided not to perform MRI brain as it was felt that the probability of an ischaemic lesion not visualised by CT was very low. Routine bloods demonstrated no abnormalities in the full blood count, liver function or renal function. The patient had been noted to be hyponatraemic for at least 2 years (around 125–130 mmol/l), but her plasma osmolarity was normal and there had been no recent changes in her plasma sodium levels. ESR was 8 mm/h. Thyroid function, blood glucose, calcium, magnesium, phosphate, serum caeruloplasmin, vitamin D and parathyroid hormone levels were all normal. The anti-streptolysin O titre was normal ( ! 200 U/ml). Anti-nuclear antibody (titre 1: 160) and anti-cardiolipin antibodies were positive, but the patient did not meet the American College of Rheumatology criteria for SLE or anti-phospholipid antibody syndrome and was anti-dsDNA negative with normal serum complement. Anti-basal ganglia antibodies were negative. Given the late age of onset and lack of family history it was decided not to perform genetic testing for Huntington’s disease. CA-125 was elevated but pelvic ultrasound and CT abdomen demonstrated no ovarian or other malignancy. The patient was discharged 12 days after admission with no further occurrence of chorea.